The complement system is an important part of the humoral immune defence in mammals that is formed by about 35 soluble and cell-surface proteins. Together these proteins enable the host to recognize ...

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.

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 ...

A complement blood test checks for autoimmune diseases or other issues with your immune system. Your doctor might test you if you have a family history of certain conditions, such as rheumatoid ...

Among people with sickle cell disease—an inherited blood disorder—acute chest syndrome (ACS) is the leading cause of death. The condition is the result of red blood cells becoming stiff, sticky, and ...

Immunotherapy is increasingly becoming standard therapy in cancer, with technology, such as checkpoint inhibitors and cell therapy, raising the efficacy bar in many forms of the disease. But the ...