Complement deficiency: Difference between revisions
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==Epidemiology== |
==Epidemiology== |
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C2 deficiency is prevalent in 120,000 people in Western countries.<ref>http:// |
C2 deficiency is prevalent in 120,000 people in Western countries.<ref>[http://patient.info/doctor/complement-deficiencies http://patient.info/doctor/complement-deficiencies Patient.info]</ref> |
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It occurs in about 1 in 10,000 persons.<ref>http://www.omim.org/entry/217000{{full|date=May 2015}}</ref> |
It occurs in about 1 in 10,000 persons.<ref>http://www.omim.org/entry/217000{{full|date=May 2015}}</ref> |
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Revision as of 12:09, 28 October 2015
| Complement deficiency | |
|---|---|
| Specialty | Hematology  |
Complement deficiency is an immunodeficiency of absent or suboptimal functioning of one of the complement system proteins.[1]
The disorders can be divided into two categories:
- Disorders of the proteins that act to inhibit the complement system (such as C1-inhibitor) can lead to an overactive response, causing conditions such as hereditary angioedema and hemolytic-uremic syndrome.[citation needed]
- Disorders of the proteins that act to activate the complement system (such as C3) can lead to an underactive response, causing greater susceptibility to infections.[citation needed]
Because there are redundancies in the immune system, many complement disorders are never diagnosed. A recent study estimated that less than 10% are identified.[2]
Hypocomplementemia
Hypocomplementemia may be used more generally to refer to decreased complement levels[3] while secondary complement disorder is to low complement levels that are not directly due to a genetic cause but secondary to another medical condition.[4]
The total hemolytic complement complement CH50 level in the blood will be low or undetectable with complement deficiencies.[citation needed]
Individual complement levels can be used to distinguish conditions:
- Systemic lupus erythematosus is associated with low C3 and C4
- Membranoproliferative glomerulonephritis causes low C3, but normal C4.
- Deficiencies of the terminal complement components are inherited in an autosomal recessive manner and cause increased susceptibility to infections by Neisseria.[5]
- Properdin deficiency is an X-linked disorder that also causes susceptibility to neisserial infections.
- C1-inhibitor deficiency or hereditary angioedema will have low C4 with normal C1 and C3 levels.[6]
Vaccinations for encapsulated organisms is crucial for preventing infections in complement deficiencies.[citation needed]
Epidemiology
C2 deficiency is prevalent in 120,000 people in Western countries.[7] It occurs in about 1 in 10,000 persons.[8]
See also
References
- ^ Winkelstein, Jerry A. (2004). "The Complement System". In Gorbach, Sherwood L.; Bartlett, John G.; Blacklow, Neil R. (eds.). Infectious Diseases. Lippincott Williams & Wilkins. pp. 8–13. ISBN 978-0-7817-3371-7.
- ^ Sjöholm, A.G.; Jönsson, G.; Braconier, J.H.; Sturfelt, G.; Truedsson, L. (2006). "Complement deficiency and disease: An update". Molecular Immunology. 43 (1–2): 78–85. doi:10.1016/j.molimm.2005.06.025. PMID 16026838.
- ^ "hypocomplementemia" at Dorland's Medical Dictionary
- ^ Complement-Related Disorders at eMedicine
- ^ Fauci, Anthony; Braunwald, Eugene; Kasper, Dennis; Hauser, Stephen; Longo, Dan; Jameson, J.; Loscalzo, Joseph, eds. (2008). Harrison's Principles of Internal Medicine (17th ed.). ISBN 978-0-07-146633-2.[page needed]
- ^ Zuraw, Bruce L. (2008). "Hereditary Angioedema". New England Journal of Medicine. 359 (10): 1027–36. doi:10.1056/NEJMcp0803977. PMID 18768946.
- ^ http://patient.info/doctor/complement-deficiencies Patient.info
- ^ http://www.omim.org/entry/217000[full citation needed]