Role in Disease
It is thought that the complement system might play a role in many diseases with an immune component, such as Barraquer-Simons Syndrome, asthma, lupus erythematosus, glomerulonephritis, various forms of arthritis, autoimmune heart disease, multiple sclerosis, inflammatory bowel disease, and ischemia-reperfusion injuries. and rejection of transplanted organs.
The complement system is also becoming increasingly implicated in diseases of the central nervous system such as Alzheimer's disease and other neurodegenerative conditions such as spinal cord injuries.
Deficiencies of the terminal pathway predispose to both autoimmune disease and infections (particularly Neisseria meningitidis, due to the role that the membrane attack complex plays in attacking Gram-negative bacteria).
Mutations in the complement regulators factor H and membrane cofactor protein have been associated with atypical haemolytic uraemic syndrome. Moreover, a common single nucleotide polymorphism in factor H (Y402H) has been associated with the common eye disease age-related macular degeneration. Polymorphisms of complement component 3, complement factor B, and complement factor I, as well as deletion of complement factor H-related 3 and complement factor H-related 1 also affect a person's risk of developing age-related macular degeneration. Both of these disorders are currently thought to be due to aberrant complement activation on the surface of host cells.
Mutations in the C1 inhibitor gene can cause hereditary angioedema, an autoimmune condition resulting from reduced regulation of the complement pathway.
Mutations in the MAC components of complement, especially C8, are often implicated in recurrent Neisserial infection.
Diagnostic tools to measure complement activity include the total complement activity test.
Read more about this topic: Complement System
Famous quotes containing the words role in, role and/or disease:
“Certainly parents play a crucial role in the lives of individuals who are intellectually gifted or creatively talented. But this role is not one of active instruction, of teaching children skills,... rather, it is support and encouragement parents give children and the intellectual climate that they create in the home which seem to be the critical factors.”
—David Elkind (20th century)
“Given that external reality is a fiction, the writer’s role is almost superfluous. He does not need to invent the fiction because it is already there.”
—J.G. (James Graham)
“It is useless to check the vain dunce who has caught the mania of scribbling, whether prose or poetry, canzonets or criticisms,—let such a one go on till the disease exhausts itself. Opposition like water, thrown on burning oil, but increases the evil, because a person of weak judgment will seldom listen to reason, but become obstinate under reproof.”
—Sarah Josepha Buell Hale 1788–1879, U.S. novelist, poet and women’s magazine editor. American Ladies Magazine, pp. 36-40 (December 1828)