This test looks for CCP (cyclic citrullinated peptide) antibodies in the blood. CCP antibodies, also called anti-CCP antibodies, are a type of antibody called autoantibodies. Antibodies and autoantibodies are proteins made by the immune system. Antibodies protect you from disease by fighting foreign substances like viruses and bacteria. Autoantibodies can cause disease by attacking the body's healthy cells by mistake.

CCP antibodies target healthy tissues in the joints. If CCP antibodies are found in your blood, it can be a sign of rheumatoid arthritis. Rheumatoid arthritis is a progressive, autoimmune disease that causes pain, swelling, and stiffness in the joints. CCP antibodies are found in more than 75 percent of people who have rheumatoid arthritis. They are almost never found in people who don't have the disease.

Other names: Cyclic citrullinated peptide antibody, anticitrullinated peptide antibody, citrulline antibody, anti-cyclic citrullinated peptide, anti-CCP antibody, ACPA.