Mucosal-associated Invariant Cells are Deficient in Systemic Sclerosis.

Systemic sclerosis (SSc) is an autoimmune disease, characterized by fibrosis of the skin and other organs, vascular impairment and deficient immune responses. Mucosal-associated invariant T cells (MAIT) have been involved in various inflammatory and autoimmune diseases. The aims of this study were to determine the frequencies of MAIT cells in the blood of patients with systemic sclerosis (SSc) and to compare their distribution in different types of SSc. Blood samples from patients with SSc and healthy controls were examined by flow cytometer to analyse the frequencies of MAIT and γδ T cells. We demonstrate that in SSc the frequencies and absolute numbers of MAIT and γδ T cells are significantly reduced in comparison with healthy controls. MAIT and γδ T cells did not correlate with C-reactive protein, BNP, pulmonary involvement or median skin fibrosis scale, steroid amount or disease duration. In addition, MAIT and γδ T cells decrease did not stratify with gender, interstitial lung disease or active digital ulcers. Functional studies are necessary to determine the signification of MAIT cells decrease in systemic sclerosis.