Single nucleotide polymorphisms in inflammatory genes and the risk of early onset of lone atrial fibrillation

Systemic low-grade inflammation is a prognostic risk factor of atrial fibrillation (AF). We hypothesized that genetic polymorphisms, which determine the rate of inflammatory cytokines, are associated with the risk of AF, independently of comorbidity. We included 192 patients with so-called lone AF and age 40 years or below, and 188 healthy controls. All patients were genotyped for single nucleotide polymorphisms (SNPs) in inflammatory genes using fluorescence-based real-time polymerase chain reaction (PCR). A case-control analysis of the C/C, C/T and T/T genotypes on IL1A-889 revealed a significant difference in both the frequency of genotypes (p = 0.03) and in the allelic frequency (p = 0.015). These differences were not significant after Bonferroni corrections. For IL1B-511, IL10-592, IL10-1082, IL18-137, IL18-607 and TNF-308 there were no significant differences, neither in genotype frequency, nor in allelic frequency between the lone AF patients and the controls. Our study failed to show an association between polymorphisms in inflammatory genes and early onset of lone AF. It remains to be established whether polymorphisms in inflammatory genes play a causative role in the pathophysiology of AF.