rate of disappearance of peripheral lymphoblasts and lymphocytes during the first week of treatment. The rate of clearance of peripheral blasts has been found to be of prognostic significance in T-lineage as well as B-lineage ALL.
The extent of clearance of leukemic cells from the blood or bone marrow during the early phase of therapy is an independent prognostic factor in acute lymphoblastic leukemia (ALL). Several methods are available to measure the minimal residual disease (MRD) remaining after initial intensive chemotherapy. The most promising are flow cytometric detection of aberrant immunophenotypes and polymerase chain reaction analysis of clonal antigen-receptor gene rearrangements. When applied together, these techniques enable one to monitor MRD in virtually all cases of ALL.