Vitamin D Effect in Rheumatoid Arthritis.

Background: Regulatory T cells (Tregs) play an important role in the maintenance of immunological tolerance, so Tregs deficiency or decrease suppressor functions may be associated with development of autoimmune diseases. Vitamin D is essential for normal bone mineralization and growth, prevention of osteopenia, osteoporosis, and nonspecific painful musculoskeletal conditions . Vitamin D is thought to have an immunomodulatory and anti-inflammatory actions, as its receptors are widely expressed in peripheral mononuclear blood cells, also its deficiency associated with several autoimmune disorders, including rheumatoid arthritis Methods: 40 patients with active RA were randomly assigned into two groups. Group I received MTX plus hydroxychloroquine, group II received MTX and hydroxychloroquine plus vitamin D supplementation for 3 months, in addition to 30 healthy volunteers as control group. Peripheral blood Tregs were measured by Flow Cytometry. Statistical Analysis. The collected data analyzed by SPSS software (version 16). The range, mean and standard deviation were calculated for quantitative variables. Categorical variables were expressed as number and percentages; Chi square was used as a test of their significance. Skewness, kurtosis; Shapiro-Wilk, and The Kolmogorov-Smirnov tests were used to test the normality for the data. The difference between two means was analyzed using the students (t) test (paired and unpaired samples- T tests). Significance was considered at p\<0.05.