Interleukin-18: interleukin-10 ratio and in-hospital adverse events in patients with acute coronary syndrome.

Introduction: Inflammatory mechanisms contribute to the development of acute coronary syndromes (ACS), and it has been suggested that an imbalance between pro- and anti-inflammatory responses may be an important determinant of recurrent cardiac events in this setting. Both increased serum levels of interleukin (IL)-18 and reduced concentrations of IL-10 have been shown to have prognostic significance in ACS. We sought to assess whether the ratio of serum IL-18/IL-10 levels has higher positive predictive value than the individual measurement of IL-10 and IL-18 in patients admitted to hospital with ACS.

Methods: We recruited 107 consecutive patients (79 men, mean age 65+/-12 years) with ACS (41 STEMI, 39 NSTEMI and 27 UA). The composite of cardiac death, recurrence of unstable angina, re-infarction, life threatening arrhythmias, and urgent revascularization during hospitalization was the pre-specified study end-point. We assessed independent predictors of the combined end-point using multiple logistic regression analysis. Serum IL-10 and IL-18 levels were measured at study entry using commercially available ELISAs.

Results: During hospitalization 44 patients (41%) had events and 63 (59%) had no events. Significantly higher odd ratios were found for IL-18/IL-10 ratio (1.74 95% CI 1.09-2.78) compared to individual IL-18 (1.46 95% CI 0.93-2.27) and 1/IL-10 (1.63 95% CI 1.04-2.56) measurements.

Conclusion: Serum IL-18/IL-10 ratio is an independent predictor of in-hospital adverse events in patients with ACS. Our study strongly endorses the notion that an imbalance between pro and anti-inflammatory forces predisposes to plaque disruption and recurrent cardiovascular events.