Serial changes in plasma levels of cytokines in patients with coronary artery disease

Objectives: Inflammation is known to be a major determinant of the progression of coronary artery disease (CAD). In the present study we have evaluated the plasma levels of cytokines tumor necrosis factor- alpha (TNF), interleukin- 1 alpha (IL- 1), interleukin- 6 (IL- 6), interferon-gamma(IFN), and interleukin- 10 (IL- 10) - to examine the association between these cytokines and C- reactive protein (CRP) in patients with CAD. Methods: Patients with acute coronary syndromes (ACS; n = 20) were compared with patients with stable angina (SA; n = 20) and with control volunteers (C; n = 20). Blood samples were collected at the time of admission from all patients and 15 and 30 days thereafter. Results: CRP levels (20.8 +/- 8.8 mg/L) (mean +/- SEM) were higher at baseline in ACS than SA patients (4.1 +/- 0.8 mg/L) or the control subjects (5.1 +/- 1.8 mg/L) (p < 0.05). At admission, IL- 6 was detected in 50% of the ACS patients and 5% of the SA patients or control subjects, while TNF was detected in 35% of the ACS and SA patients but only in 5% of control subjects. Subsequently, IL- 6 levels declined and were no longer detectable, while TNF levels increased among ACS patients at all time periods tested when compared with other patients. The presence of IL- 1 and IL- 10 were not detectable in the blood samples examined, and IFN could only be detected in the ACS group. A significant correlation was observed between IL- 6 and CRP levels (r = 0.4; p < 0.01) in all groups. There were no correlations among any of the other cytokines and CRP levels. Conclusions: Our study demonstrates raised levels of TNF, IL6, IFN, and CRP in patients with ACS and a positive correlation between IL6 and CRP but not with the other cytokines.