Quantitative assessment of Wilms tumor 1 (WT1) gene transcripts in Egyptian acute lymphoblastic leukemia patients.

Background: Accurate assessment of minimal residual disease (MRD) in acute lymphoblastic leukemia (ALL) patients after initial chemotherapy is essential to evaluate the efficacy of therapeutic regimens. Wilms tumor 1 (WT1) is a pan-leukemic marker used for identification of the leukemic clone rather than the use of individual specific molecular aberration of ALL.

Methods: Using a real-time quantitative polymerase chain reaction, bone marrow samples from 41 newly diagnosed Egyptian ALL patients; 22 adults and 19 children were examined for WT1 expression. After induction therapy, WT1 expression was reestimated in 20 ALL patients.

Results: WT1 was overexpressed in adult and pediatric ALL patients (95.4% and 89.4%, respectively). WT1 expression at diagnosis had no statistically significant impact on disease-free survival of patients (P = 0.054). However, WT1 expression increased after induction chemotherapy in the 3 pediatric patients who had relapse.

Conclusions: WT1 is a leukemia-associated molecular marker that may be used for the diagnosis and for monitoring clinical progress in ALL; it also can be used as a molecular target for adoptive immunotherapy.