Receptors for sheep erythrocytes (E) and erythrocyte‐antibody‐complement complexes (EAC) on the lymphoblasts of childhood acute lymphoblastic leukemia

Two cell-surface markers, rosette formation with sheep erythrocytes (E-rosette) as a T-cell marker and rosette formation with bovine erythrocyte-antibody-complement complex (EAC-rosette) as a B-cell marker were determined on peripheral blood lymphocytes and lymphoblasts from normal and 89 children with acute lymphoblastic leukemia (ALL). In the majority of the patients (12/15 untreated patients and 6/11 patients in relapse), lymphoblasts exhibited neither E- nor EAC-rosette formation. Lymphoblasts from one untreated patient with mediastinal mass displayed E-(50%) and EAC-rosette formation (15%). In 3 of 11 patients in relapse, lymphoblasts displayed an increase in EAC-rosette formation with progressive disease. In the remaining patients with active disease, a small and variable proportion of lymphoblasts expressed E and/or EAC-rosette formation. In 63 patients in remission, percentages of E- and/or EAC-rosette were similar (p greater than 0.05) to those of control. The results indicate a wide heterogeniety with respect to expression of lymphocyte membrane markers in lymphoblasts and in normal lymphocytes in patients with active ALL.