ACR 2010: New RA Classification Criteria Can ID At-risk Patients

A major challenge in the field of rheumatology is to identify which patients with very early symptoms that could suggest rheumatoid arthritis (RA) will go on to develop definite RA.

A study presented at the 2010 Annual Meeting of the American College of Rheumatology suggests that applying new criteria that incorporates genetic risk factors can identify which high-risk patients will have definite RA. The new criteria developed jointly by ACR and the European League Against Rheumatism (EULAR) includes anti-citrullinated protein antibody (ACPA)-positivity.

“We need stringent criteria for RA to make sure patients really have RA. We studied high-risk patients, that is, those with a family or personal history of RA and genetic markers as part of the NIH-funded Studies of the Etiology of RA [SERA],” said V. Michael Holers, MD, University of Colorado Denver, Aurora, CO. Holers was senior author of this abstract.

“The new criteria give us the opportunity to focus on a unique time point in the development of RA, prior to clinical onset. ACPA antibodies are present in the blood for years before onset of clinical disease,” he explained.

SERA enrolled approximately 1800 high-risk first-degree relatives of patients with RA who did not have RA according to the 1987 ACR/EULAR criteria. Joints, blood, bones, and oral mucosa of these patients were examined and laboratory data collected over eight or nine years. The study presented at ACR focused on identification of a cohort of patients with definite RA within the estimated 1800 SERA enrollees.

Data regarding joint distribution, duration of symptoms, ACPA status, and presence of elevated inflammatory markers were used to create an algorithm for identifying patient with definite RA (indicated by a score of >6 on this algorithm).

Of 1790 subjects available for analysis, 153 had synovitis (8.5%) in at least one joint on clinical exam. According to the new criteria, 22 (1.17%) had definite RA. Seventeen (81%) of those with definite RA were female with a mean age of 48.9 years.

The score of >6 was driven primarily from joint involvement, with the majority stemming from tender rather than swollen joints. This finding may indicate an earlier phase of RA development than what is seen in clinical practice, Holers said.

“These patients would not have met the old RA criteria, established in 1987,” Holers explained. “Using the new criteria, we can identify them. The next question is should we treatment them.”

The authors plan to follow this cohort of patients and initiate treatment at signs of progression. “A fundamental change [over the past decade] is that now we know that early aggressive treatment of RA improves long-term outcome. We may be able to move the clock back sooner before joint swelling occurs and prevent deterioration,” he suggested.