• (type iv hypersensitivity) An inflammatory response driven by T cell recognition of processed soluble or cell-associated antigens leading to cytokine release and leukocyte activation.
  Gene Ontology Dictionary
  Gene Ontology Consortium, 2021
• (type iv hypersensitivity) Delayed hypersensitivity reaction (DTH) - type IV reaction, an inflammatory response that develops 24 to 72 hours after exposure to an antigen that the immune system recognizes as foreign. DTH is mediated by T cells rather than by antibodies. Th1 cells produce interferon gamma, interleukin (IL)-2, and tumor necrosis factor-beta and promote a cell-mediated immune response.
  NCI
  U.S. National Cancer Institute, 2021
• Increased reactivity to specific antigens mediated not by antibodies but by cells.
  CRISP Thesaurus
  National Institutes of Health, 2006
• (hypersensitivity, delayed) An increased reactivity to specific antigens mediated not by antibodies but by sensitized T CELLS.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• (type iv hypersensitivity reaction) A hypersensitivity reaction triggered by sensitized T lymphocytes encountering antigens. These reactions usually develop 18 to 24 hours after exposure.
  NICHD Pediatric Terminology
  U.S. National Cancer Institute, 2021
• (delayed-type hypersensitivity response) An inflammatory response that develops 24 to 72 hours after exposure to an antigen that the immune system recognizes as foreign. This type of immune response involves mainly T cells rather than antibodies (which are made by B cells).
  NCI Dictionary of Cancer Terms
  U.S. National Cancer Institute, 2021