IL17RA in early-onset coronary artery disease: Total leukocyte transcript analysis and promoter polymorphism (rs4819554) association

Abstract

Background and aims: The interleukin-17 (IL-17) pathway would play an important role in the pathogenesis of atherosclerosis and coronary-artery disease (CAD). The IL-17 inflammatory mediators are expressed by Th17 cells, a group of CD4 + leukocytes that infiltrate the vascular milieu and are pivotal in the origin, progression, stability and rupture of the atherosclerotic lesion. Cigarette smoke compounds stimulated the expression of IL-17 and IL-17-receptors. In atherogenic mice models the deficiency of IL-17RA resulted in a reduction of the atherosclerotic lesion size and leukocyte infiltrate. We hypothesised that common the IL-17RA transcript might be differential expressed in the leukocytes from CAD patients and healthy individuals. Methods: The relative amount of the IL-17RA to ACTB transcript was determined in total leukocytes of 55 patients and 50 controls, all smokers. We genotyped the IL-17RA rs48195554 promoter polymorphisms in 390 healthy controls and 450 early-onset CAD patients. Results: Patients showed significantly higher mean IL-17RA normalised transcript value than controls (p < 0.001). For the IL-17RA rs48195554 promoter polymorphisms, IL-17RA G-carriers showed higher transcript values. However, allele and genotype frequencies did not differ between patients and controls and we thus excluded a significant association with CAD. Conclusions: The higher levels of the IL-17RA transcript among CAD-patients was in agreement with a role for the IL-17 pathway in the pathogenesis of coronary atherosclerosis.