The cyclic citrullinated peptide antibody test identifies CCP antibodies in the blood. CCP antibodies are a specific type of antibody produced by the immune system called an autoantibody. While most antibodies help the body fight disease by recognizing and neutralizing foreign substances like bacteria and viruses, autoantibodies don’t fulfill this important immune function. Instead, autoantibodies can act abnormally by targeting and attacking the body’s healthy cells and tissues. CCP antibodies are detected in most patients with rheumatoid arthritis. Although less common, CCP antibodies may be detected in other autoimmune disorders, including Sjögren’s syndrome and lupus.