The tissue distribution of the 3 alpha-fucosyl-N-acetyl lactosamine determinant recognized by the CD15 monoclonal antibodies CMRF-7 and 27.

Two monoclonal antibodies, CMRF-7 and 27, which react with cells of the granulocytic series, were obtained from hybridomas cloned from separate fusions. Biochemical studies indicate that both antibodies are of the CD15 group and react with the antigenic determinant 3 alpha-fucosyl-N-acetyl lactosamine (hapten X) expressed on some glycolipids and several different granulocyte glycoproteins with a wide range of molecular weights. The antigen was found on some promyelocytes and more differentiated granulocytes, including neutrophils and some eosinophils, but not basophils. Monocytes, lymphocytes, and erythrocytes were negative for CMRF-7 but neuraminidase treatment revealed "cryptic" sites on monocytes and some lymphoid cells. The antibody CMRF-7 reacted with the majority of acute myeloid leukemia blasts in the FAB categories M2-M5 but less frequently with M1 blasts and was positive with only 5/43 acute lymphoid leukemias. Immunoperoxidase staining of other normal human tissues indicates that this determinant is found on a range of epithelial cells in skin, the gastrointestinal tract and the genitourinary system. In addition some parts of the central nervous tissue and some endocrine organs stained with these antibodies.