ABSTRACT

The success of treatment of patients with leukemia is judged by several criteria. For the patient and clinician the most desirable outcome is sustained remission from disease and long-term survival. Unfortunately it is unlikely that complete eradication of leukemic cells is ever achieved. Hematological remission is defined as fewer than 5% blast cells in the bone marrow as determined by morphology. Disease levels below this threshold detected by more sensitive methods such as flow cytometry, cytogenetics (including FISH), and PCR are referred to as minimal residual disease (MRD). The sensitivity of PCR has extended the detection limit to one leukemic cell in one million normal cells.