Genetic variation at the chemokine receptors CCR5/CCR2 in myocardial infarction

Our objective was to examine the association between myocardial infarction (MI) and two DNA-polymorphisms at the proinflammatory chemokine receptors CCR2 (164V) and CCR5 (32 bp deletion, Delta ccr5), defining if these polymorphisms influence the age for the onset of Mi. A total of 214 patients with an age at the first MI episode < 55 years, 96 patients that suffered the first MI episode when older than 60 years, and 360 population controls were polymerase chain reaction genotyped for the CCR2-V641 and CCR5-Delta 32/wt polymorphisms. Patients and controls were male from the same Caucasian population (Asturias, northern Spain). The frequency of the deem allele was significantly higher in controls compared to patients < 55 years (P = 0.004), or in patients > 60 years compared to patients < 55 years (P = 0.002). Taking the patients > 60 years as the reference group, non-carriers of the Delta ccr5-allele would have a three-fold higher risk of suffering an episode of MI at < 55 years of age (OR = 3.06; 95% CI = 1.46-6.42). Gene and genotype frequencies for the CCR2 polymorphism did not differ between patients < 55 years and controls or patients > 60 years. Our data suggest that the variation at the CCR5 gene could modulate the age at the onset of MI. Patients carrying the Delta ccr5-allele would be protected against an early episode of MI. CCR5 and the CCR5-ligands are expressed by cells in the arteriosclerotic plaque. Thus, the protective role of Delta ccr5 could be a consequence of an attenuated inflammatory response, that would determine a slower progression of the arteriosclerotic lesion among Delta ccr5-carriers. Our work suggests that the pharmacological blockade of CCR5 could be a valuable therapy in the treatment of MI.