title: [Analysis of T-cell subpopulations. Pathophysiological concept and significance for clinical medicine].
abstract: Two T-lymphocyte subsets develop in the thymus which differ in the expression of glycoproteins on their cell surface. About 60% of the circulating T cells express the glycoprotein T4, while about 30% have the glycoprotein T8. T4 and T8 cells can be determined in the peripheral blood or various organs with monoclonal antibodies. T4 and T8 cells differ in their antigen recognition, have different functions, and can cause various pathohistological changes. T4 cells recognize the antigen in association with the HLA-D/DR/DP determinants. Upon antigenic stimulation they liberate various factors and initiate and amplify an immune response (T4 = helper/inducer T-cells). They can also be cytotoxic and are mediating effector functions via macrophage activation. T8 cells recognize the antigen in association with HLA-A/B/C determinants. They exert their cytotoxic or suppressive effector functions mainly in viral infections. The T4 or T8 cell-mediated pathohistological changes are discussed in the light of the well studied T-cell infiltrations in lepra lepromatosa or lepra tuberculosa. The T4/T8 cell dyscrasia in the peripheral blood, described in a variety of infectious, autoimmune or immunodeficiency diseases, may be due to enhanced proliferation, selective sequestration, reduced production or the elimination of a subset. T-cell subset analysis in joints, bronchial lavages and tissues has clarified the pathomechanism in a variety of autoimmune diseases, although the etiology remains obscure. For example, in rheumatoid arthritis, multiple sclerosis, and sarcoidosis, a T4 cell-mediated reaction with macrophage activation can be found. T4/T8 cell analysis may also be of value in dissecting heterogenous diseases, e.g. systemic lupus erythematosus. Of value is also the additional demonstration of membrane components reflecting T-cell activation (IL-2 receptor or DR-antigen expression) which serves to identify the activated T-cell subset in peripheral blood. Finally, T4/T8 cell analysis can be helpful in deciding treatment, as the T-cell subsets have a different sensitivity to immunosuppressive drugs.
authors.forename: W J
authors.initials: WJ
authors.lastname: Pichler
authors.forename: A
authors.initials: A
authors.lastname: Emmendörffer
authors.forename: H H
authors.initials: HH
authors.lastname: Peter
authors.forename: H R
authors.initials: HR
authors.lastname: Deicher
authors.forename: A
authors.initials: A
authors.lastname: Fontana
authors.forename: A L
authors.initials: AL
authors.lastname: de Weck
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000276:immunology; D000305:Adrenal Cortex Hormones / Q000494:pharmacology; D000938:Antigen-Presenting Cells / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology*; D000970:Antineoplastic Agents / Q000494:pharmacology; D001327:Autoimmune Diseases / Q000276:immunology; D002454:Cell Differentiation; D003095:Collagen Diseases / Q000276:immunology; D003524:Cyclosporins / Q000494:pharmacology; D006023:Glycoproteins / Q000276:immunology*; D006680:HLA Antigens / Q000276:immunology; D015395:Histocompatibility Antigens Class I; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D008285:Major Histocompatibility Complex; D009164:Mycobacterium Infections / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000187:drug effects / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D014777:Virus Diseases / Q000276:immunology
chemical_list: D000305:Adrenal Cortex Hormones; D000954:Antigens, Surface; D000970:Antineoplastic Agents; D003524:Cyclosporins; D006023:Glycoproteins; D006680:HLA Antigens; D015395:Histocompatibility Antigens Class I; C040588:Tla antigens
vernacular_title: Analyse von T-Zell-Subpopulationen. Pathophysiologisches Konzept und Bedeutung für die Klinik.