Clinical Usefulness of Monoclonal-antibody Phenotyping in Childhood Acute Lymphoblastic Leukemia

Lymphoblasts from 59 children with non-T, non-B acute lymphoblastic leukaemia were studied with monoclonal antibodies to four cell-surface proteins. 87% of the children had lymphoblasts positive for HLA-DR, 82% for p30, 75% for p24, and 72% for CALLA. The commonest composite phenotype was HLA-DR+ p30+ CALLA+ p24+. Significant correlations were seen between expression of HLA-DR, p30, and CALLA, but not p24. p30- and CALLA phenotypes were found in patients with high white-blood-cell counts (WBC) and splenomegaly. With standard chemotherapy, disease-free survival from time of remission was shorter in p30- and CALLA- patients than in others. Splenomegaly was associated with poor disease-free survival and provided prognostic information independent of phenotype. High WBC was less significant than phenotype in predicting outcome and was not independent of phenotype.