Metabolic functions of the liver during chemotherapy in children with acute lymphoblastic leukemia

Objective: The purpose of the present work was estimation of liver function using the phenazone test and commonly used biochemical tests in children w ith acute lymphoblastic leukemia (ALL) during anticancer treatment. Methods : Observations were carried out in the same 21 patients with ALL before the beginning of chemotherapy, after Protocol I and after Protocol M of the an tileukemic treatment carried out according to the program BFM 86. Results: The applied chemotherapy inhibited phenazone elimination. Both phenazone ha lf-life and metabolic clearance rate were significantly different in patien ts after treatment with anticancer drugs, especially with high-dose of meth otrexate (MTX), from those in patients before the beginning of chemotherapy (p < 0.001). Moreover, after MTX administration transaminases activity and serum bilirubin concentration were significantly higher than before treatm ent (p < 0.05). Conclusion: Our results showed that in children with acute lymphoblastic leukemia, anticancer chemotherapy decreased liver metabolic c apacity. Particularly, high-dose methotrexate treatment altered the elimina tion of phenazone by inhibiting the activity of hepatic mixed function oxid ase system. This change may lead to an increase in toxicity of active drugs which are metabolized by this enzyme system. In addition, altered activity of liver metabolic function can impair transformation of prodrugs to activ e forms. It should be considered in selection of individual drug dosages. T he objective estimation of the type and degree or liver dysfunction can onl y be achieved by the combination of a quantitative phenazone dynamic test a nd static biochemical tests.