Evaluation of cytogenetic and molecular markers with MTX-mediated toxicity in pediatric acute lymphoblastic leukemia patients.

Purpose: Pediatric acute lymphoblastic leukemia (pALL) patients have better overall survival and methotrexate (MTX) is an effective drug used in their treatment. However, the treatment-related adverse effects (TRAEs) have a bigger impact on the therapy. In this study, we have evaluated the association of polymorphisms in genes encoding proteins engaged in MTX metabolism, and the cytogenetic aberrations with TRAEs.

Methods: A total of 115 patients between the age of 1 and 18 years (average: 6.6) under maintenance therapy were selected for the study. SLC19A1 (c.80G > A), MTHFR (c.677C > T; c.1298A > C), and TYMS (c.*450_*455del) genotypes were determined using PCR techniques and Sanger sequencing. Cytogenetic and SNP findings were analyzed for any association with the reported toxicities using odds ratio, chi-square test, multifactor dimensionality reduction (MDR) analysis for synergistic effect and, multinomial logistic regression analysis for the likelihood of adverse events.

Results: Among the evaluated genetic variations, SLC19A1 (c.80G > A) was significantly associated with TRAEs (OR = 5.71, p = 0.002). Multinomial logistic regression analysis (chi-sq = 16.64, p < 0.001) and MDR analysis (chi-sq = 10.51 p < 0.001) confirmed the finding. On the other hand, no significant association was observed between adverse events and any specific cytogenetic aberration.

Conclusion: SLC19A1 facilitates the import of cyclic dinucleotides and reduced folates, evaluating genotypes in this gene can help in better management of patients on methotrexate treatment. Assessing a broader gene panel can help in finding more associated markers and delivering personalized medicine to the patients.