To determine through a systematic literature search the predictors of clinical response and radiographic progression in adult patients with rheumatoid arthritis (RA) treated with methotrexate (MTX) monotherapy.
A systematic literature search using Medline, Embase, and the Cochrane Central Register of Controlled Trials, in May 2008, and review of abstracts of the annual congresses of the American College of Rheumatology (2006-2007) and the European League Against Rheumatism (2002-2007) was performed, as part of a national initiative to develop guidelines for the use of MTX in RA.
Nine studies fulfilled the criteria set for this literature search. Male sex, low disease activity measured by composite scores (DAS or SDAI), and nonutilization of prior DMARD were predictive of good clinical response to MTX. Patients with early RA who are rheumatoid factor-positive and smokers tend to have lower response. However, this last association has not been found for patients with established disease. High disease activity before introduction of MTX monotherapy and higher activity during followup at 3 months is a predictor of more severe radiographic progression.
Among factors found to be predictive of clinical and radiographic outcomes of patients with RA treated with MTX, no factor was found to have a high predictive value. Variability in efficacy measures and statistical tests made it difficult to compare results. Followup of disease activity after 3 to 6 months of treatment seems to be a better and more useful predictor than baseline patient characteristics.