Wilms' tumor gene (WT1) expression levels as prognostic marker in pediatric acute lymphoblastic leukemia

Background Wilms' tumor gene (WT1) encodes a transcription factor that has a role in kidney development and malignancy. WT1 is shown to be overexpressed in most adult acute myeloid leukemias and hence is an adverse prognostic factor. Its use as a prognostic marker in childhood acute lymphoblastic leukemia (ALL) is controversial. Aim The aim was to study WT1 gene expression levels for diagnosis of ALL in a group of Egyptian children and to relate it to prognosis. Participants and methods This study was conducted on 140 children newly diagnosed as having ALL; assessment of WT1 gene was done by real-time PCR in bone marrow (BM) samples at diagnosis and at day 28 of treatment. Results WT1 gene expression was positive in 96 (68.6%) cases and negative in 44 (31.4%) cases. WT1 expression was related to aberrant expression of myeloid markers. There was a significant correlation between WT1 expression at diagnosis and at day 28 and minimal residual disease detected at day 28. No correlation was detected between outcome and WT1 level during follow-up. Conclusion WT1 gene expression is related to response to therapy as defined by day 28 minimal residual disease.