Anticardiolipin antibodies in polymyalgia rheumatica-giant cell arteritis: association with severe vascular complications.

PURPOSE: We studied a group of patients with polymyalgia rheumatica (PMR) with or without biopsy-proven giant cell arteritis (GCA) in order to determine the prevalence of anticardiolipin antibodies (aCL) in these disorders and their association with vascular complications. PATIENTS AND METHODS: The study consisted of 50 patients, 30 with PMR alone and 20 with associated GCA. Determinations of IgG and IgM aCL by enzyme-linked immunosorbent assay were done in the patients and in 50 age- and sex-matched healthy control subjects. We also measured von Willebrand factor (vWF) antigen, C-reactive protein, and erythrocyte sedimentation rate. RESULTS: Twenty-four (48%) of the 50 patients had aCL. Eleven were positive for IgG and five for IgM, whereas eight were positive for both. In the group of patients with PMR alone, only eight (26.6%) had aCL, while 16 of 20 patients (80%) with GCA had these antibodies (p less than 0.01). In the control group, 10 of 50 patients (20%) had positive aCL, a finding that was statistically significantly different only when compared with the finding in patients with GCA (p less than 0.01). Both isotypes of aCL were seen mainly in patients with GCA, and five of these patients had severe vascular complications. Levels of vWF antigen were significantly higher in patients with GCA as compared with patients with PMR alone; however, the highest titers did not correlate with vascular complications. Erythrocyte sedimentation rate and C-reactive protein were increased but comparable in both groups. CONCLUSION: This study demonstrates that aCL are prevalent in patients with GCA. These antibodies might imply severe vascular damage and could play an important role in the pathogenesis of the vasculopathy observed in this disease.

Lack of immunosuppressive effect of low-dose oral methotrexate on lymphocytes in rheumatoid arthritis.

Whether methotrexate (MTX) is effective in rheumatoid arthritis (RA) because of immunosuppressive and/or anti-inflammatory mechanisms of action is controversial. Many lines of investigation point to the latter. We evaluated DNA synthesis in peripheral blood lymphocytes (PBL) from 33 RA patients on oral MTX (7.5-15 mg/wk) and in 30 healthy controls by flow cytometric cell cycle analysis (CCA). DNA synthesis was also evaluated with a thymidilate synthetase activity assay (TSA) (3H-deoxyuridine incorporation) in 12 patients and 21 controls (12 on MTX and NSAID, and 9 healthy subjects). The patients had taken MTX for at least 3 months and were in different stages of clinical activity. There were no significant differences in TSA or in the cell cycle phase distributions (especially the S phase) between treated RA patients and controls. These data suggest that low-dose oral MTX does not inhibit DNA synthesis and therefore does not have an immunosuppressive effect on lymphocytes from patients with RA.