Complement deficiency
| Complement deficiency | |
|---|---|
| Classification and external resources | |
| Specialty | Lua error in Module:Wikidata at line 446: attempt to index field 'wikibase' (a nil value). |
| ICD-10 | D84.1 |
| ICD-9-CM | 279.8 |
| OMIM | 217000 120820, 120900, 610102 |
| DiseasesDB | 1847 1869 , 34381 |
| eMedicine | med/419 ped/447 |
| Patient UK | Complement deficiency |
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
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ "hypocomplementemia" at Dorland's Medical Dictionary
- ↑ Complement-Related Disorders at eMedicine
- ↑ Lua error in package.lua at line 80: module 'strict' not found.[page needed]
- ↑ Lua error in package.lua at line 80: module 'strict' not found.
- ↑ http://patient.info/doctor/complement-deficiencies Patient.info
- ↑ http://www.omim.org/entry/217000[full citation needed]
