Decreased 1,25-Dihydroxyvitamin D3 level is involved in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease

PURPOSE: 1,25-Dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] has recently been found to be involved in the development of autoimmune diseases. This study was to investigate the expression and potential role of 1,25(OH)(2)D(3) in the pathogenesis of Vogt-Koyanagi-Harada (VKH) disease. METHODS: Blood samples were obtained from VKH patients and healthy individuals. Serum 1,25(OH)(2)D(3) levels were measured using ELISA. Peripheral blood mononuclear cells (PBMCs) or cluster of differentiation (CD) 4(+) T cells were cultured with or without 1,25(OH)(2)D(3) in the presence of anti-CD3 and anti-CD28 for the measurement of cell proliferation and cytokines. The cell proliferation was detected using the Cell Counting Kit. The levels of interleukin (IL)-17 and interferon (IFN)-γ levels in the supernatants of PBMCs or CD4(+) T cells were detected by ELISA. RESULTS: 1,25(OH)(2)D(3) was significantly decreased in the serum of active VKH patients as compared with inactive VKH patients and controls. It significantly inhibited PBMCs proliferation and CD4(+) T cell proliferation. It was also able to significantly inhibit the production of IL-17 and IFN-γ by both PBMCs and CD4(+) T cells from VKH patients and controls. CONCLUSIONS: These findings suggest that decreased expression of 1,25(OH)(2)D(3) may be involved in the development of VKH disease. 1,25(OH)(2)D(3) may be potentially used in the treatment of this disease.