Since we have previously reported the frequency of aβ2GPI and aCL in RA13 and that the frequency of aPL in patients with unexplained arthralgia or arthritis has not been reported previously, we aimed, in this study, to evaluate the frequency of aβ2GPI and aCL in patients suffering from articular manifestations (arthritis or arthralgia) without evident cause. Here, FASLG is linked to arthritic joint disease.