The clinical significance of anti-DFS70 autoantibodies and its correlation with Vitamin D levels

OBJECTIVE: This study aims to investigate the clinical significance of anti-dense fine speckled 70 (DFS70) autoantibodies and its association with systemic autoimmune rheumatic diseases (SARD) related autoimmune markers and Vitamin D levels. METHODS: The study group consisted of 281 (mean age +/- SD: 45.31 +/- 15.89 years; 88.3% female) anti-DFS70 autoantibody-positive patients. All patients' sera in the study group were tested by ANA HEp-2 indirect immunofluorescent antibody (IIF) and immunoblotting (IB) methods (Euroimmun AG, Lubeck, Germany). Anti-DFS70 antibody-positive patients were divided into two subgroups. Anti-DFS70 antibody-positive patients with SARD were assigned as Group 1 (n=43), anti-DFS70 antibody-positive patients without SARD were assigned as Group 2 (n=238). A control group with anti-DFS70 negative patients with SARD were assigned as Group 3 (n=49, mean age +/- SD: 49.86 +/- 12.08; 79.6% female). The clinical characteristics, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), neutrophil/lymphocyte ratio, thrombocyte/lymphocyte ratio ( TLR), rheumatoid factor (RF), anti-cyclic citrullinated peptide (anti-CCP), and 25-hydroxyvitamin D3 (25OHD3) levels were compared between three groups. RESULTS: The majority (61.9%) of anti-DFS70 antibody positive patients had no specific diagnosis. Other systemic diseases were detected as allergic diseases (10.0%), hematological abnormalities (5.0%), thyroid diseases (3.6%), gastrointestinal system diseases (1.8%), malignancies (1.4%), and infections (1.1%). ESR, CRP levels, and TLR were lower in Group 2 than Groups 1 and 3 (p<0.05). RF and anti-CCP positivity rates were lower in Group 2 when compared with Groups 1 and 3 (p<0.05). 25OHD3 levels did not differ between three groups (p=0.103). CONCLUSION: We observed that anti-DFS70 autoantibody may be associated with organ-specific autoimmune diseases, allergic diseases, and hematological disorders. Therefore, it is essential to evaluate these pathologies in patients positive for anti-DFS70 antibodies.