Surface markers and prognostic factors in acute lymphoblastic leukemia.

We investigated the surface markers on lymphoblasts from 37 patients with acute lymphoblastic leukemia. Spontaneous rosette formation with sheep erythrocytes (E rosettes) identified T cells and the presence of surface immunoglobulin identified B cells. Eight patients had T-marker lymphoblasts; 28 had no markers (null lymphoblasts), and one patient had B-marker lymphoblasts. The eight patients with T-marker acute lymphoblastic leukemia had massive leukemic infiltration, frequently a mediastinal mass, and a poor prognosis. The T-marker lymphoblasts had a weak or negative periodic acid-Schiff reaction and a very low antigenic stimulation to allogeneic lymphocytes. The association of T-marker lymphoblasts and some of the conventional poor-risk factors appears to be reliable in predicting a poor prognosis.