Cell-Surface-Marker Phenotyping in Patients with Leukemic Non-Hodgkin Lymphomas (NHL) of Low and Intermediate Malignancy

Certain markers for B lymphocytes (SIg, EAIgG, EAIgMC3b, EAIgMC3d, M-R) and T lymphocytes (E-R, EAIgG, EAIgM) were applied in order to characterize circulating neoplastic cells in non-Hodgkin lymphomas (NHL) of low and intermediate malignancy. In all cases, the diagnoses were based on the histological examination of lymph nodes, bone marrow, or skin biopsies. According to the Kiel classification, the diagnoses were as follows: chronic lymphocytic leukemia (CLL) n = 145. Immunocytoma (Ic) n = 39. Centrocytic (Cc) and centroblastic/centrocytic lymphoma (Cb/Cc) n = 17. Hairy-cell leukemia (HCL) n = 10. Prolymphocytic leukemia (PLL) n = 6 and Sezary's syndrome n = 3. In only 8 of the 220 cases did the leukemia cells show T characteristics. In leukemic B-cell lymphoma, a uniform phenotype was observed for B-CLL, characterized by a weak SIgm staining with or without SIgD, the presence of C3d-receptors and a high percentage of M-R. This phenotype was also detected in one third of the cases of immunocytoma. The cells of BPLL and leukemic CC and CB/CC were characterized by a stronger SIg staining, a variable formation of complement receptors and, in most cases, absence of M-R. In all cases of B-cell lymphoma, the monoclonality of the cell proliferation could be confirmed by the restriction to a single L-chain type. This also applies to the 10 cases of HCL, although in the majority of these cases, several heavy-chain classes could be detected at the malignant cells.