Objective: We investigated the correlation between levels of IL-33 multifunctional inflammatory cytokine and its soluble receptor (sST2) in the sera of patients with myocardial infarction.
Methods: Blood samples were collected from 39 patients with ST Elevated Myocardial Infarction (STEMI) and 42 healthy blood donors. IL-33 and sST2 were measured in the sera by Enzyme Linked Immunosorbent Assay (ELISA) and their concentrations were compared between groups and according to clinical criteria.
Results: While there was a significant difference between healthy individuals and patients based on sST2 (p=0.002, the level of IL-33 was not significantly different between groups (p=0.17). A significant correlation between the serum levels of sST2 and IL-33 in patient group was observed (p=0.022). There were significant negative correlations between serum levels of sST2 (p=0.028) and IL-33 (p=0.091) with Ejection Fraction. While there was no difference between diabetic and non-diabetic patients regarding sST2 levels (p=0.695), a trend of lower IL-33 level was observed in diabetic patients in comparison to non-diabetes ones (p=0.057). Similarly, IL-33 was lower in smokers compared to non-smokers, although the difference did not reach the significant level (p=0.057).
Conclusion: sST2 but not IL-33 levels increase in sera of patients with STEMI. However, the correlation between the two factors in patients group implies a complex interaction between IL-33 and its receptor (s) in STEMI. The higher levels of IL-33 in non-diabetic and non-smokers highlight a difference in the Th2 responses in patients and demands further investigation.