Search results
Results from the WOW.Com Content Network
Complement deficiency is an immunodeficiency of absent or suboptimal functioning of one of the complement system proteins. [4] Because of redundancies in the immune system , many complement disorders are never diagnosed.
Complement tests C4 ... Complement 4 deficiency is a genetic condition affecting complement component 4. [1] It can present with lupus-like symptoms. [2 ...
Complement deficiencies are the result of a lack of any of these proteins. They may predispose to infections but also to autoimmune conditions. [7] C1q deficiency (lupus-like syndrome, rheumatoid disease, infections) C1r deficiency (idem) C1s deficiency; C4 deficiency (lupus-like syndrome)
Complement component 4 (C4), in humans, is a protein involved in the intricate complement system, originating from the human leukocyte antigen (HLA) system. It serves a number of critical functions in immunity, tolerance, and autoimmunity with the other numerous components.
Excessive complement activity contributes to severe Covid-19 symptoms and disease. [53] Although complement is intended to protect the body systems, under stress there can be more damage than protection. Research has suggested that the complement system is manipulated during HIV/AIDS, in a way that further damages the body. [54]
Terminal complement pathway deficiency is a genetic condition affecting the complement membrane attack complex (MAC). It involves deficiencies of C5, C6, C7, and C8. (While C9 is part of the MAC, and deficiencies have been identified, [1] it is not required for cell lysis. [2]) People with this condition are prone to meningococcal infection. [3]
Diagnosis usually consists of medical evaluation in addition to laboratory testing. Laboratory evaluation includes complement studies, in which typical cases demonstrate low C4 levels, low C1q levels, and normal C3 levels. [3] Determining the etiology, or cause, of acquired angioedema is often helpful in providing appropriate management of AAE.
The trimer provides a surface for interaction between the antigen-antibody complex and other complement components. The alpha chain may be cleaved to release C4 anaphylatoxin, a mediator of local inflammation. Deficiency of this protein is associated with systemic lupus erythematosus and type I diabetes mellitus.