Overexpression of Aiolos in Peripheral Blood Mononuclear Cell Subsets from Patients with Systemic Lupus Erythematosus and Rheumatoid Arthritis

Genetic studies demonstrate that the Aiolos polymorphisms contribute to the susceptibility to autoimmune diseases. The purpose of the study was to investigate the Aiolos expression in lymphocytes and monocytes in the peripheral blood from patients with SLE and RA, and to explore the correlation between Aiolos expression in cell subsets and laboratory measurements. Peripheral blood mononuclear cells (PBMC) from 32 patients with SLE, 35 patients with RA, and 37 healthy controls were purified. Aiolos expression in PBMC subsets was examined by flow cytometry. In SLE patients, a much higher percentage of Aiolos + CD8+ T cells and Aiolos + CD14+ monocytes was found, when compared with healthy controls (p = 8.29 × 10−5 and p = 1.01 × 10−5, respectively). Furthermore, the percentage of CD4+ and CD8+ T cells, CD19+ B cells, and CD14+ monocytes expressing Aiolos in RA patients was also determined and each found higher than that in healthy controls (p = 0.009, p = 4.11 × 10−5, p = 0.001, and p = 1.11 × 10−5, respectively). The percentage of Aiolos + CD8+ T cells was weakly correlated with ESR in SLE patients and RF in RA patients (rs = 0.37, p = 0.038; rs = 0.34, p = 0.044, respectively). On the other hand, the percentage of Aiolos + CD14+ monocytes was significantly correlated with multiple laboratory measurements, including ESR, creatinine, CRP, LDH, proteinuria, albumin, and ACCPA in patients (rs = 0.62, p < 0.001; rs = 0.65, p < 0.001; rs = 0.44, p = 0.010; rs = 0.42, p = 0.022; rs = 0.52, p = 0.013; rs = 0.34, p = 0.048, respectively). To our knowledge, it is the first study to demonstrate overexpression of Aiolos in PBMC subsets in SLE and RA patients. The results indicate that overexpression of Aiolos may contribute to pathogenesis of SLE and RA.