Renal function features in pediatric acute lymphoblastic leukemia during high-dose methotrexate chemotherapy

Introduction: High-dose Methotrexate (HD-MTX), a chemotherapy agent for acute lymphoblastic leukemia, is a cytotoxic agent for some organs, including kidneys. One of the most important toxicities due to HD-MTX is acute kidney injury due to Methotrexate crystallization in renal tubules. The prevalence of Acute kidney injury due to HD-MTX administration in pediatric ALL in dr. Soetomo General Hospital was unknown. The study aims to analyze renal function features in pediatric ALL during HD-MTX chemotherapy. Methods: An analytical observational study with a prospective approach was conducted at Dr. Soetomo General Hospital Surabaya from December 2021-July 2022. The subjects were ALL children aged 1-18 years who met inclusion and exclusion criteria. High-dose Methotrexate chemotherapy was given 3 times every 2 weeks during the consolidation phase. Laboratory examinations were performed before and after HD-MTX chemotherapy. Laboratory results were recorded to determine the GFR value. The difference test was performed using Wilcoxon signed rank test and the Friedman test with a significance value of p<0.05. Results: A total of 20 subjects, the median age was 78 months old, and boys and girls were equal. Standard Risk of ALL was in 55% of subjects, and 45% were at high risk. There was no significant difference in laboratory parameters between before and after HD-MTX chemotherapy in all cycles with a p-value >0.05. The median value of GFR in each cycle is 257.5; 243.5; 228.5. Minimal GFR was 119 ml/min/1.73 m^2, and maximum GFR was 638 ml/min/1.73 m². It showed a median value of GFR in all cycles was >175 ml/min/m² (hyperfiltration). Conclusions: We concluded there was no AKI due to HD-MTX chemotherapy in pediatric ALL. It may be caused by providing adequate hydration, urine alkalinization, and leucovorin rescue.