Efficacy of Methotrexate in Real-world Management of Giant Cell Arteritis: A Case-control Study

Objective.To determine the effect of methotrexate (MTX) on relapse risk and glucocorticoid (GC) use in a large single-institution cohort of patients with giant cell arteritis (GCA).Methods.Patients diagnosed with GCA from 1998 to 2013 with confirmed evidence of temporal artery biopsy and/or radiographic evidence of large vessel vasculitis were identified. Each patient with GCA treated with adjunct MTX (case) was matched to a similar patient with GCA treated only with GC (control). GC requirements and relapse events before and after MTX initiation (or corresponding index date) were compared using rate ratios (RR).Results.Eighty-three cases and 83 controls were identified and compared. No significant differences in age, demographics, laboratory variables, baseline disease characteristics, or mean initial prednisone doses were observed. Median [interquartile range (IQR)] time from GCA diagnosis to MTX initiation in cases was 39 (13–80) weeks and the median (IQR) starting dose was 13.5 (10–15) mg/week. RR comparing relapse rates before and after MTX initiation/index date were significantly reduced in both cases (RR 0.32, 95% CI 0.24–0.41) and controls (RR 0.60, 95% CI 0.43–0.86). The decrease in relapse rate was significantly greater in patients taking MTX than in those taking GC alone (p = 0.004). Rates of GC discontinuation did not differ between groups.Conclusion.In this large single-institution cohort, the addition of MTX to GC decreased the rate of subsequent relapse by nearly 2-fold compared to patients taking GC alone. MTX may be considered as adjunct therapy in patients with GCA to decrease the risk of further relapse events.