Komplementpuudulikkus

Komplementpuudulikkus is a medical condition characterized by a deficiency in one or more components of the complement system. The complement system is a part of the innate immune system that helps defend the body against infections. It consists of a cascade of proteins that, when activated, can lead to the destruction of pathogens, inflammation, and the clearance of immune complexes.

Deficiencies in complement components can be inherited or acquired. Inherited deficiencies are typically caused by genetic mutations that affect the production or function of specific complement proteins. Acquired deficiencies can arise from various conditions, including malnutrition, liver disease, certain cancers, and autoimmune disorders.

The clinical manifestations of complement deficiencies vary depending on which component is affected. Individuals with deficiencies in early complement components (C1, C2, C4) are at an increased risk of recurrent bacterial infections, particularly those caused by encapsulated bacteria like Streptococcus pneumoniae and Neisseria meningitidis. They may also develop autoimmune diseases, such as systemic lupus erythematosus. Deficiencies in later complement components (C3, C5-C9) are associated with a higher susceptibility to Neisseria infections, including meningococcal meningitis and gonococcal infections. These deficiencies can also impair the ability of the body to clear immune complexes, potentially contributing to various inflammatory conditions.

Diagnosis of complement deficiency involves laboratory tests to measure the levels and functional activity of complement proteins. Treatment strategies depend on the specific deficiency and its associated complications. This may include prophylactic antibiotics, vaccination, and management of autoimmune manifestations. In some cases, complement replacement therapy might be considered.