Complement deficiencies
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Immunodeficiency Main Page |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Zahir Ali Shaikh, MD[2], Anmol Pitliya, M.B.B.S. M.D.[3]
Overview
The complement system is a biochemical cascade which helps clear pathogens from an organism. It belongs to the innate immune system. Deficiencies in this cascade can lead to infections and autoimmune diseases. Complement deficiencies can be inherited or acquired (as a result of complement-consuming disease state).
Classification
| Complement Deficiencies | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Susceptibility to Infections | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HIGH | LOW | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Disseminated Nisserial Infections | Recurrent Pyogenic Infections | SLE like syndrome | Atypical hemolytic uremic syndrome | Others | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Absent CH50 & AH50 hemolytic activity, defective bacterial activity | Normal CH50, Absent AH50 hemolytic activity | C3LOF,C3,AR | C1q def: C1QA, C1QB, C1QC | C3GOF, C3, AD | C1 inhibitor SERPING1, AD | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C5 def:,C5 | Properdin def:, PFC, XL | MASP2 def:, MASP2, AR | C1r def: | FactorB, GOF, CFB, AD | Membrane attack complex inhibitor def:, CD59 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C6 def:, C6 | Factor D def:, CFD, AR | Fincolin3 def:, FCN3, AR | C1s def: | Factor H def:, CFH, AD or AR | CD55 def:, (CHAPLE disease), AR | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C7 def:, C7+vasculitis | Factor B, CFB, LOF, AR | C2 def: | Factor H related protein def:, CFHR1-5, AR, AD | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C8 def:, C8A, C8B, C8G | C4 def:, C4A, C4B, AR | Factor I def:, AR | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| C9 def:, C9 mild susceptibility | Thrombomodulin def:, THBD, AD | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Membrane cofactor protein def:, CD46, AD | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Disseminated Nisserial Infections
C5 Deficiency
- C5 deficiency is the basis of lack of phagocytosis-enhancing activity of serum. [1]
- C5 deficiency leads to the failure to form the membrane attack complex which is responsible for the lytic action of the complement.deficiency; a hypervariable exon 6 region responsible for three of six reported defects
| journal = Clinical and experimental immunology | volume = 119 | issue = 2 | pages = 255–258 | year = 2000 | month = February | pmid = 10632659
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- It is associated with recurrent disseminated gonococcal infection.[2]
- Patients present with recurrent meningitis and meningococcemia, as well as recurrent purulent otitis media.[3]
C6 Deficiency
- C6 is structurally similar to other terminal complement components, C7, C8, and C9, all of which participate in the formation of the membrane attack complex (MAC).[4]
- C6 deficiency is a genetic disorder presenting as an increased susceptibility to invasive Neisseria meningitidis infections.[5]
References
- ↑ Miller, Michael E.; Nilsson, Ulf R. (1970). "A Familial Deficiency of the Phagocytosis-Enhancing Activity of Serum Related to a Dysfunction of the Fifth Component of Complement (C5)". New England Journal of Medicine. 282 (7): 354–358. doi:10.1056/NEJM197002122820702. ISSN 0028-4793.
- ↑ R. Snyderman, D. T. Durack, G. A. McCarty, F. E. Ward & L. Meadows (1979). "Deficiency of the fifth component of complement in human subjects. Clinical, genetic and immunologic studies in a large kindred". The American journal of medicine. 67 (4): 638–645. PMID 495634. Unknown parameter
|month=ignored (help) - ↑ O. Sanal, M. Loos, F. Ersoy, G. Kanra, G. Secmeer & I. Tezcan (1992). "Complement component deficiencies and infection: C5, C8 and C3 deficiencies in three families". European journal of pediatrics. 151 (9): 676–679. PMID 1396929. Unknown parameter
|month=ignored (help) - ↑ Z. Zhu, T. P. Atkinson, K. T. Hovanky, S. B. Boppana, Y. L. Dai, P. Densen, R. C. Go, J. S. Jablecki & J. E. Volanakis (2000). "High prevalence of complement component C6 deficiency among African-Americans in the south-eastern USA". Clinical and experimental immunology. 119 (2): 305–310. PMID 10632667. Unknown parameter
|month=ignored (help) - ↑ M. R. Moya-Quiles, M. V. Bernardo-Pisa, P. Martinez, L. Gimeno, A. Bosch, G. Salgado, H. Martinez-Banaclocha, J. Eguia, J. A. Campillo, M. Muro, J. B. Vidal-Bugallo, M. R. Alvarez-Lopez & A. M. Garcia-Alonso (2013). "Complement component C6 deficiency in a Spanish family: implications for clinical and molecular diagnosis". Gene. 521 (1): 204–206. doi:10.1016/j.gene.2013.03.027. PMID 23537992. Unknown parameter
|month=ignored (help)