The role of liver transaminase levels in methotrexate intolerance in juvenile idiopathic arthritis-a cross-sectional study

Methotrexate (MTX) plays a key role when treating juvenile idiopathic arthritis (JIA), but MTX-intolerance is challenging. MTX-treatment might affect the liver, causing elevated levels of alanine aminotransferase (ALT), yet the role of ALT-levels in MTX-intolerance in JIA remains unclear. Our study aimed to investigate the association between ALT-levels during MTX-treatment and MTX-intolerance in JIA. Children (> 9 years old) diagnosed with JIA and treated with MTX (> 6 weeks) were eligible for enrollment. MTX-intolerance was assessed using the Methotrexate Intolerance Severity Score (MISS), completed by the parents, and defined as MISS ≥ 6 with at least 1 point for a behavioral/anticipatory/associative symptom. ALT-levels were determined at enrollment. A total of 118 children were enrolled (80 girls; 38 boys). MTX-intolerance was registered in 61%. ALT-levels did not differ between the MTX-intolerant group (median = 17.0 U/L [IQR: 14.0-26.0]) and the MTX-tolerant group (median = 20.5 U/L [IQR: 16.0-27.5]; p = 0.17). MTX-intolerance was prevalent in around 60% of both boys and girls. Nine out of 50 MTX-intolerant girls had elevated ALT-levels compared to 0/22 MTX-intolerant boys, however, there was no difference in median ALT levels between the two groups. Furthermore, the MTX-intolerant girls had a higher MISS (median = 14.0 [IQR: 9.3-17]) than the MTX-intolerant boys (median = 10.0 [IQR: 7.3-12]; p = 0.009). Our study did not find a difference in ALT-levels between MTX-intolerant and MTX-tolerant children. However, only MTX-intolerant girls and no MTX-intolerant boys showed elevated ALT-levels.

Pharmacological conditioning for juvenile idiopathic arthritis: a potential solution to reduce methotrexate intolerance

BACKGROUND

Methotrexate (MTX) therapy has proven to be a successful and safe treatment for Juvenile Idiopathic Arthritis (JIA). Despite the high efficacy rates of MTX, treatment outcomes are often complicated by burdensome gastro-intestinal side effects. Intolerance rates for MTX in children are high (approximately 50%) and thus far no conclusive effective treatment strategies to control for side effects have been found. To address this need, this article proposes an innovative research approach based on pharmacological conditioning, to reduce MTX intolerance.

PRESENTATION OF THE HYPOTHESIS

A collaboration between medical psychologists, pediatric rheumatologists, pharmacologists and patient groups was set up to develop an innovative research design that may be implemented to study potential improved control of side effects in JIA, by making use of the psychobiological principles of pharmacological conditioning. In pharmacological conditioning designs, learned positive associations from drug therapies (conditioning effects) are integrated in regular treatment regimens to maximize treatment outcomes. Medication regimens with immunosuppressant drugs that made use of pharmacological conditioning principles have been shown to lead to optimized therapeutic effects with reduced drug dosing, which might ultimately cause a reduction in side effects.

TESTING THE HYPOTHESIS

This research design is tailored to serve the needs of the JIA patient group. We developed a research design in collaboration with an interdisciplinary research group consisting of patient representatives, pediatric rheumatologists, pharmacologists, and medical psychologists.

IMPLICATIONS OF THE HYPOTHESIS

Based on previous experimental and clinical findings of pharmacological conditioning with immune responses, we propose that the JIA patient group is particularly suited to benefit from a pharmacological conditioning design. Moreover, findings from this study may potentially also be promising for other patient groups that endure long-lasting drug therapies.

Perceptions of Methotrexate Intolerance and Its Impact on Daily Life in School-Age Children with Juvenile Idiopathic Arthritis

PURPOSE

Methotrexate (MTX) is a disease modifying anti-rheumatic drug commonly used to treat children with Juvenile Idiopathic Arthritis (JIA). Unfortunately, half of children taking MTX will experience MTX intolerance, which includes distressing gastrointestinal and behavioural symptoms associated with weekly MTX treatment. This qualitative study aimed to explore the perceptions of school-age children with JIA experiencing MTX intolerance, how they managed MTX intolerance, and how it impacted their daily life.

DESIGN AND METHODS

An interpretive descriptive design was used. Twelve children participated in one individual 30-minute semi-structured interview using a storyboard technique to elicit their perceptions through storytelling. Interview transcripts and observational data collected during the interviews were analyzed using inductive content analysis.

RESULTS

Children described MTX intolerance as extremely challenging. Three themes emerged from the data: (1) "No kid likes taking MTX". This theme was comprised of two subthemes related to: (a) associative MTX intolerance; namely, "Talking about it sometimes makes me feel sick"; and (b) anticipatory MTX intolerance, "Before [I take it], I have a little stomach ache". Other themes included: (2) The importance of strategies and routines; and (3) Working hard to live with MTX intolerance.

CONCLUSIONS

This study sheds new light on MTX intolerance as perceived by school-aged children with JIA. Results highlight the importance of providing families and healthcare professionals with the necessary information for early recognition of MTX intolerance and optimizing care through the development of early intervention strategies.

PRACTICE IMPLICATIONS

Study findings highlight the importance of prioritizing early identification and prevention of MTX intolerance.

Prediction of methotrexate intolerance in juvenile idiopathic arthritis: a prospective, observational cohort study

BACKGROUND

Methotrexate (MTX) is an effective and safe drug in the treatment of juvenile idiopathic arthritis (JIA). Despite its safety, MTX-related gastrointestinal adverse effects before and after MTX administration, termed MTX intolerance, occur frequently, leading to non-compliance and potentially premature MTX termination. The aim of this study was to construct a risk model to predict MTX intolerance.

METHODS

In a prospective JIA cohort, clinical variables and single nucleotide polymorphisms were determined at MTX start. The Methotrexate Intolerance Severity Score was employed to measure MTX intolerance in the first year of treatment. MTX intolerance was most prevalent at 6 or 12 months after MTX start, which was defined as the outcome for the prediction model. The model was developed in 152 patients using multivariable logistic regression analysis and subsequently internally validated using bootstrapping.

RESULTS

The prediction model included the following predictors: JIA category, antinuclear antibody, parent/patient assessment of pain, Juvenile Arthritis Disease Activity Score-27, thrombocytes, alanine aminotransferase and creatinine. The model classified 77.5% of patients correctly, and 66.7% of patients after internal validation by bootstrapping. The lowest predicted risk of MTX intolerance was 18.9% and the highest predicted risk was 85.9%. The prediction model was transformed into a risk score (range 0-17). At a cut-off of ≥6, sensitivity was 82.0%, specificity 56.1%, positive predictive value was 58.7% and negative predictive value 80.4%.

CONCLUSIONS

This clinical prediction model showed moderate predictive power to detect MTX intolerance. To develop into a clinically usable tool, it should be validated in an independent cohort and updated with new predictors. Such an easy-to-use tool could then assist clinicians in identifying patients at risk to develop MTX intolerance, and in turn to monitor them closely and intervene timely in order to prevent the development of MTX intolerance.

TRIAL REGISTRATION

ISRCTN register, www.isrctn.com, ISRCTN13524271.