title: Aberrant activation of CD8+ T-cell and CD8+ T-cell subsets in patients with newly diagnosed IDDM.
abstract: Two- and three-color cytofluorimetric techniques were used to study the expression patterns of the activation antigen HLA-DR on peripheral blood immunoregulatory T-cells from 25 patients with newly diagnosed insulin-dependent diabetes mellitus (IDDM) and 14 age- and sex-matched control subjects. The mean percentage of total activated (CD3+HLA-DR+) T-cells was significantly elevated in the IDDM group compared with the control group (P < 0.001). In control subjects, basal activation of CD4+ and CD8+ lymphocytes accounted for the low percentage levels of activated T-cells. In contrast, the majority of IDDM patients showed an unbalanced activation of CD4+ and CD8+ lymphocytes with predominant activation of the CD8+ lymphocyte subset. The composition of the activated T-cell fraction was dependent on the composition of the total (activated + nonactivated) T-cell population, as indicated by the positive correlation between the CD4+/CD8+ T-cell ratios in these two cell populations (r = 0.714; P < 0.001). Excessive activation of CD8+ T-cells was attributable to similar increases in the proportions of CD8+ CD45RA+HLA-DR+ (naive) and CD8+CD45RA-HLA-DR+ (memory) cells. Analysis of the CD11b-defined subsets revealed predominant activation of CD8+ CD11b- (cytotoxic) T-cells; CD8+ CD16+ HLA-DR+ natural killer cells were unchanged. The distribution of HLA-DR+ cells among subsets of CD4+ T-cells differed from the pattern in the CD8+ population in that selective activation of CD4+ CD45RA- (memory, helper-inducer) cells accounted for the small increase in activated CD4+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Experimental and Clinical Endocrinology, University of Greifswald, Karlsburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Hehmke
authors.forename: D
authors.initials: D
authors.lastname: Michaelis
authors.forename: E
authors.initials: E
authors.lastname: Gens
authors.forename: F
authors.initials: F
authors.lastname: Laube
authors.forename: K D
authors.initials: KD
authors.lastname: Kohnert
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood; D017252:CD3 Complex / Q000032:analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D007694:Killer Cells, Natural / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male
chemical_list: D001323:Autoantibodies; D017252:CD3 Complex; D006684:HLA-DR Antigens; C024211:islet cell antibody