Interleukin-1 Two-Locus Haplotype Is Strongly Associated with Severe Chronic Periodontitis among Yemenis.

Nezar Noor Al-Hebshi,Mohammed Sultan Al-Ak'Hali,Amat-Alrahman Ahmed Shamsan

doi:10.1155/2012/231309

Nezar Noor Al-Hebshi, Mohammed Sultan Al-Ak'Hali + Show 1 more

Open Access

https://doi.org/10.1155/2012/231309

Copy DOI

Abstract

Aim. To assess IL-1A C[−889]T and IL-1B C[3954]T genotypes as well as haplotypes in relation to sever chronic periodontitis (SCP) among Yemenis. Materials and Methods. 40 cases with SCP and 40 sex- and age-matched controls were included; all were nonsmokers and free of systemic diseases. Genotyping at each locus was performed using an established PCR-RFLP assay. The Haploview and SimHap software were used to assess data for Hardy-Weinberg's equilibrium (HWE) and linkage disequilibrium (LD) and to obtain subject-level haplotypes. Multiple logistic regression was used to seek for associations in dominant, additive, and recessive models. Results. Mean plaque index (MPI) showed the strongest association with SCP (OR = 16). A significant LD was observed in the cases (D' = 0.80 and r 2 = 0.47). The genotype at each locus showed significant association with SCP in the recessive model (TT versus TC + CC) even after adjustment for MPI (OR = 6.29 & 461, resp.). The C-T haplotype conferred protection against SCP in a dominant manner (OR = 0.16). On the other hand, the T-T haplotype in double dose (recessive model) showed strong association with CP (OR = 15.6). Conclusions. IL-1 two-locus haplotype is associated with SCP in Yemenis. Haplotype-based analysis may be more suited for use in genetic association studies of periodontitis.

Highlights

Chronic periodontitis is currently viewed as an immunologically mediated destruction of tooth supporting tissues, the periodontium, provoked by specific pathogenic bacterial consortia in subgingival biofilm [1]
The IL-1 and TNF-A proteins, are strongly implicated in the pathogenesis of chronic periodontitis [7], the genes encoding them have been more extensively investigated with the biological premise that certain polymorphisms result in hyper secretion of these proinflammatory molecules and in severe periodontal destruction [8]
The purpose of this study was, to assess the association between the IL-1A C[−889]T and IL-1B C[3954]T polymorphisms and sever chronic periodontitis among Yemenis based on haplotype analysis

Summary

Introduction

Chronic periodontitis is currently viewed as an immunologically mediated destruction of tooth supporting tissues, the periodontium, provoked by specific pathogenic bacterial consortia in subgingival biofilm [1]. The occurrence, extent, and severity of the destructive process are dependent on the individual’s susceptibility to the disease, which is in turn influenced by risk factors independent of the microbial challenge [2]. Environmental factors, such as cigarette smoking, and systemic diseases, such as diabetes, are well-established, classical examples of such risk modifiers [3]. The IL-1 and TNF-A proteins, are strongly implicated in the pathogenesis of chronic periodontitis [7], the genes encoding them have been more extensively investigated with the biological premise that certain polymorphisms result in hyper secretion of these proinflammatory molecules and in severe periodontal destruction [8]

Objectives

Methods

Results