RA-related autoantibodies showed association with atherosclerosis

WASHINGTON — Rheumatoid arthritis-related autoantibodies were associated with atherosclerosis, even in patients who did not have rheumatoid arthritis, according to a presentation at the American College of Rheumatology Annual Meeting.

“We already know there is an increased prevalence of cardiovascular disease in rheumatoid arthritis, and it’s even known that there is an increased prevalence of subclinical atherosclerosis in rheumatoid arthritis,” researcher Darcy S. Majka, MD, MS, assistant professor of medicine and preventive medicine at Northwestern University, said. “We also knew that RA-related autoantibodies are present in the general population. And not all individuals with positive RA-related autoantibodies get rheumatoid arthritis.”

Researchers evaluated 6,557 participants (mean age, 62 years) who were part of the community-based Multi-Ethnic Study of Atherosclerosis (MESA) that began in 2000. At baseline, researchers used ELISA to measure rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP-2) levels, and they determined coronary artery calcification (CAC) by CT scan in African-American, Caucasian, Hispanic and Chinese patients.

Follow-up was conducted at 7.1 years for coronary heart disease (CHD) hard endpoints (including myocardial infarction, resuscitated cardiac arrest, CHD death) and cardiovascular disease (CVD) hard endpoints (including myocardial infarction, cardiac arrest, CHD death, stroke, stroke death). Adjusting for traditional CVD risk factors, researchers used logistic regression to assess associations between baseline RF/anti-CCP and CAC that were stratified by race and gender.

At baseline, 12.2% of patients had CAC levels of at least 300. After follow-up, 3% of patients had hard CHD endpoints, 4.8% had hard CVD endpoints, with RF IgM, RF IgA and anti-CCP positivity in 15.9%, 8.7% and 2.0% of patients, respectively. For RF isotypes, 4% of patients were positive for both and 20.6% were positive for either. CAC levels in Caucasian and African-American women were associated with RF and anti-CCP after adjusting for common risk factors. African-American women also demonstrated strong associations between RA-related autoantibodies and clinical CVD events. Hispanic and Chinese patients showed no clear associations.

“Caucasian and African-American women who had RA-related autoantibodies had about twice the odds of having CAC at baseline,” Majka said. “African-American women who had RA-related autoantibodies had about a twofold risk of clinical cardiovascular disease events over follow-up. There was a trend for an association in Caucasian women, but it did not reach statistical significance.

“RA-related autoantibodies are associated with both subclinical atherosclerosis … as well as clinical cardiovascular disease events,” she said. “These findings indicate that autoimmune factors may play a role in the pathogenesis of atherosclerosis, even in individuals who do not have rheumatoid arthritis.”

Disclosure: Researcher Marius C. Teodorescu declared stock, stock options or bond holdings or self-directed pension plan, as well as employment, with TheraTest Laboratories.

For more information:

Majka DS. P1664: Autoantibodies are Associated with Subclinical Atherosclerosis and Cardiovascular Endpoints in Caucasian and African-American Women in a Prospective Study: the Multi-Ethnic Study of Atherosclerosis. Presented at: American College of Rheumatology 2012 Annual Meeting; Nov. 10-14, Washington.