Complement deficiency is an immunodeficiency of absent or suboptimal functioning of one of the complement system proteins.
The disorders can be divided into two categories:
- Disorders of the proteins that act to inhibit the complement system (such as C1-inhibitor) can lead to an overactive response, causing conditions such as hereditary angioedema and hemolytic-uremic syndrome.
- Disorders of the proteins that act to activate the complement system (such as C3) can lead to an underactive response, causing greater susceptibility to infections.
Because there are redundancies in the immune system, many complement disorders are never diagnosed. A recent study estimated that less than 10% are identified.
Read more about Complement Deficiency: Hypocomplementemia
Famous quotes containing the words complement and/or deficiency:
“A healthy man, indeed, is the complement of the seasons, and in winter, summer is in his heart.”
—Henry David Thoreau (1817–1862)
“All rejection and negation indicates a deficiency in fertility: fundamentally, if only we were good plowland we would allow nothing to go unused, and in every thing, event, and person we would welcome manure, rain, or sunshine.”
—Friedrich Nietzsche (1844–1900)