Background and objectives: Some experimental studies demonstrated adverse modulation of atherothrombosis by interleukin-1beta (IL-1b). To assess the relationship between the five most common variants of three polymorphisms of the IL1b gene cluster and the complexity of coronary atherosclerosis expressed in Gensini Score (GS), and the age of onset of the first acute coronary syndrome (ACS), we assessed the patients (pts) hospitalized due to ACS in this aspect.
Materials and methods: 250 individuals were included. The single nucleotide polymorphisms of IL1b gene: transition T/C at -31 position, C/T at -511, and those of IL1 receptor antagonist gene (IL1RN)-variable number of tandem repeats allele 1, 2, 3, or 4-were determined by PCR. GS was calculated from the coronary angiogram performed at the index ACS. The impact of the presence of T or C and allele 1 to 4 at the investigated loci on the mean GS, GS greater than 40, mean age of onset of ACS, and the fraction of pts over 60 years of age at ACS were compared between the five most common genotype variants.
Results: The five most common variants were present in 203 pts (81.2%). Patients with pair 22 in ILRN had the lowest rate and those with pair 12 had the highest rate of ACS before 60 years of age (29.4 vs. 67.8%; p = 0.004). GS > 40 entailed an eight-fold increase of risk, as observed when pts with one T allele at locus -31 were compared with carriers of 2 or no T allele at this locus: OR 8.73 [CI95 4.26-70.99] p = 0.04.
Conclusion: Interleukin-1 beta is subject to frequent genetic variability and our results show a potential relationship of this polymorphism with the extent of coronary atherosclerosis and age at the first ACS.
Keywords: acute coronary syndrome; atherosclerosis; gene polymorphism; interleukin-1.