PREVALENCE OF ANTIPHOSPHOLIPID ANTIBODIES IN PATIENTS WITH ANKYLOSING-SPONDYLITIS

Objective. To establish the prevalence of antiphospholipid antibodies (aPL) in a group of patients with ankylosing spondylitis (AS). The rel ation of the antibodies with different clinical and analytical cal fea tures was studied. Methods. Eighty-four patients with AS (71 men) and 40 age and sex matched controls were studied. aPL determinations inclu ded: anticardiolipin antibodies (aCL) of the IgM, IgG, and IgA classes , the presence of lupus anticoagulant (LAC), and a false positive sero logic test for syphilis. Comparisons between variables were done by St udent t test, Mann-Whitney test and Chi squared test. Correlations bet ween aPL and clinical variables were performed by Pearson coefficients . Results. Twenty-four patients with AS (29%) had positive IgG aCL, co mpared with only 2 cases in the control group (5%) (p <0.002). There w ere no differences in other aPL determinations between patients and co ntrols. There was no correlation between the presence of aCL (Igc, IgM , or IgA) and LAC and the different aspects of the disease. Two patien ts fulfilled the criteria for antiphospholipid syndrome. Conclusion. O ur results indicate the presence of IgG aCL in patients with AS higher than in the normal population but their relation with thrombosis and other systemic manifestations seems weak.