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
Michael Kirschfink, DVM, PhD
Professor of Immunology
German Society of Immunology
International Union of Immunological Societies
International Complement Society
Institute of Immunology
University of Heidelberg
MK has sat on Roche and Euro Diagnostica advisory boards; presented a lecture for Novartis; and acted as a consultant for Back Bay Life Science Advisors, Biotest, Ionis Pharmaceuticals, Fresenius Care Germany, and Ablynx. MK is an author of references cited in this topic.
Professor Michael Kirschfink would like to gratefully acknowledge Dr D. J. Unsworth, a previous contributor to this topic.
DJU owns shares in Glaxo and Shire, and has had registration fees paid for CPD attendance at international conferences by ALK-Abelló (2015 - EACCI - Allergy) and CSL - Bearing (2016 - ESID - Immunodeficiency).
Charles Kirkpatrick, MD (UCHSC)
Professor of Medicine
Adult Immunodeficiency Program
University of Colorado Denver
CK is an author of a reference cited in this topic. CK has received speaker fees from Cention, Aventis Behring, and Bristol Myers Squibb. CK has received honorarium for speaking at the Aspen Allergy Conference, for the Colorado Allergy Society. CK ran the research programme for a biotechnology company with an approximate budget of $3.5 million.
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