A LONGITUDINAL-STUDY OF ANTICARDIOLIPIN ANTIBODY IN POLYMYALGIA-RHEUMATICA AND GIANT-CELL ARTERITIS

Objective. To determine the incidence of elevated levels of anticardio lipin antibody (aCL) in patients with newly diagnosed polymyalgia rheu matica (PMR) and/or giant cell arteritis (GCA); and to determine the r elationship between these antibodies at diagnosis and subsequent cours e of the disease over a period of 2 yrs. Methods. Ninety-eight consecu tive patients with PMR and/or GCA were examined for the presence of aC L, at presentation and every 6 mo for 2 yrs. Sixty-four patients had P MR alone, 22 had coexistent PMR and GCA, and 12 presented with pure GC A. Patients presenting with suspected clinical diagnosis, overt or cov ert, of GCA were subjected to temporal artery biopsy from the symptoma tic side within 3 days of presentation. Appropriate serological, bioch emical, and hematological investigations were undertaken at presentati on and subsequently at times of periodic assessments. One hundred heal thy age and sex matched elderly subjects were also screened for the pr esence of aCL as a control group. Results. Elevated levels of aCL were detected in 20 patients at presentation. These included 9 patients wi th PMR/GCA and 11 patients with pure PMR, During followup, IO patients with pure PMR at presentation developed GCA. These comprised 5 of the 11 patients with high aCL at presentation and 5 of the 53 patients wi th normal levels of aCL at presentation. This was statistically signif icant with relative risk (4.82, 95% CI, 1.72-13.51) of developing GCA in the presence of PMR and a high aCL at presentation. Furthermore, 3 of the 5 patients with pure GCA and high aCL at presentation progresse d to severe vascular complications (stroke, 2; anterior ischemic optic neuritis, 1) compared to none of the other patients in the study. Ele vated levels of antineutrophilic cytoplasmic antibody were also analyz ed and detected in only 4 patients, 3 with pure PMR and one with biops y proven GCA. Conclusion. This prospective study suggests that a signi ficant number of patients with PMR and/or GCA with elevated levels of aCL at presentation have increased risk of developing GCA or other maj or vascular complications. It is possible that aCL may be an independe nt prognostic marker for future vascular complications in patients wit h PMR and/or GCA.