Evaluation of Antigen-specific T Cells in Patients With Antisynthetase Syndrome and Interstitial Lung Disease

Antisynthetase syndrome (AS) is a rare overlapping myositis characterized by cellular and humoral autoimmune responses directed against aminoacyl-tRNA synthetases. Intesrtitial lung disease (ILD) is a leading cause of mortality in antisynthetase syndrome. Recently, antigen-specific IFN-γ+ CD4+ T cells have been identified in bronchoalveolar fluid (BAL) of patients with antisynthetase syndrome and ILD. Elevated levels of IL1β, IL12, IL18, TNFα, IL17A, IL22 have also been detected in peripheral blood of AS patients, especially those with progressive ILD. Implication of innate lymphoid cells (ILC) and mucosal-associated invariant T cells (MAIT) have not yet been studied in patients with AS. Targeted therapies against Th1 and Th17 cells may represent a promising treatment in patients AS patients with ILD. Investigators suppose that antigen-specific Th1 and Th17 cells, ILC and MAIT at ILD diagnosis are associated with ILD severity at diagnosis and could predict treatment response at 6 months. The main objective is to study the correlation between BAL antigen-specific Th1 and Th17 cells at ILD diagnosis and clinical evolution after 6 months of treatment according to initial ILD severity.