Anti‐Vitamin D, Vitamin D in SLE

Abstract : The aim of this study was to detect antibodies to vitamin D in systemic lupus erythematosus (SLE) and other autoimmune diseases. The results may shed light to a novel aspect of vitamin D deficiency in autoimmune diseases. Sera from 171 patients with SLE, 56 with antiphospholipid syndrome (APS), and 18 with pemphigus vulgaris (PV) were studied employing an enzyme‐linked immunosorbent assay for anti‐vitamin D antibodies along with 94 healthy blood donors. In parallel, vitamin D concentrations in the serum were determined by a DiaSorin commercial kit (LIAISON 25 OH vitamin D). Antibody‐positive and antibody‐negative individuals were compared with respect to demographic variables, SLE disease activity index (SLEDAI) score, autoantibodies profile, and serum vitamin D levels. Anti‐vitamin D antibodies were detected in 7 (4%) of 171 patients with SLE, in 2 (3.5%) of 56 of sera from patients with APS, and in 2 (11%) of 18 sera from patients with PV. Vitamin D levels were similar in both SLE groups with and without anti‐vitamin D antibodies. Demographic features, organ involvement, SLEDAI score, and autoantibodies did not differ between the groups. Except for anti‐dsDNA antibodies, in which anti‐vitamin D antibodies were strongly associated with these antibodies in sera from SLE patients ( P = 0.0004). Anti‐vitamin D antibodies are observed in a subset of patients with SLE, APS, and PV, and are associated with anti‐dsDNA antibodies in SLE. Further studies are required to explore the potential diagnostic and prognostic role of these novel antibodies in SLE.