Prevalence and evolution of anticardiolipin antibodies in giant cell arteritis during corticosteroid therapy. A prospective study of 20 consecutive cases.

IgG and IgM anticardiolipin antibodies (aCA) were studied prospectively in 20 consecutive patients (12 females, eight males, mean age 74.6 +/- 14 yr, range 62-86 yr) with giant cell temporal arteritis before and during corticosteroid therapy (days 7, 30, 90 and 180). IgG-aCA were present in 10 out of 20 cases and in nine out of 12 with positive temporal artery biopsy but were not found in 20 paired control subjects. During steroid therapy aCA levels returned to within the normal range in 60% of patients with positive aCA at day 7 and in 80% at day 30. In two cases aCA persisted during the 6-month follow-up despite clinical and biological success. No association was found between aCA and thrombotic events.