Vitamin A improve Th17 and Treg regulation in systemic lupus erythematosus.

The aim of this study was to determine the role of vitamin A in modulating T helper 17 (Th17) and regulatory T cell (Treg) balance in systemic lupus erythematosus (SLE) patients. Sixty-two female SLE patients and sixty-two female controls were measured for vitamin A levels from serum by enzyme-linked immunosorbent assay (ELISA) and percentages of Th17 and Treg from peripheral blood mononuclear cells (PBMC) by flow cytometry. We also performed an in vitro study to evaluate the effects of retinoic acid treatment (0, 0.1, 0.2, and 0.3 μg/ml) in modulating Th17/Treg balance in CD4(+) T cell culture from hypovitaminosis A SLE patients. Th17 and Treg percentages from cell cultures were measured by flow cytometry. Vitamin A levels in the SLE patients were lower compared to those in the healthy control (46.9 ± 43.4 vs. 75.6 ± 73.1 ng/ml, p = 0.015). Vitamin A levels also had a negative correlation to Th17 percentages in the SLE patients (p = 0.000, R = -0.642). Th17 percentages in the hypovitaminosis A SLE patients were higher compared to those SLE patients with normal vitamin A levels (10.9 ± 5.3 vs. 2.9 ± 2.2 %, p = 0.000). Treatment of 0.3 μg/ml of retinoic acid could increase Treg differentiation (33.9 ± 1.6 vs. 21.8 ± 1.1 %, p = 0.000) and decrease Th17 differentiation (27.2 ± 2.5 vs. 37.4 ± 1.3 %, p = 0.000). In conclusion, vitamin A has important roles in modulating Th17/Treg balance in the SLE patients shown by the significant decrease of vitamin A levels in the SLE patients which negatively correlate with Th17 population, and treatment of retinoic acid could decrease Th17 and increase Treg percentages in CD4(+) T cells cultures.