Immunomodulatory Factors Gene Polymorphisms in Chronic Periodontitis

An Overview

Zahra Heidari; Bita Moudi; Hamidreza Mahmoudzadeh-Sagheb


BMC Oral Health. 2019;19(29) 

In This Article

Abstract and Introduction


Background: Chronic periodontitis (CP), defines as destruction of the supporting tissues of the teeth and resorption of the alveolar bone. It is widespread in human populations and represent an important problem for public health. CP results from inflammatory mechanisms created by the interaction between environmental and host genetic factors that confer the individual susceptibility to the disease.

Aim: The aim of the current study was to explore and summarize some functional biomarkers that are associated with CP susceptibility.

Methods: CP is considered to be a multifactorial disease. The pathogenesis of multifactorial diseases is characterized by various biological pathways. The studies revealed that polymorphisms were associated with susceptibility to periodontal diseases. In other word, genetic variations can change the development of CP. However, there are some conflicting results, because there are different variations in frequency of some alleles in any populations. Therefore, we conducted the current review to completely understanding the special biomarkers for CP.

Results: There is some evidence that SNPs in the IL-1α, IL-1β, IL1RN, IL-6, IL-10, TNF-α, TGF-β1, IFN-γ and VDR may be associated with CP susceptibility.

Conclusion: In conclusion, numerous studies have reported the host genetic factors associated with CP susceptibility and related traits. Therefore, it is prevail to study the multiple SNPs and their effects to find the useful diagnosis methods. The current study will investigate the relationship between polymorphisms in cytokine genes and the susceptibility to the chronic periodontitis.


Accumulation of microbial plaque in gingiva can induce inflammatory responses which lead to periodontal diseases. This inflammation progresses to the periodontitis as a chronic inflammatory condition. In periodontal disease, tooth-supporting tissues are destroyed. In untreated patients, ligamentous support of the teeth is lost. Subsequently, the resorption of the alveolar bone caused loss of the teeth.[1–3]

Periodontal disease has two major forms: chronic and aggressive. Aggressive periodontitis is a rapidly progressive condition, but chronic periodontitis (CP) has a relatively slower rate. Chronic periodontitis is common in more than 30% of adults, while up to 13% of the adults will be affected by severe periodontitis.[4]

It is believed that CP has multifactorial etiopathogenesis. Host genetic, environmental and microbiological factors are the three major parameters which can determine the natural history of disease.[2] It means that, either subgingival biofilm and host genetic variations together are necessary to cause disease.[1] On the other hand, some strong evidences have been emphasized that host genetic has an important effect in the pathogenesis of periodontitis. In addition, the studies have been conducted on twins reported that the human genome may alter the frequency of the disease in half of the population.[4,5] In this regard, understanding the genetic basis of CP can be used as an early and a useful diagnostic method for detecting the susceptibility to the disease. Given that, the genes can change the etiology of disease, so we can provide the appropriate treatment methods. It is estimated that there are possibly 20 genes which may increase the relative risk for CP. However, it should be noted that the effects of these genes are not independent of environmental factors and ethnicity.[6]

In CP gram-negative anaerobic bacteria induce the attachment loss of tooth from its supporting tissues. This mechanism has been mediated by some regulatory and inflammatory cytokines. In other words, cytokines contribute to periodontitis susceptibility. Therefore, it has been suggested that insufficient production of cytokines against inflammatory activities can cause the disease. Some studies have shown that there was a relationship between cytokine SNPs and CP. Such variations can change the levels of cytokines production, which in turn may result in changes in immune responses and can cause long lasting inflammations. Therefore, study on relationship between genotype and/or allele frequencies and disease susceptibility can introduce some genotypes and alleles that can increase the risk of inflammatory disease.[7] Recently, some scientists have reported the effects of single nucleotide polymorphisms (SNPs) in candidate genes in susceptibility to CP (Table 1.).[2,8–13] It seems that the use of the genetic risk score could be useful in detection of the CP susceptibility.[14–19] However, a number of conflicting results have been reported, because there are different variations in frequency of some alleles in any populations. The aim of the current study was to explore and summarize some functional biomarkers such as Interleukin-1 and Tumor necrosis factor alpha; as pro-inflammatory cytokines; IL-6, IL-10; as regulatory cytokines; VDR; as a connective tissue metabolism-associated-gene; that are associated with CP susceptibility.