Monoclonal antibodies of IPO series against B cell differentiation antigens in leukemia and lymphoma immunophenotyping.

Monoclonal antibodies (mAbs) of IPO series were developed following immunization with human B cell lines RPMI-1788, Daudi, and spleen cells from a patient with hairy cell leukemia. Reactivity of these mAbs was studied on 19 human cell lines, mononuclear cells of 50 healthy persons and 142 patients with leukemias and lymphomas. It was shown that mAbs IPO-3, IPO-10 and IPO-24 define B cell-specific antigens expressed at different stages of maturation. MAb IPO-3 reacted with activated B lymphocytes. MAb IPO-10 defined the antigen which appears on B cell progenitors following HLA-DR and proceeding CD19, CD10, CD22, CD37; cy mu and CD20 and have been lost during terminal differentiation. The antigen detected by mAb IPO-24 was expressed throughout B cell ontogeny from pre-B cell until the B-blasts. MAb IPO-4 detected an antigen of activated T and B lymphocytes. These mAbs are useful tools in the leukemia and lymphoma phenotypic characterization and classification.