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Epigenetic modifications such as DNA methylation are both cell type and developmental age specific. Here, we show that the immunological maturation of blood cell types influences DNA methylation changes from naive cord blood to fully functional adult blood. Lymphoid cells in adult blood showed more variability than in cord blood suggesting an antigen-dependent maturation of DNA methylation in lymphoid cells throughout the lifespan. Fewer DNA methylation changes between cord and adult blood were observed in myeloid cells, particularly in monocytes, which demonstrated the least number of DNA methylation changes between cord and adult blood. We also noted differences in epigenetic ages by immune cell types within the same individuals, specifically in cord blood where monocytes were epigenetically oldest compared to the other cell types. In addition, we provide a publicly available resource to the community as an R Shiny web application to interactively explore epigenetic patterns between naive cord white blood cells and fully functional adult white blood cells for six immune cell types., Competing Interests: Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Mutations in CHRNE encoding the epsilon subunit of acetylcholine receptor result in impaired neuromuscular transmission and congenital myasthenic syndrome (CMS) with variying severity of symptoms. Although the pathophysiology is well-known, blood biomarker signatures enabling a patient-stratification are lacking. This retrospective two-center-study includes 19 recessive CHRNE-patients (AChR deficiency; mean age 14.8 years) from 13 families which were clinically characterized according to disease severity. 15 patients were classified as mildly and 4 patients as moderate to severely affected. Seven known pathogenic and one unreported variant (c.1032 + 2_1032 + 3delinsGT) were identified. Biomarker discovery was carried out on blood samples: proteomics was performed on white blood cells (WBC; n = 12) and on extracellular vesicles (EV) purified from serum samples (n = 7) in addition to amino acid profiling (n = 9) and miRNA screening (n = 18). For miRNA studies, 7 patients with other CMS-subtypes were moreover included. WBC-proteomics unveiled a significant increase of 7 and a decrease of 36 proteins. In silico studies of these proteins indicated affection of secretory granules and the extracellular space. Comparison across patients unveiled increase of two vesicular transport proteins (SCAMP2 and SNX2) in severely affected patients and indeed EV-proteomics revealed increase of 7 and decrease of 13 proteins. Three of these proteins (TARSH, ATRN & PLEC) are known to be important for synaptogenesis and synaptic function. Metabolomics showed decrease of seven amino acids/ amino acid metabolites (aspartic and glutamic acids, phosphoserine, amino adipate, citrulline, ornithine, and 1-methyhistidine). miRNA-profiling showed increase miR - 483 - 3p, miR-365a-3p, miR - 365b - 3p and miR-99a, and decrease of miR-4433b-3p, miR-6873-3p, miR-182-5p and let-7b-5p in CHRNE-patients whereas a comparison with other CMS subtypes showed increase of miR - 205 - 5p, miR - 10b - 5p, miR-125a-5p, miR-499-5p, miR-3120-5p and miR - 483 - 5p and decrease of miR - 1290. Our combined data introduce a molecular fingerprint on protein, metabolic and miRNA level with some of those playing different roles along the neuromuscular axis., Competing Interests: Declarations. Ethics approval and consent to participate: Our study was approved by the ethical committee of the University Hospital Duisburg-Essen (19-9011-BO) and for Spanish patients by ethical comitee of the Institut de Recerca Sant Joan de Deu (PIC-147-23). The study was conducted in accordance with the principles of the Declaration of Helsinki. Consent for publication: All participians or their representatives have given consent for publication of their clinical data as part of the above named studies. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Immune cells play key roles in host responses to malignant tumors. The selective pressure that immune cells elicit on tumors promotes immune escape, while tumor-associated modulation of immune cells creates an environment favorable to tumor growth and progression. In this study we used publicly available single-cell RNA sequencing (scRNA-seq) data from the translationally relevant canine osteosarcoma (OS) model to compare tumor-infiltrating immune cells to circulating leukocytes. Through computational analysis we investigated the differences in cell type proportions and how the OS TME impacted infiltrating immune cell transcriptomic profiles relative to circulating leukocytes. Differential abundance analysis revealed increased proportions of follicular helper T cells, regulatory T cells, and mature regulatory dendritic cells (mregDCs) in the OS TME. Differential gene expression analysis identified exhaustion markers (LAG3, HAVCR2, PDCD1) to be upregulated in CD4 and CD8 T cells within the OS TME. Comparisons of B cell gene expression profiles revealed an enrichment of protein processing and endoplasmic reticulum pathways, suggesting infiltrating B cells were activated following tumor infiltration. Gene expression changes within myeloid cells identified increased expression of immune suppressive molecules (CD274, OSM, MSR1) in the OS TME, indicating the TME skews myeloid cells toward an immunosuppressive phenotype. Comparisons to human literature and analysis of human scRNA-seq data revealed conserved transcriptomic responses to tumor infiltration, while also identifying species differences. Overall, the analysis presented here provides new insights into how the OS TME impacts the transcriptional programs of major immune cell populations in dogs and acts as a resource for comparative immuno-oncology research., Competing Interests: Declarations. Conflict of interest: The authors have no conflicts to disclose., (© 2025. The Author(s).)

As a highly diverse and mobile organ, the immune system is uniquely equipped to participate in tissue responses in a tunable manner, depending on the number, type, and nature of cells deployed to the respective organ. Most acute organismal stressors that threaten survival-predation, infection, poisoning, and others-induce pronounced redistribution of immune cells across tissue compartments. Here, we review the current understanding of leukocyte compartmentalization under homeostatic and noxious conditions. We argue that leukocyte shuttling between compartments is a function of local tissue demands, which are linked to the organ's contribution to adaptive physiology at steady state and upon challenge. We highlight the neuroendocrine signals that relay and organize this trafficking behavior and outline mechanisms underlying the functional diversification of leukocyte responses. In this context, we discuss important areas of future inquiry and the implications of this scientific space for clinical medicine in the era of targeted immunomodulation., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2025 Elsevier Inc. All rights reserved.)

This study aimed to investigate the potential association between white blood cell counts and the risk of lung cancer, including its subtypes, through Mendelian randomization (MR) analysis. We conducted a two-sample MR analysis using genome-wide association study (GWAS) summary statistics for the both exposure traits (eosinophil count, neutrophil count, lymphocyte count, monocyte count, basophil count, and total white blood cell count) and outcome traits (lung cancer and its subtypes). The GWAS dataset for lung cancer included 29,266 cases (11273 lung adenocarcinoma (LUAD), 7426 lung squamous cell carcinoma (LSCC), 2664 small cell lung cancer (SCLC)) and 56,450 controls. In MR analysis, we employed methods such as Inverse variance weighted (IVW), weighted median, MR-Egger regression, MR pleiotropy residual sum and outlier. MR analysis revealed an elevated total white blood cell (WBC) count significantly increased the risk of LUAD (IVW: OR = 1.484, 95% CI = 1.219-1.749, p = 0.003). The results confirmed a causal relationship between monocyte count and LUAD (IVW: OR = 1.687, 95% CI:1.542-1.830, p < 0.001). An increased total WBC count was associated with a higher risk of LUAD. Additionally, analysis of WBC subtypes counts indicated that monocyte count plays an crucial role in the elevated risk of LUAD., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics declarations: There was no need to get informed consent or ethical approval for this study again because all of the data were taken from published sources, and the informed consent and approval were received., (© 2025. The Author(s).)

It is interesting to find pathologically that leukocytes, especially neutrophils, tend to adhere in the liver sinusoids dominantly but not in the postsinusoidal venules. While both views of receptor-ligand interactions and physical trapping are proposed for mediating leukocyte adhesion in liver sinusoids, integrated investigations for classifying their respective contributions are poorly presented. With a combination of Monte Carlo simulation and immersed boundary method, this study explored numerically the effects of molecular interaction kinetics and sinusoidal mechanical properties on leukocyte adhesion in liver sinusoid jointly. Results showed that, within the range of biological limitations, the lumen stenosis ratio, leukocyte stiffness, Disse space stiffness and endothelium permeability regulate the comprehensive adhesion process in a descending order of significance in the presence of receptor-ligand interactions. While leukocyte adhesions could be mutually promoted with proper combinations of leukocyte stiffness, lumen stenosis, and molecular interaction, the binding affinity is insensitive under the conditions with low leukocyte stiffness in normal lumen stenosis and high leukocyte stiffness in high lumen stenosis. This work deepens the understanding of recruitment mechanism of leukocyte in liver sinusoids., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2024 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

Reversible transformation of bovine leukocytes by the intracellular parasites Theileria annulata and Theileria parva is central to pathogenesis of the diseases they cause, tropical theileriosis and East Coast Fever, respectively. Parasite-dependent constitutive activation of major host transcription factors such as AP-1 (Activating Protein 1) and NF-κB (Nuclear Factor-Kappa B) sustains the transformed state. Although parasite interaction with host cell signaling pathways upstream of AP-1 have been studied, the precise contribution of Theileria encoded factors capable of modulating AP-1 transcriptional activity, and other infection-altered signaling pathways is not fully understood. We previously showed that the Ta9 protein from T. annulata (TA15705) is secreted into the host cell cytoplasm and contributes to infection-induced AP-1 transcriptional activity. The current study employed RNA-seq to investigate the ability of ectopically expressed Ta9 to modulate the gene transcription profile of a bovine macrophage cell line, BoMac. RNA-seq identified 560 (400 upregulated and 160 downregulated) differentially expressed genes. KEGG analysis predicted a high number of upregulated genes associated with carcinogenesis such as CCND1, CDKN1A, ETV4, ETV5, FLI1, FRA1, GLI2, GRO1, HCK, IL7R, MYBL1, MYCN, PIM1 and TAL1. Ta9 introduction also affected genes associated with proinflammatory processes such as cytokines, chemokines, growth factors and metalloproteinases. Enrichment analysis of differentially expressed genes revealed that Ta9 is potentially involved in activating other host cell signaling pathways in addition to those that lead to induction of AP-1. Comparing our data with data on differentially expressed BoMac genes modulated by the secreted TashAT2 factor of T. annulata identified the gene encoding the tyrosine protein kinase hematopoietic cell kinase (HCK) as common to both data sets. HCK is essential for the proliferation of T. parva-transformed B cells and herein, we demonstrate that enzymatic activity of HCK is also essential for T. annulata- and T. lestoquardi-transformed macrophage proliferation., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shahin Tajeri reports article publishing charges was provided by Free University of Berlin. Shahin Tajeri reports a relationship with Free University of Berlin that includes: employment. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Ex situ normothermic perfusion (ESNP) is a method to evaluate and potentially recondition organs before transplantation. However, increased expression of inflammatory molecules, including by tissue-resident immune cells, may occur during the perfusion process, potentially negating the beneficial effects of perfusion., Methods: We used RNA sequencing to assess gene expression in 31 livers undergoing ESNP, including 23 donated after circulatory death (DCD) and 8 donated after brain death. In 7 DCD livers, a leucocyte filter was added to the circuit during perfusion. Biopsies were available for transcriptomic assessment in all cases at the start of perfusion and at varying time points postperfusion., Results: During ESNP in DCD livers, we observed an increase in proinflammatory, profibrinolytic, and prorepair pathway genes. SERPINE1 , encoding plasminogen activator inhibitor-1, was among the genes most significantly upregulated during perfusion in DCD livers, potentially promoting fibrin clot persistence in vasculature. We also found increased expression of monocyte and neutrophil recruiting chemokine and proinflammatory cytokine transcripts during ESNP, but several prorepair molecules, including thymic stromal lymphopoietin, were also upregulated. In both DCD and donation after brain death livers, interferon-gamma response genes were enriched, whereas oxidative phosphorylation genes decreased in organs with high perfusate alanine transaminase, a biomarker associated with adverse clinical outcomes. The inclusion of a leukocyte filter in the perfusion circuit mitigated the induction of inflammation/immune pathway genes during perfusion and was associated with enrichment in oxidative phosphorylation genes., Conclusions: Leukocyte removal during ESNP abrogates transcriptional changes that are associated with unfavorable clinical outcomes, potentially benefiting human livers undergoing ESNP., Competing Interests: C.J.E.W. has received honoraria for lectures from Organox Ltd. The other authors declare no conflicts of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Introduction: Sepsis is a life-threatening condition caused by a dysregulated immune response to infection, leading to organ failure. Despite its significant global burden, the underlying mechanisms of immune dysfunction in sepsis remain incompletely understood. This study explores the role of DNA methylation in white blood cells in sepsis pathogenesis., Methods: A prospective case-control study was conducted to compare DNA methylation profiles between patients with community-acquired sepsis and matched controls who had similar infections but did not develop sepsis. Whole blood samples from these patients were analyzed using the Infinium MethylationEPIC v2.0 kit, enabling genome-wide methylation analysis. Selected genes with differential methylation were validated by pyrosequencing., Results: Significant differential DNA methylation patterns were identified between septic and non-septic individuals uising. Our results suggest that DNA methylation changes are closely linked to the pathophysiological processes of sepsis, influencing immune cell activation, inflammation, and organ dysfunction. The most prominent findings include the hypomethylation of immune-related genes ( SERPINA1, AZU1, MPO , and SLX4 ), which were strongly correlated with clinical severity and inflammatory markers such as SOFA scores and PCT levels. Correlation analyses demonstrated significant associations between the methylation levels of these genes and clinical severity markers, such as SOFA score and PCT levels. Notably, SLX4 hypomethylation showed the highest predictive value for poor prognosis (AUC 0.821), while SERPINA1 hypomethylation exhibited strong diagnostic potential for sepsis (AUC 0.858)., Discussion: Our results underscore the potential of DNA methylation changes, particularly in immune-related genes, to enhance the early detection of sepsis and to stratify patients based on severity. Future research should explore the therapeutic implications of these epigenetic alterations in sepsis care., Competing Interests: JG-G is employed by the company EpiDisease S.L. JLG-G and FVP are co-founders and own shares in EpiDisease S.L., an Spin-Off of the Consortium Center for Biomedical Network Research of the ISCIII. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025 López-Cruz, García-Giménez, Madrazo, García-Guallarte, Piles, Pallardó and Artero.)

Objective: Accelerated ageing indexed by telomere attrition is suggested in schizophrenia spectrum- (SCZ) and bipolar disorders (BD). While inflammation may promote telomere shortening, few studies have investigated the association between telomere length (TL) and markers of immune activation and inflammation in severe mental disorders., Methods: Leucocyte TL defined as telomere template/amount of single-copy gene template (T/S ratio), was determined in participants with SCZ ( N = 301) or BD ( N = 211) and a healthy control group (HC, N = 378). TL was analysed with linear regressions for associations with levels of 12 immune markers linked to SCZ or BD. Adjustments were made for a broad range of potential confounding variables. TL was measured by quantitative polymerase chain reaction (qPCR) and the immune markers were measured by enzyme immunoassays., Results: A positive association between levels of soluble tumour necrosis factor receptor 1A (sTNF-R1) and TL in SCZ ( β = 0.191, p = 0.012) was observed. Plasma levels of the other immune markers were not significantly associated with TL in the BD, SCZ or HC groups., Conclusion: There was limited evidence of association between immune markers and TL in SCZ and BD. The results provide little support for involvement of immune dysregulation, as reflected by current systemic markers, in telomere attrition-related accelerated ageing in severe mental disorders.

Background: Few studies have explored the association between DNA methylation and physical activity. The aim of this study was to evaluate the association of objectively measured hours of sedentary behavior (SB) and moderate physical activity (MPA) with DNA methylation. We further aimed to explore the association between SB or MPA related CpG sites and cardiometabolic traits, gene expression, and genetic variation., Results: For discovery, we performed cross sectional analyses in pregnant women from the Epigenetics in pregnancy (EPIPREG) sample with both DNA methylation (Illumina MethylationEPIC BeadChip) and objectively measured physical activity data (SenseWear™ Pro 3 armband) (European = 244, South Asian = 109). For EWAS of SB and MPA, two main models were designed: model (1) a linear mixed model adjusted for age, smoking, blood cell composition, including ancestry as random intercept, and model (2) which was additionally adjusted for the total number of steps per day. In model 1, we did not identify any CpG sites associated with neither SB nor MPA. In model 2, SB was positively associated (false discovery rate, FDR < 0.05) with two CpG sites within the VSX1 gene. Both CpG sites were positively associated with BMI and were associated with several genetic variants in cis. MPA was associated with 122 significant CpG sites at FDR < 0.05 (model 2). We further analyzed the ten most statistically significant MPA related CpG sites and found that they presented opposite associations with sedentary behavior and BMI. We were not able to replicate the SB and MPA-related CpG sites in the Avon Longitudinal Study of Parents and Children (ALSPAC). ALSPAC had available objectively measured physical activity data from Actigraph (without steps/day available) and leucocyte DNA methylation data collected during adolescence (n = 408, European)., Conclusion: This study suggests associations of objectively measured SB and MPA with maternal DNA methylation in peripheral blood leukocytes, that needs to be confirmed in larger samples of similar study design., Competing Interests: Declarations. Ethics approval and consent to participate: In STORK G, all participants consisted of adult women who provided their informed written consent, and we had ethical approval from the Norwegian Regional Committee for Medical Health Research Ethics South East (ref. no. 2015/1035). In ALSPAC, informed consent was obtained for all participants. For children up to age 16 this was provided by the main caregiver or legal guardian (mostly mothers), and after the age of 16, the consent was provided by the teenagers themselves. Ethics approval for the study was obtained from the ALSPAC Law and Ethics Committee and the local National Health Service Research Ethics Committee. The study was performed in line with the Declaration of Helsinki. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

During tumor immunosurveillance, leukocytes play a crucial role in the cellular defense system, working collaboratively with other immune components to recognize and eliminate aberrant cells. Integral to this process is the integrin Lymphocyte Function-Associated Antigen 1 (LFA-1). LFA-1 facilitates adhesion during leukocyte migration and helps establish stable cell-to-cell contacts between leukocytes and their targets. Additionally, as a receptor, LFA-1 signaling activates leukocytes, promoting their differentiation and effector functions against cancer. However, tumors can develop mechanisms to evade immune clearance by disrupting LFA-1 functions or hijacking its pathways. In this review, we first detail how leukocytes utilize LFA-1 during immunosurveillance and then explore how tumors counteract this process in the tumor microenvironment (TME) by either altering LFA-1 functions or exploiting it to drive tumorigenesis. Moreover, we discuss therapeutic strategies targeting LFA-1, including inhibitors tested in laboratory studies and animal models, highlighting their potential as anticancer interventions and the need for further research to evaluate their clinical utility., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2025 Upadhyay, Murugu and Svensson.)

Background: Type 2 diabetes (T2D) has been linked to changes in DNA methylation levels, which can, in turn, alter transcriptional activity. However, most studies for epigenome-wide associations between T2D and DNA methylation comes from cross-sectional design. Few large-scale investigations have explored these associations longitudinally over multiple time-points., Methods: In this longitudinal study, we examined data from the Cooperative Health Research in the Region of Augsburg (KORA) F4 and FF4 studies, conducted approximately seven years apart. Leucocyte DNA methylation was assessed using the Illumina EPIC and 450K arrays. Linear mixed-effects models were employed to identify significant associations between methylation sites and diabetes status, as well as with fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), homoeostasis model assessment of beta cell function (HOMA-B), and homoeostasis model assessment of insulin resistance (HOMA-IR). Interaction effects between diabetes status and follow-up time were also examined. Additionally, we explored CpG sites associated with persistent prediabetes or T2D, as well as the progression from normal glucose tolerance (NGT) to prediabetes or T2D. Finally, we assessed the associations between the identified CpG sites and their corresponding gene expression levels., Results: A total of 3,501 observations from 2,556 participants, with methylation measured at least once across two visits, were included in the analyses. We identified 64 sites associated with T2D including 15 novel sites as well as known associations like those with the thioredoxin-interacting protein (TXNIP) and ATP-binding cassette sub-family G member 1 (ABCG1) genes. Of these, eight CpG sites exhibited different rates of annual methylation change between the NGT and T2D groups, and seven CpG sites were linked to the progression from NGT to prediabetes or T2D, including those annotated to mannosidase alpha class 2a member 2 (MAN2A2) and carnitine palmitoyl transferase 1 A (CPT1A). Longitudinal analysis revealed significant associations between methylation and FPG at 128 sites, HbA1c at 41 sites, and HOMA-IR at 57 sites. Additionally, we identified 104 CpG-transcript pairs in whole blood, comprising 40 unique CpG sites and 96 unique gene transcripts., Conclusions: Our study identified novel differentially methylated loci linked to T2D as well as to changes in diabetes status through a longitudinal approach. We report CpG sites with different rates of annual methylation change and demonstrate that DNA methylation associated with T2D is linked to following transcriptional differences. These findings provide new insights into the molecular mechanisms of diabetes development., Competing Interests: Declarations. Ethics approval and consent to participate: Ethical approval for the KORA cohort was granted by the ethics committee of the Bavarian Medical Association and all procedures were conducted in accordance with the principles of the Declaration of Helsinki. All research participants provided signed informed consent before participating in any research activities. The KORA data protection procedures were approved by the responsible data protection officer of the Helmholtz Zentrum München. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Exposure to metals has been related to alterations in leukocyte telomere length (LTL), an aging marker. However, the evidence regarding this relationship in children and adolescents, as well as the underlying mechanisms, remains unclear. Therefore, we aimed to explore the individual and mixture effects of metals on LTL in children and adolescents and to assess the mediating role of thyroid hormones and the modifying effect of a healthy lifestyle. In a cross-sectional study performed in Liuzhou, China, we assessed 5 serum thyroid hormones, 18 urinary metals, and LTL among 1050 children and adolescents aged 6-18 years. We employed multivariate linear regression and weighted quantile sum (WQS) regression to assess the associations of urinary metals with LTL in children and adolescents. Mediation analyses were conducted to explore the effects of thyroid hormones on these relationships. Urinary cobalt (Co), nickel (Ni), strontium (Sr), mercury (Hg), cadmium (Cd), and thallium (Tl) were related to a shorter LTL in children and adolescents. The WQS regression showed a 6.31% (95% CI: -8.76%, -3.79%) decrease in LTL per quartile increase in the WQS index, and identified Ni (23.3%), Sr (21.7%), and Tl (18.0%) as the major contributors. Mediation analyses showed that triiodothyronine (T3) mediated 14.8% and 8.1% of the associations of urinary Sr and Hg with LTL, respectively, and suppressed 9.3% of the association with urinary Co. Furthermore, the inverse associations of Sr, Cd, and Tl with LTL were attenuated among participants who adopted a healthy lifestyle. Our findings suggested that exposure to Co, Ni, Sr, Cd, Hg, Tl, and their mixture were related to a shorter LTL in children and adolescents, potentially mediated by thyroid hormones. Additionally, adopting a healthy lifestyle may alleviate these adverse effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Dengue virus (DENV) poses a considerable threat to public health on a global scale, since about two-thirds of the world's population is currently at risk of contracting this arbovirus. Being transmitted by mosquitoes, this virus is associated with a range of illnesses and a small percentage of infected individuals might suffer from severe vascular leakage. This leakage leads to hypovolemic shock syndrome, generally known as dengue shock syndrome, organ failure, and bleeding complications. The severe form of this disease is believed to be, at least partially, associated with inflammatory and thrombotic states. These issues are significantly affected by the activation of platelets and leukocytes, as well as their interactions, which may influence its prognosis. The platelets present in a thrombus are able to attract leukocytes to the site of injury. The intricate process leads to the significant accumulation, activation, and migration of leukocytes, thereby promoting thrombotic events and triggering inflammatory responses. The occurrence of these events, combined with the direct viral infection of endothelial cells, leads to vascular endothelialitis, the disruption of cellular membranes, and the subsequent release of DAMPs. As a result, considerable damage occurs in the endothelium, which activates neutrophils and platelets; thisleads to their interaction and initiates the process of Netosis. Collectively, these processes exacerbate inflammatory and thrombotic conditions. In this respect, current research has focused on understanding whether effective anti-inflammatory protocols can prevent thrombotic events or, conversely, if efficient anticoagulant regimens may lead to a reduction in cytokine storms and tissue damage. This review article aims to illuminate the platelet leukocyte crosstalk, detailing the mechanisms through which platelets may play a role in the pathogenesis of DENV. The research outputs are particularly important in severe cases, in which case their interactions with leukocytes can exacerbate both inflammation and thrombosis in a mutually reinforcing manner., Competing Interests: Declarations. Ethical approval: This article does not contain any studies with human participants or animals performed by any of the authors. Consent for publication: Not applicable. Consent form: This study does not use animal or human samples. Competing interests: The authors declare no competing interests., (© 2025. The Author(s), under exclusive licence to Springer Nature B.V.)

White blood cells (WBCs), also known as leukocytes, are one of the most significant parts of the immune system. They generate antibodies, protect the body from illnesses, and heal wounds. Accurate estimation of WBCs is key for diagnosing cancer, infections, leukemia, lymphoma, and other diseases. However, the widely used Complete Blood Count (CBC) test presents challenges, including prick anxiety, discomfort, and logistical inconvenience to patients. This study introduces a ubiquous White Blood Cell counting system, UbiWhite, a novel smartphone-based, non-invasive system for real-time WBC counting from fingertip videos. Our system uses optical and magnetic techniques to provide accurate WBC counts without blood extraction. An initial experimentation was carried out on 20 adult participants to verify the system's effectiveness compared to standard CBC tests (IRB #4051). The developed algorithms exhibit 1.04 and 1.23 RMSE, respectively. Our innovation provides an easy, affordable, and instantaneous solution for monitoring WBCs in various healthcare settings, including homes and critical care units. Additionally, it serves as a beacon of hope for low- and middle-income nations, where access to and affordability of traditional lab tests are limited., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Hemophilia A (HA) is associated with FVIII coagulation insufficiency or inactivity leading to excessive bleeding. Elevated FVIII, on the contrary, is associated with thrombophilia, thrombosis, myocardial infarctions, and stroke. Active FVIII (aFVIII) uses its C2 domain to bind to blood cells' membranes, consequently carrying out its coagulative function. We developed a reliable flow cytometry (FC) method for FVIII detection that can be utilized for assessing surface-bound FVIII on leukocytes in different coagulation/clinical states; we analyzed 49 pediatric subjects, encompassing patients with HA, other coagulopathies, venous thrombosis, and normal coagulation. Interestingly, the total leukocyte surface FVIII showed a declining trend across thrombosis, normal, and hypo-coagulation states. As expected, the leukocytes of HA patients displayed significantly lower levels of cellular-surface FVIII in comparison to patients with thrombosis. However, no significant correlation was observed between circulating levels of FVIII in plasma and the levels of FVIII bound to leukocytes, indicating that the differences in FVIII surface binding are not directly proportional to the availability of FVIII in the circulation and suggesting a specific binding mechanism governing the interaction between FVIII and leukocytes. Intriguingly, when analyzing the distinct blood subpopulations, we observed that surface FVIII levels were significantly elevated in classical monocytes of thrombosis patients compared to HA patients, healthy controls, and patients with other coagulopathies. Our study highlights the reliability of our FC platform in assessing FVIII abundance on leukocytes' membranes across coagulation states. Monocytes, particularly in cases of thrombosis, exhibit active binding of FVIII on their surface, suggesting a potential role in the pathophysiology of thrombosis that requires further investigation.

Background: Leukocyte telomere length (LTL) shortening, a biomarker of telomere attrition, has been linked to multiple diseases. However, the relationship between LTL and digestive diseases remains uncertain. This study aimed to investigate the association between LTL and the risk of digestive diseases., Methods: A cohort analysis of over 500,000 participants from the UK Biobank (UKB) between 2006 and 2021 was conducted to estimate the associations of LTL with more than 90 common digestive diseases. LTL was quantified using multiplex quantitative polymerase chain reaction, and cases of each disease were determined according to inpatient and primary care data. Multivariable Cox proportional hazards regression analysis was used to evaluate the associations of LTL with the risk of digestive diseases. Furthermore, such associations were also evaluated after stratification by sex and ethnicity., Results: After a mean follow-up time of 11.8 years, over 20 International Classification of Diseases, 10th Revision ( ICD-10 ) codes were showed to be associated with telomere attrition. LTL shortening is associated with an increased risk of several digestive diseases, including gastroesophageal reflux disease (K21: hazard ratio [HR] = 1.30, 95% confidence interval [95% CI]: 1.19-1.42), esophageal ulcer (K221: HR = 1.81, 95% CI: 1.22-2.71), Barrett's esophagus (K227: HR = 1.58, 95% CI: 1.14-2.17), gastritis (K29: HR = 1.39, 95% CI: 1.26-1.52), duodenal ulcer (K26: HR = 1.55, 95% CI: 1.14-2.12), functional dyspepsia (K30X: HR = 1.36, 95% CI: 1.06-1.69), non-alcoholic fatty liver disease (NAFLD) (K760: HR = 1.39, 95% CI: 1.09-1.78), liver cirrhosis (K74: HR = 4.73, 95% CI: 3.27-6.85), cholangitis (K830: HR = 2.55, 95% CI: 1.30-5.00), and hernia (K43: HR = 1.50, 95% CI: 1.17-1.94; K44: HR = 1.29, 95% CI: 1.17-1.42). The risk of rectal polyps (K621: HR = 0.77, 95% CI: 0.63-0.92) decreased per unit shortening of LTL., Conclusions: This study suggests that LTL shortening is associated with an increased risk of most digestive diseases except for rectal polyps. These findings may provide some clues for understanding the pathogenesis of digestive diseases., (Copyright © 2024 The Chinese Medical Association, produced by Wolters Kluwer, Inc. under the CC-BY-NC-ND license.)

Hand osteoarthritis (HOA), characterized by an earlier onset age and reduced susceptibility to mechanical stress compared with knee and hip osteoarthritis, is considered a suitable disease for identifying predictive biomarkers of osteoarthritis. In particular, DNA methylation variants, expected to contribute to HOA susceptibility, hold potential as osteoarthritis biomarkers. In this study, leukocyte DNA methylation patterns were analyzed in blood samples from patients with HOA, aiming to identify disease-specific biomarkers for osteoarthritis. Using DNA methylation microarrays, we analyzed samples from three subjects with HOA and three age- and gender-matched healthy individuals. For validation, pyrosequencing analysis was conducted using samples from 16 to 9 subjects with and without HOA, respectively. From 735,026 probes in the DNA methylation array, the Top 100 CpG sites associated with HOA, based on low adjusted P-values, including those targeting bone morphogenetic protein 7 (BMP7), SBF2-AS1, PLOD2, ICOS, and CSF1R were identified. Validation analysis revealed significantly higher methylation levels in the BMP7-related site in the HOA group compared with the control group, even after adjusting for age, gender, and body mass index (p = 0.037). In contrast, no significant difference was observed in the other selected CpG sites between the HOA and control groups. This study highlights the significantly increased frequency of methylation at the specific BMP7 site in leukocytes of patients with HOA, suggesting its potential as a biomarker for HOA. Measurement of methylation levels at the CpG sites identified in this study offers a potential approach to prevent future osteoarthritis progression, providing valuable insights into disease management., (© 2024 The Author(s). Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

The continuous contact between blood and the foreign surface of the extracorporeal membrane oxygenation (ECMO) circuit contributes to hemostatic, inflammatory, and other physiological disturbances observed during ECMO. Although previous studies have extensively investigated blood samples from patients on ECMO, cell adsorption to the ECMO circuit as an additional factor that could potentially influence clinical outcomes, has largely been overlooked. Here we provide a detailed immunofluorescence (IF) protocol designed to characterize cellular binding on ECMO circuits collected from patients. Extracorporeal membrane oxygenation circuits were collected from three pediatric patients and an albumin primed-only ECMO circuit was used as control. Circuit samples from five different sites within each ECMO circuit were collected and processed for the IF protocol. CD14 and CD42a antibodies were used to identify platelets and leukocytes bound to each ECMO circuit sample and images captured using inverted fluorescence microscopy. The protocol enables the comprehensive characterization of platelet and leukocyte binding to ECMO circuits collected from patients, which could in turn extend our knowledge of the characteristics of circuit binding and may provide guidance for improved ECMO circuit design., Competing Interests: G.M. is the president of the Extracorporeal Life Support Organization (ELSO). The other authors have no conflicts of interest to report., (Copyright © ASAIO 2024.)

Streptococcus pneumoniae is a leading cause of community-acquired pneumonia. Intercellular adhesion molecule-1 (ICAM-1) is an adhesion molecule that is highly expressed on the pulmonary capillary endothelium, alveolar epithelium, and other cell types within the lung. ICAM-1 plays important roles in leukocyte adhesion, migration, and motility. To determine the contributions of ICAM-1 to bacterial clearance and leukocyte kinetics during pneumonia, mice were inoculated with S. pneumoniae and evaluated 1, 4, and 7 days later. Our results show that Icam1 -/- mice have a greater number of viable bacteria within the lung at each time point. The impaired clearance observed in Icam1 -/- mice was not due to an impediment in leukocyte recruitment. In fact, Icam1 -/- mice had a greater number of neutrophils and recruited inflammatory macrophages in the lung tissue and the alveoli/airways on day 7 . In contrast, fewer alveolar macrophages were present in the bronchoalveolar lavage (BAL) of Icam1 -/- mice. The loss of body weight and the concentrations of inflammatory mediators in the BAL were also significantly greater in Icam1 -/- mice. Mechanistic studies to understand the defect in clearance show that neutrophils and macrophage subpopulations had no defect in phagocytosis or acidification of phagosomes. RNA sequencing reveals many differences in gene expression but no suggestion of a defect in phagocytosis or killing. Thus, ICAM-1 is necessary for the clearance of S. pneumoniae and for the resolution of pneumonia but is not required for the recruitment of neutrophils or inflammatory macrophages into the pneumonic lung parenchyma or the alveoli/airways during S. pneumoniae- induced pneumonia. NEW & NOTEWORTHY Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. Our study examined ICAM-1, an adhesion molecule that is expressed on most cell types and plays important roles in leukocyte adhesion, migration, and motility. The data demonstrate that ICAM-1 is necessary for the clearance of S. pneumoniae and for the resolution of pneumonia but is not required for the recruitment of neutrophils or inflammatory macrophages into the pneumonic lung parenchyma or the alveoli/airways.

Advances in genetic, pharmacologic, and sequencing technology have led to new insight into the role of lymphatics in health and disease. This includes fundamental aspects of the crosstalk between immune cells with cardiac lymphatics. At the interface between leukocytes and lymphatic endothelial cells, myeloid populations are sources of lymphatic growth factors during inflammation. Lymphatic endothelial cells also secrete signals that activate leukocytes, including to antigen presenting cells. Taken together, a view of the lymphatic vasculature as a supplemental cardiac immune hub is emerging. Herein, we discuss reciprocal cell and molecular crosstalk between leukocytes and lymphatics in the myocardium, with implications for health and cardiac inflammation., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

P2X7 is an extracellular adenosine 5'-triphosphate (ATP)-gated cation channel that plays various roles in inflammation and immunity. P2X7 is present on peripheral blood monocytes, dendritic cells (DCs), and innate and adaptive lymphocytes. The anti-human P2X7 monoclonal antibody (mAb; clone L4), used for immunolabelling P2X7 or blocking P2X7 activity, is a murine IgG2 b antibody, but its ability to mediate complement-dependent cytotoxicity (CDC) is unknown. In this study the functionality of this mAb was confirmed by inhibition of ATP-induced Ca 2+ responses in HEK-293 cells expressing P2X7 (HEK-P2X7). Spectrophotometric measurements of lactate dehydrogenase release demonstrated that the anti-P2X7 mAb mediated CDC in HEK-P2X7 but not HEK-293 cells. Further, flow cytometric measurements of the viability dye, 7-aminoactinomycin D, showed that this mAb mediated CDC in human RPMI 8226 but not mouse J774 cells. Immunolabelling with this mAb and flow cytometry revealed that relative amounts of cell surface P2X7 varied between human peripheral blood leukocytes. As such, the anti-P2X7 mAb preferentially mediated CDC of leukocytes that displayed relatively high cell surface P2X7, namely monocytes, DCs, natural killer T cells, myeloid-derived suppressor cells, and T helper 17 cells. Together, this data highlights a novel approach to target cellular P2X7 and to limit unwanted P2X7 functions., (© 2025 The Author(s). European Journal of Immunology published by Wiley‐VCH GmbH.)

Exposure to acute stressors can induce multiple physiological changes in vertebrates such as altering circulating hormone and enzyme levels as well as leukocyte counts, and interactions between endocrine and immune function may produce suites of physiological changes following acute stress. Previously, we showed that presence of human observers elicited only a weak elevation of plasma corticosterone levels in cottonmouths. Additional variables, however, must be considered to understand if changes in physiological parameters are highly generalized or vary among sexes or with context. Here we tested effects of more intense acute stressors (i.e., confinement for 2 h or 4 h or repeated blood sampling) on plasma corticosterone and lactate concentrations and the number of circulating leukocytes. In addition to testing for sex differences, we also tested two predictions frequently found in the stress physiology literature: (1) because glucocorticoids are involved in mobilization of leukocytes, corticosterone levels should covary with the heterophil to lymphocyte ratio, (2) since one of the major functions of corticosterone is to mobilize energy stores, baseline corticosterone levels (i.e., in immediately bled snakes) should be elevated in individuals in poor body condition. We found that neither sex nor body condition influenced corticosterone responses to confinement. However, repeated blood sampling had a pronounced effect- snakes bled both upon capture and at 2 h had higher corticosterone levels than snakes bled only once at 2 h or even at 4 h. Plasma lactate and the percent azurophils (but not the heterophil to lymphocyte ratio) were also elevated in confined snakes, and both were positively correlated with plasma corticosterone. Our results indicate a pronounced and nuanced effect of confinement stress on the physiology of cottonmouths., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Hypothyroidism, characterized by inadequate production of thyroid hormones, and malaria, a mosquito-borne infectious disease caused by Plasmodium parasites, are significant health concerns worldwide. Understanding the interplay between these two conditions could offer insights into their complex relationship and potential therapeutic strategies. To induce hypothyroidism, pharmacological inhibition of thyroid hormone synthesis was employed. Subsequently, mice were infected with Plasmodium berghei ANKA to simulate cerebral malaria infection. It needs to monitor the progression of the disease in male mice before it can identify infiltrating immune system populations of interest in the brain by multiparametric techniques such as flow cytometry., (© 2025. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Anaplasma phagocytophilum is an obligatory intracellular bacterium that causes tick-borne zoonosis called human granulocytic anaplasmosis. Mechanisms by which Anaplasma replicates inside of the membrane-bound compartment called "inclusion" in neutrophils are incompletely understood. A small GTPase Rab27a is found in the secretory granules and multivesicular endosomes. In this study we found Rab27a-containing granules were localized to Anaplasma inclusions in guanine nucleotide-dependent manner, and constitutively active Rab27a enhanced Anaplasma infection and dominant-negative Rab27a inhibited Anaplasma infection. Rab27a effector, JFC1 is known to mediate docking/fusion of Rab27a-bearing granules for exocytosis in leukocytes. shRNA stable knockdown of Rab27a or JFC1 inhibited Anaplasma infection in HL-60 cells. Similar to Rab27a, both endogenous and transfected JFC1 were localized to Anaplasma inclusions by immunostaining or live cell imaging. The JFC1 C2A domain that binds 3'-phosphoinositides, was sufficient and required for JFC1 and Rab27a localization to Anaplasma inclusions which were enriched with phosphatidylinositol 3-phosphate. Nexinhib20, the small molecule inhibitor specific to Rab27a and JFC1 binding, inhibited Anaplasma infection. Taken together, these results imply elevated phosphatidylinositol 3-phosphate in the inclusion membrane recruits JFC1 to mediate Rab27a-bearing granules/vesicles to dock/fuse with Anaplasma inclusions, the lumen of which is topologically equivalent to the exterior of the cell to benefit Anaplasma proliferation., (Copyright © 2023 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Telomere shortening has been linked to type 2 diabetes (T2D) and its complications. This study aims to determine whether leukocyte telomere length (LTL) could be a useful marker in predicting the onset of complications in patients suffering from T2D. Enrolled study subjects were 147 T2D patients. LTL was measured using a quantitative PCR method. Key subject's demographics and other clinical characteristics were also included. T2D patients with the shortest LTL had higher TC and non-HDL levels, compared to subjects with the longest LTL ( p = 0.013). Also, T2D patients suffering from diabetic nephropathy showed significant differences in LDL levels ( p = 0.023). While in the group of T2D patients with diabetic retinopathy, significant differences were observed for parameters, such as duration of diabetes ( p = 0.043), HbA1c ( p = 0.041), TC ( p = 0.003), LDL ( p = 0.015), Non-HDL ( p = 0.004) and TG ( p = 0.045). Logistic regression analysis confirmed a significant risk of association of TC and Non-HDL levels with LTL in the 3rd tertile LTL for the crude model adjusted for sex and age, with respective odds ratios of 0.71 (95% CI 0.56-0.91) and 0.73 (95% CI 0.58-0.91). No significant associations were found between LTL in T2D patients and the prevalence of common T2D complications. Nevertheless, a significant association was demonstrated between LTL and some markers of dyslipidemia, including in T2D patients with either diabetic nephropathy or retinopathy. Therefore, analysis of LTL in T2D patients' leukocytes demonstrates a promising potential as a marker in predicting the onset of complications in T2D. This could also help in establishing an effective treatment strategy or even prevent and delay the onset of these severe complications.

The aim of the study was to investigate the potential preventive use of short-chain fatty acids (SCFAs) to modulate inflammatory responses in gilthead seabream (Sparus aurata) skin. Initially, in vitro experiments were conducted to evaluate the effects of various concentrations of butyric acid, acetic acid and propionic acid, as well as their combination, on the cytotoxicity and cell viability of three different cell lines. The results determined the safe concentration of SCFAs, which was then used for an in vivo study. Fish were allocated into six groups and administered different combinations of SCFAs via intramuscular injection, followed by an injection of carrageenan as an inflammatory agent. Skin samples were taken from the injection site three hours post-administration and used to analyse gene expression and immunohistochemistry. The results demonstrated that treatment with SCFAs resulted in increased expression of proinflammatory and anti-inflammatory genes and leucocyte markers in the inflamed skin of fish. The highest gene expression and recruitment of acidophilic granulocytes were observed in fish injected with propionic acid and carrageenan. It is concluded that acetic acid is the most effective anti-inflammatory SCFA tested in gilthead seabream exposed to acute inflammation induced by carrageenan injection. Acetic acid exhibited the most pronounced direct anti-inflammatory effect, although propionic acid appeared to play a significant role in several mechanisms contributing to the resolution of inflammation and recruitment of immune cells to the site of carrageenan-inflamed area in gilthead seabream skin., Competing Interests: Declarations. Competing interests: The authors declare no competing interests. Ethics approval: All experimental protocols were approved by the Ethical Committee of the University of Murcia (protocol code A13150104) following the European Union guidelines for animal handling (2010/63/EU) and the ARRIVE guidelines., (© 2024. The Author(s).)

Background: The tolerance and dynamic regulation of the maternal immune system during pregnancy are pivotal for ensuring fetal health. Immune cell subsets play a complex and crucial role in this process, closely linked to the neonatal health status. Despite recognizing the significance of dysregulation in the quantity and activity of immune cells in neonatal disease occurrence, their specific roles remain elusive, resulting in a dearth of clinically viable interventions for immune-mediated neonatal diseases. Materials and Methods: Employing two-sample Mendelian randomization (MR) methodology, this study systematically investigated 446 leukocyte features ( N  = 500,675), including leukocyte subsets, absolute cell (AC) counts, and morphological parameters (MP) and their correlation with seven adverse fetal outcomes ( N  = 1,100,458), encompassing fetal growth restriction (FGR), preterm birth (PTB), neonatal jaundice (NNJ), digestive system disorders of fetus and newborn (DSDFN), hemorrhagic and hematological disorders of fetus and newborn (HDFN), respiratory distress of newborn (RDN), and transitory disorders of metabolism specific to fetus and newborn (TDMSFN). Results: The results unveiled significant causal relationships between 301 leukocyte subsets and these seven adverse fetal outcomes, with 259, 245, 15, 44, 11, 32, and 68 pairs of notable associations for each adverse outcome, respectively. Furthermore, the study highlighted potential pathogenic mechanisms underlying the mutual influence among neonatal diseases. MR results indicated FGR as a robustly correlated risk factor for PTB and NNJ and showed a reciprocal causal relationship between NNJ and FGR. PTB exhibited a positive correlation with HDFN. Conclusions: This study provided profound insights into the intricate regulatory mechanisms of leukocyte subsets in neonatal diseases, paving the way for new avenues in the diagnosis and treatment of associated disorders., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 Hong Chen et al.)

Aims: Infective endocarditis (IE) poses a significant clinical challenge, necessitating nuanced diagnostic tools for early and accurate detection. The diagnostic role of the hybrid technique of single-photon emission tomography-computed tomography with technetium-99 m-hexamethylpropyleneamine oxime-labelled leukocytes ([ 99m Tc]Tc-HMPAO-SPECT/CT) has evolved in recent years. This single-center study assessed whether the recent inclusion in the 2023 European Society of Cardiology modified diagnostic criteria of IE (2023 ESC) of infectious lesions detected with [ 99m Tc]Tc-HMPAO-SPECT/CT affects their diagnostic performance., Methods and Results: Between 2015 and 2019, we enrolled 205 consecutive adults with suspected IE. All participants underwent [ 99m Tc]Tc-HMPAO-SPECT/CT scans (370-740 MBq). Scans were deemed positive in the presence of intracardiac abnormal tracer uptake and/or within the cardiac implantable electronic device. Patients were prospectively followed-up for 12 ± 10 months. Local device infection (LDI) or IE was diagnosed in 75 (36.6 %) patients, while 72 (35.1 %) [ 99m Tc]Tc-HMPAO-SPECT/CT results returned positive. Moreover, extracardiac infectious foci were detected in 25 % of [ 99m Tc]Tc-HMPAO-SPECT/CT scans. The inclusion of both intracardiac and extracardiac lesions detected with [ 99m Tc]Tc-HMPAO-SPECT/CT yields significantly higher sensitivity (p = 0.003) and negative predictive value (NPV) (p = 0.009)., Conclusion: The inclusion of [ 99m Tc]Tc-HMPAO-SPECT/CT into the IE diagnostic work-up improves the appropriate classification of patients. For patients with IE, the extended inclusion of lesions detected with [ 99m Tc]Tc-HMPAO-SPECT/CT in the ESC 2023 diagnostic criteria significantly improves sensitivity and NPV while reducing potential IE misdiagnoses. This pioneering imaging modality is poised to become an integral component of clinical practice, promising to advance IE diagnosis and management., Competing Interests: Declaration of competing interest The authors have no relevant conflicts of interest to disclose., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The influence of circulating white blood cells and inflammatory factors on pruritus is gradually recognized by the public, but the specific causal relationship is still unknown. In this study, we included inflammatory cytokine profiles from 8293 healthy subjects, genetic data on blood cells from various ethnic and ancestry backgrounds, including 746,667 individuals, and 1370 patients of European descent with pruritus for a bidirectional 2-sample Mendelian randomization (MR) analysis. We employed several robust statistical methods, including the inverse variance weighted, weighted median, and the MR-Egger method. We further refined our analysis through a meticulous sensitivity assessment using the leave-one-out strategy, evaluated the heterogeneity of our findings using Cochran's Q test, and addressed potential pleiotropic effects through the MR-Egger intercept test. Ultimately, a reverse MR analysis was conducted to assess the potential for reverse causation. Genetic prediction data indicate a positive correlation between eosinophil cell count and the risk of developing pruritus (odds ratio [OR] = 1.31, 95% confidence interval [CI] = 1.09-1.55, P = .003). Furthermore, elevated levels of stromal-cell-derived factor 1 alpha (OR = 1.80, 95% CI: 1.15-2.77, P = .009), monokine induced by gamma interferon (OR = 1.23, 95% CI: 1.04-1.46, P = .015), and cutaneous T-cell-attracting chemokine (OR = 1.24, 95% CI: 1.01-1.53, P = .043) are all associated with an increased risk of pruritus occurrence, respectively. No evidence of horizontal pleiotropy or heterogeneity was observed among the genetic variants (P > .05), and the leave-one-out analysis confirmed the stability and robustness of this association. The reverse MR analysis demonstrated the absence of reverse causality. Our research delineates the causal links between eosinophil cell count, stromal-cell-derived factor 1 alpha, monokine induced by gamma interferon, cutaneous T-cell-attracting chemokine levels, and pruritus susceptibility. These insights may present promising avenues for enhancing the management and therapeutic strategies for patients suffering from pruritus., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: It is necessary to find latent indicators to predict the survival of alcohol-associated liver disease (ALD) patients. Leukocyte telomere length (LTL) was regarded as an indicator of prognosis in several diseases. However, the relationships between LTL and survival as well as cause-specific mortality in ALD patients were still unknown., Objective: This study aimed at exploring the underlying link between LTL and the risk of mortality in patients with ALD., Methods: The LTL and survival data were gathered from the National Health and Nutrition Examination Survey (NHANES) 1999-2002. The connection between LTL and mortality was assessed by Cox regression models and stratified analyses. The non-linear relationship was explored by restricted cubic spline (RCS) analysis. Sensitivity analyses were used to evaluate the robustness of our findings., Results: LTL was a negative factor for all-cause mortality (all p -value < 0.05). The risk of cardiovascular disease (CVD)-related death was decreased in Q3 ( p < 0.001) and Q4 levels of LTL ( p < 0.001) compared with the Q1 group. Shorter LTL resulted in higher cancer-caused mortality ( p = 0.03) in the Q2 group. Longer LTL improved survival especially for elder patients ( p for trend < 0.001) or men ( p for trend = 0.001). Moreover, there were L-shaped correlations between LTL and all-cause mortality ( p for non-linearity = 0.02), as well as cancer-related mortality ( p for non-linearity < 0.001). Four sensitivity analyses proved the robustness of our findings., Conclusion: Our research found that longer LTL improved survival in patients with ALD and decreased CVD and cancer-related mortality. LTL decreased all-cause mortality especially for patients older than 65 years or men. LTL might be a useful biomarker for prognosis among patients with ALD. More prospective studies are needed to assess the relevance between LTL and mortality and explore the underlying mechanisms between them., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yi, Guo, Jiang, Duan, Xue, Zhao, He and Xia.)

Kidney fibrosis is the common pathological pathway in progressive chronic kidney disease (CKD), and current treatments are largely ineffective. The C-X-C chemokine receptor 4 (CXCR4) is crucial to fibrosis development. By using neural cell adhesion molecules as scaffolds with binding loops that mimic the shape of shark antibodies, fully humanized single-domain i-bodies have been developed. The first-generation i-body, AD-114, demonstrated antifibrotic effects in a mouse model of folic acid (FA)-induced renal fibrosis. The second-generation i-body, AD-214, is an Fc-fusion protein with an extended half-life, enhanced activity, and a mutated Fc domain to prevent immune activation. To investigate the renoprotective mechanisms of AD-214, RPTEC/TERT1 cells (a human proximal tubular cell line) were incubated with TGF-b1 with/without AD-214 and the supernatant was collected to measure collagen levels by Western blot. Mice with unilateral ureteral obstruction (UUO) received AD-214 intraperitoneally (i.p.) every two days for 14 days. Kidney fibrosis markers and kidney function were then analyzed. AD-214 suppressed TGF-b1-induced collagen overexpression in RPTEC/TERT1 cells. In UUO mice, AD-214 reduced extracellular matrix (ECM) deposition, restored kidney function, and limited leukocyte infiltration. In a scratch assay, AD-214 also inhibited macrophage migration. To conclude, i-body AD-214 attenuates UUO-induced kidney fibrosis by inhibiting leukocyte infiltration and macrophage migration.

Not much is currently known about disturbances in insulin signaling and glucose transport in leukocytes of women with gestational diabetes mellitus (GDM) during and after pregnancy. In this study, the expression of insulin signaling ( INSR , IRS1 , IRS2 and PIK3R1)- and glucose transporter ( SLC2A1 , SLC2A3 and SLC2A4 )-related genes in the leukocytes of 92 pregnant women was assayed using quantitative RT-PCR. The cohort consisted of 44 women without GDM (NGT group) and 48 with GDM (GDM group) at 24-28 weeks of gestation. GDM women were then tested again one year after childbirth (pGDM group: 14 women (29.2%) with abnormal glucose tolerance (AGT) and 34 women (70.8%) with normoglycemia). The GDM and NGT groups were closely matched for gestational age and parameters of obesity, such as pre-pregnancy body mass index (BMI), pregnancy weight, and gestational weight gain (GWG) ( p > 0.05). Compared to the NGT group, the GDM and pGDM groups were hyperglycemic, but the GDM group featured a more highly insulin-resistant condition than the pGDM group, as reflected by higher fasting insulin (FI) levels and the values of the homeostasis model assessment for insulin resistance (HOMA-IR) ( p < 0.05). In leukocytes from the GDM and pGDM groups, PIK3R1 , SLC2A1 , and SLC2A3 were upregulated and IRS1 was downregulated, with a larger magnitude in fold change (FC) values for PIK3R1 and IRS1 in the GDM group and for SLC2A1 and SLC2A3 in the pGDM group. The expression of SLC2A4 was unchanged in the GDM group but upregulated in the pGDM group, where it was inversely correlated with HOMA-IR ( rho = -0.48; p = 0.007). Although the INSR and IRS2 levels did not significantly differ between the groups, the IRS2 transcript positively correlated with pregnancy weight, fasting plasma glucose, FI, and HOMA-IR in the GDM group. Our findings indicate that pronounced quantitative changes exist between the GDM and pGDM groups with respect to the expression of certain genes engaged in insulin signaling and glucose transport in leukocytes, with insulin resistance of a variable degree. These data also highlight the relationship of leukocyte SLC2A4 expression with insulin resistance in the postpartum period.

Hypertension is the leading risk for cardiovascular disease and worldwide mortality. Uncontrolled blood pressure worsens with age and its control is part of public health strategies especially for older adults. Telomere length (TL) has been associated with hypertension, with age and sex as relevant confounding factors, but it is not clear whether hypertension control in older adults impacts on TL and if this relationship is consistently age and sex dependent. TL was assessed in leukocytes of 369 hypertensive patients. Individuals were >60 years male (169) and female (200) and have been diagnosed and treated for hypertension for at least four years. TL was measured by RT-PCR using a commercial probe. Regression models were developed considering systolic and diastolic blood pressure control as dependent variables and age, sex, glucose, and lipid levels as confounding factors. TL showed a mean of 7.5 ± 5.1 Kb, and no difference between males and females was observed. We identified a significant association between systolic blood pressure control and TL ( p value = 0.039) and a trend for diastolic blood pressure ( p value = 0.061). These observations confirm and expand previous reports showing that hypertension control can have an impact on TL and consequently on other factors of healthy aging.

Telomere length is an important biomarker of biological aging and is affected by nutrition and physical activity. This study investigated the effects of diets with different fat contents and increased physical activity on certain pro/anti-inflammatory and oxidative stress markers and aging. The study is performed in a randomized, experimental, and controlled design with 48 rats, 8 weeks old, divided into 6 different groups (Control (C), exercise (E), unsaturated fat diet (USF), saturated fat diet (SF), unsaturated fat diet + exercise (USF + E), and saturated fat diet + exercise (SF + E)). The rats performed aerobic swimming exercise for 50 days and were fed a diet with different fat content. TAS, TOS, and MDA levels were determined by colorimetric analysis while 8-OHdG, IL-10, and TNF-α were determined by ELISA. Additionally, leukocyte telomere length is determined by the PCR method. Weight changes were also recorded. Plasma TOS, OSI, and TNF-α were lowest in the USF group and highest in the SF and SF + E groups. MDA, 8-OHdG and TG levels were highest in the SF group. The lowest IL-10 level was detected in group C. TL level was the highest in the USF group. There was also a moderate, negative, and significant correlation between telomeres and TOS, OSI, and TNF-α. The groups with the highest body weight gain were C, SF, and SF + E. Diets low in saturated fat or high in unsaturated fat, and physical activity were associated with leukocyte telomere length and alteration of oxidative and pro/anti-inflammatory markers., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate whether micronutrient intake from food as well as the regular uptake of specific vitamins and/or minerals are associated with leucocyte telomere length (LTL)., Methods: This is a cross-sectional study using data from 422,693 UK Biobank participants aged from 40 to 69 years old, during 2006-2010. LTL was measured as the ratio of telomere repeat number to a single-copy gene and was log e -transformed and z-standardized (z-LTL). Information concerning supplement use was collected at baseline through the touchscreen assessment, while micronutrient intake from food were self-reported through multiple web-based 24 h recall diaries. The association between micronutrient intake or supplement use and z-LTL was assessed using multivariable linear regression models adjusting for demographic, lifestyle and clinical characteristics., Results: About 50% (n = 131,810) of the participants, with complete data on all covariates, self-reported regular supplement intake. Whilst overall supplement intake was not associated with z-LTL, trends toward shorter z-LTL with regular vitamin B (-0.019 (95% CI: -0.041; 0.002)) and vitamin B9 (-0.027 (-0.054; 0.000)) supplement intake were observed. z-LTL was associated with food intake of pantothenic acid (-0.020 (-0.033; -0.007)), vitamin B6 (-0.015 (-0.027; -0.003)), biotin (0.010 (0.002; 0.018)) and folate (0.016 (0.003; 0.030)). Associations of z-LTL with these micronutrients were differentiated according to supplement intake., Conclusion: Negative associations equivalent to a year or less of age-related change in LTL between micronutrient intake and LTL were observed. Due to this small effect, the clinical importance of the associations and any relevance to the effects of vitamin and micronutrient intake toward chronic disease prevention remains uncertain., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To assess the functional state and age-related characteristics of autophagy in peripheral blood leukocytes as a risk factor for the development of inflammaging using the example of the servicemen of the DefenseForces of Ukraine and clean-up workers of the Chornobyl accident., Materials and Methods: A total of 103 male patients aged 28-77 (56,48 ∓ 9,05) years were examined. They included: the main group - 23 servicemen of the Defense Forces of Ukraine aged 44-59 (50,21 ∓ 5,13) years; the comparison group - 57 clean-up workers of the Chornobyl accident aged 56-63 (60,31 ∓ 1,78) years; and the control group -23 civilians aged 28-77 (53,26 ∓ 15,98) years. The individuals in the main and control groups were divided according to age into subgroups under 50 years and over 50 years. Clean-up workers were divided into 3 subgroups depending on the radiation dose: І - D < 100 mSv, ІІ - 100 < D < 500 mSv and ІІІ - D > 500 mSv. Analysis of autophagyparameters in peripheral blood leukocytes (PB) was performed using flow cytometry and polymerase chain reaction., Results: In patients of the main group, the autophagy activity factor (AAF) of granulocytes and the expression of theSQSTM1 gene in PB leukocytes decreased. A decrease in chloroquine-induced accumulation of LC3B protein in leukocytes, AAF in PB monocytes and the expression of the MTOR, RB1CC1 and MAP1LC3B genes was revealed in servicemenof the Defense Forces of Ukraine under 50 years of age. The spontaneous levels of LC3B protein and AAF in monocytesand the expression level of PIK3C3, ULK1 and MAP1LC3B genes in PB leukocytes were increased in servicemen of theDefense Forces of Ukraine over 50 years of age. The clean-up workers of different dose groups showed a decrease inthe AAF in lymphocytes and granulocytes, the LC3B level in monocytes after incubation with chloroquine, the expression of the MTOR, RB1CC1, SQSTM1, ULK1, MAP1LC3B, BECN1 and PIK3C3 genes in PB leukocytes, and the AAF of monocytes was higher. Similar changes were revealed in the indices of chloroquine-induced LC3B accumulation in lymphocytes and monocytes of the clean-up workers and servicemen of both age groups, as well as the spontaneous LC3B protein level in PB monocytes of the clean-up workers irradiated at doses above 100 mSv and civilians over 50 years old., Conclusions: Unidirectional dysregulation of autophagy was established in the servicemen of the Defense Forces ofUkraine and the clean-up workers of the Chornobyl accident. The existing changes in autophagy parameters can leadto disruption of the functioning of the autophagic apparatus of leukocytes at the level of mRNA and protein, as wellas signaling pathways, and be associated with age-related changes at both the cellular and organismal levels. Theemergence of new and persistent earlier stress factors as a result of the war creates an additional load on the mechanisms of maintaining homeostasis, which is observed in individuals exposed to ionizing radiation more than 30years later. The found intergroup differences and similarities can activate the same or similar mechanisms of pathological processes, which will ultimately increase the risks of developing age-associated chronic somatic pathologyin younger age groups., (L. M. Zvarych, D. A. Bazyka.)

Purpose: L-Ascorbic acid (vitamin C) is an essential water-soluble vitamin that plays an important role in various physiological functions, including immune health. The stability of vitamin C in the gastrointestinal tract its bioavailability is limited. This study aimed to investigate if a liposomal form of vitamin C can increase absorption compared to standard vitamin C., Methods: In a randomized, double-blind, placebo-controlled, crossover fashion, 19 males and 8 females (n = 27; 36.0 ± 5.1 years, 165.0 ± 6.9 cm, 70.6 ± 7.1 kg) ingested a single-dose of placebo (PLA), 500 mg vitamin C (VIT C), and 500 mg liposomal vitamin C (LV-VIT C, LipoVantage ® , Specnova, LLC, Tyson Corner, VA, USA). Venous blood samples were collected 0, 0.5-, 1-, 1.5-, 2-, 3-, 4-, 6-, 8-, 12-, and 24-hours after ingestion and were analyzed for plasma and leukocyte vitamin C concentration., Results: VIT C and LV-VIT C demonstrated significantly greater Cmax and AUC 0 - 24 in plasma and in leukocytes compared to placebo (p < 0.001). Additionally, LV-VIT C had significantly higher Cmax (plasma + 27%, leukocytes + 20%, p < 0.001) and AUC 0 - 24 (plasma + 21%, leukocytes + 8%, p < 0.001) values as compared to VIT C., Conclusion: Liposomal formulation of vitamin C increases absorption into plasma and leukocytes., Trial Registration: Clinical Trials Registry - India (CTRI/2023/04/051789)., (© 2024. The Author(s).)

Many virus types affect the blood clotting system with correlations to pathology that range widely from thrombosis to hemorrhage linking to inflammation. Here we overview the intricate crosstalk induced by infection between proteins on the virus encoded by either the host or virus genomes, coagulation proteins, platelets, leukocytes, and endothelial cells. For blood-borne viruses with an outer covering acquired from the host cell, the envelope, a key player may be the cell-derived trigger of coagulation on the virus surface, tissue factor (TF). TF is a multifunctional transmembrane cofactor that accelerates factor (F)VIIa-dependent activation of FX to FXa, leading to clot formation. However, the nascent TF/FVIIa/FXa complex also facilitates G protein-coupled modulation of cells via protease-activated receptor 2. As a viral envelope constituent, TF can bypass the physiological modes of regulation, thereby initiating the activation of neighboring platelets, leukocytes, and endothelial cells. A thromboinflammatory environment is predicted due to feedback amplification in response to cellular release of cytokines, procoagulant proteins, neutrophil extracellular traps, and stimulus-induced accessibility of adhesive receptors, resulting in cellular aggregates. The pathobiological effects of thromboinflammation ultimately contribute to innate and adaptive immunity for viral clearance. In contrast, the preceding stages of viral infection may be enhanced via the TF-protease axis., Competing Interests: Declaration of competing interests There are no competing interests to disclose., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Changes in leukocyte populations may confound the disease-associated miRNA signals in the blood of cancer patients. We aimed to develop a method to detect differentially expressed miRNAs from lung cancer whole blood samples that are not influenced by variations in leukocyte proportions. The Ref-miREO method identifies differential miRNAs unaffected by changes in leukocyte populations by comparing the within-sample relative expression orderings (REOs) of miRNAs from healthy leukocyte subtypes and those from lung cancer blood samples. Over 77% of the differential miRNAs observed between lung cancer and healthy blood samples overlapped with those between myeloid-derived and lymphoid-derived leukocytes, suggesting the potential impact of changes in leukocyte populations on miRNA profile. Ref-miREO identified 16 differential miRNAs that target 19 lung adenocarcinoma-related genes previously linked to leukocytes. These miRNAs showed enrichment in cancer-related pathways and demonstrated high potential as diagnostic biomarkers, with the LASSO regression models effectively distinguishing between healthy and lung cancer blood or serum samples (all AUC > 0.85). Additionally, 12 of these miRNAs exhibited significant prognostic correlations. The Ref-miREO method offers valuable candidates for circulating biomarker detection in cancer that are not affected by changes in leukocyte populations.

Cytomegalovirus (CMV) reactivation after stem cell or solid organ transplantation remains a major cause of morbidity and mortality in this setting. T-cell receptor (TCR)-like antibodies bind to intracellular peptides presented in major histocompatibility complex (MHC) molecules on the cell surface and may have the potential to replace T-cell function in immunocompromised patients. Three previously selected CMV-specific, human leukocyte antigen (HLA)-restricted (HLA-A*0101, HLA-A*0201 and HLA-B*0702) Fab-antibodies (A6, C1 and C7) were produced as IgG antibodies with Fc optimization. All antibodies showed specific binding to CMV peptide-loaded tumor cell lines and primary fibroblasts expressing the corresponding MHC-I molecules, leading to specific target cell lysis after the addition of natural killer (NK) cells. When deployed in combination as an antibody pool against target cells expressing more than one matching HLA allele, cytotoxic effects were amplified accordingly. CMV-specific TCR-like antibodies were also able to mediate their cytotoxic effects through neutrophils, which is important considering the delayed recovery of NK cells after stem cell transplantation. When tested on patient blood obtained during CMV reactivation, CMV-specific antibodies were able to bind to and induce cytotoxic effects in lymphocytes. CMV-specific TCR-like antibodies may find application in patients with CMV reactivation or at risk of CMV reactivation. In contrast to previous HLA/peptide-directed therapeutic approaches, the concept of a TCR-like antibody repertoire covering more than one HLA allele would make this therapeutic format available to a much larger group of patients.

The rs72613567:TA polymorphism in 17-beta hydroxysteroid dehydrogenase 13 (HSD17B13) has been found to reduce the progression from steatosis to metabolic dysfunction-associated steatohepatitis (MASH). In this study, we sought to define the pathogenic role of HSD17B13 in triggering liver inflammation. Here, we demonstrate that HSD17B13 forms liquid-liquid phase separation (LLPS) around lipid droplets in the livers of MASH patients. The dimerization of HSD17B13 supports the LLPS formation and promotes its enzymatic function. HSD17B13 LLPS increases the biosynthesis of platelet activating factor (PAF), which in turn promotes fibrinogen synthesis and leukocyte adhesion. Blockade of the PAF receptor or STAT3 pathway inhibits the fibrinogen synthesis and leukocyte adhesion. Importantly, adeno-associated viral-mediated xeno-expression of human HSD17B13 exacerbates western diet/carbon tetrachloride-induced liver inflammation in Hsd17b13-/- mice. In conclusion, our results suggest that HSD17B13 LLPS triggers liver inflammation by promoting PAF-mediated leukocyte adhesion, and targeting HSD17B13 phase transition could be a promising therapeutic approach for treating hepatic inflammation in chronic liver disease., (© The Author(s) (2024). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, CEMCS, CAS.)

Psychosocial stress has been proposed to induce a redistribution of immune cells, but a comparison with an active placebo-psychosocial stress control condition is lacking so far. We investigated immune cell redistribution due to psychosocial stress compared to that resulting from an active placebo-psychosocial stress but otherwise identical control condition. Moreover, we tested for mediating effects of endocrine parameters and blood volume changes. The final study sample comprised 64 healthy young men who underwent either a psychosocial stress condition (Trier Social Stress Test; TSST; n = 38) or an active placebo-psychosocial stress control condition (PlacTSST; n = 26). Immune cell counts and hemoglobin, epinephrine, norepinephrine, ACTH, renin, and aldosterone levels, as well as those of saliva cortisol, were determined before and up to 30 min after the TSST/PlacTSST. The TSST induced greater increases in total leukocyte, monocyte, and lymphocyte levels as compared to the PlacTSST ( p 's ≤ 0.001), but in not granulocyte counts. Neutrophil granulocyte counts increased in reaction to both the TSST and PlacTSST ( p 's ≤ 0.001), while eosinophil and basophil granulocyte counts did not. The psychosocial stress-induced increases in immune cell counts from baseline to peak (i.e., +1 min after TSST cessation) were independently mediated by parallel increases in epinephrine (ab's ≤ -0.43; 95% CIs [LLs ≤ -0.66; ULs ≤ -0.09]). Subsequent decreases in immune cell counts from +1 min to +10 min after psychosocial stress cessation were mediated by parallel epinephrine, renin, and blood volume decreases (ab's ≥ 0.17; 95% CIs [LLs ≥ 0.02; ULs ≥ 0.35]). Our findings indicate that psychosocial stress specifically induces immune cell count increases in most leukocyte subpopulations that are not secondary to the physical or cognitive demands of the stress task. Increases in the number of circulating neutrophil granulocytes, however, are not psychosocial stress-specific and even occur in situations with a low probability of threat or harm. Our findings point to a major role of epinephrine in mediating stress-induced immune cell count increases and of epinephrine, renin, and blood volume changes in mediating subsequent immune cell count decreases from +1 min to +10 min after psychosocial stress cessation.

Background: Although it is established that caloric restriction offers metabolic and clinical benefits, the molecular mechanisms underlying these effects remain unclear. Thus, this study aimed to investigate whether caloric restriction can modulate mitochondrial function and remodeling and stimulate autophagic flux in the PBMCs of patients with obesity., Methods: This was an interventional study of 38 obese subjects (BMI >35 kg/m 2 ) who underwent 6 months of dietary therapy, including a 6-week very-low-calorie diet (VLCD) followed by an 18-week low-calorie diet (LCD). We determined clinical variables, mitochondrial function parameters (by fluorescence imaging of mitochondrial ROS and membrane potential), and protein expression of markers of mitochondrial dynamics (MNF1, MFN2, OPA, DRP1 and FIS1) and autophagy (LC3, Beclin, BCL2 and NBR1) by Western blot., Results: Caloric restriction induced an improvement in metabolic outcomes that was accompanied by an increase in AMPK expression, a decrease of mitochondrial ROS and mitochondrial membrane potential, which was associated with increased markers of mitochondrial dynamics (MFN2, DRP1 and FIS1) and activation of autophagy as evidenced by augmented LC3 II/I, Beclin1 and NBR1, and a decrease in BCL2., Conclusion: These findings shed light on the specific molecular mechanisms by which caloric restriction facilitates metabolic improvements, highlighting the relevance of pathways involving energy homeostasis and cell recovery, including mitochondrial function and dynamics and autophagy., Competing Interests: Declaration of competing interest Declarations of interest: None., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Canine parvovirus disease (CPVD) is one of the most common causes of viral diarrhea in dogs. The disease has a mortality rate of up to 90% if left untreated, and can cause gastroenteritis, vomiting, mucoid/hemorrhagic diarrhea, lymphopenia and even immunosuppression. Based on the effects of canine parvovirus type 2 (CPV-2) on the immune system, we investigated the effects of the CPV-2 on hematological indices and the expression of certain immune molecules in blood leukocytes of CPV-positive and non-CPV dogs. The dogs were (para)clinically evaluated, and their disease status was confirmed by antigen rapid detection kits and polymerase chain reaction (PCR). To elucidate the nature of the immunosuppression seen in CPVD, we investigated the expression of caspases 3/7 and 9, and some lectin family molecules such as galectin-1 (important in viral adhesion) and Mincle (macrophage‑inducible C‑type lectin receptor), in blood leukocytes using reverse transcription quantitative PCR (RT-qPCR). We observed remarkable lymphopenia, lower Hb concentration and higher red blood cell distribution width (RDW) value in CPV-positive dogs. No significant changes in expression of caspases 3/7 and 9 were detected, but galectin-1 and Mincle showed remarkable down and up-regulation, respectively. This proves that the immunosuppression seen in most CPVD is not caused by lymphocyte apoptosis in blood, and that Mincle is partially involved in the immune response to CPV-2. The observed changes in galectin-1 and Mincle may be a defense mechanism against parvovirus by potentially preventing the parvovirus from adhering to the cells. Further research is, nonetheless, needed to elucidate the possible roles of these molecules in CPV-2 pathogenesis and the immune system's response to parvovirus., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Long Covid results from the damage caused by SARS-CoV-2, involving the release of cytokines and the continuous activation of immune cells. This cross-sectional study investigates leukocyte and cytokine profiles in Long Covid patients in the Amazon, a region where such studies are limited. Blood samples were analysed for differential leukocyte counts and cytokine levels. We suggest elevated lymphocyte counts in hospitalised patients and those with severe COVID-19. Higher eosinophil counts were observed in patients with up to three months of Long Covid, and increased monocyte counts in those with up to six months. IL-2 levels were higher in patients with fewer symptoms and Long Covid duration of more than three months, whereas IL-10 may remain elevated for up to 12 months. We suggest positive correlations between neutrophils, monocytes, eosinophils, and lymphocytes with different cytokines (IFN-γ, IL-6, IL-4, IL-17a, IL-2). Women were associated with lower hospitalisation rates and longer durations of Long Covid; increased lymphocyte counts were linked to hospitalisation due to COVID-19, while higher monocyte counts were associated with Long Covid durations of up to six months. We suggest that Long Covid patients may exhibit alterations in inflammatory markers, indicating a persistently pro-inflammatory microenvironment that tends to diminish after 12 months of Long Covid., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Background: Skin fibrosis is the typical pathological manifestation of systemic sclerosis (SSc) and localized scleroderma (LS); it has an unclear aetiology and few effective treatments. Although excessive collagen secretion by fibroblasts is the primary cause of skin fibrosis, evidence has suggested that vascular damage is the initiating event and that various cell types, including fibroblasts, work together to contribute to the pathogenesis of skin fibrosis., Objectives: To explore the relationship between vascular endothelial cell lesions and immune cell infiltration, along with the interactions between various cell types within the fibrotic skin ecosystem., Methods: Single-cell RNA sequencing was performed on skin biopsies from three healthy donors and seven patients with SSc. Additional data from three patients with localized scleroderma available in the Gene Expression Omnibus (GSE160536) were integrated by Harmony. CellChat (version 1.5.0) was used to analyse the cell communication network. A Transwell® assay and a bleomycin (BLM) mouse model were used to explore the role of atypical chemokine receptor 1 (ACKR1; 'Duffy antigen') in immune cell infiltration. Milo single-cell Western blot was used to show fibroblast subcluster activation., Results: A total of 62 295 cells were obtained and subpopulations of stromal and immune cells identified. Interaction network analysis found that multiple chemokines secreted by macrophages, pericytes and proinflammatory fibroblasts could bind with ACKR1, which was highly expressed by endothelial cells in lesional skin. The Transwell® assay revealed that overexpression of ACKR1 in human umbilical vein endothelial cells facilitated leucocyte infiltration following treatment with interleukin-8. BLM mice showed enhanced ACKR1 expression, massive immune cell infiltration and skin fibrosis that was attenuated by ACKR1 inhibition. Furthermore, infiltrated macrophages expressing high levels of transforming growth factor (TGF)-β1 or platelet-derived growth factor B (PDGFB) could activate secreted frizzled-related protein 2 (SFRP2)/asporin (ASPN)+ fibroblasts to contribute to the excessive accumulation of extracellular matrix. It was also found that the SOX4-ASPN axis plays an important role in the TGF-β signalling cascade and the aetiology of skin fibrosis., Conclusions: Our results reveal that high expression of ACKR1 by endothelial cells in fibrotic skin tissue promotes immune cell infiltration and that SFRP2/ASPN+ fibroblasts synergize to exacerbate skin fibrosis., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Association of Dermatologists. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: WHIM (Warts, Hypogammaglobulinemia, Infections, and Myelokathexis) syndrome is an ultra-rare, combined primary immunodeficiency and chronic neutropenic disorder characterized by a range of clinical presentations, including peripheral neutropenia, lymphopenia, and recurrent infections. WHIM syndrome is most often caused by gain-of-function mutations in the gene encoding C-X-C chemokine receptor 4 (CXCR4). As such, inhibition of CXCR4 with XOLREMDI ® (mavorixafor), an orally bioavailable CXCR4 antagonist, demonstrated clinically meaningful increases in absolute neutrophil and lymphocyte counts and concomitant reduction in infections in patients with WHIM syndrome, resulting in its recent U.S. Food and Drug Administration approval. The impact of CXCR4 antagonism on other aspects of the pathobiology in WHIM syndrome, such as lymphopoiesis and leukocyte trafficking between primary and secondary lymphoid organs, is less understood., Methods: In the current study, the effects of CXCR4 antagonism on leukocyte trafficking and distribution in primary and secondary lymphoid organs were investigated in a mouse model of WHIM syndrome carrying the heterozygous Cxcr4 1013 mutation. Cxcr4 +/1013 and Cxcr4 wild-type mice received the orally bioavailable CXCR4 antagonist X4-185. Blood, spleen and bone marrow samples were collected for numeration, flow cytometry, and functional studies., Results: Cxcr4 +/1013 mice exhibited profound peripheral blood leukopenia as seen in patients with WHIM syndrome. CXCR4 antagonism corrected circulating leukopenia and mobilized functional neutrophils without disrupting granulopoiesis in the bone marrow of Cxcr4 +/1013 mice. Furthermore, Cxcr4 +/1013 displayed aberrant splenic T and B-cell counts and frequency. Treatment with X4-185 normalized splenic T-cell abnormalities, correcting the reduced CD8 + T-cell numbers, restoring the CD4/CD8 T-cell ratio, and ameliorating peripheral blood T-cell lymphopenia. In addition, CXCR4 antagonism was able to correct the abnormal frequencies and numbers of splenic marginal zone and follicular B cells in Cxcr4 +/1013 mice, and ultimately normalize B-cell lymphopenia in the peripheral circulation., Conclusions: Our study provides comprehensive evidence that oral dosing with a CXCR4 antagonist can effectively correct WHIM-associated neutrophil and lymphocyte abnormalities in a mouse model of WHIM syndrome. These findings extend our understanding of how targeting the dysregulated CXCR4 signaling pathway can ameliorate the pathogenesis of WHIM syndrome., Competing Interests: CN, KZ, HM, BM, RJ, and AT are employees and shareholders of X4 Pharmaceuticals. LR, MKh, MKa, BS, VG, VR, ZA, ME and KB had a research agreement with X4 Pharmaceuticals. The handling editor TT declared a past collaboration with the authors KZ and AT., (Copyright © 2024 Roland, Nguyen, Zmajkovicova, Khamyath, Kalogeraki, Schell, Gourhand, Rondeau, Abou Nader, Monticelli, Maierhofer, Johnson, Taveras, Espéli and Balabanian.)

This study aimed to measure relative telomere length (RTL) in blood leukocytes of advanced-stage NSCLC patients either with or without Osimertinib-induced ADRs and determine whether RTL could serve as a biomarker of Osimertinib-induced ADRs. Blood leukocytes RTL were measured in 63 advanced-stage NSCLC patients and 62 age-matched healthy controls using real-time polymerase chain reaction. In patients with advanced-stage NSCLC, RTL was significantly shorter than that in healthy controls (P < 0.001). Compared to patients without ADRs and those with mild/moderate ADRs, patients with severe ADRs exhibited significantly decreased RTL (P < 0.001, P < 0.001, respectively). ROC curve analysis uncovered a diagnostic value of RTL as a biomarker of Osimertinib-induced ADRs (AUC = 1.000, P < 0.001). Kaplan-Meier analysis revealed a significant association between shorter RTL and increased cumulative incidence of Osimertinib-induced ADRs in patients with advanced-stage NSCLC (P < 0.001). Shorter RTL in blood leukocytes would reflect the occurrence of Osimertinib-induced ADRs and might emerge as a promising biomarker for identifying advanced-stage NSCLC patients who are at risk of experiencing Osimertinib-induced ADRs, particularly those with severe ADRs., (© 2024. The Author(s).)