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Background: Anifrolumab, a monoclonal antibody targeting the type 1 interferon (IFN-I) signaling pathway, holds promise as a therapeutic intervention for systemic lupus erythematosus (SLE). However, its use is associated with an increased risk of infections, particularly viral infections like herpes zoster (HZ). Results from the clinical trials on anifrolumab show yearly rates of upper respiratory tract infections of 34% and HZ of 6.1%. An increased frequency of other specific viral infections, including herpes simplex virus (HSV), was not reported. Case Reports: Here, we present 2 cases of patients with SLE treated with anifrolumab, both experiencing severe adverse reactions in the form of disseminated herpesvirus infections, specifically disseminated HSV-2 and varicella zoster virus (VZV, HZ encephalitis). To the best of our knowledge, no previous reports of severe disseminated HSV-2 or HZ have been published in anifrolumab-treated patients. The patient in case 1 experienced a primary HSV-2 infection following anifrolumab treatment, potentially explaining the severity of the infection. The patient in case 2 had a history of previous HZ skin infections, which may have increased her risk of disseminated infection. Both patients recovered from the infections with minor sequelae, but they still require prophylactic antiviral treatment. These cases highlight the critical role of IFN-I immunity in protecting against herpesvirus infections. Conclusions: Thorough risk assessment before anifrolumab initiation, considering the patient's viral infection history, vaccination status, and potential exposure risks, is essential. Administration of recombinant zoster vaccine before anifrolumab therapy may benefit susceptible individuals. [ABSTRACT FROM AUTHOR]

This case report discusses a patient with systemic lupus erythematosus (SLE) treated with low-dose azathioprine who developed progressive multifocal leukoencephalopathy (PML). PML is a rare, severe, demyelinating disease linked to John Cunningham polyomavirus (JCV) reactivation. Treated with pembrolizumab, an immune checkpoint inhibitor, the patient initially improved. However, after the fourth dose, her condition rapidly worsened resulting in treatment discontinuation and death. Similar cases highlight the complex interplay of factors in PML development in SLE patients, including immunosuppression and genetic factors. The use of pembrolizumab in PML and SLE necessitates careful consideration of potential complications. [ABSTRACT FROM AUTHOR]

Objective: Rituximab (RTX)‐treated patients exhibit suboptimal responses to COVID‐19 vaccines. However, existing research primarily involves patients already receiving RTX when vaccines were introduced, failing to account for the current landscape where patients are vaccinated before initiating RTX. Our objective was to compare the serological response to COVID‐19 vaccines in patients vaccinated before or after RTX initiation. Methods: We included 254 RTX‐treated patients with autoimmune inflammatory rheumatic diseases (AIIRDs) and 113 blood donors (BDs) in a retrospective, observational cohort study. Patients were categorized based on the timing of RTX treatment relative to primary COVID‐19 vaccination. Serological vaccine responses were assessed using three immunoassays, and logistic regression analysis was used to identify predictors of serological response. Results: Patients vaccinated before initiating RTX treatment had significantly higher seroconversion rates of SARS‐CoV‐2 immunoglobulin G (87%) and neutralizing antibodies (91%) compared with those receiving RTX before and after vaccination (n = 132) (61% and 65%, respectively). In the logistic regression analysis, a positive serological response was associated with the number of vaccines administered >9 months after the last RTX treatment. Patients receiving the highest number of vaccines with >9 months after RTX showed a response comparable to that of the BDs. Conclusion: Vaccinating before RTX initiation yields a robust serological response in patients with AIIRDs. Furthermore, we highlight the reversibility of antibody impairment after RTX treatment cessation, provided that adequate vaccinations occur within a minimum of 9 months after RTX. Our findings offer essential insights for clinical decision‐making regarding COVID‐19 vaccination and RTX treatment, alleviating concerns about future RTX use. [ABSTRACT FROM AUTHOR]

Anifrolumab is a new therapeutic approach for individuals with systemic lupus erythematosus (SLE) directed at blocking the type 1 interferon pathway. Despite the expanding body of literature on Anifrolumab, an essential aspect remains absent: the subjective patient experience of treatment effects and implications on patients' health-related quality of life (HRQoL). The present study aimed to fill this void by elucidating the nuanced perspectives of SLE patients receiving Anifrolumab treatment by conducting qualitative in-depth interviews (IDIs). SLE patients at Aarhus University Hospital who had received at least three infusions of Anifrolumab were approached for inclusion in the study, which comprised two main elements: (1) qualitative IDIs and (2) collection of patient data from electronic medical records (EMRs). The IDIs were semi-structured and based on a discussion guide that included open-ended and close-ended questions. Verbatim transcripts were coded and analysed using qualitative software to understand concepts important to patients and to understand patients' own experiences before and after Anifrolumab therapy. A clinical chart review was conducted using EMR data at baseline, 3 months, and 6 months after Anifrolumab initiation. IDIs were completed with 14 patients, and EMR data was collected from 16 patients (treatment days range: 62-474). Of the 23 symptoms spontaneously reported by patients prior to Anifrolumab treatment, fatigue, joint pain, sun sensitivity, joint stiffness, skin rashes, and hair loss were the most common. Most symptoms improved, and none worsened during treatment. Patients reported significant impacts of disease on daily life before treatment: day-to-day activities, social life, emotional aspects, physical activity, concentration/memory, work/employment, and family/romantic relationships. Patients reported improvements in all aspects after treatment but were still impacted. From the EMR data, we observed a fall in disease activity after treatment initiation with a concomitant reduction in the use of corticosteroids. This study provides valuable insights into the subjective experiences of SLE patients treated with Anifrolumab, and the findings collectively contribute to a comprehensive understanding of the treatment's efficacy from the patients' perspective and its tangible effects on both subjective and objective parameters in SLE patients. [ABSTRACT FROM AUTHOR]

Systemic Lupus Erythematosus (SLE) is a multifaceted, multisystem autoimmune disorder with diverse clinical expressions. While prevalence reports vary widely, pulmonary involvement accounts for significant morbidity and mortality in SLE. This comprehensive review explores the spectrum of pulmonary disease in SLE, including upper airway manifestations (e.g., laryngeal affection), lower airway conditions (e.g., bronchitis, bronchiolitis, bronchiectasis), parenchymal diseases (e.g., interstitial lung disease, acute lupus pneumonitis, diffuse alveolar hemorrhage), pleural diseases (e.g., serositis, shrinking lung syndrome), and vascular diseases (e.g., pulmonary arterial hypertension, pulmonary embolism, acute reversible hypoxemia syndrome). We discuss diagnostic modalities, treatment strategies, and prognosis for each pulmonary manifestation. With diagnostics remaining a challenge and with the absence of standardized treatment guidelines, we emphasize the need for evidence-based guidelines to optimize patient care and improve outcomes in this complex disease. [ABSTRACT FROM AUTHOR]

Objective. We have previously reported elevated levels of the complement lectin pathway proteins L-ficolin and H-ficolin in patients with axial spondyloarthritis (axSpA) compared with healthy controls. The aim of the present study was to investigate these biomarkers in a cross-sectional cohort of patients suffering from low back pain (LBP). Further, we aimed to investigate changes in lectin pathway protein levels after initiation of adalimumab (ADA; a tumor necrosis factor inhibitor) in a longitudinal cohort of patients with axSpA. Methods. Lectin pathway protein levels (mannan-binding lectin [MBL], collectin liver 1, H-ficolin, L-ficolin, M-ficolin, MBL-associated serine protease [MASP]-1, MASP-2, MASP-3, MBL-associated protein 19 [MAp19], and MAp44) in EDTA plasma were determined in 2 well-characterized cohorts: (1) a clinical cross-sectional cohort of patients with LBP, including patients with axSpA (n = 23), patients with unspecific LBP (uLBP) with ≥ 1 SpA features (n = 55), and patients with uLBP without SpA features or magnetic resonance imaging findings suggestive of axSpA (n = 64); and (2) a randomized double-blinded, placebo-controlled trial cohort of patients with axSpA (n = 49) initiating ADA therapy. Lectin pathway protein levels were determined using immunoassays. Results. Plasma levels of L-ficolin and M-ficolin were significantly increased in the cross-sectional cohort of newly diagnosed patients with axSpA compared with clinically relevant controls with uLBP (all P < 0.05). Both L-ficolin and M-ficolin decreased significantly after ADA therapy (P < 0.05). Conclusion. L-ficolin and M-ficolin levels are elevated in newly diagnosed patients with axSpA compared with clinically relevant controls. Both L-ficolin and M-ficolin levels decrease significantly after initiating ADA therapy. These findings provide new insights into the inflammatory processes in axSpA and support the involvement of complement in axSpA pathogenesis. [ABSTRACT FROM AUTHOR]

Complement activation is a hallmark of systemic lupus erythematosus (SLE) and can proceed through the classical (CP), lectin (LP), or alternative pathway (AP). When managing SLE patients, pathway-specific complement activation is rarely monitored as clinical assays are unavailable. In this study, we aim to differentiate between CP- or LP-mediated complement activation in SLE patients by quantifying pathway-specific protein complexes, namely C1s/C1-inhibitor (C1-INH) (CP-specific activation) and MASP-1/C1-INH (LP-specific activation). Levels for both complexes were assessed in 156 SLE patients and 50 controls using two newly developed ELISAs. We investigated whether pathway-specific complement activation was associated with disease activity and lupus nephritis (LN). Disease activity stratification was performed using SLEDAI scores assessed at inclusion. C1s/C1-INH concentrations were significantly increased in active SLE patients (SLEDAI ≥6) when compared with SLE patients with low disease activity (SLEDAI <6, P < 0.01) and correlated with SLEDAI score (r =.29, P < 0.01). In active LN, MASP-1/C1-INH plasma concentrations were significantly increased compared with nonactive LN (P = 0.02). No differences in MASP-1/C1-INH plasma concentrations were observed between active SLE patients and patients with low disease activity (P = 0.11) nor did we observe a significant correlation with disease activity (r = 0.12, P = 0.15). Our data suggest that the CP and the LP are activated in SLE. The CP is activated in active SLE disease, whereas activation of the LP might be more specific to disease manifestations like LN. Our results warrant further research into specific complement pathway activation in SLE patients to potentially improve specific-targeted and tailored-treatment approaches. Complement activation is a hallmark of systemic lupus erythematosus (SLE), but when managing SLE patients, pathway-specific complement activation is rarely monitored, as clinical assays are unavailable. In this study, we aim to differentiate between classical- or lectin pathway-mediated complement activation in 156 SLE patients by quantifying pathway-specific protein complexes, namely C1s/C1-INH (classical pathway-specific activation) and MASP-1/C1-INH (lectin pathway-specific activation). Our data suggest that the classical pathway is activated in active SLE disease, whereas activation of the lectin pathway might be more specific to disease manifestations like lupus nephritis. [ABSTRACT FROM AUTHOR]

Objectives: We investigated the effect of a two-dose messenger ribonucleic acid (mRNA) vaccine on antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and patient behaviour and shielding concerning fear of coronavirus disease 2019 (COVID-19) in patients with systemic lupus erythematosus or rheumatoid arthritis. Methods: Three hundred and three patients and 44 blood donors were included. All patients received two doses of an mRNA vaccine and had total antibodies against SARS-CoV-2 measured before vaccination and 2 and 9 weeks after the second vaccination. Further, patients answered an electronic questionnaire before and after vaccination concerning behaviour, anxiety, and symptoms of depression (Patient Health Questionnaire-9). Results: Significantly fewer patients (90%) had measurable antibodies against SARS-CoV-2 compared to blood donors (100%) after the second vaccination (P < .001). Treatment with rituximab was the strongest predictor of an unfavourable vaccine response, as only 27% had measurable antibodies. Nearly all patients (97%) not treated with rituximab experienced seroconversion. Prednisone and methotrexate had a negative effect on seroconversion, but no effect of age or comorbidity was observed. Patients experienced significant improvement after vaccination in 10 out of 12 questions regarding behaviour and fear of COVID-19, while no change in Patient Health Questionnaire-9 or anxiety was observed. Conclusion: We find a very high seroconversion rate among rheumatic patients and reduced self-imposed isolation and shielding after COVID-19 vaccination. [ABSTRACT FROM AUTHOR]

Objectives To investigate the effect of either a booster vaccine (one dose) or revaccination (two doses 3 weeks apart) on the antibody response to the COVID-19 mRNA vaccines in patients with rheumatic disease (RD) treated with rituximab (RTX) who had not produced vaccine-reactive antibodies after the initial two vaccine doses. Further, to examine if B cell levels in peripheral blood predicted seroconversion. Methods We included 91 RTX-treated RD patients previously vaccinated against COVID-19. Patients were offered revaccination or a single booster vaccination with an mRNA vaccine. Serum total antibodies against SARS-CoV-2 spike protein were measured before and 6 weeks after the last vaccine dose. B cells (CD19+CD45+) were measured by flow cytometry at inclusion. Results Of RD patients with undetectable SARS-CoV-2 antibody levels before inclusion, seroconversion was seen in 38% 6 weeks after the booster dose and 32% after revaccination. Patients receiving revaccination had significantly higher antibody levels than patients receiving a booster dose (P  < 0.001). In both univariate and multivariate logistic regression analysis, only B cells higher than 10/µl before boost or revaccination were associated with seroconversion (P  = 0.009 and P  = 0.01, respectively). Seroconversion was independent of age, gender, diagnosis, cumulative RTX dose, RTX treatment time and time since last RTX treatment. Conclusion Continuously impaired humoral response to mRNA vaccines was found in most RTX-treated patients after a booster dose or revaccination. Seroconversion was observed in approximately one-third of the patients. Measurable B cells before boosting or revaccination was the strongest predictor of antibody response after boost or revaccination. [ABSTRACT FROM AUTHOR]

Objective: Patients with chronic rheumatic diseases (CRDs), such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), require special attention during the COVID‐19 pandemic as they are considered at risk of severe infections. Our objective was to assess the seroprevalence of SARS–CoV‐2 in patients with SLE and RA and to assess patient behavior, disease‐related symptoms, and mental health. Methods: More than 900 participants were included: 405 patients with RA or SLE (CRD patients) and 513 blood donors. All participants had blood SARS–CoV‐2 total antibodies measured (sensitivity 96.7%, specificity 99.5%) and answered a questionnaire concerning behavior, anxiety, and symptoms of depression (Patient Health Questionnaire 9). The CRD patients were further asked about physical activity, adherence to medication, and disease‐related symptoms. Results: CRD patients had a significantly lower seroprevalence of SARS–CoV‐2 antibodies (n = 1 of 365, 0.3%) compared to blood donors (n = 10 of 513, 1.9%; P = 0.03). Almost 60% of patients were unable to exercise as usual, and increased pain and disease activity was experienced by 34% and 24% of patients, respectively. Almost 10% of patients reduced or discontinued their immunosuppressive treatments at their own initiative. Symptoms of moderate depression were present in 19% of patients compared to 6.8% of blood donors (P < 0.001). Conclusion: Low seroprevalence in patients with CRDs indicates successful mitigation of exposure to SARS–CoV‐2. However, this mitigation appears to occur at the expense of physical activity, experience of increased pain, disease activity, and symptoms of depression. There is a need for care providers to be aware of these negative side effects and for further studies to investigate the possible long‐term consequences. [ABSTRACT FROM AUTHOR]

Objectives: Over the past decades new international guidelines recommend that pregnant Systemic lupus erythematosus (SLE) patients are monitored closely in a multi-professional team throughout pregnancy. The importance of low disease activity before pregnancy and continued treatment during pregnancy has been established. However, there is still a high risk of adverse pregnancy outcome (APO). The APO in a Danish SLE cohort was evaluated and compared with the results in a previous study cohort from the same centre and referral area. Methods: This retrospective cohort study used the local patient registry to identify pregnancies in SLE patients followed at the Department of Rheumatology, Aarhus University Hospital, Denmark, from January 2010 to October 2020. In total, 66 pregnancies were registered in 41 women. Data were compared with a previous retrospective study (1990–2010) from the same hospital. Results: Adverse pregnancy outcome occurred in 65% of pregnancies. Forty-seven pregnancies resulted in a live birth, while 15 ended in miscarriages. Compared to the 1990–2010 cohort, a numerical reduction in preterm deliveries (7.58% vs. 17.9%) and emergent caesarean (6.1% vs. 15.5%) was observed, although not reaching statistical significance (p =.07 in both cases). Further, a higher average birth weight (3045 g vs. 2870 g) as well as a higher number of pregnancies and live births per year were observed. Gestational hypertension was significantly reduced from 23.8% to 13.6% (p =.05). Significantly more patients were treated with prednisolone (66.7% vs 35.7%, p =.0002), hydroxychloroquine (6% vs. 73.4%, p <.0001) and acetylsalicylic acid (39.3% vs. 73.1%, p =.0001) in 2010–2020 compared to the 1990–2010. Conclusion: We observed significant improvements in the frequency of some APOs in the recent 2010–2020 cohort compared with the previous cohort followed from 1990 to 2010. However, even though a specialized multi-professional team closely follows SLE patients through their pregnancies, pregnancy in SLE still carries a high risk of APO. [ABSTRACT FROM AUTHOR]

Objective. We aimed to investigate (1) whether patients with rheumatic disease (RD) treated with rituximab (RTX) raise a serological response toward the coronavirus disease 2019 (COVID-19) mRNA vaccines, and (2) to elucidate the influence of time since the last RTX dose before vaccination on this response. Methods. We identified and included 201 patients with RDs followed at the outpatient clinic at the Department of Rheumatology, Aarhus University Hospital, who had been treated with RTX in the period 2017-2021 and who had completed their 2-dose vaccination series with a COVID-19 mRNA vaccine. Total antibodies against the SARS-CoV-2 spike protein were measured on all patients and 44 blood donors as reference. Results. We observed a time-dependent increase in antibody response as the interval from the last RTX treatment to vaccination increased. Only 17.3% of patients developed a detectable antibody response after receiving their vaccination = 6 months after their previous RTX treatment. Positive antibody response increased to 66.7% in patients who had RTX 9-12 months before vaccination. All blood donors (100%) had detectable antibodies after vaccination. Conclusion. Patients with RDs treated with RTX have a severely impaired serological response toward COVID-19 mRNA vaccines. Our data suggest that the current recommendations of a 6-month interval between RTX treatment and vaccination should be reevaluated. [ABSTRACT FROM AUTHOR]

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were launched in December 2020. Vaccination of patients with rheumatic diseases is recommended, as they are considered at higher risk of severe COVID-19 than the general population. Patients with rheumatic disease have largely been excluded from vaccine phase 3 trials. This study explores the safety and reactogenicity of BNT162b2 among patients with rheumatic diseases. Patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), median age 58.8 years, 285 subjects in total, were vaccinated twice with the BNT162b2 (Pfizer/BioNTech). Questionnaires on reactogenicity matching the original phase 3 study were answered seven days after completed vaccination. The majority of SLE and RA patients experienced either local (78.0%) or systemic reactions (80.1%). Only 1.8% experienced a grade-4 reaction. Compared to the original study, we found more frequent fatigue [Odds ratio (OR) 2.2 (1.7–2.8)], headache [OR 1.7 (1.3–2.2)], muscle pain [OR 1.8 (1.4–2.3)], and joint pain [OR 2.3 (1.7–3.0)] in patients. In contrast, the use of antipyretics was less frequent [OR 0.5 (0.3–0.6)]. Patients with SLE and RA experience reactogenicity to the Pfizer-BioNTech BNT162b2 COVID-19 vaccine. Reactogenicity was more frequent in patients, however, not more severe compared with healthy controls. [ABSTRACT FROM AUTHOR]

Objective: With a vaccine effectiveness of 95% for preventing coronavirus disease 2019 (COVID‐19), Pfizer‐BioNTech BNT162b2 (BNT162b2) was the first vaccine against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) to be approved. However, immunosuppressive therapy was an exclusion criterion in the phase 3 trial that led to approval. Thus, extrapolation of the trial results to patients with rheumatic diseases treated with immunosuppressive drugs warrants caution. Methods: Patients with systemic lupus erythematosus (SLE; n = 61) and rheumatoid arthritis (RA; n = 73) were included from the COPANARD (Corona Pandemic Autoimmune Rheumatic Disease) cohort, followed since the beginning of the COVID‐19 pandemic. Patients received the BNT162b2 vaccine between December 2020 and April 2021. All patients had total antibodies against SARS‐CoV‐2 measured before vaccination and 1 week after the second vaccination (VITROS Immunodiagnostic Products). Results: Of 134 patients (median age, 70 years), 77% were able to mount a detectable serological response to the vaccine. Among patients treated with rituximab, only 24% had detectable anti–SARS‐CoV‐2 antibodies in their serum after vaccination. The time since the last rituximab treatment did not seem to influence the vaccine response. No significant difference was observed between patients with RA or SLE when adjusting for treatment, and no correlation between antibody levels and age was detected (r = −0.12; P = 0.18). Conclusion: Antibody measurements against SARS‐CoV‐2 in patients with RA and SLE after two doses of the BNT162b2 vaccine demonstrated that 23% of patients could not mount a detectable serological response to the vaccine. B cell–depleting therapy (BCDT) is of specific concern, and our findings call for particular attention to the patients receiving BCDT. [ABSTRACT FROM AUTHOR]

Objective: To investigate how genetics influence the risk of smoking-related systemic lupus erythematosus (SLE) manifestations.Methods: Patients with SLE (ndiscovery cohort=776, nreplication cohort=836) were genotyped using the 200K Immunochip single nucleotide polymorphisms (SNP) Array (Illumina) and a custom array. Sixty SNPs with SLE association (p<5.0×10-8) were analysed. Signal transducer and activator of transcription 4 (STAT4) activation was assessed in in vitro stimulated peripheral blood mononuclear cells from healthy controls (n=45).Results: In the discovery cohort, smoking was associated with myocardial infarction (MI) (OR 1.96 (95% CI 1.09 to 3.55)), with a greater effect in patients carrying any rs11889341 STAT4 risk allele (OR 2.72 (95% CI 1.24 to 6.00)) or two risk alleles (OR 8.27 (95% CI 1.48 to 46.27)).Smokers carrying the risk allele also displayed an increased risk of nephritis (OR 1.47 (95% CI 1.06 to 2.03)). In the replication cohort, the high risk of MI in smokers carrying the risk allele and the association between the STAT4 risk allele and nephritis in smokers were confirmed (OR 6.19 (95% CI 1.29 to 29.79) and 1.84 (95% CI 1.05 to 3.29), respectively).The interaction between smoking and the STAT4 risk allele resulted in further increase in the risk of MI (OR 2.14 (95% CI 1.01 to 4.62)) and nephritis (OR 1.53 (95% CI 1.08 to 2.17)), with 54% (MI) and 34% (nephritis) of the risk attributable to the interaction. Levels of interleukin-12-induced phosphorylation of STAT4 in CD8+ T cells were higher in smokers than in non-smokers (mean geometric fluorescence intensity 1063 vs 565, p=0.0063).Lastly, the IL12A rs564799 risk allele displayed association with MI in both cohorts (OR 1.53 (95% CI 1.01 to 2.31) and 2.15 (95% CI 1.08 to 4.26), respectively).Conclusions: Smoking in the presence of the STAT4 risk gene variant appears to increase the risk of MI and nephritis in SLE. Our results also highlight the role of the IL12-STAT4 pathway in SLE-cardiovascular morbidity. [ABSTRACT FROM AUTHOR]

Proteases play a central role in regulating renal pathophysiology and are increasingly evaluated as actionable drug targets. Here, we review the role of proteolytic systems in inflammatory kidney disease. Inflammatory kidney diseases are associated with broad dysregulations of extracellular and intracellular proteolysis. As an example of a proteolytic system, the complement system plays a significant role in glomerular inflammatory kidney disease and is currently under clinical investigation. Based on two glomerular kidney diseases, lupus nephritis, and membranous nephropathy, we portrait two proteolytic pathomechanisms and the role of the complement system. We discuss how profiling proteolytic activity in patient samples could be used to stratify patients for more targeted interventions in inflammatory kidney diseases. We also describe novel comprehensive, quantitative tools to investigate the entirety of proteolytic processes in a tissue sample. Emphasis is placed on mass spectrometric approaches that enable the comprehensive analysis of the complement system, as well as protease activities and regulation in general. [ABSTRACT FROM AUTHOR]

Nanotechnology enables investigations of single biomacromolecules, but technical challenges have limited the application in liquid biopsies, for example, blood plasma. Nonetheless, tools to characterize single molecular species in such samples represent a significant unmet need with the increasing appreciation of the physiological importance of protein structural changes at nanometer scale. Mannose-binding lectin (MBL) is an oligomeric plasma protein and part of the innate immune system through its ability to activate complement. MBL also serves a role as a scavenger for cellular debris, especially DNA. This may link functions of MBL with several inflammatory diseases in which cell-free DNA now appears to play a role, but mechanistic insight has been lacking. By making nanoparticle tracking analysis possible in human plasma, we now show that superoligomeric structures of MBL form nanoparticles with DNA. These oligomers correlate with disease activity in systemic lupus erythematosus patients. With the direct quantification of the hydrodynamic radius, calculations following the principles of Taylor dispersion in the blood stream connect the size of these complexes to endothelial inflammation, which is among the most important morbidities in lupus. Mechanistic insight from an animal model of lupus supported that DNA-stabilized superoligomers stimulate the formation of germinal center B cells and drive loss of immunological tolerance. The formation involves an inverse relationship between the concentration of MBL superoligomers and antibodies to double-stranded DNA. Our approach implicates the structure of DNA-protein nanoparticulates in the pathobiology of autoimmune diseases. [ABSTRACT FROM AUTHOR]

We do not understand why non-white ethnicity and chronic kidney disease increase susceptibility to COVID-19. The lectin pathway of complement activation is a key contributor to innate immunity and inflammation. Concentrations of plasma lectin pathway proteins influence pathway activity and vary with ethnicity. We measured circulating lectin proteins in a multi-ethnic cohort of chronic kidney disease patients with and without COVID19 infection to determine if lectin pathway activation was contributing to COVID19 severity. We measured 11 lectin proteins in serial samples from a cohort of 33 patients with chronic kidney impairment and COVID19. Controls were single plasma samples from 32 patients on dialysis and 32 healthy individuals. We demonstrated multiple associations between recognition molecules and associated proteases of the lectin pathway and COVID-19, including COVID-19 severity. Some of these associations were unique to patients of Asian and White ethnicity. Our novel findings demonstrate that COVID19 infection alters the concentration of plasma lectin proteins and some of these changes were linked to ethnicity. This suggests a role for the lectin pathway in the host response to COVID-19 and suggest that variability within this pathway may contribute to ethnicity-associated differences in susceptibility to severe COVID-19. [ABSTRACT FROM AUTHOR]

Protease inhibitors influence a range of innate immunity and inflammatory pathways. We quantified plasma concentrations of key anti-inflammatory protease inhibitors in chronic haemodialysis patients with coronavirus disease 2019 (COVID-19). The samples were collected early in the disease course to determine whether plasma protease inhibitor levels associated with the presence and severity of COVID-19. We used antibody-based immunoassays to measure plasma concentrations of C1 esterase inhibitor, alpha2-macroglobulin, antithrombin and inter-alpha-inhibitor heavy chain 4 (ITIH4) in 100 serial samples from 27 haemodialysis patients with COVID-19. ITIH4 was tested in two assays, one measuring intact ITIH4 and another also detecting any fragmented ITIH4 (total ITIH4). Control cohorts were 32 haemodialysis patients without COVID-19 and 32 healthy controls. We compared protease inhibitor concentration based on current and future COVID-19 severity and with C-reactive protein. Results were adjusted for repeated measures and multiple comparisons. Analysis of all available samples demonstrated lower plasma C1 esterase inhibitor and α2M and higher total ITIH4 in COVID-19 compared with dialysis controls. These differences were also seen in the first sample collected after COVID-19 diagnosis, a median of 4 days from diagnostic swab. Plasma ITIH4 levels were higher in severe than the non-severe COVID-19. Serum C-reactive protein correlated positively with plasma levels of antithrombin, intact ITIH4 and total ITIH4. In conclusion, plasma protease inhibitor concentrations are altered in COVID-19. [ABSTRACT FROM AUTHOR]

We aimed at establishing a sensitive and robust assay for estimation of systemic complement activation at complement component C3 level in mouse and human plasma samples. In order to capture the activation products iC3b and C3dg in a specific and physiological relevant manner we utilized a construct consisting of the iC3b/C3dg-binding site of human complement receptor 2 (CR2) attached to an Fc-part of mouse IgG. This construct binds C3dg and iC3b from both mice and humans. We purified the CR2-IgG construct from mouse B myeloma cell line supernatants, J558L-CR2-IgG, by protein G affinity chromatography. The CR2-IgG construct was used for capturing C3 fragments in microtiter wells and an anti-mouse or an anti-human-C3 antibody was used for detection of bound C3 fragments. Initially we tested the specificity of the assays with the use of purified C3 fragments. Further, with the use of the CR2-based assay, we measured an up to three-fold higher signal in activated mouse serum as compared to non-activated mouse serum, whereas activated serum from a C3 knock-out mouse gave no signal. We tested in vivo generated samples from a mouse experiment; complement activation was induced by injecting cobra venom factor or heat aggregated IgG into C57bl6 mice, followed by withdrawal of EDTA blood samples at different time points and measurement of iC3b/C3dg. We observed a clear time-dependent distinction in signals between samples with expected high and low complement activation. Furthermore, with the use of the assay for human C3 fragments, we observed that patients with systemic lupus erythematosus (SLE) (n = 144) had significantly higher iC3b/C3dg levels as compared to healthy individuals (n = 144) (p < 0.0001). We present two functional immunoassays, that are able to measure systemic levels of the C3-activation products iC3b and C3dg in mice and humans. To our knowledge, these are the first assays for complement activation that use a physiological relevant capture construct such as CR2. These assays will be a relevant tool when investigating mouse models and human diseases involving the complement system. [ABSTRACT FROM AUTHOR]

Purpose: Ficolin-3 deficiency is caused by a mutation (+1637delC) in the FCN3 gene. It is a rare condition and has been associated with both infection and autoimmune disease including systemic lupus erythematosus (SLE). Here we investigated if ficolin-3 deficiency is more frequent in patients than in controls and tried to identify a common phenotype among ficolin-3 deficient individuals. Since a significant part of patients identified with ficolin-3 deficiency was diagnosed with SLE, we explored whether the heterozygous state of the FCN3+1637delC variant represents a risk factor in the development of SLE. Further, we examined other possible causes of ficolin-3 deficiency when the FCN3+1637delC is not present. Methods: A systematic literature search for studies measuring ficolin-3 was carried out. We examined 362 SLE patients and 596 controls for the presence of the variant FCN3+1637delC. We established assays for measurements of ficolin-3 and of auto-antibodies against ficolin-3. We sequenced the coding and non-coding regions of the FCN3 gene in an SLE patient with ficolin-3 deficiency not carrying the +1637delC. Results: Ficolin-3 deficiency leads to an 8-time increased odds of having a disease (p < 0.05). Three out of nine patients with deficiency had SLE. The heterozygous state of the deficiency variant is not associated with increased risk of developing SLE (p = 0.18). Conclusion: By systematically reviewing the literature for the described cases of ficolin-3 deficiency, an autoimmune phenotype is emerging. Thirty-three percent of the ficolin-3 deficient patients had SLE. Heterozygosity for the FCN3 gene deletion causing the deficiency does not seem to be associated with the development of SLE. [ABSTRACT FROM AUTHOR]

objectives: In 2012, hypocomplementemia was included in the classification criteria of systemic lupus erythematosus (SLE). The suggested measurement of C3 or C4 often reflect disease activity poorly. Our objective was to establish an assay measuring C3dg, which is generated following complement activation, and to evaluate the assay in a cross-sectional SLE cohort. Method: We included SLE patients (n = 169) and controls (n = 170) and developed a modified C3dg assay where C3dg fragments were separated from the large plasma proteins by polyethylene glycol (PEG), and the supernatant containing the C3dg fragment was used for analysis in an antibody-based sandwich-type assay. Gel permeation chromatography and western blotting were used to establish the optimal conditions for PEG precipitation. Results: 16% PEG was optimal for separating C3dg from C3 and the larger protein fragments. The assay showed a high degree of stability when using EDTA plasma, and measurements correlated well with commercially available complement activation assays. SLE patients had higher concentrations in plasma of C3dg than controls (p < 0.05). ROC analysis showed that the C3dg activation fragment of C3 with an AUC of 0.96 (Cl 0.94-0.98) was superior to C3 (AUC 0.52) in differentiating between patients and controls. Conclusion: Our results present a modified assay for the measurement of C3dg. We demonstrate that C3dg was superior to conventional C3 measurements in discriminating SLE patients from controls. We suggest that C3dg should be considered as a complement activation measurement in the SLE classification criteria. [ABSTRACT FROM AUTHOR]

Despite neurosurgical treatment, a subarachnoid hemorrhage (SAH) can cause a debilitating stroke. The case fatality rate ranges from 27 to 44%, and many survivors are left permanently disabled; therefore, the need for improved treatment is obvious. Furthermore, subdural hemorrhages (SDHs) have a cumulative recurrence rate of 14% in the first year and are potentially fatal. The aim of this systematic review is to assess and discuss the evidence for the role of tranexamic acid (TXA) in treatment of SAH and SDH. Systematic literature searches were performed in MEDLINE, Embase, Scopus, and Web of Science (1946-2016). The inclusion criteria were TXA-treated group and control group; SAH or SDH verified by imaging, intraoperatively or at autopsy; human subjects; English; and an objective outcome. The search terms matched 443 records. Eight studies including nontraumatic SAH patients and one study including traumatic intracranial bleeding met the inclusion criteria. Comparing TXA-treated nontraumatic patients with controls, we found an overall odds ratio (OR) for rebleeding of 0.41 (95% confidence interval [CI]: 0.26-0.64), six studies reported the mortality rate with an overall OR of 0.88 (95% CI: 0.68-1.12), four studies reported no statistically significant difference on the Glasgow Outcome Scale, and one study showed a statistically significant increased risk of cerebral ischemia, whereas seven studies found no statistically significant difference. No studies including SDH patients met the inclusion criteria. TXA reduced the overall risk of rebleeding following nontraumatic SAH. A nonsignificant reduction in mortality was demonstrated in nontraumatic SAH without substantial indication of increased risk of ischemic lesions. [ABSTRACT FROM AUTHOR]

Objective Human endogenous retroviruses (HERVs) are remnants of past retroviral infections in the human genome and have been implicated in different aspects of human biology. The aim of this study was to identify HERVs that are associated with the pathogenesis of rheumatic diseases such as systemic lupus erythematosus (SLE). Methods The study subjects included 45 female patients with SLE and 50 healthy controls matched for geographic area, age, and sex. Real-time reverse transcription-polymerase chain reaction analysis was used to examine the transcription levels of 11 genes with coding capacity for complete envelope (Env) protein in these individuals. In this way, 1 HERV locus was identified as a potential modulator of autoimmunity. The env gene encoded by this HERV locus was cloned and examined for the ability to express a functional protein with immunosuppressive potential. Results Expression of the env59 gene was negatively correlated with pathogenetic factors of human autoimmune rheumatic diseases, including such factors as the levels of interleukin-6 (IL-6) and Toll-like receptor 7. This gene was capable of encoding a fully functional Env glycoprotein that was found to contain a domain, the immunosuppressive (ISU) domain, that, when evaluated ex vivo in patients with SLE and those with rheumatoid arthritis as well as in animal models, showed strong antiinflammatory activity, including the ability to lower IL-6 levels. Conclusion The env59 gene has been adapted by the immune system as a control mechanism in autoimmunity. The peptides derived from the ISU domain contained in the Env59 protein may be useful as potentially new biologic treatments in rheumatic diseases such as SLE. [ABSTRACT FROM AUTHOR]

Background: It has been suggested that polymorphisms in Toll-like Receptors (TLRs) are associated with Rheumatoid Arthritis (RA), but the implicated alleles have differed between studies. The aim of this investigation was to explore whether polymorphisms of TLR genes are associated with RA in a predominantly Caucasian population from Denmark using a case–control approach. Findings: DNA samples (3 university hospital outpatient clinics) were obtained from patients with RA (n = 704) and healthy controls (n = 639) in a Danish population. TLR single nucleotide polymorphisms (SNPs) were selected based on the previously reported associations with chronic autoimmune diseases. Genotyping for the TLR SNPs was performed using Sequenom Multiplex technology. We identified one SNP in TLR3, [(rs3775291, P = 0.02, OR (95% CI) 1.31 (1.1087-1.5493)] significantly associated with the whole RA cohort. Subgroup analysis according to IgM rheumatoid factor (RF) and anti-cyclic citrinullated peptide (CCP) status suggested a significant association of sero-negative RA with the rs3775291 A allele and disease activity in this subset. Conclusion: These observations on a RA population of Danish ancestry suggest that variations in the TLR3 locus may be implicated in the pathogenesis of sero-negative RA. Since this TLR3 SNP has previously been associated with systemic lupus erythematous (SLE), the present findings support the notion that TLR3 genetic variants may represent a common risk factor in different chronic inflammatory conditions, including RA and SLE. [ABSTRACT FROM AUTHOR]

Objectives. Toll-like receptors (TLRs) are pattern-associated receptors in innate immunity that may be involved in the recognition of self-antigens and the production of pathogenic autoantibodies. This study was undertaken to examine whether polymorphisms of TLR genes are associated with SLE and to determine the expression of various TLRs in peripheral blood mononuclear cells (PBMCs) of patients with SLE.Methods. The TLR polymorphisms in a cohort of 143 Danish lupus patients and 432 healthy Danish blood donors were analysed. Groups were age matched. Genotyping for the TLR single-nucleotide polymorphisms (SNPs) was performed using Sequenom Multiplex technology. In addition, the mRNA expression of TLRs in PBMCs from 56 SLE patients and 56 healthy controls was studies by quantitative real-time PCR.Results. We found a genetic association with SLE and three SNPs located within the TLR3, TLR8 and TLR9 genes (rs3775291, P = 0.006; rs37648, P = 0.013; rs352143, P < 0.02). Furthermore, the relative TLR7, TLR8, IFN-α and LY6E mRNA expression levels were significantly higher in SLE patients than in healthy controls (P < 0.0001, P < 0.0001, P = 0.0004 and P < 0.0001, respectively).Conclusion. These results obtained from a female lupus population of Danish ancestry suggest that variations in TLR3, TLR8 and TLR9 genes are implicated in the pathogenesis of the disease. If these polymorphisms are associated with innate immune dysfunction they may add to the growing field of theoretically well founded new therapeutic targets. [ABSTRACT FROM PUBLISHER]