Introduction: Coronary artery disease (CAD) is one of the leading causes of morbidity and mortality worldwide and is mainly driven by chronic inflammation and endothelial dysfunction. Interleukin-18 (IL-18) is among the inflammatory mediators involved, and IL-18 gene polymorphisms may also influence disease pathogenesis. This study aimed to evaluate the diagnostic and prognostic significance of biomarkers and IL-18 variants in CAD in order to improve non-invasive early detection and risk stratification.
Methods: This prospective case-control study included 200 Kurdish subjects recruited at the Erbil Cardiac Centre, comprising 100 patients with CAD confirmed by angiography and 100 controls. Clinical evaluation was supplemented with biochemical and hematological tests. Serum IL-18 and hsCRP levels were measured using ELISA and turbidimetry, respectively, while IL-18 SNPs (-607 T/G; rs1946518) were genotyped using ARMS-PCR.
Results: The findings showed a significant increase in IL-18 and hsCRP levels in CAD patients compared with controls. Notably, the TT and GG genotypes of IL-18 rs1946518 were observed only in patients, and these genotypes were associated with increased biomarker levels. No significant differences were detected in the genotype distribution, allele frequencies, or haplotype frequencies of IL-18 gene polymorphisms between the CAD and control groups. Positive correlations were observed between IL-18 expression and hsCRP, indicating a shared inflammatory process.
Conclusion: Elevated IL-18 levels, together with IL-18 gene polymorphisms, suggest a synergistic role of genetic and inflammatory factors in CAD progression among patients with coronary atherosclerosis. Integrated assessment enhances diagnostic accuracy, supporting its potential as a non-invasive approach for early CAD detection and risk stratification.
