AB0918 Auto-antibodies in patients with ankylosing spondylitis untreated with biologic therapy

Background AnkylosingSpondylitis (AS) is a chronic inflammatory disease belonging to the spondylarthropathy group without immunity marker. Presence of auto-antibodies was unusual and frequently induced by biologic treatment. Objectives to evaluate the frequency and clinical significance of anti nuclear antibodies, (ANA), anti-DNA, anti-ENA, rheumatoid factor (RF) and anti-keratin antibody (AKA) in patients with AS before any biologic therapy. Methods We have performed a cross sectional study of 100 patients who fulfilled the modified New York Criteria for AS. Screening for auto-antibodies was performed by indirect immunofluorescence (Hep2 cells for ANA, Chritidia luciliae for anti-DNA and rat oesophagus for AKA), by ELISA for anti-ENA and by Latex for RF. Statistical analysis was performed by X2 test and Student t test. Significance was accepted for p<0.05. Results Eighty nine men and 11 women were recruited, their mean age was 37, 9±11.7 years. The mean disease duration was 12.3±9.7 years, the mean age at the onset of the disease was 26,6±10,2 years. Peripheral arthritis was found in 76 patients and extra articular clinical pattern was found in 24 patients (anterior uveitis in 18 cases). Among patients with AS, 24 patients have at least one autoantibody, 22 patients have ANA with level <1/200 in all cases, anti-ENA were found in two patients, AKA in 6 patients and RF in 4 patients. No relation was found between presence of auto-antibodies and articular or extra-articular clinical pattern in patients with ankylosing spondylitis. Conclusions Auto-antibodies seem to be frequent in AS but their level was low in most of cases and seems to have no impact in clinical pattern. Disclosure of Interest None Declared