Normal equivalent cells of B cell malignancies: analysis with monoclonal antibodies

Abstract

Summary. Immunoglobulin heavy chain expression and reactivity of monoclonal antibodies RFA‐1, ‐2, ‐3, ‐4 and OKT10 discriminate between majority B lymphocyte populations in the bone marrow and in peripheral lymphoid organs. In this study normal tissues and various B cell malignancies were studied in cell suspensions and tissue sections. Pre‐B acute lymphoblastic leukaemia and multiple myeloma apparently reflect the phenotypes on normal B lineage cells of the bone marrow, while centroblastic‐centrocytic lymphoma, B chronic lymphoid leukaemia (CLL) and prolymphocytic leukaemia (PLL) show the characteristics of distinct peripheral B lymphoid subsets found at different sites in the lymphoid tissue. These ‘normal equivalent’ cells are centroblasts and centrocytes in the germinal centre, CLL‐like cells at the edge of the germinal centre (a minority population) and strongly Ig positive cells in the lymphocyte corona. Malignant cells in macroglobulinaemia are apparently more closely related to PLL and the corresponding normal peripheral B cells (in the corona) than to myeloma cells or the equivalent normal plasma cells in the bone marrow.