In the Pursuit of Methotrexate Treatment Response Biomarker in Juvenile Idiopathic Arthritis-Are We Getting Closer to Personalised Medicine?

Glutathione S-Transferase Gene Polymorphisms as Predictors of Methotrexate Efficacy in Juvenile Idiopathic Arthritis

Because of the unpredictable efficacy of methotrexate (MTX) in the treatment of juvenile idiopathic arthritis (JIA), the possibility of a favourable outcome is reduced in more than 30% of patients. To investigate the possible influence of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) gene deletion polymorphisms on MTX efficacy in patients with JIA, we determined these polymorphisms in 63 patients with JIA who did not achieve remission and 46 patients with JIA who achieved remission during MTX therapy. No significant differences were observed in the distribution of single GSTM1 or GSTT1 deletion polymorphisms or their combination between the two groups: 58.7% to 63.5%; p = 0.567, 17.4% to 22.2%; p = 0.502, and 13% to 12.7%; p = 0.966, respectively. Our results suggest that GSTM1 and GSTT1 deletion polymorphisms do not influence the efficacy of MTX in patients with JIA. Additional studies are required to determine the possible influence of GST deletion polymorphisms on MTX efficacy in patients with JIA.

Precision medicine in juvenile idiopathic arthritis-has the time arrived?

The introduction of disease-modifying anti-rheumatic drug therapies for treating children and adolescents with chronic arthritis (ie, juvenile idiopathic arthritis [JIA]) has revolutionised care and outcomes. The biologic revolution continues to expand, with ever-changing immunological targets coming to market after basic research and clinical trials. The first class of biologics that was beneficial for children with JIA was tumour necrosis factor (TNF) inhibitors. If used early and aggressively, TNF inhibitors are capable of inducing disease remission for most of the seven subtypes of JIA, with the exception of systemic JIA (which more frequently responds to interleukin [IL]-1 or IL-6 inhibition). Nevertheless, there are still subsets of patients with JIA with disease that is difficult to treat or who develop extra-articular features that require a different therapeutic approach. Although finding an effective biological therapy for individual children with JIA can be trial and error, ongoing research and clinical trials are providing insight into a more personalised approach to care. In addition, redefining the JIA classification, in part based on shared similarities with various adult arthritides, could allow for extrapolation of knowledge from studies in adults with chronic arthritis.

Prefilled pen versus prefilled syringe: a pilot study evaluating two different methods of methotrexate subcutaneous injection in patients with JIA

BACKGROUND

Methotrexate is the most commonly used disease-modifying antirheumatic drug recommended in the treatment of juvenile idiopathic arthritis. It can be administered orally or subcutaneously, the latter method is associated with fewer side effects and higher drug bioavailability. Nevertheless, the pain associated with injection is a considerable drawback of this treatment option in the pediatric population. Currently, there are two single-use subcutaneous injection devices available: the prefilled syringe and the prefilled pen. This prospective, two-sequence crossover study aimed to compare ease of use, frequency of therapy side effects, injection-site pain and parent/patient preference of those methotrexate parenteral delivery systems.

METHODS

Twenty-three patients with juvenile idiopathic arthritis, already treated with subcutaneous methotrexate in the form of prefilled syringe in the period October 2018 - April 2019 completed a questionnaire evaluating their experience with this device. Subsequently, children received a one-month supply of pen autoinjector and completed the same questionnaire, regarding their experience with the new methotrexate delivery system. If the patient was not performing the injections himself the questionnaires were completed by the caregiver administrating MTX. The results obtained in both questionnaires were compared using the Wilcoxon matched-pairs signed-rank test.

RESULTS

82,6% patients and their caregivers voted for the prefilled pen as their preferred method of subcutaneous methotrexate administration. Moreover, the injection with the prefilled pen was reported as less painful in comparison to the prefilled syringe (p < 0.01). Side effects of methotrexate were less pronounced after the prefilled pen treatment, this difference was most prominent regarding gastrointestinal adverse events associated with the injection (p < 0.01).

CONCLUSION

Administration of methotrexate using the pen device is a promising way of subcutaneous methotrexate delivery in children with juvenile idiopathic arthritis, as the injection is less painful and associated with fewer side effects.

DANILKO K, A. MALIEVSKY V, O. KARIMOV D, B. BAKIROV A, V. VIKTOROVA T. The relationship of the immune response mediator genes’ polymorphic variants with the methotrexate efficacy in juvenile idiopathic arthritis

Background/aim

The aim of the study was to analyze the relationship of the immune response mediator genes’ polymorphic loci (TNFA rs1800629, LTA rs909253, IL1B rs16944, IL2-IL21 rs6822844, IL2RA rs2104286, IL6 rs1800795, IL10 rs1800872, MIF rs755622, CTLA4 rs3087243, NFKB1 rs28362491, PTPN22 rs2476601, PADI4 rs2240336) variants with the methotrexate efficacy in juvenile idiopathic arthritis (JIA).

Materials and methods

The study included 274 JIA patients from the Republic of Bashkortostan, Russia. Achieving the American College of Rheumatology Pediatric 30 (ACR Pedi 30) response was regarded as the presence of the response to methotrexate (otherwise, as the absence), while achieving clinical remission on medication (Wallace et al., 2011) - as the sufficient response (otherwise, as the insufficient). Genotyping was conducted by the real-time polymerase chain reaction.

Results

Associations with an altered risk of the nonresponse to methotrexate in JIA were observed for the alleles/genotypes of the lociIL10 rs1800872 (in girls) and NFKB1 rs28362491 (in girls); with an altered risk of the insufficient response to methotrexate in JIA – for the alleles/genotypes of the loci IL1B rs16944 (in boys), CTLA4 rs3087243 (in boys), NFKB1 rs28362491 (in girls) and the haplotype TNFA rs1800629*A - LTA rs909253*G (in girls).

Conclusion

As a result of the study, the relationship of the alleles/genotypes of the IL1B rs16944, IL10 rs1800872, CTLA4 rs3087243, NFKB1 rs28362491 polymorphic lociand the TNFA rs1800629*A - LTA rs909253*G haplotype with the methotrexate efficacy in JIA was established (taking into account the differences by sex).

Disease modifying drugs for rheumatological diseases: a brief history of everything

The rheumatological diseases are a group of chronic, painful, degenerative and debilitating conditions with an increasing prevalence across the globe. The pathogenesis of these disorders is complex, overlapping and not fully understood. As such, it is difficult and time consuming to achieve correct diagnosis and complete remission for an individual patient. In this review we describe the most common forms of inflammatory arthritis and discuss how the management and treatment options for these rheumatic diseases have developed over time. We outline the successes and the limitations of current treatment regimens and discuss the economic burden of the current options. With advancements in understanding of disease mechanisms, we discuss the importance of the biologics revolution in the context of rheumatological disease and how the development of biosimilars and small molecule inhibitors will impact current treatment options in order to alleviate some of the cost burden of biological therapies. The ideal treatment strategy for the future would involve personalized and predictive medicine where by treatments can be tailored to an individual patient's needs in order to achieve fast and successful remission with no adverse events.

Methotrexate and its mechanisms of action in inflammatory arthritis

Despite the introduction of numerous biologic agents for the treatment of rheumatoid arthritis (RA) and other forms of inflammatory arthritis, low-dose methotrexate therapy remains the gold standard in RA therapy. Methotrexate is generally the first-line drug for the treatment of RA, psoriatic arthritis and other forms of inflammatory arthritis, and it enhances the effect of most biologic agents in RA. Understanding the mechanism of action of methotrexate could be instructive in the appropriate use of the drug and in the design of new regimens for the treatment of RA. Although methotrexate is one of the first examples of intelligent drug design, multiple mechanisms potentially contribute to the anti-inflammatory actions of methotrexate, including the inhibition of purine and pyrimidine synthesis, transmethylation reactions, translocation of nuclear factor-κB (NF-κB) to the nucleus, signalling via the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway and nitric oxide production, as well as the promotion of adenosine release and expression of certain long non-coding RNAs.

Early and Accurate Prediction of Clinical Response to Methotrexate Treatment in Juvenile Idiopathic Arthritis Using Machine Learning

Background and Aims: Accurately predicting the response to methotrexate (MTX) in juvenile idiopathic arthritis (JIA) patients before administration is the key point to improve the treatment outcome. However, no simple and reliable prediction model has been identified. Here, we aimed to develop and validate predictive models for the MTX response to JIA using machine learning based on electronic medical record (EMR) before and after administering MTX.

Materials and Methods: Data of 362 JIA patients with MTX mono-therapy were retrospectively collected from EMR between January 2008 and October 2018. DAS44/ESR-3 simplified standard was used to evaluate the MTX response. Extreme gradient boosting (XGBoost), support vector machine (SVM), random forest (RF), and logistic regression (LR) algorithms were applied to develop and validate models with 5-fold cross-validation on the randomly split training and test set. Data of 13 patients additionally collected were used for external validation.

Results: The XGBoost screened out the optimal 10 pre-administration features and 6 mix-variables. The XGBoost established the best model based on the 10 pre-administration variables. The performances were accuracy 91.78%, sensitivity 90.70%, specificity 93.33%, AUC 97.00%, respectively. Similarly, the XGBoost developed a better model based on the 6 mix-variables, whose performances were accuracy 94.52%, sensitivity 95.35%, specificity 93.33%, AUC 99.00%, respectively.

Conclusion: Based on common EMR data, we developed two MTX response predictive models with excellent performance in JIA using machine learning. These models can predict the MTX efficacy early and accurately, which provides powerful decision support for doctors to make or adjust therapeutic scheme before or after treatment.