Detection of minimal residual leukemia in acute lymphoblastic leukemia

Morphologic, immunologic, enzymatic and cytogenetic methods detect residual leukemic cells at the level of 5%. The early detection of leukemia by these methods has failed to improve outcome for children with residual disease. The use of molecular biologic techniques, particularly those involving the polymerase chain reaction, can detect 1 leukemic cell among 10,000 or even 100,000 normal cells. At this time, it is essential to conduct the proper clinical trials to determine the clinical utility of methods so sensitive and specific.