Definition:
The complement system is the name of a group of proteins that move through the bloodstream, and complement levels -- as the name implies -- measure the activity of those proteins. Working within the immune system, the proteins play a role in the development of inflammation. The test is often used to monitor patients with systemic lupus erythematosus (SLE) and other autoimmune diseases to see if treatment is working. Though it can point to a number of conditions, a decreased complement level can point toward SLE and lupus nephritis.
Source:
Complements Medline Plus Medical Encyclopedia. National Institutes of Health. May 2007.
