Cellular Origin of Human Lymphoid Malignancies as Based on Immunologic Analysis of Membrane Differentiation Antigens

Abstract

Cell surface antigens of 80 patients with human lymphoid malignancies—33 cases of T-cell malignancy, including five cases of acute lymphoblastic leukemia (ALL) and 28 cases of lymphoma, and 47 cases of non-T cell malignancy, including 15 cases of ALL and 32 cases of lymphoma—were analyzed with 11 monoclonal antibodies, and their cellular origins were determined according to the expression of differentiation antigens. The T-cell malignancies were divided into four major categories according to their differentiation antigens: 1) pre-T cell type, 2) thymic T-cell type, 3) inducer/helper T-cell type, 4) suppressor/cytotoxic T-cell type. Two cases of ALL were of the pre-T cell type. Thymic T-cell type is further divided into early thymocyte type, common (cortical) thymocyte type and mature (medullary) thymocyte type, but we did not see the mature thymocyte type in this series. Two cases of ALL and five of lymphoblastic lymphoma were of the early thymocyte type. Only one case of ALL was of the common thymocyte type. Of the inducer/helper T-cell type, there were seven cases of adult T-cell leukemia (ATL), five cases of medium-sized and large cell type of lymphoma, one case of CLL and one case of mycosis fungoides. On the other hand, the tumor cells of three patients with IBL-like T-cell lymphoma, one with Lennert's lymphoma and one with the mixed cell type of non-Hodgkin's lymphoma expressed the suppressor/cytotoxic T-cell phenotype. The cellular origin of four cases of T-cell malignancy could not be determined. Among the 47 cases of non-T cell malignancy, 15 cases of peroxidase-negative acute leukemia were classified as null cell type (one case), unknown type with only la-like antigen (two cases), lymphoid stem cell type (eight cases—53.3%), pre-B cell type (two cases) and immature B-cell type (two cases). Among 32 non-T cell lymphomas, 26 expressed the mature B-cell phenotype (two cases of CLL, two cases of chronic lymphosarcoma cell leukemia, eight cases of medium-sized cell type lymphoma and 14 cases of large cell type of lymphomas). In five cases of medium and large cell type of non-Hodgkin's lymphoma, the phenotype of presecretory B-cells was expressed. Classification of ALL as L1- or L2-morphology according to the scoring system of the FAB classification did not correlate with the cellular origin. However, the majority of cALL antigen-positive ALL cases were in the L1 morphology category.