Methotrexate Hepatotoxicity in Children with Juvenile Idiopathic Arthritis: A Single-Center Study

Background: Juvenile idiopathic arthritis (JIA) could be disabling if left untreated. Methotrexate (MTX) is well known as a cornerstone in management. However, its adverse effects may limit treatment. Objective: The objective of this study was to evaluate the frequency of hepatotoxicity based on liver chemistry in JIA children receiving MTX. Methods: An observational case-control study of children with JIA who attend the Pediatric Rheumatology Unit, Cairo University Pediatric Hospital, Egypt, from January 2018 to December 2018 was carried out. Data were retrieved for 80 children; 50 (62.5%) were prescribed MTX. Their demographic, clinical characteristics, mean dose, duration of MTX therapy and other medications were described. Hepatotoxicity was defined as at least one value above the normal laboratory range of either ALT or AST during the study period. Results: Fourteen patients developed hepatotoxicity, giving an incidence of 28%. Children receiving MTX had higher alanine aminotransferase (ALT) interquartile range (IQR) (26 [21-359] vs. 23[20-32]; p =0.003), higher aspartate aminotransferase (AST) interquartile range (IQR) (31 [22-267] vs. 28[2-35] IU/L; p <0.001), and lower alkaline phosphatase (ALP) mean (±SD) (98±35.5 vs. 256 ± 39.5 IU/L; p <0.001). However, there were no significant differences in age, sex, weight, type of JIA, and duration of MTX treatment (p< 0.05). Conclusion: Hepatotoxicity due to MTX, based on liver chemistry, is common among children with JIA.