Expression of Wilms tumor gene (WT1) in children with acute leukemia

Wilms tumor gene (WT1) expression occurs in various malignancies including adult leukemia. WT1 expression was studied in children with acute leukemia according to morphological types and immunophenotypes. RT-PCR was used to e xamine relative level of WT1 transcripts from the peripheral blood of 15 ch ildren diagnosed with acute leukemia: 12 acute lymphoblastic leukemias (ALL s) and 3 acute myelogenous leukemias (AMLs) 8 ALLs newly diagnosed, 2 ALLs in first marrow relapse, 2 ALLs in remission over 2 years, 2 AMLs newly dia gnosed, and I AML in second marrow relapse. Six healthy adult volunteers we re studied for controls. WT1 was detectable in 7 out of 10 ALLs and all 3 A MLs, but not in 2 ALLs in remission and the controls. The expression levels were higher for AMLs than for ALLs. According to the types of ALL, WT1 was detectable in 2 out of 2 non-T group II, 4 out of 6 non-T group III, but n ot in one CD20(+) non-T,group IV while one TALL showed a relatively high le vel. WT1 expression was detectable more frequently in ALL-L-2 than in ALL-L I and with higher level for ALL-L-2. WT1 expression was frequently noted in children with acute leukemia. The results suggest that WT1 transcripts may prove to be a significant tumor marker possibly as an MRD monitor in evalu ating remission status and early relapse, and may also prove to be useful i n predicting outcomes in acute leukemia in children.