Association between IFN-γ +874A/T and IFN-γR1 (-611A/G, +189T/G, and +95C/T) Gene Polymorphisms and Chronic Periodontitis in a Sample of Iranian Population

A Systematic Review and Meta-Analysis on Multiple Cytokine Gene Polymorphisms in the Pathogenesis of Periodontitis

Aim

Periodontitis is an inflammatory disease that destroys both soft and hard periodontal tissues. However, a complex periodontal cytokine network remains unclear. This systematic review explored multiple cytokine gene polymorphisms in the pathogenesis of periodontitis.

Material and Methods

A systematic search was performed using the databases from previous publications, which indicated the association between cytokine polymorphisms and periodontitis pathogenesis. Meta-analysis was conducted using fixed or randomized models to calculate the significance of multiple cytokine polymorphisms. A total of 147 articles were analyzed with polymorphisms in 12 interleukins [Th1 (IL-2, IFN-γ, and TNF-α), Th2 (IL-4 and IL-13), Th17 (IL-1α, IL-1β, IL-6, and IL-17), and Treg cytokines (IL-10 and TGF-β)]. Doi plot was used to probe the occurrence of publication bias.

Results

The polymorphisms of IL-2 and TNF-α of Th1 cytokine family may be associated with the pathogenesis or the prevention of periodontitis risk, while the polymorphism of IFN-γ is not related to periodontitis risk. The polymorphisms for IL-4 and IL-13 of Th2 cytokine family are not found to be associated with the pathogenesis of periodontitis. For the polymorphisms of the members of Th17 cytokine family, different IL-1α polymorphisms may have inverse actions in the pathogenesis of periodontitis. IL-1β is a noteworthy cytokine biomarker in periodontitis development and progression. IL-6 may have a protective function in the inflammatory responses of periodontitis, and IL-17 has a weak relationship the inflammatory responses. The polymorphisms for the members of Treg cell cytokines may have a protective function against periodontitis risk. LFK indexes show the major asymmetry due to publication bias.

Conclusion

IL-1β is a notable cytokine biomarker in periodontitis risk. Treg cytokines favor an anti-inflammatory and protective environment. Further data are needed to confirm the present conclusion due to publication bias.

Interferon-Gamma (IFNg) +874A/T Polymorphism Does Not Significantly Affect the Severity of Periodontitis

OBJECTIVES

Interferon-gamma (IFNg) is an immune-regulatory cytokine with a role in host responses to periodontitis. Genetic factors have been reported to modify the corresponding protein expression. The objective of this study was to evaluate the association and role of IFNg polymorphisms, such as IFNg +874 A/T, and the susceptibility to periodontitis.

MATERIALS AND METHODS

A total of 100 unrelated subjects were included in the present study. Genomic deoxyribonucleic acid (DNA) was obtained from peripheral blood of 43 patients with mild periodontitis and 57 patients with severe periodontitis. The determined clinical parameters of periodontitis included probing depth, clinical attachment loss, and papilla bleeding index. The oral hygiene indicators were also assessed. The level of IFNg was determined from the gingival crevicular fluid by enzyme-linked immunosorbent assay technique. The IFNg +874 A/T polymorphisms were analyzed from peripheral blood by the method of restriction fragment length polymorphism-polymerase chain reaction.

STATISTICAL ANALYSIS

Statistical analysis of the results was conducted using chi-squared testing for categorical data. Independent t-tests and Mann-Whitney U tests were used for numeric data. Kruskal-Wallis testing was used to compare genotypes concerning for IFNg +874 A/T polymorphism. A p-value < 0.05 was assumed for statistical significance.

RESULTS

Analysis of the IFNg +874 A/T polymorphism showed no significant differences with the level of IFNg. No significant differences were observed either in IFNg +874 A/T polymorphism between the subjects with mild periodontitis and those with severe periodontitis (p > 0.05). The subjects with severe periodontitis showed marginally but not significantly higher levels of IFNg compared with subjects with mild periodontitis (p > 0.05).

CONCLUSION

The polymorphism of IFNg +874 A/T was not associated with the level of IFNg nor with the risk of periodontitis in this study.

Micheliolide alleviates ankylosing spondylitis (AS) by suppressing the activation of the NLRP3 inflammasome and maintaining the balance of Th1/Th2 via regulating the NF-κB signaling pathway

Background

Ankylosing spondylitis (AS) is a common form of inflammatory arthritis. Micheliolide (MCL), a sesquiterpene lactone, is reportedly involved in the alleviation of inflammatory response. This study aimed to investigate the mechanism of MCL in the treatment of AS.

Methods

Mice were randomly divided into five groups: the sham group, the MCL (50 mg/kg) group, the AS model group, the AS + MCL (20 mg/kg) group, and the AS + MCL (50 mg/kg) group. After the addition of the inhibitor celastrol, mice were randomly divided into five groups: the sham group, the AS model group, the AS + MCL (50 mg/kg) group, the AS + Celastrol (1 mg/kg) group, and the AS + Celastrol (1 mg/kg) + MCL (50 mg/kg) group.

Results

Compared with the AS model mice, the protein expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-18 were decreased after MCL treatment. The protein expression levels of capase-1 p10, IL-1β p17, NOD-like receptor family and pyrin domain containing 3 (NLRP3), caspase-1, and apoptosis-associated speck-like protein (ASC) were also reduced. The protein expression levels of Interferon (IFN)-γ were down-regulated, but levels of IL-4 were increased. Western blotting and immunohistochemistry revealed that the levels of p-IκB α were up-regulated, while the levels of phosphorylated-p65 were down-regulated. After the addition of celastrol, MCL treatment significantly reduced the levels of p-p65, NLRP3, caspase-1, and ASC. Meanwhile, the levels of IFN-γ were markedly down-regulated, but the levels of IL-4 were enhanced.

Conclusions

Our study found that MCL suppressed the activation of NLRP3 inflammasome and maintained the balance of Th1/Th2 via regulating NF-κB signaling. Therefore, MCL could potentially be used to treat AS.

Elevated immunoexpression of interferon-gamma in placenta tissue samples from pregnancies complicated with preeclampsia compared to the placenta previa

AIM

The present study aimed to compare the immunohistochemical expression of interferon-gamma (IFN-γ) in placentas from pregnancies complicated with preeclampsia (PE) and placenta previa (PP) and normal healthy placentas.

METHODS

Placentas were collected from cases of PE, PP and normal pregnancies as a control group (10 placentas in each group). All the deliveries were at full-term (37-42 weeks) by cesarean section and newborns were without any complications or diseases. Expression of IFN-γ in the placenta was determined using immunohistochemical methods and findings were compared. Statistical analysis was performed by Mann-Whitney and Kruskal-Wallis tests for comparing the mean values of IFN-γ expression in the placentas from PE, PP and control groups. Our results showed that the immunoexpression of IFN-γ in syncytiotrophoblast cells, extravillous trophoblast cells, vascular endothelium and basal plate of the placenta from PE group were more than control and PP groups (P < 0.05) and in PP group were more than the control group (P < 0.05).

CONCLUSION

We concluded that the immunoexpression of IFN-γ was increased significantly in placenta tissue samples of the PE group compared to the PP group and normal pregnancies. It is proposed that IFN-γ has an important role in the different mechanisms of PE and PP progression.

Association of IFN-γ polymorphisms with ankylosing spondylitis risk

The case‐control study was designed to investigate the genetic effects of interferon‐gamma (IFN‐γ) rs2069727 and rs1861494 polymorphisms on ankylosing spondylitis (AS) susceptibility in a Chinese Han population. Blood samples were collected from 108 AS patients and 110 healthy controls. IFN‐γ polymorphisms were genotyped by polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP). Hardy‐Weinberg equilibrium (HWE) test was performed in control group. Odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using chi‐square test to evaluate the association between AS susceptibility and IFN‐γ polymorphisms, and the results were adjusted by logistic regressive analysis. The frequency of rs2069727 CC genotype was much higher in cases than that in controls, suggested its significant association with increased AS risk (adjusted OR = 5.899, 95% CI = 1.563‐22.261; P = .009). In addition, C allele also showed close association with increased risk of AS (adjusted OR = 2.052, 95% CI = 1.286‐1.704, P  = 0 .003). While the genotype and allele frequencies of IFN‐γ rs1861494 polymorphism were not significantly different between patients and controls (P  > 0.05 for all), IFN‐γ rs2069727 polymorphism is significantly associated with increased AS risk in a Chinese Han Population.

Interferon gamma gene polymorphisms and chronic hepatitis B infections in an Iranian population

BACKGROUND AND AIMS

Chronic hepatitis B is an important health problem in all countries. I Interferon gamma is a pro-inflammatory Th1 cytokines, which can exert antiproliferative and antitumor activity. Some SNPs in IFN-γ and IFN-γR1 genes may influence the susceptibility to HBV. Here, we evaluated the impact of interferon gamma (+874 T/A) and its receptor (-611A/G, +189G/C and +95C/T) polymorphisms and the risk of HBV in Iranian patients.

MATERIALS AND METHODS

SNPs of interferon gamma and its receptor genotypes were determined in 221 infected patients with HBV and 200 people without HBV using ARMS-PCR and PCR- RFLP method.

RESULTS

In this study, we showed an obvious relationship between IFN-γ SNPs and susceptibility to chronic HBV. Our findings suggest that IFN-γ-874A allele increases the risk of disease and carriers of the T allele have reduced susceptibility to infection. In addition, there was not any relationship between the -611A/G, +189G/C and +95C/T regions of IFN-γ R1 and HBV.

CONCLUSIONS

Our observations demonstrate +874 T/A SNP as a predicting factor in patients who have the risk of HBV.

Immunomodulatory factors gene polymorphisms in chronic periodontitis: an overview

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.

Are There Any Common Genetic Risk Markers for Rheumatoid Arthritis and Periodontal Diseases? A Case-Control Study

Background

Several studies suggest that there is a biologically plausible connection between rheumatoid arthritis (RA) and periodontal diseases (PD). Both disorders are characterized as multifactorial diseases potentially sharing common risk factors. Based on the inflammatory nature of RA and PD, the impact of genetic variations of genes of the immune system on both diseases was studied in this study.

Materials and Methods

We conducted a case-control study (n = 201) comparing 101 RA patients suffering from periodontal disease of different severities (no/mild PD vs. severe PD) with 100 systemically healthy controls without RA and severe PD. The genotype, allele, and haplotype distributions of 22 SNPs of 13 pro- and anti-inflammatory cytokines were assessed applying sequence-specific PCR.

Results

Evaluating the impact of cytokine SNPs in RA, we identified the G allele of rs1801275 in IL4Rα (p = 0.043) and the G allele of rs361525 in TNFα (p = 0.005) as disease-associated risk factors in bivariate analyses. In multivariate analyses, these significant associations could not be proven. The A allele of rs2430561 in IFNγ was indicative for severe periodontitis among the patients with rheumatoid arthritis (p = 0.039). Investigating the impact of rs2430561 in IFNγ on comorbidity using binary logistic regression analyses, the A allele was confirmed as an independent risk factor for severe periodontal disease and RA (p = 0.024).

Conclusions

These results emphasize the association of genetic variations in proinflammatory cytokines (TNFα and IFNγ) and cytokine receptor (IL4Rα) and RA and periodontal diseases. In multivariate analyses, the A allele of IFNγ was proven to be a significant marker of RA and PD comorbidities. The study broadens the knowledge about disease-specific differences in genetic composition and provides an improved understanding of a possible association of both diseases.

IFN-γR2 is strongly expressed on endothelial cells of gingival tissues from patients with chronic periodontitis

OBJECTIVE

Chronic periodontitis (CP) is characterized by gingival inflammation and bone destruction. It has been reported that interferon-gamma (IFN-γ) levels are high in CP patients; however, the IFN-γ receptor (IFN-γR) has not been studied in gingival tissue from these patients. To evaluate IFN-γ levels and IFN-γR expression in gingival tissue biopsies from chronic periodontitis patients compared with healthy subjects (HS).

MATERIAL AND METHODS

Gingival tissues were obtained from all study subjects, CP (n = 18) and healthy subjects (HS) (n = 12). A tissue section of each study subject was embedded in paraffin blocks to determine the expression of IFN-γ R (IFN-γR1 and IFN-γR2) through immunohistochemistry. Another section of the tissue was homogenized and IFN-γ was measured by the ELISA technique.

RESULTS

No significant differences were found in the IFN-γR1 expression within the cell layers of the gingival tissue of the study groups. When analyzing the IFN-γR2 expression it was found that IFN-γR2 is strongly expressed in the endothelial cells of CP patients when compared to HS (p<0.05). IFN-γ concentrations in the gingival tissue were significantly higher in CP patients than in HS. No significant correlation between IFN-γ levels and the expression of IFN-γR1 and IFN-γR2 was found. However, a positive correlation between IFN-γ levels and clinical parameters [probing depth (PD) and clinical attachment level (CAL)] was found.

CONCLUSION

The study of IFN-γR expression in gingival tissue samples from patients with CP showed an increase only in the IFN-γR2 chain in endothelial cells when compared to HS.

CCR5, MCP-1 and VDR Gene Polymorphisms Are Associated with the Susceptibility to HBV Infection

Genetic variants of chemokine and regulatory cytokines play functional roles in chronic HBV infection. The objective of the study, was to evaluate the association between the CCR5D32, CCR5-2459A/G, MCP-1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C SNPs and HBV susceptibility, in samples of Iranian populations. The CCR5D32, CCR5-2459A/G, MCP1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C polymorphisms were analyzed by polymerase chain reaction and PCR-RFLP using 100 chronic HBV infected (HBV) patients, 40 spontaneously recovered HBV (SR) subjects and 100 healthy controls (C). Also, serum levels of protein were monitored. The study showed that the existence of CCR5-2459A, MCP1-2518G and VDR-CC alleles significantly increased risk of chronic HBV infection. In addition, WtAGCC haplotype had a higher frequency in HBV patients than C and SR groups and might relate to the natural history of the infection. Statistical analysis indicated positive correlations between CCR5-2459A/G, MCP1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C genotypes and serum levels of the CCR5, MCP-1 and VDR in HBV patients. According to the statistical analysis, significant associations with susceptibility to chronic HBV infection was observed with CCR5-2459A/G, MCP1-2518A/G, VDR-APa1A/C, VDR-Taq1T/C polymorphisms. In addition, no association of the CCR5D32 SNP with the disease was found.

Analysis of interleukin-10 gene polymorphisms in patients with chronic periodontitis and healthy controls

BACKGROUND

Interleukin-10 (IL-10) is an anti-inflammatory cytokine that has important roles in the periodontal diseases. The IL10-1082, -819, and -592 polymorphisms in the promoter region of IL-10 gene have been associated with various IL-10 expressions. The aim of this study was to investigate the association between these gene polymorphisms with chronic periodontitis in a sample of Iranian populations from Southeast of Iran.

MATERIALS AND METHODS

IL-10 single nucleotide polymorphisms were analyzed in 210 patients with chronic periodontitis (CP) and 100 individuals without CP by polymerase chain reaction-restriction fragment length polymorphism method. Statistical analysis of data was performed using the Chi-square test. The risk associated with single alleles, genotypes, and haplotypes were calculated by performing a multiple logistic regression analysis to estimate the odds ratio (OR) and 95% confidence interval (CI). P < 0.05 for statistical significance.

RESULTS

The prevalences of AG and GG genotypes of IL10-1082 were significantly different between CP and control groups in comparison to AA genotype (OR = 2.671; CI = 1.482-4.815; P = 0.001 for AG vs. AA, OR = 4.151; CI = 2.128-8.097; P < 0.001 for GG vs. AA). In addition, subjects with at least one IL10-1082-G allele were significantly had an increased risk for CP (OR = 2.157; CI = 1.531-3.038; P < 0.001). The distribution of the IL10-819 and IL10-592 genotypes was not different between CP and control subjects (P = 0.109 and P = 0.139, respectively). The combination of different genotypes showed that GCC haplotype was significantly different between groups (OR = 4.379; CI = 1.077-17.807; P = 0.039).

CONCLUSION

The results demonstrated that IL10-1082 polymorphism was a putative risk factor for chronic periodontitis and associated with increased susceptibility to CP.

Effect of Interferon-γ Polymorphisms on Ankylosing Spondylitis: A Case-Control Study

Background

This research aimed to explore the effects of interferon-γ (IFN-γ) polymorphisms and expression profile on susceptibility to ankylosing spondylitis (AS) in a Chinese population.

Material/Methods

Blood samples were collected from 89 AS patients and 106 healthy controls. IFN-γ polymorphisms were genotyped by polymerase chain reaction (PCR) and sequencing methods. The genotype distribution of polymorphism in the control group was detected by Hardy-Weinberg equilibrium (HWE). Odds ratios (OR) with 95% confidence intervals (95%CI) were calculated using the χ² test to evaluate the association between AS susceptibility and IFN-γ polymorphisms. Moreover, serum IFN-γ level was measured by ELISA.

Results

rs1861493 and rs2430561 polymorphisms were conformed to be in HWE in genotypes distribution of the control group (P>0.05 for both). However, only TT genotype and T allele of rs2430561 presented significantly higher frequencies in AS patients than in healthy controls (P=0.04 and 0.03, respectively), indicating that they obviously increased the risk of AS in a Chinese population (OR=2.54, 95%CI=1.01–6.40; OR=1.60, 95%CI=1.04–2.46). In AS patients, serum IFN-γ level was higher than in controls, and its expression patterns showed significant association with genotypes of rs2430561.

Conclusions

IFN-γ rs2430561 polymorphism may contribute to the risk of AS through influencing IFN-γ expression.

Quantitative Parameters of Interdental Gingiva in Chronic Periodontitis Patients with IFN-γ Gene Polymorphism

Chronic periodontitis (CP), an infectious disease resulting in inflammation within the periodontal tissue, is the main cause of adult tooth loss. CP is a multi-factorial disorder and the interaction between multiple genetic and environmental factors results in the manifestation of this disease. Recent researches in periodontitis has focused on cytokine gene polymorphisms that play important role in periodontal inflammation, but few studies investigated histological change that occur during CP in the supporting tissue of teeth. The aims of this study were to investigate the association of IFN-γ +874 A/T polymorphisms and quantitative parameters of interdental gingiva in CP patients. The study samples were interdental gingiva biopsies from 60 individuals including 38 patients and 22 healthy subjects. After determination of IFN-γ +874 A/T gene polymorphism by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR), patients were divided in three subgroups: 10 AA, 18 AT and 10 TT. After slides preparation, quantitative parameters were estimated by Cavalieri's point-counting method. Statistical analyses were performed using Mann-Whitney and Kruskal-Wallis test to compare differences between groups. The volume density (Vv) of epithelium, connective tissue and its components were significantly different between the control and CP groups (P&lt;0.05). Statistically significant differences in the Vv of collagenous and non-collagenous matrix of interdental gingiva between AA, AT and TT groups were found (P&lt;0.05). Result of present study shows that IFN-γ +874 A/T is strongly associated with some quantitative parameters of connective tissue constituents of interdental papilla in CP patients.

The association between interleukin-28B gene polymorphisms as a potential biomarker and the risk of chronic Periodontitis in an Iranian population

BACKGROUND

Chronic Periodontitis (CP) is a common inflammatory disease affects supporting tissues of the teeth and can lead to tooth loss. The objective of this study was to determine the relationship between polymorphisms in the IL-28B gene and chronic periodontitis in an Iranian population.

METHODS

Two hundred and ten CP patients and one hundred healthy subjects were enrolled in the present case-control study. The rs12979860 and rs8099917 SNPs were identified using RFLP and T-ARMS-PCR methods respectively.

RESULTS

SNP analysis revealed that the G allele of rs8099917 SNP and T allele of rs12979860 SNP increased susceptibility to CP compared to the A allele and C allele (p < 0.0001, OR = 2.712, CI = 1.783-4.126; p < 0.0001, OR = 2.538, CI = 1.784-3.613 respectively). In addition, the CT/GT, TT/GG and TT/GT haplotypes were predominant in CP patients and significantly associated with the increased risk of CP.

CONCLUSION

IL-28B polymorphisms may be useful predictive factors for chronic periodontitis and correlated to the susceptibility to CP infection in our population.

Is there an association between IFN-γ +874A/T polymorphism and periodontitis susceptibility?: A meta-analysis

BACKGROUND

Interferon-γ (IFN-γ) is a key proinflammatory cytokine which plays a critical role in the pathogenesis and progression of periodontitis. The single nucleotide polymorphism of +874A/T in human IFN-γ gene can influence the secretion of IFN-γ and affect periodontitis susceptibility. However, the findings of published studies are inconsistent. Therefore, the goal of this meta-analysis is to investigate whether there is an association between IFN-γ +874A/T polymorphism and periodontitis susceptibility.

METHODS

PubMed and the Cochrane Library were searched for eligible clinical studies. The odds ratio (OR) and 95% confidence interval (CI) of each study were pooled to estimate the strength of association between +874A/T and periodontitis. Subgroup analyses were performed to explore whether particular characteristics of studies were related to the overall results.

RESULTS

Seven studies and a total of 1252 periodontitis patients and 1622 periodontitis-free control subjects were included. No difference was observed in genotype distribution and allele frequency between periodontitis patients and control (T vs A: OR  =  1.01, 95% CI: 0.90-1.13, P  =  .878; TT vs AA: OR  =  1.07, 95% CI: 0.87-1.32, P  =  .537; AT vs AA: OR  =  1.00, 95% CI: 0.81-1.23, P  =  .996; TT+AT vs AA: OR  =  1.00, 95% CI: 0.84-1.19, P  =  .990; TT vs AA+AT: OR  =  1.03, 95% CI: 0.86-1.23, P  =  .733). Besides, the subgroup analysis based on ethnicity, type of periodontitis, and smoking status failed to identify significant differences in each model, either.

CONCLUSIONS

The results of this meta-analysis suggest that IFN-γ +874 A/T polymorphism may not contribute to periodontitis susceptibility. High quality and well-designed studies which combine genetic and other environmental risk factors are needed to validate this conclusion in the future.

Gene polymorphisms of macrophage migration inhibitory factor affect susceptibility to chronic hepatitis B virus infection in an Iranian cohort

Macrophage migration inhibitory factor (MIF), a key proinflammatory mediator, plays important roles in chronic diseases. In this study, an attempt was made to clarify the associations between some functional polymorphisms such as MIF-173 G/C, MIF 95 bp and 189 bp insertion/deletion (I/D) polymorphisms and chronic hepatitis B virus (HBV) infection. Polymorphisms were assessed in 221 HBV patients and 200 normal subjects. MIF-173 G/C and MIF 95 bp and 189 bp I/D polymorphisms were genotyped using PCR-RFLP and PCR, respectively. When allele and genotype frequencies of the variants were compared between patients and controls by the χ(2) test, it was found that the frequency of MIF-173 G/C genotypes differed significantly between patients with chronic HBV and healthy controls (P < 0.05). Carriers of the MIF -173-C allele were at significantly higher risk of HBV infection than carriers of the MIF -173-G allele (P = 0.009, OR = 1.549, 95% CI = 1.114 - 2.155). Moreover, 95 bp I/D polymorphism was not associated with CP and the 185 bp I/D variant was not polymorphic in our group of subjects. The frequency of haplotypes did not differ significantly between groups (χ(2)  = 11.391, P = 0.181). Our results suggest that MIF -173 G/C variant increases the risk of HBV in Iranian subjects. Further studies with larger sample sizes and different ethnicities are required to validate our findings.

Association of macrophage migration inhibitory factor gene polymorphisms with chronic periodontitis in a South Eastern Iranian population

Background:

Macrophage migration inhibitory factor (MIF) is a key proinflammatory mediator. It plays a vital role in immune response against the oral disease. MIF is a regulator of innate immunity, and bacterial antigens can stimulate serum level of this protein. In experimental gingivitis, the expression level of MIF increases and this increment positively correlates with oral plaque index. The single nucleotide polymorphisms in the gene encoding the MIF protein can control the function of MIF. The aim of the present study was a clarification of the associations between MIF-173 G/C, MIF 95 bp, and 189 bp insertion/deletion (I/D) polymorphisms and chronic periodontitis (CP) compared with healthy controls.

Materials and Methods:

This case–control study was carried out on 210 CP patients and 100 normal subjects. MIF-173 G/C and MIF 95 bp and 189 bp I/D polymorphisms were genotyped, using polymerase chain reaction–restriction fragment-length polymorphism (PCR-RFLP) and PCR, respectively. Allele and genotype frequencies of the variants were compared between patients and controls using Chi-square. test. The value of P < 0.05 was considered statistically significant.

Results:

The study findings showed that MIF-173 G/C polymorphism, especially the C allele increased the risk of CP. The 95-bp I/D polymorphism was not associated with CP and the 185-bp I/D variant was not polymorphic in our population.

Conclusion:

Therefore, MIF-137 G/C variant increased the risk of CP in the South East of the Iranian population. In other words, polymorphisms in MIF gene influence clinical outcome of CP infection and influence the susceptibility to disease. Further studies with larger sample sizes and different ethnicities are required to validate our findings.