2003 Volume 17 Issue 1 Pages 9-15
Measuring minimal residual disease (MRD) in children with acute lymphoblastic leukemia (ALL) is becoming increasingly important. Several studies have shown that MRD assays can provide unique and important information about treatment response and risk of relapse. Flow cytometry is a practical and widely applicable approach for monitoring MRD in patients with ALL. It relies on the identification of immunophenotypes that are expressed in leukemic cells but not in normal cells in bone marrow and peripheral blood. These phenotypes can identify one leukemic cell among 10, 000 normal cells, and are currently applicable to approximately 95% of children with ALL. There is a strong correlation between flow cytometric measurements of MRD during clinical remission and treatment outcome, suggesting that these assays should be useful to guide the intensity of therapy.
