Complement proteins moderate the actions of specific antibodies, aid the processing and removal of immune complexes, and modify T-cell and B-cell responses.
Complement deficiencies can be inherited, or acquired. Acquired complement deficiencies may occur as a result of infection (e.g., recurrent meningococcal or disseminated gonococcal infection) or in conjunction with chronic rheumatological or autoimmune disease (e.g., systemic lupus erythematosus or cryoglobulinaemia).
Diagnosis is based on clinical and/or family history and characteristic serological and molecular findings; only a few specialised laboratories provide comprehensive diagnostics.
Suspicious presentations include meningococcal meningitis in individuals over the age of 5 years, recurrent bacterial infections, angio-oedema without urticaria, inflammatory disorders of the renal and ophthalmic system, and autoimmune manifestations.
- Complement physiology
- Inherited complement deficiencies
- Clinical presentation
- Diagnostic tests
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