Anticardiolipin and anti‐beta 2‐glycoprotein I antibodies in patients with unexplained articular manifestations

OBJECTIVE: To determine the frequency of antiphospholipid antibodies (aPL) in patients with unexplained articular manifestations. MATERIAL AND METHODS: Three hundred thirteen patients suffering from arthritis or arthralgia without evident cause and 266 healthy blood donors (HBD) were included in the study. Anticardiolipin antibodies (aCL) and anti‐beta 2‐glycoprotein I antibodies (aβ2GPI) were measured by ELISA. RESULT: Out of the 313 patients, 250 were females and 63 were males. The mean age of patients was 49 ± 14 years (17–87 years). One hundred eleven patients have arthralgia and 202 have arthritis. The frequency of aCL and/or aβ(2)GPI (24.9%) was significantly higher in patients than in HBD (10.9%). The frequency of aβ2GPI was 23.6% in patients and 9.4% in the control group (p < 10(−3)). aβ2GPI‐IgA was significantly more frequent in patients than in the control group (20.4% vs. 7.5%, p < 10(−3)). aβ2GPI was most commonly observed than aCL in patients (23.6% vs. 6.4%, p < 10(−6)). IgA isotype of aβ2GPI was the most frequent in 20.4% of patients while IgG and IgM were detected in 5.4% and 2.9% respectively. CONCLUSION: This study showed that aPL were common in patients with articular manifestations and were mainly directed against β(2)GPI. The role of these antibodies remains to be specified.