Type IV hypersensitivity
Type IV hypersensitivity | |
---|---|
Other names | delayed-type hypersensitivity; DTH; cell-mediated hypersensitivity |
Specialty | Immunology |
Type IV hypersensitivity, in the Gell and Coombs classification of allergic reactions, often called delayed-type hypersensitivity, is a type of hypersensitivity reaction that can take a day or more to develop.[1] Unlike the other types, it is not humoral (not antibody-mediated) but rather is a type of cell-mediated response. This response involves the interaction of T cells, monocytes, and macrophages.
This reaction is caused when
multinucleated giant cells
.
The overreaction of the helper T cells and overproduction of cytokines damage tissues, cause inflammation, and cell death. Type IV hypersensitivity can usually be resolved with topical corticosteroids and trigger avoidance.[1]
Forms
This section needs additional citations for verification. (May 2017) |
Disease | Target antigen | Effects |
---|---|---|
Allergic contact dermatitis[2] | Environmental chemicals, like nickel ), topical medication
|
skin rash, and blisters
|
Autoimmune myocarditis[2] | Myosin heavy chain protein
|
Cardiomyopathy |
Diabetes mellitus type 1[2]
|
Pancreatic beta cell proteins (possibly insulin, glutamate decarboxylase) | Insulitis, beta cell destruction |
Granulomas[3] | Various, depending on underlying disease | Walled-off lesion containing macrophages and other cells |
Some peripheral neuropathies
|
Schwann cell antigen | Neuritis, paralysis |
Hashimoto's thyroiditis[2] | Thyroglobulin antigen | hard goiter , follicular thymitis
|
Inflammatory bowel disease[2] | Enteric microbiota and/or self antigens
|
Hyperactivation of T-cells, cytokine release, recruitment of macrophages and other immune cells, inflammation |
Multiple sclerosis[2] | Myelin antigens (e.g., myelin basic protein) | Myelin destruction, inflammation |
Rheumatoid arthritis[2] | Possibly citrullinated self proteins
|
Chronic arthritis, inflammation, destruction of articular cartilage and bone |
Tuberculin reaction (Mantoux test)[3] | Tuberculin | Induration and erythema around injection site indicates previous exposure
|
An example of a
TNF-α which recruits multiple monocytes to the site of infection. These cells differentiate into epithelioid cells which wall off the infected cells, but results in significant inflammation
and local damage.
Some other clinical examples:
- Urushiol-induced contact dermatitis[5]
- Chronic transplant rejection
- Coeliac disease
- Giant cell arteritis
- Graft-versus-host disease[6]
- Leprosy
See also
References
- ^ PMID 22165815.
- ^ ISBN 978-1455737871.
- ^ a b "Hypersensitivity reactions". microbiologybook.org. University of South Carolina School of Medicine - Microbiology and Immunology On-line. Retrieved 29 May 2016.
- S2CID 19523447. Retrieved 18 June 2017.
- PMID 32965899. Retrieved 28 November 2021.
- ^ Walter Duane Hinshaw (26 June 2021). "eMedicine - Hypersensitivity Reactions, Delayed".