Complement deficiencies

Author: Brian Wu PhD. MD Candidate, Keck School of Medicine, Los Angeles, USA; Chief Editor: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, October 2015.

What is a complement deficiency?

Complement is a group of more than 30 proteins found in blood and tissues throughout the body. They play an important role in immune system function through enhancing the inflammatory response and pathogen elimination. A deficiency in any one of these complement proteins can cause a wide range of symptoms, stemming from:

Complement deficiencies are considered to be rare disorders and compromise between 1–10% of all cases of primary immunodeficiency. Complement deficiency is also known as hypocomplementaemia.

What causes a complement deficiency?

Complement deficiencies are inherited. Most are autosomal recessive traits with the exception of a deficiency of the CI inhibitor, which is autosomal dominant, and properdin deficiency, which is X-linked.

What are the signs and symptoms of a complement protein deficiency?

Complement deficiencies affect various organs.

What are the risk factors for complement deficiencies?

The risk factors for complement deficiencies include:

How is a complement deficiency diagnosed?

Complement deficiencies are commonly diagnosed with the following tests:

How is a complement deficiency treated?

There are no specific treatments available as yet for complement deficiencies.

Treatment can include:

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