Background Ankylosing spondylitis (AS) is an autoimmune disease with high disability rate, and it is sometimes difficult to distinguish from generalized osteoarthritis (GOA). Deoxyribonuclease 1-like 3 (DNASE1L3) was associated with a variety of autoimmune diseases. However, the serum DNASE1L3 level in AS and GOA remain unreported. Herein, this study was designed to gauge serum DNASE1L3 level in patients with AS and GOA, and to discern the utility of serum DNASE1L3 as a biomarker for assessing the severity of patients with AS. Methods The study population consisted of 60 patients with AS, 60 patients with GOA and 60 control subjects. Serum DNASE1L3 levels were measured using enzyme-linked immunosorbent assay (ELISA) assay. Disease activity were assessed with Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) in AS patients. Results Our data showed that serum DNASE1L3 levels were significantly higher in patients with AS than that of the healthy controls and patients with GOA. Serum DNASE1L3 levels in patients with AS were positively correlated with BASDAI scores, C3 and C-reactive protein (CRP). Furthermore, serum DNASE1L3 showed higher discriminatory accuracy in the diagnosis of AS from GOA (AUC = 0.851, sensitivity = 78.33% and specificity = 81.67%). Conclusions Elevated Serum DNASE1L3 levels in patients with AS were significantly associated with the clinic features and disease activity. DNASE1L3 could be a serum biomarker with a positive diagnostic value in patients with AS, and which could be used as a differential diagnostic indicator for GOA and AS.
