Clinical and laboratory outcomes during the treatment of rheumatoid arthritis with methotrexate

Methotrexate for treating rheumatoid arthritis

BACKGROUND

Methotrexate is a folic acid antagonist widely used for the treatment of neoplastic disorders. Methotrexate inhibits the synthesis of deoxyribonucleic acid (DNA), ribonucleic acid (RNA) and proteins by binding to dihydrofolate reductase. Currently, methotrexate is among the most commonly used drugs for the treatment of rheumatoid arthritis (RA). This is an update of the previous Cochrane systematic review published in 1997.

OBJECTIVES

To evaluate short term benefits and harms of methotrexate for treating RA compared to placebo.

SEARCH METHODS

The Cochrane Musculoskeletal Group Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched from 1966 to 1997 and then updated to November 2013. The search was complemented with a bibliography search of the reference lists of trials retrieved from the electronic search.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials comparing methotrexate (MTX) monotherapy against placebo alone in people with RA. Any trial duration and MTX doses were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently determined which studies were eligible for inclusion, extracted data and assessed risk of bias. Outcomes were pooled using mean differences (MDs) for continuous variables or standardized mean differences (SMDs) when different scales were used to measure the same outcome. Pooled risk ratio (RR) was used for dichotomous variables. Fixed-effect models were used throughout, although random-effects models were used for outcomes showing heterogeneity.

MAIN RESULTS

Five trials with 300 patients were included in the original version of the review. An additional two trials with 432 patients were added to the 2013 update of the review for a total of 732 participants. The trials were generally of unclear to low risk of bias with a follow-up duration ranging from 12 to 52 weeks. All trials included patients who have failed prior treatment (for example, gold therapy, D-penicillamine, azathioprine or anti-malarials); mean disease duration that ranged between 1 and 14 years with six trials reporting more than 4 years; and weekly doses that ranged between 5 mg and 25 mg.

BENEFITS

Statistically significant and clinically important differences were observed for most efficacy outcomes. MTX monotherapy showed a clinically important and statistically significant improvement in the American College of Rheumatology (ACR) 50 response rate when compared with placebo at 52 weeks (RR 3.0, 95% confidence interval (CI) 1.5 to 6.0; number needed to treat (NNT) 7, 95% CI 4 to 22). Fifteen more patients out of 100 had a major improvement in the ACR 50 outcome compared to placebo (absolute treatment benefit (ATB) 15%, 95% CI 8% to 23%).Statistically significant improvement in physical function (scale of 0 to 3) was also observed in patients receiving MTX alone compared with placebo at 12 to 52 weeks (MD -0.27, 95% CI -0.39 to -0.16; odds ratio (OR) 2.8, 95% CI 0.23 to 32.2; NNT 4, 95% CI 3 to 7). Nine more patients out of 100 improved in physical function compared to placebo (ATB -9%, 95% CI -13% to -5.3%). Similarly, the proportion of patients who improved at least 20% on the Short Form-36 (SF-36) physical component was higher in the MTX-treated group compared with placebo at 52 weeks (RR 1.5, 95% CI 1.0 to 2.1; NNT 9, 95% CI 4 to 539). Twelve more patients out of 100 showed an improvement of at least 20% in the physical component of the quality of life measure compared to placebo (ATB 12%, 95% CI 1% to 24%). No clinically important or statistically significant differences were observed in the SF-36 mental component.Although no statistically significant differences were observed in radiographic scores (that is, Total Sharp score, erosion score, joint space narrowing), radiographic progression rates (measured by an increase in erosion scores of more than 3 units on a scale ranging from 0 to 448) were statistically significantly lower for patients in the MTX group compared with placebo-treated patients (RR 0.31, 95% CI 0.11 to 0.86; NNT 13, 95% CI 10 to 60). Eight more patients out of 100 showed less damage to joints measured by an increase in erosion scores compared to placebo (ATB -8%, 95% CI -16% to -1%). In the one study measuring remission, no participants in either group met the remission criteria. These are defined by at least five of (≥ 2 months): morning stiffness of < 15 minutes, no fatigue, no joint pain by history, no joint tenderness, no joint swelling, and Westergren erythrocyte sedimentation rate (ESR) of < 20 mm/hr in men and < 30 mm/hr in women.

HARMS

Patients in the MTX monotherapy group were twice as likely to discontinue from the study due to adverse events compared to patients in the placebo group, at 12 to 52 weeks (16% versus 8%; RR 2.1, 95% CI 1.3 to 3.3; NNT 13, 95% CI 6 to 44). Compared to placebo, nine more people out of 100 who took MTX withdrew from the studies because of side effects (ATB 9%, 95% CI 3% to 14%). Total adverse event rates at 12 weeks were higher in the MTX monotherapy group compared to the placebo group (45% versus 15%; RR 3.0, 95% CI 1.4 to 6.4; NNT 4, 95% CI 2 to 17). Thirty more people out of 100 who took MTX compared to those who took placebo experienced any type of side effect (common or rare) (ATB 30, 95% CI 13% to 47%). No statistically significant differences were observed in the total number of serious adverse events between the MTX group and the placebo group at 27 to 52 weeks. Three people out of 100 who took MTX alone experienced rare but serious side effects compared to 2 people out of 100 who took a placebo (3% versus 2%, respectively).

AUTHORS' CONCLUSIONS

Based on mainly moderate to high quality evidence, methotrexate (weekly doses ranging between 5 mg and 25 mg) showed a substantial clinical and statistically significant benefit compared to placebo in the short term treatment (12 to 52 weeks) of people with RA, although its use was associated with a 16% discontinuation rate due to adverse events.

Methotrexate for rheumatoid arthritis

OBJECTIVES

To estimate the short-term efficacy and toxicity of methotrexate (MTX) for the treatment of rheumatoid arthritis (RA).

SEARCH STRATEGY

We searched the Cochrane Musculoskeletal Group trials register, and Medline, up to July 1997, using the search strategy developed by the Cochrane Collaboration (Dickersin 1994). The search was complemented with bibliography searching of the reference list of the trials retrieved from the electronic search. Key experts in the area were contacted for further published and unpublished articles.

SELECTION CRITERIA

Randomized controlled trials and controlled clinical trials comparing MTX against placebo in patients with RA.

DATA COLLECTION AND ANALYSIS

Two reviewers determined the studies to be included based on inclusion and exclusion criteria (GW, MSA). Data were independently abstracted by two reviewers (EB, MSA), and checked by a third reviewer (BS) using a pre-developed form for the rheumatoid arthritis sub-group of the Cochrane Musculoskeletal Group. The same two reviewers, using a validated scale (Jadad 1996) assessed the methodological quality of the trials independently. Rheumatoid arthritis outcome measures were extracted from the publications. The pooled analysis was performed using standardized mean differences (SMDs) for joint counts, pain, and global and functional assessments. Weighted mean differences (WMDs) were used for erythrocyte sedimentation rate (ESR). Toxicity was evaluated with pooled odds ratios (OR) for withdrawals. A chi-square test was used to assess heterogeneity among trials. Fixed effects models were used throughout and random effects for outcomes showing heterogeneity.

MAIN RESULTS

Five trials and 300 patients were included. A statistically significant benefit was observed for MTX when compared to placebo. Statistically significant differences were observed for all measures except ESR. The standardized weighted difference (effect size) between MTX and placebo for the various outcome measures varied between -0.43 and -1.5. No differences were observed in the total number of withdrawals and dropouts (OR = 0.95), although patients on MTX were three times more likely to discontinue treatment because of adverse reactions (OR=3.47) and four times less likely to withdraw due to lack of response (OR=0.22).

REVIEWER'S CONCLUSIONS

Twenty-two percent of people on MTX withdrew due to adverse effects compared to seven percent of the placebo group. MTX has a substantial clinically and statistically significant benefit in the short term treatment of patients with RA.

Clinical, laboratory, radiographic, and histopathologic features of methotrexate-associated lung injury in patients with rheumatoid arthritis: a multicenter study with literature review

OBJECTIVE

To describe the clinical, laboratory, radiologic, and histopathologic features of methotrexate (MTX)-induced lung injury in a combined cohort of selected patients with rheumatoid arthritis (RA) and all cases reported in the English-language literature.

METHODS

Retrospective combined cohort review and abstraction from the medical literature. Case reports were obtained from 6 centers that had 4 or more cases of potential MTX lung injury per site. RA patients who were seen between 1981 and 1993 and who satisfied predetermined criteria for the presence of MTX lung injury were identified.

RESULTS

Twenty-seven patients satisfied the criteria for definite MTX lung injury, and 2 for probable MTX lung injury. Predominant clinical features of MTX lung injury included shortness of breath in 27 patients (93.1%), which was present for 23.5 +/- 22.3 days (mean +/- SD), cough in 24 (82.8%), present for 26.9 +/- 28.5 days, and fever in 20 (69.0%), present for 10.4 +/- 12.8 days. Five patients (17.2%) died, compared with 12 of 68 (17.6%) reported in the medical literature. Four of the 6 patients who were re-treated with MTX after an initial pulmonary event developed recurrent lung toxicity, resulting in 2 deaths, compared with a recurrence rate of 3 of 6 in the literature.

CONCLUSION

MTX lung injury is most often a subacute process, in which symptoms are commonly present for several weeks before diagnosis. Approximately 50% of the cases are diagnosed within 32 weeks from initiation of MTX treatment. A patient who recovers from MTX lung injury should not be re-treated. Earlier recognition and drug withdrawal may avoid the serious and sometimes fatal outcome that has been observed in this and other studies.

The value of C-reactive protein measurement in rheumatoid arthritis

Since 1973, assessment of serum concentrations of C-reactive protein (CRP) has been advocated as a objective measure of disease activity in rheumatoid arthritis (RA). Our review of clinical experience with CRP measurement suggests it has at least two important roles to play in the management of RA. First, persistently elevated CRP levels have prognostic value. In general, such elevated levels are found in those patients who are at greater risk for continuing joint deterioration and therefore may need more aggressive treatment and supportive care. Second, in general, improvement in CRP levels is an objective indication that a drug has produced a beneficial effect and thus may be useful to the physician for monitoring effects of therapy. Since CRP may be elevated in a number of conditions besides RA, a diagnosis of RA must be made before using CRP as a prognostic factor.

One year treatment with low dose methotrexate in rheumatoid arthritis: effect on class specific rheumatoid factors

We evaluated the effect of a one-year treatment of low dose methotrexate (MTX) on class specific rheumatoid factors in 27 patients with rheumatoid arthritis (RA). Enzyme-linked immunosorbent assay (ELISA) showed after 6 and 12 months a significant reduction of IgM-RF, IgA-RF and IgG-RF levels from the baseline values. During MTX treatment, changes of each RF isotype were not correlated with any other isotype and its corresponding immunoglobulin changes. Moreover, immunological changes were not related to the improvement of clinical parameters. Our results showed that low dose MTX can specifically affect levels of RF isotypes, which are involved in the immune pathogenesis of RA.

The impact of endpoint measures in rheumatoid arthritis clinical trials

In clinical trials on the effectiveness of disease-modifying antirheumatic drugs (DMARDs) in patients with rheumatoid arthritis (RA), it is common to apply a large number of endpoint measures. This practice has several disadvantages. To determine which endpoint measures are most valuable, reports of 32 clinical trials on six DMARDs were reviewed. The frequency with which each endpoint measure was used is described and discussed, as well as the frequency with which the values of each endpoint were significantly different in statistical comparisons within or between groups, thus showing ability to discriminate between drugs not equally effective. The results of this review are discussed and compared with other reports in the literature on the choice of endpoint measures in RA clinical trials. The authors conclude that it is still common practice to evaluate multiple outcome measures. The number of measures could be reduced by using only those that are generally considered important, are sensitive to change, and are able to differentiate between drugs in clinical trials. A joint count, assessment of pain, a questionnaire on functional status, and measurement of erythrocyte sedimentation rate are sufficient.