Methotrexate for juvenile idiopathic arthritis.

BACKGROUND

Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood. Methotrexate has broad immunomodulatory properties and is the most commonly used disease-modifying antirheumatic drug (DMARD). This is an update of a 2001 Cochrane review. It supports a living guideline for children and young people with JIA.

OBJECTIVES

To assess the benefits and harms of methotrexate for children and young people with juvenile idiopathic arthritis.

SEARCH METHODS

The Australian JIA Living Guideline Working Group created a registry of all randomised controlled trials (RCTs) of JIA by searching CENTRAL, MEDLINE, Embase, and trials registries. The date of the most recent search of online databases was 1 February 2023.

SELECTION CRITERIA

We searched for RCTs that compared methotrexate with placebo, no treatment, or another DMARD (with or without concomitant therapies) in children and young people (aged up to 18 years) with JIA.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. The main comparison was methotrexate versus placebo. Our outcomes were treatment response, sustained clinically inactive disease, function, pain, participant global assessment of well-being, serious adverse events, and withdrawals due to adverse events. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We identified three new trials in this update, bringing the total number of included RCTs to five (575 participants). Three trials evaluated oral methotrexate versus placebo, one evaluated methotrexate plus intra-articular glucocorticoid (IAGC) therapy versus IAGC therapy alone, and one evaluated methotrexate versus leflunomide. Doses of methotrexate ranged from 5 mg/m/week to 15 mg/m/week in four trials, and participants in the methotrexate group of the remaining trial received 0.5 mg/kg/week. Trial size varied from 31 to 226 participants. The average age of participants ranged from four to 10 years. Most participants were females and most had nonsystemic JIA. The study that evaluated methotrexate plus IAGC therapy versus IAGC therapy alone recruited children and young people with the oligoarticular disease subtype of JIA. Two placebo-controlled trials and the trial of methotrexate versus leflunomide were adequately randomised and blinded, and likely not susceptible to important biases. One placebo-controlled trial may have been susceptible to selection bias due to lack of adequate reporting of randomisation methods. The trial investigating the addition of methotrexate to IAGC therapy was susceptible to performance and detection biases. Methotrexate versus placebo Methotrexate compared with placebo may increase the number of children and young people who achieve treatment response up to six months (absolute difference of 163 more per 1000 people; risk ratio (RR) 1.67, 95% confidence interval (CI) 1.21 to 2.31; I = 0%; 3 trials, 328 participants; low-certainty evidence). However, methotrexate compared with placebo may have little or no effect on pain as measured on an increasing scale of 0 to 100 (mean difference (MD) -1.10 points, 95% CI -9.09 to 6.88; 1 trial, 114 participants), improvement in participant global assessment of well-being (absolute difference of 92 more per 1000 people; RR 1.23, 95% CI 0.88 to 1.72; 1 trial, 176 participants), occurrence of serious adverse events (absolute difference of 5 fewer per 1000 people; RR 0.63, 95% CI 0.04 to 8.97; 3 trials, 328 participants), and withdrawals due to adverse events (RR 3.46, 95% CI 0.60 to 19.79; 3 trials, 328 participants) up to six months. We could not estimate the absolute difference for withdrawals due to adverse events because there were no withdrawals in the placebo group. All outcomes were reported within six months of randomisation. We downgraded the certainty of the evidence to low for all outcomes due to indirectness (suboptimal dosing of methotrexate and diverse outcome measures) and imprecision (few participants and low event rates). No trials reported function or the number of participants with sustained clinically inactive disease. Serious adverse events included liver derangement, abdominal pain, and inadvertent overdose. Methotrexate plus intra-articular corticosteroid therapy versus intra-articular corticosteroid therapy alone Methotrexate plus IAGC therapy compared with IAGC therapy alone may have little or no effect on the probability of sustained clinically inactive disease or the rate of withdrawals due to adverse events up to 12 months in children and young people with the oligoarticular subtype of JIA (low-certainty evidence). We could not calculate the absolute difference in withdrawals due to adverse events because there were no withdrawals in the control group. We are uncertain if there is any difference between the interventions in the risk of severe adverse events, because none were reported. The study did not report treatment response, function, pain, or participant global assessment of well-being. Methotrexate versus an alternative disease-modifying antirheumatic drug Methotrexate compared with leflunomide may have little or no effect on the probability of treatment response or on function, participant global assessment of well-being, risk of serious adverse events, and rate of withdrawals due to adverse events up to four months. We downgraded the certainty of the evidence for all outcomes to low due to imprecision. The study did not report pain or sustained clinically inactive disease.

AUTHORS' CONCLUSIONS: Oral methotrexate (5 mg/m/week to 15 mg/m/week) compared with placebo may increase the number of children and young people achieving treatment response but may have little or no effect on pain or participant global assessment of well-being. Oral methotrexate plus IAGC injections compared to IAGC injections alone may have little or no effect on the likelihood of sustained clinically inactive disease among children and young people with oligoarticular JIA. Similarly, methotrexate compared with leflunomide may have little or no effect on treatment response, function, and participant global assessment of well-being. Serious adverse events due to methotrexate appear to be rare. We will update this review as new evidence becomes available to inform the living guideline.