Relationship between vitamin D and disease activity in some rheumatic diseases

Abstract

Most people are aware that vitamin D deficiency in young children can lead to rickets, a condition where the bones become weak and soft. Many of the benefits of vitamin D relate to its role in the modulation of immune system. So, vitamin D may play role in autoimmune rheumatic diseases. There are two groups: patients group and control group. The control group included 20 healthy volunteers. Patients group included 100 rheumatic patients, 30 with rheumatoid arthritis (RA), 20 with systemic lupus erythematosus (SLE), 30 with osteoartheritis (OA), 10 with Behcet’s disease, 10 with ankylosing spondylitis (AS). Venous blood samples were taken for determination of erythrocyte sedimentation rate (ESR), serum 1. 25(OH) 2 D3 levels and serum C reactive protein (CRP) levels. The disease activity in different target groups was assessed using Disease Activity Score including 28 joint counts (DAS28) in RA patients, SLE disease activity index (SLEDAI) in SLE patients, Western Ontario and McMaster Universities Arthritis Criteria (WOMAC) in OA patients, The American College of Rheumatology (ACR) criteria in Behcet’s patients and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in A.S. patients. The mean value of vitamin D serum levels were significantly lower in each of RA, SLE, Behcet’s disease and AS patients (mean ± SD) (13.47 ± 8.17, 19.32 ±10.67, 17.64 ±8.79 and 17.81 ±8.11 respectively) in comparison to control group (26.61 ± 6.44, p-value ≤0.05). While, There is no significance difference between the OA (22.95 ±9.3) and control groups, as p-value of 0.178. As regard the comparison of vitamin D serum level between the active RA, SLE, OA, Behcet’s disease and AS patients and the inactive groups, the difference was found to be statistically insignificant (p-value >0.05). In the patients group DAS28 in RA patients, SLEDAI in SLE patients, WOMAC in OA patients, ACR criteria in Behcet’s patients and BASDAI in AS were significantly higher in active groups as compared with inactive groups. In the present study no association was observed between vitamin D levels and disease activity scales DAS28, SLEDAI, WOMAC, and ACR. While there is a significant negative correlation between vitamin D levels and BASDAI. Vitamin D deficiency occurs at a higher rate in patients with RA, SLE, Behcet’s disease and A.S. While, no association was observed between vitamin D levels and disease activity scales in the RA, SLE, OA, and Behcet’s disease patients. Key words: Vitamin D, immune system, rheumatic autoimmune diseases, activity and severity.