title: Sarcoidosis--immunopathogenetic concepts.
abstract: Sarcoidosis is a chronic granulomatous disorder characterized by an accumulation of activated lymphocytes, predominantly T helper cells, expressing the Th1 phenotype and macrophages at sites of disease activity. Although the cause of sarcoidosis has not been elucidated, several lines of evidence suggest that granuloma formation results from exposure to one or more antigens, eliciting a T lymphocyte response. The induction and evolution of granuloma formation results from a complex interplay between diverse cell types, cytokines, and chemokines. Genetic polymorphisms may influence the clinical expression of the granuloma formation and disease outcome. This article discusses in depth the key cellular elements and signals that generate and orchestrate the sarcoid granulomatous response. The precise factors inciting the sarcoid granulomatous response have not yet been identified, but chronic exposure to microbial agents, their products, or inorganic substances may be important in the pathogenesis.
authors.affiliation: Department of Pneumology, University Medical Center, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Gernot
authors.initials: G
authors.lastname: Zissel
authors.forename: Antje
authors.initials: A
authors.lastname: Prasse
authors.forename: Joachim
authors.initials: J
authors.lastname: Müller-Quernheim
mesh_terms: D000938:Antigen-Presenting Cells / Q000276:immunology; D049109:Cell Proliferation; D003115:Colony-Stimulating Factors / Q000276:immunology; D016207:Cytokines / Q000276:immunology; D020022:Genetic Predisposition to Disease; D015769:Granuloma, Respiratory Tract / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D006801:Humans; D016676:Macrophages, Alveolar / Q000276:immunology; D011110:Polymorphism, Genetic; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D017565:Sarcoidosis, Pulmonary / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D037182:T-Cell Antigen Receptor Specificity; D013601:T-Lymphocytes / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D003115:Colony-Stimulating Factors; D016207:Cytokines; D011948:Receptors, Antigen, T-Cell; D014409:Tumor Necrosis Factor-alpha