Assessment of TNF-α expression in unstable atherosclerotic plaques, serum IL-6 and TNF-α levels in patients with acute coronary syndrome and rheumatoid arthritis

The role of inflammatory cytokines is well researched in acute coronary syndrome (ACS) and rheumatoid arthritis (RA), but not in the presence of both conditions. This study aimed to compare TNF-α expression, serum TNF-α, IL-6, and hs-CRP in ACS patients with RA (n = 46) with ACS patients without RA (n = 49) and healthy controls (n = 50). TNF-α expression was assessed from coronary artery samples, taken during coronary artery bypass surgery. Serum levels TNF-α, IL-6, and hs-CRP were measured 24 and 48 h after cardiac surgery. Stronger TNF-α expression was observed in the ACS patients with RA versus the ACS patients without RA, p = 0.001. Serum TNF-α, IL-6, and hs-CRP at the 24th h were significantly elevated in both patient groups and distinguished them from the healthy controls with accuracy ranging from 80 to 99%. At the 48th h, serum TNF-α and IL-6 in the ACS group without RA decreased to those of the healthy controls but remained high in the group with RA. ACS cases with RA could be correctly identified from the levels of IL-6 (AUC = 0.885, 95% CI 0.791 to 0.938) and TNF-α (AUC = 0.852, 95%CI 0.720 to 0.922). Our results suggest that the presence of RA in ACS cases is likely to provoke stronger TNF-α expression on atherosclerotic plaques, aggravate the pro-inflammatory response, and sustain it even after the cardiac stress is lowered. In ACS cases with RA, long-term monitoring and control of TNF-α and IL-6 levels can be a useful preventive strategy.