There are several reasons why you might have high complement C4 levels over 45 milligrams per deciliter. If you have had a recent injury or infection, you’re likely to have more C4 in your blood.

Disruption of the complement system appears to precede the onset of islet autoimmunity (IA), making it a potential early warning sign of type 1 diabetes (T1D), according to a new report.

The complement system plays a part in glomerular disease. There are two main forms of glomerular disease: dense deposit disease and C3 glomerulonephritis. Learn more about them both.

The immune system has evolved to act as a first responder against infections, and scientists have revealed how it knows when to activate.

But if the complement system remains in its microbe-fighting state after the viruses and bacteria are eliminated, “it starts damaging healthy cells,” he said.

Researchers have discovered that SARS-CoV-2 hijacks three important host proteins that dampen the activity of the complement system, a key component of early antiviral immunity. This significantly ...