Complement component 3, often called C3, is an essential protein of the immune system. This protein plays a vital role in the body’s innate immune system, providing: the first line of defense against ...

Complement 3 glomerulopathy (C3G) is a rare kidney disease that affects your body’s innate immune system (complement system). Complement 3 glomerulopathy (C3G) is a kidney disease that’s caused by ...

A complement C4 (also known as a complement component 4, or simply C4) is a test to measure the level of C4 proteins you have in your blood. These proteins play a role in how your immune system ...

The complement system is a key component of innate and adaptive immunity and therefore acts as a vital defense against invading pathogens. Deficiencies in the complement system are associated with ...

Most people infected with the SARS-CoV-2 virus recover after the acute illness. However, a significant proportion of infected individuals develop long-lasting symptoms with a wide range of ...

Scientists have identified a persistent change in a handful of blood proteins in people with long Covid that indicates that an important part of their immune system remains on high alert for months ...