Objective: It has been reported that the cytokines play an important role in the pathogenesis of cardiovascular diseases. The aim of this study was to evaluate the serum levels of interleukin (IL)-13, IL-17 and IL-18 in patients with ischemic heart disease (IHD) and also to clarify their association with traditional risk factors of disease.
Methods: A total of 60 patients with IHD as having acute myocardial infarction (AMI; n=30) or unstable angina (UA; n=30) and 30 sex- and age- matched healthy subjects as a control group were enrolled to this cross-sectional, case-controlled study. Serum samples were collected from all participants (for AMI patients at 3-5 days after events and for UA at admission time) and tested for the IL-13, IL-17 and IL-18 by use of ELISA method. Statistical analysis was performed using ANOVA, Student t, Kruskal-Wallis, Mann-Whitney U and Chi-square tests as appropriate.
Results: The frequencies of subjects with detectable levels of IL-13 were 6.7%, 20% and 33.3% in AMI, UA and control groups, respectively. The frequency of subjects with detectable levels of IL-13 in control group was significantly higher as compared to AMI group and total group of patients with IHD (p<0.02 and p<0.05, respectively). The mean serum levels of IL-17 in AMI group (6.68+/- 1.2 pg/ml) and UA group (5.48+/- 1.01 pg/ml) were significantly higher than that observed in control group (2.07+/- 0.60 pg/ml; p<0.005 and p<0.04, respectively). Moreover, the mean serum levels of IL-18 in UA group (122.92+/- 18.16 pg/ml) were significantly higher than in control group (67.82+/- 5.98 pg/ml; p<0.03). The mean serum levels of IL-18 in IHD patients without a certain traditional risk factor including non-hypertensive patients (120.14+/- 17.04 pg/ml), non-dyslipidemic patients (131.86+/- 20.04 pg/ml), non-diabetic patients (111.96+/- 14.71 pg/ml) and non-smoker patients (113.93+/- 16.41 pg/ml) were significantly higher as compared to control group (p<0.04, p<0.004, p<0.03 and p<0.03, respectively). Although, the mean serum levels of IL-18 in patients with a certain traditional risk factor were higher in comparison to control group, but the differences were not significant. The means serum levels of IL-17 in patients with or without a certain traditional risk factor were also markedly higher as compared to healthy group.
Conclusions: These results showed that the higher serum levels of IL-17 and IL-18 were associated with IHD. The presence or absence of a certain traditional risk factors of IHD may influence the serum levels of cytokines. These findings may be considered to improve the predictive or prognostic values of inflammatory cytokines for IHD and also to design possible novel therapeutic approaches.