Methotrexate for ankylosing spondylitis

Abstract

Background: Ankylosing spondylitis (AS) is a chronic inflammatory disease of unknown cause, characterized by sacroiliitis and spondylitis. To date, treatment of AS has been limited to the alleviation of symptoms, mainly using non-steroidal anti-inflammatory drugs (NSAIDs). For patients refractory or intolerant to NSAIDs, the disease modifying antirheumatic drugs (DMARDs) have been used as a second line approach. Methotrexate (MTX) is currently one of the most widely used DMARDs and its efficacy in rheumatoid arthritis (RA) has been confirmed (Suarez-Almazor 2003). There is uncertainty whether MTX works in the treatment of AS.

Objectives: To evaluate the efficacy and toxicity of methotrexate in the treatment of ankylosing spondylitis.

Search strategy: Relevant randomised and quasi-randomised trials in any language were sought using the following sources: CENTRAL (Cochrane Central Register of Controlled Trials, Issue 2, 2003), MEDLINE (1966 to June Week 4 2003), EMBASE (1980 to 2003 Week 26), CINAHL (1982 to June Week 3 2003) and the reference section of retrieved articles.

Selection criteria: We evaluated randomised and quasi-randomised trials examining the efficacy of methotrexate on AS.

Data collection and analysis: Unblinded trial reports were reviewed independently by two reviewers according to the selection criteria. Disagreements on the inclusion of the studies were resolved, where necessary, by recourse to a third reviewer. The methodological quality of included trials were independently assessed by the same reviewers on randomization, concealment, blindness (participants, care providers and outcome investigators), description of withdrawals and drop-outs and intention-to-treat analysis. The same reviewers independently entered the data extracted from the included trials, using RevMan's double entry facility. In the absence of significant heterogeneity, results were combined using weighted mean difference or standardised mean difference for continuous data, and relative risk for dichotomous data.

Main results: Two trials met the inclusion criteria. Altan 2001compared naproxen plus MTX (7.5 mg/week orally) with naproxen alone and Roychowdhury 2002 compared MTX (10 mg/week orally) with placebo. The duration of the trials were 12 months and 24 weeks, respectively. They assessed different outcomes except for C-reactive protein (CRP). The included trials treated a total of 81 patients and assessed more than 10 outcomes relevant to the review, covering function, pain, peripheral arthritis/enthesitis, morning stiffness, patient and physician global assessment, CRP and erythrocyte sedimentation rate (ESR). No significant difference between intervention groups was found favouring MTX over no MTX. No serious side effect was reported in either trial.

Reviewers' conclusions: There was no statistically significant benefit of MTX in the examined outcomes for AS patients. High quality, larger sample and longer period of randomized controlled trials (possibly with higher dosage of MTX) are needed to verify the uncertainty about the efficacy and toxicity of MTX for the treatment of AS.