Acute myelogenous leukemia heteroantisera

Abstract

Antisera were raised in New Zealand white rabbits to acute myelogenous leukemia (AML) cells. Reactivity of the antisera against normal T lymphocytes was eliminated by pretreating the rabbits with anti-leukocyte serum (ALS) and precoating the immunizing cell with ALS. Following absorption with acute lymphocytic leukemia (ALL) cells the antisera appeared to be specific for certain acute leukemia cells. By complement-dependent cytotoxicity testing leukemia cells from 10 46 AML and 2 23 ALL patients were positive. The cytotoxicity titers ranged from 1:8 to 1:32. The undiluted sera showed no reactivity with normal peripheral blood B or T lymphocytes, normal granulocytes, chronic myelocytic leukemia cells, or chronic lymphocytic leukemia cells. Two recently initiated AML cell lines (KG and ML3) were positive and a third AML line (HL60) was negative. Several other B- and T-cell lines were negative. Positive ALL cells were able to remove the cytotoxicity against positive AML cells suggesting a common antigen(s) was involved. The AML antigen was not expressed on myeloid stem cells (CFU-C) from normal human bone marrow.