1,25-Dihydroxyvitamin D3 Regulates T helper and B Lymphocyte Responses Substantially in Drug-Naive Primary Sjögren?s Syndrome Patients? Mononuclear Cells.

A correlation between vitamin D deficiency and primary Sjogren?s Syndrome (pSS) has already been described. The limited data have been reported regarding the pathological relevance of vitamin D in pSS. In this study, the modulatory effect of 1,25-dihydroxyvitaminD3 on T and B lymphocytes of pSS patients was investigated. PBMC were isolated from pSS patients? venous blood samples and cultured in the presence and absence of 1,25-dihydroxyvitaminD3 (10mM) for 5 days. Lymphocyte proliferation, intracellular IFN-? and IL-17 expressions in CD4+T cells, naive, memory and total B lymphocytes, and cytokine secretions in culture supernatants were analyzed via flow cytometry. 1,25-dihydroxyvitaminD3 significantly decreased CD4+T and B lymphocyte proliferative responses in drug-naive (p<0.005) and treated pSS patients (p<0.05) compared to PBMC cultures alone. 1,25-dihydroxyvitaminD3 significantly decreased IFN-? and IL-17 secreting CD4+T cells in both drug naive and treated subjects by increasing CD4+CD25+FoxP3+Treg cell frequency. Plasma B lymphocytes significantly reduced and total memory B lymphocytes notably increased in the presence of 1,25-dihydroxyvitaminD3 in pSS patients? mononuclear cell cultures (p<0.05). IFN-? and IL-17 cytokine levels in culture supernatants significantly reduced and IL-10 levels significantly enhanced in drug naive pSS patients? PBMC cultures with 1,25-dihydroxyvitaminD3 (p<0.05). 1,25-dihydroxyvitaminD3 regulated immune responses substantially in drug-naive pSS patients.