Assessing methotrexate intolerance and its prevalence in rheumatoid arthritis: Development and validation of the MISA questionnaire

Methotrexate Intolerance in Juvenile Idiopathic Arthritis: Definition, Risks, and Management

Juvenile idiopathic arthritis is the most common rheumatic disorder in childhood and adolescence posing a significant threat of short-term and long-term disability if left untreated. Methotrexate is a folic acid analog with various immunomodulatory properties. It has demonstrated significant efficacy for the treatment of juvenile idiopathic arthritis, often considered the preferred first-line disease-modifying anti-rheumatic drug given as monotherapy or in combination with biological drugs. Despite this, there is a considerable risk for treatment disruptions owing to the high prevalence of methotrexate intolerance, with symptoms such as nausea, stomach ache, vomiting, and behavioral symptoms. Many different risk factors for the intolerance have been proposed including gender, age, disease activity, treatment duration, dosing and administration, and genetic and psychological factors. As the studies have shown contradictory results, many questions are left unanswered. Therefore, a consensus regarding outcome measures and reporting is crucial. In this review, we describe the identification and assessment of methotrexate intolerance and evaluate potential risk factors, genetic associations as well as management strategies.

Assessment of oral methotrexate intolerance in Japanese adult patients with rheumatoid arthritis

AIM

The objective of this study was to assess the gastrointestinal side (GI) effects of oral methotrexate (MTX) in Japanese adult patients with rheumatoid arthritis (RA).

METHODS

In this single-center retrospective study, 112 Japanese adult patients (over 18 years old) with RA were examined by Methotrexate Intolerance and Severity assessment in Adults (MISA) questionnaire.

RESULTS

Forty-five (40.2%) of patients were MTX intolerant (MISA score ≥1). Twelve patients (11.2%) were moderate-to-severe MTX intolerant (MISA cross-product score ≥4). The most common GI side effects of MTX were gastric discomfort (26.8%), followed by loss of appetite or dysgeusia (14.3%), fatigue and lethargy (12.5%), and nausea (10.7%).

CONCLUSIONS

Japanese adult patients with RA showed a high prevalence of MTX intolerance even in low-dose oral MTX. The MISA questionnaire was practical for finding patients with MTX intolerance.

Long-term persistence of oral methotrexate and associated factors in rheumatoid arthritis: a retrospective cohort study

There is little data on long-term persistence/continuation of methotrexate among Indian Rheumatoid arthritis patients. We assembled a retrospective single-center cohort consisting of RA patients (fulfilling 1987 ACR criteria) started on methotrexate as part of three academic studies (including two RCTs) from 2011 to 2016. Oral methotrexate was started at 7.5 or 15 mg per week with a target dose of 25 mg per week. Between August and December 2020, all patients were contacted (telephonically) and data were obtained from clinic files to evaluate self-reported continuation/persistence of methotrexate and reasons for discontinuation. Survival analysis using Kaplan-Meier and cox-regression were used to assess methotrexate continuation rates and factors associated with its discontinuation. This study included 317 patients with rheumatoid arthritis, with mean age and disease duration (at enrollment) of 43 years and 2 years; And positive rheumatoid factor and anti-CCP in 69 and 75%. At follow-up, 16 patients (5%) had died, whereas 103 (32.5%) had discontinued methotrexate. On Kaplan-Meier survival analysis, the mean survival (continuation) time for methotrexate was 7.3 years (95% CI 7-7.6 years). The actuarial continuation/persistence of methotrexate at 3, 5 and 9 years was 92, 81 and 51%, respectively. Among those who discontinued methotrexate, common reasons were remission of disease, symptomatic adverse effects (intolerance), perceived lack of efficacy and socioeconomic reasons. On multivariable cox-regression, symptomatic adverse effects during the first 12-24 weeks (Hazard ratio, 95% CI 1.8 (1.2-2.8)) and anti-CCP positivity (Hazard ratio, 95% CI 0.6 (0.3-1.0)) were significantly associated with hazard of discontinuation. Persistence or continuation of methotrexate was found to be good and comparable to reports in other centers world-wide. Apart from remission, the most important cause of methotrexate discontinuation was symptomatic adverse effects (intolerance).

Difficult-to-treat rheumatoid arthritis (D2T RA): clinical issues at early stages of disease

OBJECTIVES

Most studies on difficult-to-treat rheumatoid arthritis (D2T RA) have focused on established RA. Here, we analyse whether disease activity in the early stages of RA could influence progression to a D2T RA under real-life conditions. Other clinical and treatment-related factors were also analysed.

METHODS

A longitudinal multicentre study of patients with RA was conducted from 2009 to 2018. Patients were followed up until January 2021. D2T RA was defined based on EULAR criteria (treatment failure, signs suggestive of currently active/progressive disease and management being perceived as problematic by the rheumatologist and/or patient). The main variable was disease activity in the early stages. The covariates were sociodemographic, clinical and treatment-related factors. We ran a multivariable logistic regression analysis to investigate risk factors associated with progression to D2T RA.

RESULTS

The study population comprised 631 patients and 35 (5.87%) developed D2T RA. At the time of diagnosis, the D2T RA group were younger, with a higher disability, 28-joint Disease Activity Score (DAS28) score, tender joint count and pain scores. In our final model, DAS28 was not statistically significantly associated with D2T RA. No differences were found between groups for therapy. Disability was independently associated with D2T RA (OR: 1.89; p=0.01).

CONCLUSIONS

In this cohort of patients newly diagnosed with RA, our results do not allow us to prove the influence of active disease according to DAS28. However, we did find that younger patients and those with elevated initial disability scores are more likely to develop D2T RA regardless of other factors.