Molecular mechanisms of autophagic memory in pathogenic T cells in human arthritis

T-cell resilience is critical to the immune pathogenesis of human autoimmune arthritis. Autophagy is essential for memory T cell generation and associated with pathogenesis in rheumatoid arthritis (RA). Our aim here was to delineate the role and molecular mechanism of autophagy in resilience and persistence of pathogenic T cells from autoimmune arthritis. We demonstrated \u201cAutophagic memory\u201d as elevated autophagy levels in CD4+ memory T cells compared to CD4+ naive T cells and in Jurkat Human T cell line trained with starvation stress. We then showed increased levels of autophagy in pathogenic CD4+ T cells subsets from autoimmune arthritis patients. Using RNA-sequencing, transcription factor gene regulatory network and methylation analyses we identified MYC as a key regulator of autophagic memory. We validated MYC levels using qPCR and further demonstrated that inhibiting MYC increased autophagy. The present study proposes the novel concept of autophagic memory and suggests that autophagic memory confers metabolic advantage to pathogenic T cells from arthritis and supports its resilience and long term survival. Particularly, suppression of MYC imparted the heightened autophagy levels in pathogenic T cells. These studies have a direct translational valency as they identify autophagy and its metabolic controllers as a novel therapeutic target

Endothelial and Inflammation Biomarker Profiles at Diagnosis Reflecting Clinical Heterogeneity and Serving as a Prognostic Tool For Treatment Response in Two Independent Cohorts of Patients With Juvenile Dermatomyositis

Objective: Juvenile dermatomyositis (DM) is a heterogeneous systemic immune-mediated vasculopathy. This study was undertaken to 1) identify inflammation/endothelial dysfunction–related biomarker profiles reflecting disease severity at diagnosis, and 2) establish whether such biomarker profiles could be used for predicting the response to treatment in patients with juvenile DM. Methods: In total, 39 biomarkers related to activation of endothelial

Air pollution exposure during critical time periods in gestation and alterations in cord blood lymphocyte distribution: a cohort of livebirths

<p>Abstract</p> <p>Background</p> <p>Toxic exposures have been shown to influence maturation of the immune system during gestation. This study investigates the association between cord blood lymphocyte proportions and maternal exposure to air pollution during each gestational month.</p> <p>Methods</p> <p>Cord blood was analyzed using a FACSort flow cytometer to determine proportions of T lymphocytes (CD3⁺cells and their subsets, CD4⁺and CD8⁺), B lymphocytes (CD19⁺) and natural killer (NK) cells. Ambient air concentrations of 12 polycyclic aromatic hydrocarbons (PAH) and particulate matter < 2.5 micrometer in diameter (PM_2.5) were measured using fixed site monitors. Arithmetic means of these pollutants, calculated for each gestational month, were used as exposure metrics. Data on covariates were obtained from medical records and questionnaires. Multivariable linear regression models were fitted to estimate associations between monthly PAH or PM_2.5and cord blood lymphocytes, adjusting for year of birth and district of residence and, in further models, gestational season and number of prior live births.</p> <p>Results</p> <p>The adjusted models show significant associations between PAHs or PM_2.5during early gestation and increases in CD3⁺and CD4⁺lymphocytes percentages and decreases in CD19⁺and NK cell percentages in cord blood. In contrast, exposures during late gestation were associated with decreases in CD3⁺and CD4⁺fractions and increases in CD19⁺and NK cell fractions. There was no significant association between alterations in lymphocyte distribution and air pollution exposure during the mid gestation.</p> <p>Conclusions</p> <p>PAHs and PM_2.5in ambient air may influence fetal immune development via shifts in cord blood lymphocytes distributions. Associations appear to differ by exposure in early versus late gestation.</p

Opportunistic infections in immunosuppressed patients with juvenile idiopathic arthritis: analysis by the Pharmachild Safety Adjudication Committee

Background To derive a list of opportunistic infections (OI) through the analysis of the juvenile idiopathic arthritis (JIA) patients in the Pharmachild registry by an independent Safety Adjudication Committee (SAC). Methods The SAC (3 pediatric rheumatologists and 2 pediatric infectious disease specialists) elaborated and approved by consensus a provisional list of OI for use in JIA. Through a 5 step-procedure, all the severe and serious infections, classified as per MedDRA dictionary and retrieved in the Pharmachild registry, were evaluated by the SAC by answering six questions and adjudicated with the agreement of 3/5 specialists. A final evidence-based list of OI resulted by matching the adjudicated infections with the provisional list of OI. Results A total of 772 infectious events in 572 eligible patients, of which 335 serious/severe/very severe non-OI and 437 OI (any intensity/severity), according to the provisional list, were retrieved. Six hundred eighty-two of 772 (88.3%) were adjudicated as infections, of them 603/682 (88.4%) as common and 119/682 (17.4%) as OI by the SAC. Matching these 119 opportunistic events with the provisional list, 106 were confirmed by the SAC as OI, and among them infections by herpes viruses were the most frequent (68%), followed by tuberculosis (27.4%). The remaining events were divided in the groups of non-OI and possible/patient and/or pathogen-related OI. Conclusions We found a significant number of OI in JIA patients on immunosuppressive therapy. The proposed list of OI, created by consensus and validated in the Pharmachild cohort, could facilitate comparison among future pharmacovigilance studies

Galectin-9 and CXCL10 as biomarkers for disease activity in juvenile dermatomyositis: a longitudinal cohort study and multi-cohort validation

OBJECTIVE: Objective evaluation of disease activity is challenging in patients with juvenile dermatomyositis (JDM) due to lack of biomarkers, but crucial to avoid both under- and overtreatment. Recently, we identified two proteins that highly correlate with JDM disease activity: galectin-9 and CXCL10. Here, we validate galectin-9 and CXCL10 as biomarkers for disease activity, assess disease-specificity and investigate their potency to predict flares. METHODS: Galectin-9 and CXCL10 were measured in serum samples of 125 unique JDM patients in three international cross-sectional cohorts and a local longitudinal cohort, by multiplex immunoassay. Disease-specificity was examined in 50 adults with (dermato)myositis and 61 patients with other systemic autoimmune diseases. RESULTS: Galectin-9 and CXCL10 outperformed the currently used marker creatine kinase (CK) to distinguish between JDM patients with active disease and remission, both cross-sectionally and longitudinally (area ROC curve: 0.86-0.90 for galectin-9 and CXCL10, 0.66-0.68 for CK). The sensitivity and specificity were 0.84 and 0.92 for galectin-9, and 0.87 and 1.00 for CXCL10. In 10 prospectively followed patients with a flare, continuously elevated or rising biomarker levels suggested an imminent flare up to several months before symptoms, even in absence of elevated CK. Galectin-9 and CXCL10 distinguished between active disease and remission in adults with (dermato)myositis and were suited for measurement in minimally-invasive dried blood spots. CONCLUSIONS: Galectin-9 and CXCL10 were validated as sensitive and reliable biomarkers for disease activity in (J)DM. Implementation of these biomarkers into clinical practice, as tools to monitor disease activity and guide treatment, might facilitate personalized treatment strategies

Pediatric rheumatology in Southeast Asia: Insights from the Singapore experience

10.1007/s11926-010-0159-1Current Rheumatology Reports132117-12

Antiphospholipid syndrome antibodies - Snippets from the laboratory

Proceedings of Singapore Healthcare22181-8