[An extremely high serum methotrexate concentration associated with acute renal failure in a patient with acute lymphoblastic leukemia after conduction of high dose consolidation].

Acute renal failure (ARF) is one of rare and severe methotrexate (MT)-induced complications in patients with acute lymphoblastic leukemia. A case of MT-induced renal dysfunction with an extremely high serum MT concentration is reported. This toxicity required conduction of hemodiafiltration for extracorporeal MT elimination. The presence of homozygous mutation of methylene-tetrahydrofolate reductase reflects an individual metabolism of MT and its renal clearance.