Anti-CCP and RF IgM: predictors of impaired endothelial function in rheumatoid arthritis patients

To determine whether the presence of anti-cyclic citrullinated peptide (anti-CCP) antibodies and rheumatoid factor immunoglobulin M (RF IgM) is associated with endothelial dysfunction in patients with rheumatoid arthritis (RA).

We studied the presence of anti-CCP antibodies and RF IgM and endothelial function in terms of the reactive hyperaemic index (RHI) in 53 consecutive RA patients. Endothelial function was measured by using a finger plethysmograph.

RHI was significantly lower in anti-CCP-positive RA patients (n = 33, RHI = 1.78, SD = 0.30) than in anti-CCP-negative RA patients (n = 20, RHI = 2.19, SD = 0.59; p = 0.008). A similar result was found in RF IgM-positive patients (n  =  34, RHI = 1.77, SD = 0.30) vs. RF IgM-negative patients (n = 19, RHI = 2.23, SD = 0.58; p = 0.003). There were no significant differences between the groups regarding age, gender, traditional cardiovascular risk markers, Disease Activity Score using 28 joint counts (DAS28), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), extra-articular manifestations (EAMs), use of glucocorticosteroids, statins, angiotensin-converting enzyme (ACE) inhibitors, and non-steroidal anti-inflammatory drugs (NSAIDs).

The presence of anti-CCP antibodies and RF IgM was related to impaired endothelial function independent of other cardiovascular risk factors in RA patients. Thus, these autoantibodies might reflect an early reversible stage of the atherosclerotic process, and may indicate increased risk of cardiovascular disease (CVD). Further studies are needed to explore whether anti-CCP antibodies and RF IgM may act directly or indirectly to cause endothelial dysfunction, or merely reflect endothelial dysfunction in RA patients.