title: T cell malignancy in Richter's syndrome presenting as hyper IgM. Induction and characterization of a novel CD3+, CD4-, CD8+ T cell subset from phytohemagglutinin-stimulated patient's CD3+, CD4+, CD8+ leukemic T cells.
abstract: A patient is described, having Richter's syndrome and immunodeficiency with hyper IgM, who developed suppressor T cell lymphoma (CD3+, CD4-, CD8+) following untreated helper-suppressor T cell chronic lymphocytic leukemia (CD3+, CD4+, CD8+). The neoplastic T cells in both malignancies expressed interleukin (IL) 2 receptors but were deficient in typical CD2+ and CD5+ pan T antigens. Additionally, a large percentage of malignant lymph node T cells expressed HLA-DR+ activation antigens. In vitro immunoglobulin-production experiments demonstrated that the patient's leukemic blood T cells had an excess helper function for IgM synthesis but a suppressor function for IgG and IgA synthesis by normal B and T cells. The leukemic blood T cells demonstrated a poor response to phytohemagglutinin (PHA). A defect in IL 2 receptor expression was evident in PHA-stimulated leukemic blood T cells. Of interest was the observation that PHA stimulated the induction of a novel CD3+, CD4-, CD8+ T cell subset from patient's CD3+, CD4+, CD8+ leukemic blood T cells. These PHA-induced CD3+, CD4-, CD8+ T cell subsets produced an elevated proliferative response to PHA and concanavalin A, had a helper cell function for IgM synthesis and produced highly elevated amounts of IL 2.
authors.affiliation: Department of Immunology, King Saud University, College of Medicine, Abha, Saudi Arabia.
authors.forename: S
authors.initials: S
authors.lastname: Raziuddin
authors.forename: H M
authors.initials: HM
authors.lastname: Assaf
authors.forename: B
authors.initials: B
authors.lastname: Teklu
mesh_terms: D000368:Aged; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis*; D017252:CD3 Complex; D016827:CD8 Antigens; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology*; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000276:immunology*; D008297:Male; D010641:Phenotype; D010835:Phytohemagglutinins / Q000494:pharmacology; D011948:Receptors, Antigen, T-Cell / Q000032:analysis*; D015375:Receptors, Interleukin-2 / Q000032:analysis; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D016827:CD8 Antigens; D006684:HLA-DR Antigens; D007075:Immunoglobulin M; D010835:Phytohemagglutinins; D011948:Receptors, Antigen, T-Cell; D015375:Receptors, Interleukin-2