Study On The Mechanism Of Vitamin D In Systemic Lupus Erythematosus

Background:In recent years,the role of vitamin D in regulating immunity has gradually been discovered.There is increasing evidence that vitamin D plays an important role in the pathogenesis and progression of SLE,especially in regulating T lymphocytes.The mechanism of vitamin D in systemic lupus erythematosus(SLE)is not clear.Objective:This is a cross-sectional study to assess vitamin D3 levels in systemic lupus erythematosus(SLE)patients and their relationship to inflammatory markers,immune status and disease activity,at the same time,to explore its mechanism of immune regulation preliminarily.Methods:54 SLE patients and 50 healthy controls(HC)were enrolled in the study during the same period.Medical records were collected and disease activity was assessed using the SLE Disease Activity Index score(SLEDAI-2000)of all SLE patients.Flow cytometry was used to detect the percentages of follicular helper T cells(Tfh),regulatory T cells(Treg)and T helper 1,2,17(Th1,Th2,Th17)cell subsets in peripheral blood of all humans.Plasma cytokine levels,including interferon-γ(INF-γ),transforming growth factor-β1(TGF-β1)and interleukin-6(IL-6)were measured by ELISA.The data were analyzed with serum 25-(OH)D3 levels in SLE patients.At the same time,general information of healthy controls were collected.Results:The 25-(OH)D3 deficiency in lupus patients with moderate and severe activity was more pronounced.Serum 25-(OH)D3 concentration was negatively correlated with 2 4-hour urine protein level.The use of therapeutic drugs had no effect on 25-(OH)D3 level in SLE.The percentages of peripheral blood Thl and Th17 cells in patients were significantly higher than controls,while the percentage of Treg was decreased.Tfh and Th2 cells were not changed.Plasma cytokines,including INF-γ,IL-6 and TGF-β1 were significantly higher in SLE patients than in controls.The level of 25-(OH)D3 with lupus in moderate and severe active groups decreased significantly with the increase of the percentage of Thl and Th17 cells,and it negatively correlated with plasma IL-6.Conclusion:Serum 25-(OH)D3 deficiency was significant in moderately.and severely active SLE patients.The ability of 25-(OH)D3 to regulate immunity may be achieved by inhibiting T lymphocyte-mediated inflammatory response and the production of some cytokines.