Dual B and T markers in acute and chronic lymphocytic leukemia

Leukemic cells from 20 patients with chronic lymphocytic leukemia (CLL) and 60 patients with acute lymphocytic leukemia (ALL) were studied for T- and B-lymphocyte cell surface membrane markers. B-cell markers included surface membrane immunoglobulin, erythrocyte-antibody complement rosette formation, and B-cell (a-like or HLA-DR) antigens detected by a B-cell antiserum. T-cell markers included spontaneous sheep red blood cell rosette formation and a cytotoxic reaction to a specific T-cell antiserum. Seven patients with CLL and two with ALL had dual B and T markers. We propose that dual B- and T-cell markers are more common in CLL and ALL patients than previously reported. With newer and more sensitive tests for identification of B and T cells, this observation may be recognized more frequently.