CRP and IL-1B gene polymorphisms and CRP in blood in periodontal disease

Recent studies have suggested an association between periodontal disease (PD) and the systemic polygenic diseases such as cardiovascular disease (CVD). These are thought to be associated because of interrelated environmental, epigenetic, and genetic risk factors. The involved candidate genes include the IL-1B gene, encoding the pro-inflammatory cytokine IL-1β, and the CRP gene encoding the C-reactive protein (CRP), also a known marker of inflammation. However, as the details are not well known on the genetic variation influencing the risk factors, this work aimed to evaluate the distribution of selected polymorphisms of IL-1B and CRP genes, and serum CRP level, in comparison with the PD status. For this purpose, periodontal health was assessed, serum CRP levels measured and polymorphism status of IL-1B and CRP genes determined from samples of peripheral blood taken from 101 consenting Indonesian adult males. The results show that severe PD was significantly associated with age and smoking, as expected, but not with the polymorphisms of IL-1B or CRP (1444). However, a significantly lower fraction of subjects with normal periodontal health than subjects with PD showed the heterozygous type polymorphism of CRP (717). There was no significant difference in the fraction of cases with elevated serum CRP level between subjects with normal health and those with PD, and further study with a larger sample is recommended. The observed association between polymorphism of CRP (717) and periodontal health is suggested as a complementary indicator of the risk to PD for the Indonesian male population.