Study: Screening for Antibodies Appears to Predict Rheumatoid Arthritis

A blood test to determine the presence of certain antibodies appears to accurately predict rheumatoid arthritis in patients already known to have some form of arthritis, according to a study presented October 26 at the American College of Rheumatology Annual Scientific Meeting in Orlando, FL.

Treatment for rheumatoid arthritis is likely to be more effective when the disease is not yet fully established. That reinforces the importance of making the diagnosis of rheumatoid arthritis as early as possible.

However, physicians sometimes suspect that their patients have arthritis, but after doing the usual check-up, physical examination and x-rays, may not be able to definitively diagnose the condition as being rheumatoid arthritis.

This doubt can set into motion a waiting game in which the physician keeps tabs on the patient over time to see whether the symptoms worsen or improve on their own.

Speaking at a press conference, lead researcher Dr. Floris Van Gaalen, of Leiden University Medical Center in the Netherlands, said their study showed that the presence of antibodies to cyclic citrullinated peptide (CCP) enable a doctor to predict rheumatoid arthritis.

Gaalen and his colleagues studied 936 patients who were known to have arthritis of an uncertain type and tested them for the presence of antibodies to CCP.

After two weeks, 318 of these patients were still undiagnosed. After following these patients for some time, 40 percent were diagnosed with rheumatoid arthritis. Of these, rheumatoid arthritis developed in only 25 percent of the patients who tested negative for the presence of antibodies to CCP and in a whopping 93 percent of the patients who tested positive for antibodies to CCP.

According to Van Gaalen, the message that the study sends to physicians is that they should test for the presence of antibodies to CCP if they cannot make a diagnosis of rheumatoid arthritis in a patient that they know to have arthritis.

Screening for CCP antibodies may give you a great clue as to whether the patient will or will not progress to rheumatoid arthritis, Van Gaalen told reporters. "If you have CCP antibodies, then very likely you will progress to rheumatoid arthritis."

However, Van Gaalen said he could not recommend such screening for people who are not yet believed to have arthritis, noting that the CCP antibody test is only beneficial for people with arthritis.

Van Gaalen said he and his colleagues are currently investigating if treating these patients early on prevents chronic disabling disease.

Other sources: The American College of Rheumatology