“Hypersensitivity refers to undesirable (damaging, discomfort-producing and sometimes fatal) reactions produced by the normal immune system. Hypersensitivity reactions require a pre-sensitized (immune) state of the host. The four-group classification was expounded by P. H. G. Gell and Robin Coombs in 1963.”
“ype 4 hypersensitivity is often called delayed type as the reaction takes two to three days to develop. Unlike the other types, it is not antibody mediated but rather is a type of cell-mediated response.
CD8+ cytotoxic T cells and CD4+ helper T cells recognise antigen in a complex with either type 1 or 2 major histocompatibility complex. The antigen-presenting cells in this case are macrophages which secrete IL-12, which stimulates the proliferation of further CD4+ T cells. CD4+ T cells secrete IL-2 and interferon gamma, further inducing the release of other Type 1 cytokines, thus mediating the immune response. Activated CD8+ T cells destroy target cells on contact while activated macrophages produce hydrolytic enzymes and, on presentation with certain intracellular pathogens, transform into multinucleated giant cells. ”
a source for another day-search for chemical hypersensitivity:
search for relationship between dopamine related behavioral problems (such as gambling) and the immune response system.
Intersect between psychology and the hyperactivated immune system.
Stressors to the immune system.Possible connection to Chronic Fatigue Syndrom.
It’s easier to think of the immune system as a “singular organ” rather than a number of reactions within the body. Even though its distributed thoughout the body and you really don’t see it.