Increased IFN-γ+ and TNF-α+ mucosal-associated invariant T cells in patients with aplastic anemia

Abstract

Background: Aplastic anemia (AA) is known as an autoimmune disease in which T cell activation is aberrant. It has been reported that unconventional T cells, mucosal-associated invariant T (MAIT) cells, play an important role in several autoimmune diseases, but it is unclear if they are involved in AA. Methods: In this study, we for the first time analyzed the proportions, phenotypes, and cytokine properties of MAIT cells in AA by flow cytometry. Results: We found that the percentage of circulating MAIT cells was generally higher for CD3+, CD8+, and CD8− T cells in AA patients compared with healthy individuals. Moreover, the percentage of IL-18Rα-, NKG2D-, IFN-γ-, and TNF-α- positive MAIT cells was also significantly higher in AA patients. In addition, the percentage of IFN-γ+ CD3+ or TNF-α+CD8− MAIT cells had a significant negative correlation with the absolute neutrophil count. Conclusions: We present the first observation of MAIT cells in patients with AA. MAIT cells are associated with a higher frequency of IFN-γ and TNF-α production and may contribute to the pathogenesis of AA.