Anti-cyclic citrullinated peptide antibody is a protein produced as part of the process that leads to joint inflammation in rheumatoid arthritis (RA). The anti CCP antibody test can help doctors diagnose RA and determine how severe it is likely to be.
What are antibodies?
Antibodies are proteins and are normally made by the immune system in response to bacteria, viruses, and other foreign substances. Sometimes, however, antibodies are made when the immune system malfunctions and attacks the body’s own tissues, as happens in RA. Anti-CCP antibodies are of this type. They form in response to inflammatory proteins called citrullinated peptides. The antibodies are present in the blood of many people with RA from its very earliest stages, and even when a person’s arthritis is “undifferentiated” (meaning it’s not clear what type of arthritis it is). According to the American College of Rheumatology, roughly 95 percent of people with undifferentiated arthritis who test positive for anti-CCP antibodies eventually develop RA.
About the anti CCP antibody test
This strongly suggests that the anti-CCP antibody test can detect RA very early on with a high degree of accuracy, so using the test can lead to a faster diagnosis and earlier treatment than is otherwise possible. For this reason it may have some advantages over other blood tests for RA. For example, the test for the antibody known as rheumatoid factor, traditionally used in diagnosing RA, is not always helpful early on because the antibody sometimes does not shown up in the blood until later in the disease, and sometimes it does not show up at all. Furthermore, rheumatoid factor is found in people with diseases other than RA and in healthy people.
Early treatment of RA is important because it reduces the amount of damage that RA does to the joints. In addition, studies have shown that the more anti-CCP antibodies there are in the blood in early RA, the more severe the RA is likely to be. Having this information can help doctors decide how aggressive treatment should be.