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 ...

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.

We were unable to process your request. Please try again later. If you continue to have this issue please contact [email protected]. FORT WORTH, Texas — In patients with suspected lupus, ...

Age-related macular degeneration is the most common cause of blindness in Western populations. Susceptibility is influenced by age and by genetic and environmental factors. Complement activation is ...

Please provide your email address to receive an email when new articles are posted on . Low complement levels prior to pregnancy are associated with an increased risk for adverse outcomes, including ...

A gamma-globulin factor in the serum of patients with systemic lupus erythematosus that reacts with isolated cell nuclei 1 or nucleoprotein 2,3 has been detected in many ways. 4 The standard method of ...

The complement system is an innate immune response that leads to increased inflammation. The drug pegcetacoplan—a complement inhibitor—was approved for medical use in the United States in 2021 to ...