Your complement system consists of a group of important proteins in your bloodstream. These proteins help your immune system fight off harmful invaders, such as bacteria, and other foreign substances.

A complement blood test checks for autoimmune diseases or other issues with your immune system. Your doctor might test you if you have a family history of certain conditions, such as rheumatoid ...

The complement system is an important part of the humoral immune defence in mammals that is formed by about 35 soluble and cell-surface proteins. Together these proteins enable the host to recognize ...

PHILADELPHIA - A team from the University of Pennsylvania School of Medicine and Utrecht University has deciphered a key step in an evolutionarily old branch of the immune response. This system, ...

Scientists have published new details of their research into the complement reaction, an immune system response that kills thousands annually. Researchers have teased out the molecular process that ...

Medically reviewed by Matthew Wosnitzer, MD Complement 3 glomerulopathy (C3G) is a rare kidney disease that is also considered an autoimmune disorder. There is no single cure for C3G, but several ...