The Effect of Folate Status on Methotrexate Serum Level and Response in Children with Acute Lymphoblastic Leukemia

Abstract

Background: Children in our area are more prone to folate deficiency due to many reasons including leukemia. The folate status of patients especially prior to therapy could influence methotreaxate therapeutic effect or toxicity Patients and Methods: A total of 34 children newly diagnosed with acute lymphoblastic leukemia, and 25 normal healthy children were included as a control group. Parameters measured include; Serum folate, Serum methotrexate, blood parameters, liver function tests, blood urea and serum creatinine that were measured before initiation of chemotherapy, during treatment and following completion. Result: Newly diagnosed ALL children have low folate level at the time of diagnosis (5.26 ± 3.82 ng/ml, mean±sd) which is significantly lower than control group (11.16 ± 5.20 ng/ml, mean±sd) (p value ˂ 0.0001). Leukemic children that have low folate is 20 with a serum level (3.12 ± 1 ng/ml, mean±sd), normal folate level is found in only 14 leukemic children and their level (8.83 ± 4.14 ng/ml, mean±sd). Low WBC and platelets count was detected following the first methotrexate dose which returns back to normal afterward. Folate serum level of all leukemic children at end of all doses is significantly elevated (14.58 ± 5.3 ng/ml, mean±sd) (p value ˂ 0.0001). Conclusion: Serum folate level is low in a considerable number of newly diagnosed ALL children before the initiation of treatment protocol, this lead to more hematological toxicity following the first methotrexate dose. It is recommended that serum folate should be measured and deficiency corrected prior to cytotoxic therapy to reduce toxicity.