Anti-mitochondrial antibodies are not a hallmark of severity in idiopathic inflammatory myopathies

International audienceAnti‐mitochondrial antibodies type 2 (AMA2) are the hallmarks of primary biliary cholangitis (PBC) [1]. AMA2 have also been described in 11.3% of idiopathic inflammatory myopathies (IIM) then associatedwith cardiac involvement, muscular atrophy and granuloma (table 1) [2]

CD8+T-bet+ cells as a predominant biomarker for inclusion body myositis

International audienceBackground: Myositis is a heterogeneous group of muscular auto-immune diseases with clinical and pathological criteria that allow the classification of patients into different sub-groups. Inclusion body myositis is the most frequent myositis above fifty years of age. Diagnosing inclusion body myositis requires expertise and is challenging. Little is known concerning the pathogenic mechanisms of this disease in which conventional suppressive-immune therapies are inefficacious.Objectives: Our aim was to deepen our understanding of the immune mechanisms involved in inclusion body myositis and identify specific biomarkers.Methods: Using a panel of thirty-six markers and mass cytometry, we performed deep immune profiling of peripheral blood cells from inclusion body myositis patients and healthy donors, divided into two cohorts: test and validation cohorts. Potential biomarkers were compared to myositis controls (anti-Jo1-, anti-3-hydroxyl-3-methylglutaryl CoA reductase-, and anti-signal recognition particle-positive patients).Results: Unsupervised analyses revealed substantial changes only within CD8+ cells. We observed an increase in the frequency of CD8+ cells that expressed high levels of T-bet, and containing mainly both effector and terminally differentiated memory cells. The senescent marker CD57 was overexpressed in CD8+T-bet+ cells of inclusion body myositis patients. As expected, senescent CD8+T-bet+ CD57+ cells of both patients and healthy donors were CD28nullCD27nullCD127null. Surprisingly, non-senescent CD8+T-bet+ CD57- cells in inclusion body myositis patients expressed lower levels of CD28, CD27, and CD127, and expressed higher levels of CD38 and HLA-DR compared to healthy donors. Using classification and regression trees alongside receiver operating characteristics curves, we identified and validated a frequency of CD8+T-bet+ cells >51.5% as a diagnostic biomarker specific to inclusion body myositis, compared to myositis control patients, with a sensitivity of 94.4%, a specificity of 88.5%, and an area under the curve of 0.97.Conclusion: Using a panel of thirty-six markers by mass cytometry, we identify an activated cell population (CD8+T-bet+ CD57- CD28lowCD27lowCD127low CD38+ HLA-DR+) which could play a role in the physiopathology of inclusion body myositis, and identify CD8+T-bet+ cells as a predominant biomarker of this disease

Anti-NXP2 Dermatomyositis: a severe muscle and skin disease

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Rituximab and Cyclophosphamide in Antisynthetase Syndrome–related Interstitial Lung Disease: An Observational Retrospective Study

International audienceObjective Antisynthetase syndrome (AS)-related interstitial lung disease (ILD) has a poor prognosis. Intravenous cyclophosphamide (IV CYC) and rituximab (RTX) are the main treatments currently used for moderate to severe ILD. Here, we compare the efficacy of CYC followed by standard immunosuppressive treatment (IST) versus RTX in AS-related ILD. Methods This observational retrospective study was conducted between 2003 and 2016 in 3 tertiary care centers. All patients with AS-related ILD and treated with CYC or RTX with at least 6 months of follow-up were included. Pulmonary progression-free survival (PFS), defined according to the American Thoracic Society guidelines, was assessed at 6 months and 2 years. All severe adverse events (AE) were recorded. Results Sixty-two patients were included. Thirty-four patients received 2–12 monthly IV CYC pulses, followed by standard IST in 30 cases (88%). The RTX group included 28 patients. Following the initial Day 1 to Day 15 infusions, RTX was repeated every 6 months in 26 cases (93%) and 15 patients (54%) concomitantly received another IST. The median steroid dose was similar between both groups. Although RTX and CYC demonstrated similar PFS at 6 months (92% vs 85%, respectively), RTX was superior at 2 years (HR 0.263, 95% CI 0.094–0.732, P = 0.011). Interestingly, lower diffusing lung capacity for carbon monoxide (DLCO) at baseline was independently predictive of poor 2-year PFS [0.965 (0.936–0.995), P = 0.023]. Forced vital capacity and DLCO improved in both groups without significant differences. Serious AE were similar in both groups. Conclusion Despite similar PFS at 6 months, RTX was associated with a better 2-year PFS compared to CYC in patients with AS-related ILD

Rapamycin vs. Placebo for the Treatment of Inclusion Body Myositis: improvement of the 6 min walking distance, a functional scale, the FVC and muscle quantitative MRI

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Anti-PM-Scl antibodies–positive patients encompass three different groups with distinct prognoses

International audienceAbstract Objective To help identify homogeneous subgroups among patients with anti-PM-scleroderma-antibodies (PM-Scl-Abs) positive auto-immune diseases regardless of diagnostic classifications. Material and methods This multicentric (four hospitals) retrospective study collected all consecutive patients (from 2011 to 2021) with positive testing for anti-PM-Scl-Abs in a context of CTD. Subgroups of patients with similar clinico-biological phenotypes were defined using unsupervised multiple correspondence analysis and hierarchical clustering analysis of the features recorded in the first year of follow-up. Results One hundred and forty-two patients with anti-PM-Scl-Abs were evaluated and 129 patients were included in the clustering analysis and divided into three clusters. Cluster 1 (n = 47) included patients with frequent skin thickening, digestive involvement and interstitial lung disease (ILD) with non-specific interstitial pneumonia (NSIP). They were more likely to develop progressive fibrosing ILD. Cluster 2 (n = 36) included patients who all featured NSIP with frequent organizing pneumonia–associated pattern and mechanic’s hands. This subgroup had increased risk of relapse and ILD was characterized by a good functional outcome. Cluster 3 (n = 46) was characterized by predominant or isolated musculoskeletal involvement and frequently matched UCTD criteria. Although very frequent among anti-PM-Scl-Abs positive patients, muscle involvement was less discriminating compared with skin thickening and ILD pattern to classify patients into subgroups. Conclusion Anti-PM-Scl-Abs associated auto-immune diseases are segregated into three subgroups with distinct clinical phenotype and outcomes. Skin thickening and NSIP are determinant predictors in segregation of theses populations

Ultrasensitive Interferons quantification in idiopathic inflammatory myopathies serve as biomarkers of activity in dermatomyositis and anti-synthetase syndrome

Abstract Objectives Inflammatory idiopathic myopathies (IIM) are a heterogeneous group of disorders, ranging from a muscle-specific autoimmune disease to a systemic one that are difficult to assess. Recent insights into IIM pathogenesis highlighted the role of interferon (IFN) in the pathophysiology. The aim of this study was to test if IFN serum levels can a use as a biomarker of disease activity in IIM. Methods IFN type I and II were measured using an ultrasensitive detection technology and assess the potential of IFN. Results One hundred and fifty-two patients (dermatomyositis (DM); n=50, anti-synthetase syndrome (ASyS); n=46, immune-mediated necrotizing myopathy (IMNM); n=32, inclusion body myositis (IBM); n=24) and 33 age-matched healthy donors were included. IFN-α levels were higher only in DM (0.07 pg/ml [0.03-0.23], p<0.005) and ASyS groups (0.07 [0.02-0.16], p<0.05) compared with controls (0.02 [0.01-0.05]). IFN-β was increased only in DM and IFN-γ among all IIM. IFN-α levels were correlated with disease activity in DM (r=0.76, p<0.0001). The predictive accuracy of IFN-α level to discriminate active and non-active disease was excellent as reflected by an area under the ROC-curve of 0.88. Using an IFN-α level cut-off above 0.11 pg/ml, the sensitivity was 75% and the specificity was 96% in DM patient. IFN-α and IFN-γ were correlated with disease activity in ASyS groups (r=0.55 and r=0.46 p<0.05)). Conclusions IFNs are promising biomarker for DM and ASyS disease activity

Granulomatous Myositis: Heterogeneity and Response to Treatment

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Anti-RNP antibodies delineate a subgroup of necrotizing myositis

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