The immunopathological role of vitamin D in patients with SLE: data from a single centre registry in Hungary.

Objectives: Disproportionate vitamin D levels may play an important role in the development of certain systemic autoimmune and rheumatic diseases. The aim of the present study was to investigate the prevalence of vitamin D insufficiency in patients with systemic lupus erythematosus (SLE) and to compare serological and clinical parameters in patients with different vitamin D levels from a single centre registry in Central-Eastern Europe. Methods: A total of 177 patients with SLE were enrolled in the study. 25-Hydroxyvitamin D [25(OH)D] levels were measured by chemiluminescent immunoassay ( CLIA). Autoantibody profiles, complement 3 (C3) and C4, clinical symptoms, and disease activity (using the SLE disease activity index, SLEDAI) of the patients were assessed. Results: Vitamin D concentration in the total SLE group investigated was 26.88 ±± 13.25 ng//mL. Vitamin D levels were normal (≥≥ 30 ng//mL) in 18.1%% of patients, insufficient (15--30 ng//mL) in 44.6%%, and deficient (< 15 ng//mL) in 37.3%%. The vitamin levels were significantly reduced in postmenopausal compared to premenopausal patients (p == 0.02). Patients with pericarditis (p == 0.013), neuropsychiatric diseases (p == 0.01), and deep vein thrombosis (p == 0.014) had reduced vitamin D levels. SLEDAI score was significantly increased in patients with reduced vitamin D levels (p == 0.038). Anti-double-stranded (ds)DNA autoantibody concentrations increased from normal to insufficient and further increased from insufficient to deficient patient subsets (p == 0.021). Anti-Smith antigen (anti-Sm) concentrations increased (p < 0.001), C4 levels decreased (p == 0.027), and immunoglobulin (Ig)G concentration increased (p == 0.034) in patients with reduced vitamin D levels. Conclusions: Our data suggest that vitamin D deficiency in SLE may play a role in perpetuation of the disease. [ABSTRACT FROM AUTHOR]