Prognostic Value of Lymphocyte Surface Markers in Acute Myeloid Leukemia

We studied the expression of cell surface antigens associated with myeloid and lymphoid leukemias on bone marrowderived blast cells from 339 patients with newly diagnosed de novo acute myeloid leukemia (AML) enrolled on Cancer and Leukemia Group B (CALGB) chemotherapy protocols. Surprisingly, of 211 cases studied for the expression of CD2 (T-cell marker, sheep erythrocyte binding receptor for T lymphocytes) 45 were positive (21%). In addition, of 298 patients studied for CD19 (B-lymphocyte marker), 41 were positive (14%). Overall, of 170 patients studied for both CD2 and CD19, 56 (33%) were positive. Interestingly, central review of the French-American-British (FAB) morphology of the CD2and CD19-positive cases showed that FAB M3 was twice as frequent, and M4E eight times as frequent compared with the CD2and CD19-negative cases. Of 22 lymphocyte antigen-positive cases in which cells were available for studies of lg or T-cell antigen receptor (TCR) gene rearrangement, 20 were germline, one had a rearranged lg heavy chain gene, and one had rearranged TCRp and lg heavy chain genes. The presence of messenger RNA for CD2 was demonstrated in four CD2 surface antigen-positive cases, thus validating the cell surface data. Lymphocyte antigen-positive cases had karyotypes commonly seen in AML; 71% of cases with an abnormal clone had t(8;21)(q22;q22), inversion