Effect of combined treatment with prednisone and methotrexate versus prednisone alone over laboratory parameters in giant cell arteritis

OBJECTIVE:To compare the effect of combined treatment with prednisone and methotrexate (MTX) versus prednisone alone over laboratory parameters in giant cell arteritis (GCA). PATIENTS AND METHODS:We performed a double-blind, placebo-controlled, randomized clinical trial about usefulness of treatment with prednisone and MTX versus prednisone and placebo in GCA (Ann Intern Med 2001;134:106-114). As a part of follow-up of patients (n=42), we performed laboratory analysis in 20 time points during the two-year period of follow-up. To analyze differences, we calculated the area under the curve (AUC) for erythrocyte sedimentation rate (ESR), hemoglobin, and platelets, and compared the results in both groups adjusting by time of follow-up, existence of relapses and dose of prednisone. RESULTS:A total of 724 laboratory measurements were done. Median value of ESR was 33 [18-56] in patients with placebo and 26 [15-44] in patients with MTX (P=0.0002). No significant differences were observed in ESR during relapses. The mean ESR value followed a parallel course in both groups, but was lower in the group with MTX than in the group with placebo in 18 of 20 time points of follow-up. The AUC of ESR by time of follow-up was 28,461.7±12,326 in the group with placebo and 19,598.4±8,117 in the group with MTX (mean difference 8,863, 95% CI 1.542-16.184; P=0.019). The course of other laboratory parameters paralleled, without statistical significance, those observed for ESR. CONCLUSIONS:These data, along with clinical data, suggest that MTX might play a role as a disease-modifying agent in the treatment of GCA.