What is Complement C3?

Complement C3 is a complex biological system which works in conjunction with antibodies and other factors to protect the body from invasion by pathogens. When activated by either the classical or alternative pathway Complement acts on biological membranes and may cause cell death. Complement C3 and complement C4 levels are important in determining inherited or acquired deficiencies.

Complement testing can be used to help diagnose the cause of recurrent microbial infections, unexplained swellings or inflammation. In addition, low levels of complement C3 can be found in patients diagnosed with Systemic Lupus Erythematosus (SLE), a form of lupus, which is a chronic autoimmune disease that triggers inflammation in different organs and tissues of the body and can cause widespread inflammation and tissue damage in the affected organs. Periodic tests should be carried out to help monitor known long term diseases that affect the complement system.