Granulomatous inflammation is which type of hypersensitivity? -
Several autoimmune disorders, as well as pathologic reactions to environmental chemicals and persistent microbes, are now known to be caused by T cells . The occurrence and significance of T lymphocyte-mediated tissue injury have been increasingly appreciated as the methods for detecting and purifying T cells from patients' circulation and lesions have improved. This group of diseases is of great clinical interest because many of the new, rationally designed biologic therapies for immune-mediated inflammatory diseases have been developed to target abnormal T cell reactions. Two types of T cell reactions are capable of causing tissue injury and disease: (1) cytokine-mediated inflammation, in which the cytokines are produced mainly by CD4+ T cells, and (2) direct cell cytotoxicity, mediated by CD8+ T cells . In inflammation, exemplified by the delayed-type hypersensitivity (DTH) reaction, CD4+ T cells of the TH1 and TH17 subsets secrete cytokines, which recruit and activate other cells, especially macrophages, and these are the major effector cells of injury. In cell-mediated cytotoxicity, cytotoxic CD8+ T cells are responsible for tissue damage. Robbins 9 th edition page no. 118
Type I
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Type IV
General pathology