title: Identification of activated T cells and the suppressor/inducer subset in patients suffering from severe aplastic anemia.
abstract: In patients with severe aplastic anemia (SAA), lymphocyte subpopulations were examined for the presence of HLA-DR and 2H4 (suppressor/inducer subset) antigen-expressing cells by flow cytometric analysis. Investigations were performed on peripheral blood lymphocytes before and after therapy with antithymocyte globulin (ATG) and methylprednisolone (MP), as well as on bone-marrow lymphocytes before therapy. Before treatment, only the absolute numbers of CD4+ T cells and the CD4+HLA-DR+/CD8+HLA-DR+ activated T cell ratio were significantly decreased (p less than 0.01 and p less than 0.001, respectively). Following successful ATG/MP treatment, a decrease in the CD4+/CD8+ T cell ratio was found. Regarding the suppressor/inducer subset, only absolute numbers of CD4+/2H4+ cells were somewhat higher in treated patients; the percentages were the same in all groups of patients. Studies performed on bone-marrow lymphocytes showed significantly decreased percentages of CD4+ and CD8+ T lymphocytes, which also express HLA-DR antigen. No significant changes in the distribution of activated T cells following ATG/MP therapy were found, suggesting that these cells play no major role in the pathogenesis of the disease.
authors.affiliation: Institute of Clinical Chemistry and Laboratory Diagnostics, University of Vienna, Austria.
authors.forename: U
authors.initials: U
authors.lastname: Köller
authors.forename: W
authors.initials: W
authors.lastname: Hinterberger
authors.forename: L
authors.initials: L
authors.lastname: Gschwandtler
authors.forename: R
authors.initials: R
authors.lastname: Grümayer
authors.forename: O
authors.initials: O
authors.lastname: Majdic
authors.forename: W
authors.initials: W
authors.lastname: Knapp
mesh_terms: D000741:Anemia, Aplastic / Q000097:blood / Q000276:immunology* / Q000473:pathology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001853:Bone Marrow / Q000276:immunology; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D008213:Lymphocyte Activation; D010641:Phenotype; D013601:T-Lymphocytes / Q000145:classification* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000145:classification* / Q000276:immunology
chemical_list: D000945:Antigens, Differentiation, T-Lymphocyte; D006684:HLA-DR Antigens