Flow cytometric analysis of normal and neoplastic human hematopoietic surface antigens

Normal and neoplastic human hematopoietic cells were examined for surface markers by a variety of techniques including cytotoxicity assays using anti-HTLA and anti-Ia antiserum with viability measured by trypan blue exclusion and automated flow cytometry; E- and EAC-rosette binding assays and surface immunoglobulin measured by a fluorescence-activated cell sorter. In most cases there was good agreement among these assays. However, one case of CLL of T origin (92% E-rosette-positive) also showed significant amounts of Ia antigen by cytotoxicity tests; additionally, a case of CML in blast crisis demonstrated no E or EAC markers or surface immunoglobulin, but the majority of cells were lysed by both anti-HTLA and anti-Ia antiserum. Thus, Ia is not an exclusive B cell marker.