Characterization of a novel T-cell lymphoma cell line established from a patient with systemic lupus erythematosus-associated lymphoma

A malignant lymphoma developed in a 46-year-old male patient who had had systemic lupus erythematosus (SLE) for 18 years. The lymphoma was at disease stage IV at initial examination, and the patient died shortly thereafter. The lymphoma cells were cultured in vitro, and a continous cell line, named SMZ-1, was established. The SMZ-1 cells, as well as the parental lymphoma cells, were of helper/inducer T-cell immunophenotype; they were positive for CD2, CD3, and CD4 antigens, and negative for CD8. Expression of CD5 and CD7 antigens was observed in a small percentage of the cells. The activation markers identified by antibodies against CD25, CD71, and HLA-DR antigens were positive. Cytogenetic analysis revealed that the SMZ-1 cells had a characteristic translocation between chromosomes 6 and 14 [t(6;14)(p21.1;q24)]. Southern blot analysis of DNA extracted from the cells demonstrated clonal rearrangement of the T cell receptor β-chain gene. Integration of the human T-cell lymphotrophic virus type I (HTLV-I) genome was negative. The SMZ-1 cell line should thus provide a useful model for characterization of peripheral T-cell lymphomas.