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.

Complement 3 glomerulopathy (C3G) is diagnosed with a combination of a clinical evaluation, blood tests, urine tests, and a renal (kidney) biopsy. The only way to definitively diagnose C3G and its ...

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 ...