Unexpected absence of a myeloid surface antigen (3-fucosyl- N-acetyllactosamine) in promyelocytic leukemia

Abstract

According to the criteria of the FAB classification we diagnosed acute promyelocytic leukemia in 19 out of 191 AML blast cell populations. The reaction pattern with the anti-myeloid monoclonal antibodies VIM2, MCS2 and MY9 and the MHC-class II antibody VID1 in all cases showed the characteristics which were expected from the normal granulopoiesis. The monoclonal antibody VIM-D5, which recognizes the myeloid cell surface structure 3-fucosyl- N-acetyllactosamine (3-FAL), was not reactive with the majority of promyelocytic blast cells, however. In 13 cases 3-FAL was not detectable and in 6 cases only low or moderate reactivity of VIM-D5 with blast cells was observed. The phenotype of leukemic promyelocytes thus differs from the majority of normal promyelocytes in this respect.