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Objective Subclinical gut inflammation is common in spondylarthritis, but the immunologic abnormalities underlying this process are undefined. Perturbation of the interleukin-23 (IL-23)/Th17 axis has emerged as a fundamental trigger of chronic inflammation. This study was undertaken to investigate the expression and tissue distribution of IL-23/Th17–related molecules in Crohn's disease (CD) and in subclinical gut inflammation in ankylosing spondylitis (AS). Methods Quantitative gene expression analysis of Th1/Th2 and IL-23/Th17 responses was performed in intestinal biopsy samples obtained from 12 patients with CD, 15 patients with AS, and 13 controls. IL-23 tissue distribution and identification of IL-23–producing cells were evaluated by immunohistochemistry. Results We demonstrated a strong and significant up-regulation of IL-23p19 transcripts in the terminal ileum in patients with AS and patients with CD. IL-23 was abundantly produced by infiltrating monocyte-like cells in inflamed mucosa from AS and CD patients. Notably, we also identified Paneth cells as a major source of IL-23 in patients with AS, patients with CD, and normal controls. Unlike CD, in AS patients, IL-23 was not associated with up-regulation of IL-17 and the IL-17–inducing cytokines IL-6 and IL-1β. Finally, while the Th1-related cytokines interferon-γ, IL-12p35, and IL-27p28 were overexpressed only in CD patients, IL-4, IL-5, and STAT-6 were also significantly increased in AS patients. Conclusion Our findings indicate that overexpression of IL-23, but not IL-17, is a pivotal feature of subclinical gut inflammation in AS. Identification of resident Paneth cells as a pivotal source of IL-23 in physiologic and pathologic conditions strongly suggests that IL-23 is a master regulator of gut mucosal immunity, providing a pathophysiologic significance to the reported association between IL-23 receptor polymorphisms and intestinal inflammation.

Programmed cell death‐1 (PD‐1) signaling downregulates the T‐cell response, promoting an exhausted state in tumor‐infiltrating T cells, through mostly unveiled molecular mechanisms. Dynamin‐related protein‐1 (Drp1)‐dependent mitochondrial fission plays a crucial role in sustaining T‐cell motility, proliferation, survival, and glycolytic engagement. Interestingly, such processes are exactly those inhibited by PD‐1 in tumor‐infiltrating T cells. Here, we show that PD‐1pos CD8+ T cells infiltrating an MC38 (murine adenocarcinoma)‐derived murine tumor mass have a downregulated Drp1 activity and more elongated mitochondria compared with PD‐1neg counterparts. Also, PD‐1pos lymphocytic elements infiltrating a human colon cancer rarely express active Drp1. Mechanistically, PD‐1 signaling directly prevents mitochondrial fragmentation following T‐cell stimulation by downregulating Drp1 phosphorylation on Ser616, via regulation of the ERK1/2 and mTOR pathways. In addition, downregulation of Drp1 activity in tumor‐infiltrating PD‐1pos CD8+ T cells seems to be a mechanism exploited by PD‐1 signaling to reduce motility and proliferation of these cells. Overall, our data indicate that the modulation of Drp1 activity in tumor‐infiltrating T cells may become a valuable target to ameliorate the anticancer immune response in future immunotherapy approaches., PD‐1 signaling prevents TCR‐dependent Drp1 activation and subsequent mitochondrial fragmentation in T cells. In turn, this reduces both proliferation and migration of activated T cells. Cancer cells exploit this mechanism to downregulate T‐cell functionality within the tumor microenvironment, favoring tumor progression. These findings shed light on a new possible therapeutical approach for the treatment of solid cancers. (image made in BioRender).

Reliable biomarkers are needed to avoid diagnostic delay and its devastating effects in patients with primary central nervous system (CNS) lymphoma (PCNSL). We analysed the discriminating sensitivity and specificity of myeloid differentiation primary response (88) (MYD88) L265P mutation (mut-MYD88) and interleukin-10 (IL-10) in cerebrospinal fluid (CSF) of both patients with newly diagnosed (n=36) and relapsed (n=27) PCNSL and 162 controls (118 CNS disorders and 44 extra-CNS lymphomas). The concordance of MYD88 mutational status between tumour tissue and CSF sample and the source of ILs in PCNSL tissues were also investigated. Mut-MYD88 was assessed by TaqMan-based polymerase chain reaction. IL-6 and IL-10 messenger RNA (mRNA) was assessed on PCNSL biopsies using RNAscope technology. IL levels in CSF were assessed by enzyme-linked immunosorbent assay. Mut-MYD88 was detected in 15/17 (88%) PCNSL biopsies, with an 82% concordance in paired tissue-CSF samples. IL-10 mRNA was detected in lymphomatous B cells in most PCNSL; expression of IL-6 transcripts was negligible. In CSF samples, mut-MYD88 and high IL-10 levels were detected, respectively, in 72% and 88% of patients with newly diagnosed PCNSL and in 1% of controls; conversely, IL-6 showed a low discriminating sensitivity and specificity. Combined analysis of MYD88 and IL-10 exhibits a sensitivity and specificity to distinguish PCNSL of 94% and 98% respectively. Similar figures were recorded in patients with relapsed PCNSL. In conclusion, high detection rates of mut-MYD88 and IL-10 in CSF reflect, respectively, the MYD88 mutational status and synthesis of this IL in PCNSL tissue. These biomarkers exhibit a very high sensitivity and specificity in detecting PCNSL both at initial diagnosis and relapse. Implications of these findings in patients with lesions unsuitable for biopsy deserve to be investigated.

Among the family of regulatory Bcells, the subset able to produce interleukin-10 (IL-10) is the most studied, yet its biology is still a matter of investigation. The DNA methylation profiling of the il-10 gene locus revealed a novel epigenetic signature characterizing murine Bcells ready to respond through IL-10 synthesis: a demethylated region located 4.5 kb from the transcription starting site (TSS), that we named early IL10 regulatory region (eIL10rr). This feature allows to distinguish Bcells that are immediately prone and developmentally committed to IL-10 production from those that require a persistent stimulation to exert an IL-10-mediated regulatory function. These late IL-10 producers are instead characterized by a delayed IL10 regulatory region (dIL10rr), a partially demethylated DNA portion located 9 kb upstream from the TSS. A demethylated region was also found in human IL-10-producing Bcells and, very interestingly, in some B-cell malignancies, such as chronic lymphocytic leukemia and mantle cell lymphoma, characterized by an immunosuppressive microenvironment. Our findings define murine and human regulatory Bcells as an epigenetically controlled functional state of mature Bcell subsets and open a new perspective on IL-10 regulation in Bcells in homeostasis and disease.

Aims Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that, in some instances, may show a granulomatous reaction associated with a favourable prognosis and occasional spontaneous regression. In the present study, we aimed to define the tumour microenvironment (TME) in four such cases, two of which regressed spontaneously. Methods and results All cases showed aggregates of tumour cells with the typical morphology, molecular cytogenetics and immunophenotype of BL surrounded by a florid epithelioid granulomatous reaction. All four cases were Epstein-Barr virus (EBV)-positive with type I latency. Investigation of the TME showed similar features in all four cases. The analysis revealed a proinflammatory response triggered by Th1 lymphocytes and M1 polarised macrophages encircling the neoplastic cells with a peculiar topographic distribution. Conclusions Our data provide an in-vivo picture of the role that specific immune cell subsets might play during the early phase of BL, which may be capable of maintaining the tumour in a self-limited state or inducing its regression. These novel results may provide insights into new potential therapeutic avenues in EBV-positive BL patients in the era of cellular immunotherapy.

The most frequently detected alterations of squamous cervical epithelia consist of metaplastic/reactive conditions and human papillomavirus (HPV)-related dysplastic lesions. These latter are traditionally identified as cervical intraepithelial neoplasia (CIN1, 2 or 3) or, in the Bethesda System, as low-grade squamous intraepithelial lesions (LSIL), including CIN1, and high-grade SIL, including CIN2 and CIN3. Some HPV-induced lesions, which are not characterized by obvious dysplasia, are often diagnosed as LSIL. In these lesions, which are hereafter referred to as cervical atipical lesions (CAL), histological features of HPV infection (namely, koilocytosis, multinucleation, acanthosis, papillomatosis, parakeratosis, individual cell keratinization, mitoses in the lower basal third of the epithelium, hyperplasia of basal layers and absence of distinct basal cell layer) can be either inconsistently present or only mildly/focally evident, raising the question of differential diagnosis between HPV-associated changes and repair/reactive or metaplastic changes. In addition, cervical reactive/metaplastic conditions and LSIL can also be contemporaneously present, making the diagnosis even more challenging. Of note, a clear trend to over-diagnose normal, metaplastic or reactive cervical epithelium as HPV-associated LSIL has been reported, leading to therapeutic, reproductive, sexual and social consequences. To improve the diagnosis and management of CAL, it is important to identify among them those lesions that are HPV associated, mainly those harbouring high-risk (HR)-HPV.

Objectives: Solid second primary cancers (SPC) have become an issue of extensive research. The purpose of the present study was to estimate the standardised incidence ratio (SIR) and the absolute excess risk (AER) of SPC in patients with splenic marginal zone lymphoma (SMZL). Methods: We investigated the incidence of additional cancers in 129 patients consecutively diagnosed with SMZL in three Italian haematological centres, asking the cooperating doctors for additional information on initial and subsequent therapies and on the onset and type of second cancers. Results: Twelve SPC were recorded (9.3%); the 3- and 5-yr cumulative incidence rates were 5.5% and 18.3% respectively, with an SIR of 2.03 [95% confidence interval (CI): 1.05–3.56; P < 0.05; AER ¼ 145.81]. Of 12 SPC observed, four were urinary tract neoplasms (SIR, 3.70; 95% CI: 1.01–9.48; P < 0.05; AER ¼ 70.06), four were lung cancers (SIR, 9.16; 95% CI: 1.41–13.25; P < 0.05; AER ¼ 85.50) and the other four were hepatic carcinoma, endometrial cancer, breast cancer and colorectal cancer. Conclusions: Our findings evidence a high frequency of additional cancers in patients with SMZL and suggest that the incidence rate of SPC is significantly different from that expected in the general population. The frequency of cases with urinary tract and lung malignancies in our series is higher than expected. Although confirmatory data are needed, it is our opinion that SMZL patients are at risk of second cancer and should be carefully investigated on diagnosis and monitored during the follow-up.

BACKGROUND Splenic marginal zone lymphoma (SMZL) is a well defined pathologic entity. However, questions regarding the bone marrow infiltration rate, the minimal diagnostic data set, and therapy remain unanswered. METHODS Clinical-pathologic features and outcomes of 57 consecutive patients who had splenomegaly with no clinically significant lymphadenomegaly and who were diagnosed with SMZL with or without (±) villous lymphocytes (VL) were reviewed. RESULTS SMVL ± VL occurred mostly in elderly males (median age, 62 years ± 10 years; male-to-female ratio, (1.85). Anemia was recorded in 49% of patients, and 30% of patients had moderate thrombocytopenia. Leukocytosis and leukopenia were found in 33% and 14% of patients, respectively, and typical VL were found in 84% of patients. Serology for hepatitis C virus infection was positive in 16% of patients, and a small monoclonal component was detected in 36% of patients. The bone marrow was infiltrated with an intrasinusoidal component in all patients. Thirteen patients were monitored using a watch-and-see policy, and they remained alive 1–5 years after diagnosis. Overall, 21 patients (36%) underwent splenectomy; and, in all patients, the diagnosis of SMZL was confirmed histologically in the surgical specimens. Twenty-five patients received single-agent therapy, which included either alkylators or pentostatine, and they achieved an overall response rate (ORR) of 65% and 87%, respectively: Polychemotherapy was administered to 6 patients (ORR, 83%). The median survival for all patients in the series was not reached, and it is expected that 70% of patients will be alive at 5 years. CONCLUSIONS Up to 20% of patients who had SMZL ± VL could be monitored using a watch-and-wait policy. The bone marrow intrasinusoidal infiltration pattern may be a valuable diagnostic hallmark, thus obviating diagnostic splenectomy. The issues regarding prognostic stratification and the best therapeutic strategy need to be addressed in properly designed, prospective trials. Cancer 2004. © 2004 American Cancer Society.