USEFUL PANEL OF ANTIBODIES FOR THE CLASSIFICATION OF ACUTE-LEUKEMIA BY IMMUNOHISTOCHEMICAL METHODS IN BONE-MARROW TREPHINE BIOPSY SPECIMENS

To evaluate the feasibility of acute leukemia typing on routinely proc essed bone marrow biopsy specimens, 72 cases of previously established acute leukemia covering the spectrum of 17 known subtypes were studie d immunohistochemically. Most leukemic myeloblasts were positive for m yeloperoxidase in 16 (84%) of 19 cases of acute myeloid leukemia, M1-M 4, and M6. Most leukemic cells in 11 of 12 M4 and M5 cases were positi ve for CD68 (PG-M1). All six M6 cases stained with hemoglobin. Leukemi c megakaryoblasts in three of four M7 cases were positive for factor V III-related antigen. Almost all leukemic cells of 8 T-lineage acute ly mphoblastic leukemia (ALL) and 19 B-lineage ALL cases were positive fo r CD3 and CD79a (HM57), respectively. Staining with CD20 (L26) was pos itive in the more differentiated B-lineage ALL cases and strongest in L3. Immunohistochemical typing of acute leukemia is possible for most types using this panel of cell lineage-specific antibodies.