Association of Polymorphisms in the Human IFN-γ and IL-4 Gene with Oral Lichen Planus: A Study in an Ethnic Chinese Cohort

Association of polymorphisms in Th1/Th2-related cytokines (IFN-γ, TGFβ1, IL-1β, IL-2, IL-4, IL-18) with oral lichen planus: A pooled analysis of case–control studies

Background/purpose

Increasing evidence suggests that single-nucleotide polymorphisms (SNPs) in Th1/Th2-related cytokine genes correlated with oral lichen planus (OLP) susceptibility. However, these results were inconsistent and inconclusive. Hence, the aim of this study is to draw a more precise estimation of the genetic associations between SNPs in 6 cytokines (IFN-γ, IL-18, TGFβ1, IL-1β, IL-2, IL-4) and OLP.

Materials and methods

A systematic literature search was conducted to identify all eligible case-control studies on the association between SNPs in 6 cytokines and OLP susceptibility. Odds ratios (ORs) and 95% confidence intervals (CIs) from each study were pooled to estimate the strength of the association.

Results

A significant association of IFN-γ (874A/T) polymorphism with OLP was found (OR, 1.49; 95%CI, 1.22-1.81; P < 0.001) based on 6 eligible studies. A significant association of IL-18 (137G/C) polymorphism with OLP was found (OR, 1.64; 95%CI, 1.24-2.18; P < 0.001) based on 3 studies. A marginally significant association of TGFβ1 (509C/T) polymorphism in allele model with OLP was found (OR, 1.31; 95%CI, 1.01-1.71; P = 0.05) based on 4 studies. Nevertheless, lack of significant association of IL-1β (3954C/T), IL-2 (330T/G), IL-4 (590C/T), and IL-18 (607C/A) polymorphisms with OLP was found (P > 0.05) based on 3 studies, respectively.

Conclusion

This is the first meta-analysis to investigate the associations of 6 cytokines polymorphisms with OLP, suggesting that SNPs in IFN-γ, IL-18, and TGFβ1 may act as genetic factors for OLP risk. Further well-designed studies with larger sample size and multiple ethnicities are needed to validate these associations.

Rise and exacerbation of oral lichen planus in the background of SARS-CoV-2 infection

Oral Lichen Planus (OLP) is a chronic inflammatory disorder whose exact etiology remains unknown. Inflammatory mediators, cytotoxic CD8+ T cells and mast cells have been hypothesized to mediate the pathogenesis of OLP. COVID-19 pandemic caused by SARS-CoV-2 is marked by cytokine storms in the affected patients. Altered T-cell responses marked by exhaustion of T-cell count with hyperaggressive remaining T-cells and presence of cross-reactive antibodies render infected humans as fertile grounds for development of multisystem disorders. In addition, Vitamin D deficiency in COVID-19 patients can further modify the T cell mediated immunity. Increased circulating cytokines and hyperactive CD8+ T cells can alter the oral immune barriers rendering them susceptible to oral disorders. Due to the widespread immune dysregulation, it is possible that patients of COVID-19 may develop OLP in the aftermath or during recovery. The paper explores the pathogenic mechanism behind development OLP as post-COVID condition on account of their target receptor, T-cell responses, cytokine profile, mucosal immune barriers and nutrition deficiency.

Role of interleukin-4 in pathogenesis of oral lichen planus: A systematic review

Background

Oral lichen planus (OLP) is a premalignant mucocutaneous disease that affects 1-2% of the adult population. Immunological factor may act as etiological factor. The cellular immune cells such as T cells are important in pathogenesis of OLP. Interleukin-4 (IL-4) is secreted by T-helper 2 (Th2). Several studies have been carried out on the role of IL-4 in OLP. The aim of this study was to review the level of IL-4 in OLP, effective factors in the production of IL-4 and its role in the development of OLP.

Material and Methods

A search in PubMed was performed on the literature published from 2000 until august 2019 using the following keywords: “oral lichen planus” or “OLP” and “interleukin-4” or “IL-4”.

Results

Originally, 37 articles were considered, of which 28 case-control articles were selected according to the inclusion/exclusion criteria.

Conclusions

This review study shows that IL-4 plays a key role in the development of OLP. According to the past studies, there are several factors contributing to the production of this cytokine. Identification of the routes of production of IL-4 and its role in OLP might be useful for development of new preventive and therapeutic methods in management of patients with OLP.

Key words:Interleukin 4, oral lichen planus, pathogenesis.

Serum and salivary interleukin-4 levels in patients with oral lichen planus: A systematic review and meta-analysis

OBJECTIVE

Cytokines have an important role in keratinocyte immune damage and can act in the pathogenesis of different cutaneous diseases. Accordingly, in the literature, interleukin 4 (IL-4) concentration has been previously investigated in patients affected by oral lichen planus (OLP).

STUDY DESIGN

The present meta-analysis evaluated the serum and salivary levels of IL-4 in connection with several OLP variants. The search was performed from 1995 in Cochrane Library and 1983 in Scopus, PubMed, and Web of Science to September 2018. The quality of the studies included in the meta-analysis was assessed using the Newcastle-Ottawa Scale assessment. The analyses were done by Review Manager 5.3 using mean difference (MD) and 95% confidence intervals (CIs).

RESULTS

Out of 108 studies retrieved in the databases, only 10 were included and analyzed in quantitative synthesis. The pooled MD of the serum and salivary IL-4 levels in OLP patients compared with the controls was 6.36 picograms/milliliter (pg/mL) (95% CI: 1.47, 11.24; P = .01) and 2.67 pg/mL (95% CI: 2.66, 2.68; P < .00001), respectively. In addition, the pooled MD of serum and salivary IL-4 level was 1.30 pg/mL (95% CI: -0.35, 2.95; P = .12) and 1.83 pg/mL (95% CI: 0.26, 3.40; P = .02), respectively, in patients with erosive, erythematous, bullous, and ulcerative variants of OLP compared with patients with reticular OLP.

CONCLUSIONS

This meta-analysis found that OLP patients present elevated serum and salivary IL-4 levels, thus indicating that IL-4 may represent a potential salivary biomarker for the disease. By contrast, clinicians must be aware that even other factors (e.g., secondary infection) may influence its concentration.

Assessment of Interleukin-18 gene polymorphism and serum levels in oral lichen planus in an Indian population

BACKGROUND

Oral lichen planus (OLP) is a chronic, inflammatory disease with uncertain etiology. The aim of this study was to assess Interleukin-18 (IL-18) gene polymorphism and serum levels in OLP cases of Indian origin and to compare them with a control population of similar background.

METHODS

The assessment of single-nucleotide polymorphisms (SNPs) of IL-18 gene at promoter regions -137(G/C) and -607(C/A) was done in 70 OLP cases and 70 healthy controls using sequence-specific primer-polymerase chain reaction (SSP-PCR). In a subset of this cohort, comprising of 41 OLP cases and 41 controls, serum IL-18 levels were assessed using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Mean serum levels of IL-18 among OLP cases were significantly higher when compared to controls. Genotypic and allelic frequencies of IL-18 at position -137(G/C) showed that GG genotype and allele G was significantly higher in OLP cases, whereas, GC genotype and C allele was high in the control group. Polymorphism of IL-18 at position -607(C/A) showed no significant differences.

CONCLUSIONS

Gene polymorphism at -137GG genotype and allele G seems to be associated with genetic susceptibility to OLP whereas -137GC and allele C may have a protective role against its development. However, our study lacks clear statistical correlation, the differences observed could be caused by sampling problems and the results could not be fully representative of Indian patients with OLP. Further studies are warranted to explore the role of IL-18 genetic polymorphisms in OLP development.

Evaluation of serum and salivary interferon-γ levels in patients with oral lichen planus: a systematic review and meta-analysis of case-control studies

OBJECTIVE

Cytokines have regulatory and leading roles in the immunopathogenesis of oral lichen planus (OLP). Here, we present the findings of a meta-analysis that evaluated serum and salivary interferon-γ (IFN-γ) levels in patients with OLP compared with those in controls and the correlation of this cytokine with the progression of OLP.

STUDY DESIGN

Four databases-PubMed, Web of Science, Scopus, and Cochrane Library-were searched, from their start dates to November 2017, for reports in all languages on the effect of OLP on salivary and serum IFN-γ.

RESULTS

Eleven studies were included and analyzed in this meta-analysis. The pooled mean difference (MD) values were estimated to be 3.60 pg/mL (P = .23) and -0.02 pg/mL (P = 1.00) for serum and salivary levels of IFN-γ, respectively, in the patients with OLP compared with controls. The pooled MD values were -2.52 pg/mL (P = .03) and -2.01 pg/mL (P = .20) for serum and salivary IFN-γ levels in the erosive type, respectively, compared with the nonerosive type.

CONCLUSIONS

According to the results of meta-analysis, there was no statistically significant differences in IFN-γ levels between the OLP group and the control group both in serum and salivary levels and also between erosive and nonerosive types of OLP at the salivary level; so this cytokine is not considered to have an important role in the pathogenesis or severity of OLP.

Interferon gamma and interleukin 8 gene polymorphisms in patients with hepatitis C virus related oral lichen planus

OBJECTIVES

This study aimed to determine the association of rs2430561 and rs4073 polymorphisms in the Interferon gamma (IFN-ɤ) and Interleukin 8 (IL-8) genes, respectively, with hepatitis C virus-related oral lichen planus and disease severity.

DESIGN

This is a case-control study. 60 subjects were equally divided into patients with and without oral lichen planus. They were further subdivided into hepatitis C virus seropositive and seronegative patients. All patients were genotyped for IFN-γ rs2430561 thymine to adenine (T > A) and IL-8 rs4073 adenine to thymine (A > T) polymorphisms. All patients with oral lichen planus had their lesions measured and documented using the Escudier scoring system.

RESULTS

Disease activity was significantly higher in the "oral lichen planus/hepatitis C virus-positive" patients than in the "oral lichen planus/hepatitis C virus-negative" patients (P = 0.003). IFN-γ rs2430561 T > A and IL-8 rs4073 A > T genotypes and allele frequencies were not associated with the oral lichen planus group or the normal group. Stratification of the two groups into HCV and non-HCV-infected patients or into erosive and non-erosive types revealed no significant associations. The "A-allele-containing" genotypes of IL-8 rs4073 A > T were significantly more prevalent in the patients with oral lichen planus than in those without.

CONCLUSION

Hepatitis C virus infection is associated with the development of erosive oral lichen planus. The A-allele of IL-8 rs4073 A > T may have a role in the development and progression of oral lichen planus.

Lack of Association between Oral Lichen Planus and Hepatitis B and C Virus Infection - a Report from Southeast Iran

Background: Oral lichen planus (OLP) is a chronic autoimmune disease with an unknown etiology. Dentists are usually the first medical practitioners to diagnose this condition although it also affects body parts other than the oral mucosa. Several studies have reported an association between the OLP and hepatitis B and C infections. This study aimed to determine the prevalence of hepatitis B virus (HBV) antigen and hepatitis C virus (HCV) antibodies in patients with OLP compared with healthy controls. Methods: In this case‒control study, 50 patients with clinical and histopathological characteristics of OLP, and 50 age- and sex-matched healthy controls supplied serum samples (5 mL) for evaluation by ELISA. Data were analyzed using SPSS Software, version 21. Chi-square test was applied as appropriate. Results: In this study, the 50 patients with OLP (33 females and 17 males) had a mean age of 42.0 ± 14.5 years, and the 50 healthy subjects (33 females and 17 males) a mean age of 41.9 ± 13.7 years. None demonstrated any evidence of HBV antigen or HCV antibodies. Discussion: We could not detect any association between OLP and viral hepatitis. This could be attributed to a lower prevalence of hepatitis viruses compared to other countries or genotypic variation or other etiological factors contributing in our cases.

Serum cytokine profile and clinicopathological findings in oral lichen planus, oral lichenoid lesions and stomatitis

The objective of this study was to examine if clinical and histopathological variables in patients with oral lichen planus (OLP), oral lichenoid lesions (OLL), and generalized stomatitis display different cytokine profiles and if concomitant contact allergy influences this profile. Forty-nine patients and 29 healthy age- and gender-matched subjects were included. Demographic and clinical data immunohistochemical findings in mucosal specimens, results of contact allergy testing, and serum levels of tumor necrosis factor-α, interferon-γ, interleukin (IL)-6, IL-10, IL-12p40, and IL-12p70 were analyzed and compared between groups. Nineteen patients had OLP, primarily with ulcerative lesions on the buccal mucosa, 19 patients had OLL, and 11 patients had generalized stomatitis. All patients had oral symptoms, mainly stinging and burning. Nineteen patients and 10 healthy subjects had contact allergies, primarily to fragrance ingredients. Patient groups did not differ with regard to oral symptoms, clinical pattern of the lesions, or contact allergy. Serum cytokine levels did not differ between the different patient groups and were not related to histopathological findings. The patients had higher levels of IL-6 than the healthy subjects. Interferon-γ, IL-12p40, and IL-12p70 were below detection limit. Our findings indicate that OLP, OLL, and generalized stomatitis cannot be discriminated by means of the selected serum cytokines, and that the presence of concomitant contact allergy does not influence the cytokine expression.

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.

Association between polymorphisms in interleukins and oral lichen planus: A meta-analysis

BACKGROUND

More and more studies have suggested that single-nucleotide polymorphisms (SNPs) in interleukin (IL) genes are correlated with an increased risk of developing oral lichen planus (OLP). However, these results were inconsistent. Therefore, the aim of this meta-analysis is to retrieve and comprehensively analyze all related clinical studies to investigate the association of ILs gene polymorphisms with the OLP risk.

METHODS

PubMed, Embase, and the Cochrane Library were searched for eligible studies to evaluate the association between IL polymorphisms and the OLP. The odds ratios (ORs) and 95% confidence intervals (CIs) from each study were pooled to estimate the strength of the association. Statistical analyses were performed by using STATA software.

RESULTS

In all 6 studies, including 4 SNPs (IL6-174G/C, IL10-592C/A, IL10-819C/T, and IL10-1082G/A), 362 OLP patients and 622 non-OLP control subjects from five different countries were investigated. As for the IL6-174G/C, IL10-819C/T, and IL10-1082G/A, no evidence was found to support the association between SNP and OLP susceptibility in any genetic models. However, as for IL10-592C/A, a significant relationship between them was identified in all of comparison models (C vs A: OR = 0.724, 95% CI = 0.585-0.897, P = 0.003; CC vs AA: OR = 0.447, 95% CI = 0.276-0.722, P = 0.001; AC vs AA: OR = 0.585, 95% CI = 0.387-0.883, P = 0.011; CC+AC vs AA: OR = 0.544, 95% CI = 0.365-0.809, P = 0.003; CC vs AA+AC: OR = 0.715, 95% CI = 0.515-0.994, P = 0.046).

CONCLUSION

With the presently available evidence, this meta-analysis fails to show the statistical associations between IL6-174G/C, IL10-819C/T, and IL10-1082G/A and OLP susceptibility in any genetic models. However, the A allele and AA genotype in IL10-592C/A polymorphism may increase the risk of OLP. In the future, more well-designed studies with larger sample sizes are needed.

The G allele in IL-10-1082 G/A may have a role in lowering the susceptibility to panic disorder in female patients

BACKGROUND

Immune system activation is involved in the pathophysiology of panic disorder (PD). We investigated INF-γ+874 A/T, TNF-α-308 G/A, and IL-10-1082 G/A single nucleotide polymorphisms (SNPs) to determine their association with PD.

METHOD

This study enroled 135 PD patients and 135 healthy controls. INF-γ+874 A/T (rs2430561), TNF-α-308 G/A (rs1800629), and IL-10-1082 G/A (rs1800896) were genotyped.

RESULTS

There were no differences in genotypes or allele frequencies between the patient and control groups, regardless of accompanying agoraphobia. However, for female patients, the G allele frequency in IL-10 SNP was higher in the control group than in the patient group. Additionally, the female control group had a higher frequency of the A/G and G/G genotype in the IL-10 SNP than the female patient group.

CONCLUSION

We suggest that the G allele in IL-10-1082 G/A might have a role in reducing the manifestations of PD in female patients. Further studies are needed to extend and confirm our findings.

Association of genetic polymorphisms in interferon-γ, interleukin-6 and transforming growth factor-β1 gene with oral lichen planus susceptibility

BACKGROUND

Oral lichen planus (OLP) is a premalignant mucocutaneous disease in which genetic factors and immune responses play a major role. Cytokines play an important role in the pathogenesis and disease progression of OLP. The aim of this study was to investigate the impact of gene polymorphisms of T helper cell subtype Th1 and Th2 cytokines, interferon-gamma (IFN-γ), interleukin-6 (IL-6) and transforming growth factor (TGF)-β1 on OLP susceptibility in a Saudi cohort.

METHODS

Forty two unrelated patients with OLP and 195 healthy controls were genotyped for IFN-γ (874A/T), IL-6 (174G/C) and TGF-β1 (509C/T) polymorphisms.

RESULTS

The frequency of genotype AT of IFN-γ (874A/T) was significantly higher while genotype AA was lower in OLP patients as compared to controls (P < 0.05). The frequency of T containing genotypes (AT + TT) was also higher in OLP patients as compared to that in controls (P = 0.003). The frequencies of allele T was higher while that of allele A lower in patients than the controls however the difference was not statistically significant (P = 0.07). There was no significant difference in the frequencies of alleles and genotypes of IL-6 (174G/C) and TGF-β1 (509C/T) polymorphisms between patient and control groups. These results indicated that genotype AT of IFN-γ (874A/T) polymorphism is associated with OLP risk and genotype AA is protective to OLP. On the other hand the polymorphisms IL-6 (174G/C) and TGF-β1 (509C/T) may not be associated with OLP risk in our population.

CONCLUSION

It is concluded that IFN-γ (874A/T) polymorphism is associated with the susceptibility of OLP, however further studies with large sample size involving different ethnic populations should be conducted to strengthen our results.

MicroRNAs in oral lichen planus and potential miRNA-mRNA pathogenesis with essential cytokines: a review

Oral lichen planus (OLP) is a potentially premalignant condition with unknown pathogenesis. Immune and inflammatory factors are thought to play important roles in the development of OLP, and cytokines, such as interferon (IFN)-γ and tumor necrosis factor (TNF)-α, can act as critical players in the immunopathogenesis of OLP. MicroRNAs (miRNAs) are closely correlated with cytokines in various inflammation-related diseases. In patients with OLP, miRNA-146a and miRNA-155 are increased in peripheral blood mononuclear cells, and numerous miRNAs have been shown to exhibit altered expression profiles in lesions. Although the microRNA-messenger RNA (miRNA-mRNA) network is thought to be involved in the development of OLP, in-depth studies are lacking. Here, we summarize current data on the mechanisms of action of miRNAs regulating typical cytokines in OLP, including interleukin (IL)-10, IL-17, IL-22, IFN-γ, and TNF-α, to study the genetic basis of the pathogenesis of OLP and to provide prospects of therapy.

Etiology and pathogenesis of oral lichen planus: an overview

Oral lichen planus is a noninfectious, chronic inflammatory condition that involves the oral mucosal stratified squamous epithelium and the underlying lamina propria and may be accompanied by skin lesions. This overview describes the current understanding of the immunopathologic mechanisms implicated in oral lichen planus.

Salivary Interferon Gamma and Interleukin-4 Levels in Patients Suffering from Oral Lichen Planus

Objective

Oral lichen planus (OLP) is a chronic inflammatory disease. Immunological factor may act as etiological factor. The cellular immune cells such as T cells are impor- tant in pathogenesis. Interferon gamma (IFN-γ) and interleukin 4 (IL-4) are secreted by T-helper 1 (Th1) and Th2, respectively. The aim of this study was to investigate the cor- relation between salivary levels of IFN-γ and IL-4 with OLP.

Materials and Methods

This case control study included sixty three Iranian OLP patients who were selected from the Department of Oral Medicine of Ahvaz Jundishapur University of Medical Sciences from January to July 2013. An equal number of healthy volunteers were also selected as a control group. The OLP patients were then divided into two follow- ing sub-groups: reticular (n=30) and erythematous/ulcerative (n=33). All patients had no systemic disease and received no medication. IFN-γ and IL-4 levels in whole unstimulated saliva (WUS) were measured using the enzyme-linked immunosorbent assay (ELISA) test. Data analysis was done using t test, ANOVA, least significant difference (LSD) test, and the Kruskal-Wallis test.

Results

Reticular OLP patients showed higher salivary IFN-γ (7.74 ± 0.09 pg/ml ) and IL-4 (3.876 ± 0.05 pg/ml) levels compared with the control group, indicating that difference was significant. Salivary IFN-γ/IL-4 ratio significantly increased compared with control group (P=0.042). Salivary IFN-γ and IL-4 levels between sub-groups (re- ticular and erythematous/ulcerative) were not significantly different (2.6 ± 0.06 and 2.3 ± 0.05, respectively, P<0.05).

Conclusion

Salivary IFN-γ and IL-4 levels were increased in OLP patients. An increase of salivary IFN-γ/IL-4 ratio in OLP patients showed that Th1 might have a dominant role in the OLP pathogenesis.

The association between oral lichen planus and hepatitis C virus infection; a report from northeast of iran

Background:

The association between hepatitis C virus (HCV) infection and oral lichen planus (OLP) has been the focus of many studies. Fifteen percent of HCV infections lead to sets of extrahepatic manifestations including lichen planus (LP). The prevalence of HCV is heavily influenced by geographical location.

Objectives:

This study aimed to evaluate the relationship between OLP and HCV infection in Mashhad, northeast of Iran.

Materials and Methods:

Blood samples were taken from 134 OLP patients and 134 healthy controls (without OLP) to screen for anti-HCV by ELISA (third generation) and reverse transcription polymerase chain reaction (RT-PCR) for HCV-RNA.

Results:

Of the 134 OLP patients only three (2.23 %) had HCV infection where both anti-HCV and HCV-RNA were positive. All controls were negative for both anti-HCV and HCV-RNA (P = 0.082).

Conclusions:

Our investigation illustrated that the prevalence of hepatitis C was higher among OLP patients compared to the control group. These findings are in line with previous results that reported a hepatitis C prevalence of 0.19% among the general population of Mashhad.

Association of single nucleotide polymorphisms in MPO and COX genes with oral lichen planus

Oral lichen planus (OLP) is an intractable, chronic inflammatory disorder, and its pathogenesis is still largely unknown. Some literatures supported that genes involved in both oxidative stress and prostaglandin metabolism play an important role in the process of inflammation. To explore their association with OLP, we investigated four single nucleotide polymorphisms (SNPs) from myeloperoxidase (MPO) and cyclooxygenase (COX) genes in 475 Chinese individuals (242 case and 233 controls) by MassArray. Although the genotype distributions had no significant differences between the patients and controls, we found that in different gender, rs2243828 from MPO displayed the statistically significant variance genotype frequencies between patients and controls (P = 0.018 in females, P = 0.035 in males). Moreover, for the major allele recessive model, this SNP also showed a significant difference between case and control groups in males (P = 0.015). In this study, we first observed significant association with MPO polymorphism and OLP risk in different gender groups in Chinese, suggesting MPO polymorphism is a gender-specific risk factor of OLP probably by influencing sex hormone-sensitive elements to regulate inflammatory gene expression networks, and we further revealed that oxidative stress was actually involved in the pathogenesis of this disease. Moreover, these findings inspire us some constructive solutions to the treatment of this disease.

The mucosal immune system in the oral cavity-an orchestra of T cell diversity

The mucosal immune system defends against a vast array of pathogens, yet it exhibits limited responses to commensal microorganisms under healthy conditions. The oral-pharyngeal cavity, the gateway for both the gastrointestinal and respiratory tracts, is composed of complex anatomical structures and is constantly challenged by antigens from air and food. The mucosal immune system of the oral-pharyngeal cavity must prevent pathogen entry while maintaining immune homeostasis, which is achieved via a range of mechanisms that are similar or different to those utilized by the gastrointestinal immune system. In this review, we summarize the features of the mucosal immune system, focusing on T cell subsets and their functions. We also discuss our current understanding of the oral-pharyngeal mucosal immune system.

Th1 and Th2 polymorphisms in Sjögren's syndrome and rheumatoid arthritis

BACKGROUND

Sjogren's syndrome is characterized by T-cell infiltration of exocrine glands leading to parenchymal destruction and impaired glandular function. This process is orchestrated by cytokines, whose secretion can be regulated by genetic polymorphisms.

MATERIALS AND METHODS

The aim of this study was to investigate the influence of interleukin-6 -174G/C, interleukin-10 -1082G/A, tumor necrosis factor-α -308G/A, interferon-γ +874A/T gene polymorphisms in (RA) and secondary Sjögren's syndrome (sSS). A study sample that comprised of 138 Brazilian patients was divided into three groups: RA (n = 66), sSS (n = 20), and healthy controls - C (n = 52). Patients were subjected to Schirmer's test, unstimulated salivary flow rate, biopsy of minor salivary glands, and serological tests for diagnosing SS. Genomic DNA was obtained from saliva samples and submitted to genotyping. The association between genotypes/alelle frequency and SS susceptibility was tested, as well as their association with clinical features of SS.

RESULTS

Tumor necrosis factorα (TNFα)-308GA polymorphisms differed significantly between AR, SS, and C patients (P = 0.008). IL-6 overall G carriers and TNFα A carriers had a higher risk of presenting SS (P = 0.021). IL-6 polymorphism distribution was also distinctive regarding lymphocytic infiltration at the minor salivary glands (P = 0.026) and Schirmer's test (P = 0.035).

CONCLUSION

These results suggest that IL-6 -174GC and TNFα-308GA gene polymorphisms are associated with susceptibility to SS. Additionally, IL-6 polymorphism could influence lymphocytic infiltration of salivary glands and diminish lachrymal gland function.

Effect of IL-12B, IL-2, TGF-β1, and IL-4 polymorphism and expression on hepatitis B progression

The hepatitis B virus (HBV) infection-induced chronic inflammation is considered to be the major etiological factor for HBV-related disease chronicity. Cytokines act as the key coordinators of the inflammatory responses involved in HBV disease pathogenesis. The present study assessed association among IL-12B(+1188), IL-2(-330), TGF-β1(-509), and IL-4(-590) genotypes; mRNA; and protein levels with HBV-hepatocellular carcinoma (HCC) risk in India. For this, 403 subjects (153 controls, 67 inactive HBV-carriers, 62 chronic-active HBV patients, 62 HBV-cirrhotics, and 59 HBV-HCC ssubjects) were enrolled in the study. The genotyping was carried by polymerase chain reaction (PCR)-restriction fragment length polymorphism (IL-12+1188A/C, IL-2-330T/G, and TGF-β1-509C/T), and allele specific (AS)-polymerase chain reaction (IL-4-590C/T). Enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction methods were used for assessing protein and the mRNA expression, respectively, of the mentioned cytokines. The study revealed that the IL-12B(+1188) CC genotype shared a significant positive association with hepatitis, among controls. While, in the case of IL-2(-330), both the TG and GG genotypes were not significantly associated with HCC risk. The TGF-β1(-509) TT genotype acted as a potential protective factor for cirrhosis and the HCC risk, among carriers. On the contrary, the IL-4(-590) CT genotype was found to be a vital protective factor for the development of hepatitis, among carriers. Besides, IL-12B, TGF-β1, and IL-2 seem to be majorly involved in the development of HCC, while, IL-4 might be responsible for the progression of the HBV disease till cirrhosis development. These initial findings are indicative of the vital role of genotypes and/or levels of IL-12B, IL-2, IL-4, and TGF-β1 in HBV disease chronicity in Indian population.

Inflammation-related cytokines in oral lichen planus: an overview

Cytokines are powerful mediators which play a central role in both innate and adapted immune responses. Aberrant productions of cytokines may lead to the onset of immune deficiency, allergy or autoimmunity, which are involved in the mechanisms of various immune-mediated inflammatory diseases. Oral lichen planus (OLP) is a chronic inflammation disease affecting the oral mucosa with unknown aetiology. Previous studies have described the abnormal expression patterns of various inflammation-related cytokines, such as IL-1, 2, 4, 5, 6, 8, 10, 12, 17, 18, TGF-β, IFN-γ and TNF-α, in lesions, saliva, serum and peripheral blood mononuclear cells from patients with OLP, which may reflect the immune dysregulation status and emerge as central players in the immunopathogenesis of OLP. Besides, the gene polymorphisms of several cytokines such as IFN-γ, TNF-α, IL-4, IL-10 have been found to be involved in the susceptibility of OLP. In this review, we gave a brief introduction of the characteristics and biological functions of these inflammation-related cytokines and summarized for the first time the current knowledge on the involvement of inflammation-related cytokines in OLP. Further research on the exact roles of these cytokines will aid the understanding of the pathogenesis and the identification of novel therapeutic approaches of OLP.

TNF-alpha -308G>A polymorphism is associated with suicide attempts in major depressive disorder

BACKGROUND

Despite the substantial role of the cytokine network in depression and suicide, few studies have investigated the role of genetic polymorphisms of pro- and anti-inflammatory cytokines in suicide in major depressive disorder (MDD). The aim of this study was to investigate whether tumor necrosis factor-alpha (TNF-alpha) -308G>A, interferon-gamma (IFN-gamma) +874A>T, and interleukin-10 (IL-10) -1082A>G are associated with increased risk for suicide attempts in MDD.

METHODS

Among patients with MDD, 204 patients who had attempted suicide and 97 control patients who had not attempted suicide were recruited. A chi-square test was used to identify a possible risk genotype or allele type for suicide. A subsequent multivariate logistic regression analysis was conducted to investigate the influence of a risk genotype or allele type adjusted for other environmental factors. The lethality of the suicide attempt was also tested between genotype and allele types among suicidal patients with MDD.

RESULTS

The GG genotype of the TNF-alpha -308G>A polymorphism was found to significantly increase risk for suicide attempt (adjusted OR=2.630, 95% CI=1.206 to 5.734). IFN-gamma +874A>T and IL-10 -1082A>G were not associated with risk for suicide. Lethality of the suicide attempt was not associated with any of the three cytokine genotypes or allele types.

LIMITATIONS

Limitations include a relatively small sample size and a cross-sectional design.

CONCLUSIONS

TNF-alpha -308G>A polymorphism is an independent risk factor for suicide attempts in MDD. Future studies should clarify the neural mechanisms by which the GG genotype of TNF-alpha -308G>A influences suicide in MDD.

Association of cytokine gene polymorphisms with oral lichen planus in Malayalam-speaking ethnicity from South India (Kerala)

Oral lichen planus (OLP) is a chronic mucocutaneous condition that affects the oral mucous membrane as well as skin. It is a chronic cell-mediated autoimmune condition where the T-cell-mediated immune response plays an important part in the pathogenesis by causing damage to basal keratinocytes in oral mucosa. Cytokine gene polymorphisms have an unquestionable role in the orchestration of the immune response, leading to different functional scenarios, which in turn influence the outcome of the disease establishment and evolution. The purpose of this study was to understand the role of these cytokine gene polymorphisms in the tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and IL-6 genes with OLP in 101 individuals of Malayalam-speaking ethnicity from South India (Kerala). We further investigated the role of these polymorphisms in patients suffering from OLP with other comorbid factors. Genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism. The results demonstrate that the A allele in the TNF-α -308 polymorphism could play an important role in the susceptibility to OLP. IL-1β +3954 in OLP was associated with other comorbid factors in both allelic and genotypic combinations. However, when patients suffering from OLP were stratified to understand the involvement of other comorbid factors, we observed that the T and C alleles were independent risk factors for chronic periodontitits and diabetes mellitus. On the other hand, IL-6 -597 did not show any disease association with OLP in the study population. This study indicates that proinflammatory cytokines are an important factor in understanding the disease burden of OLP and their comorbid factors.

Oral lichen planus: focus on etiopathogenesis

Lichen planus is a chronic mucocutaneous inflammatory disease, which frequently affects the oral mucosa of white females over 40 years old. Its aetiology remains uncertain and the pathogenesis is still the object of much speculation. The present paper presents the most well known antigens, and describes the action of different cells and proteins associated with the development of that disease, as well as the possible agents involved with its malignant transformation. Different external agents, especially virus, and internal agents, like stress, and the heat shock protein antigen expression, associated or not, can alter the basal keratinocytes of the oral mucosa making them susceptible to apoptosis by CD8(+) cytotoxic T cell as well as activate matrix metalloproteinase and mast cell degranulation, which produce a great range of inflammatory mediators and cytokines determining the clinical onset of the disease. Regarding carcinogenesis, since it is a complex process and presents multifactorial origin, it is believed that there may be a synergism between intrinsic, such as inflammation mediators, and extrinsic agents (tobacco, alcohol, viral infections) for the OLP malignant transformation to occur. However, further studies are needed to better understand the origin, pathogenesis and process of malignant transformation of OLP.

The T allele of the interferon-gamma +874A/T polymorphism is associated with bipolar disorder

BACKGROUND

Previous studies have shown that patients with bipolar disorder (BD) tend to have altered immune system function. Several studies have reported that changes in interferon-gamma (IFN-γ) may play an important role in the development of BD.

AIMS

To investigate the relationship between IFN-γ and BD, 156 patients with BD and 175 control subjects were genotyped for the IFN-γ +874A/T single nucleotide polymorphism.

RESULTS

We detected significant differences in the genotype distributions and allele frequencies of the IFN-γ +874A/T single nucleotide polymorphism (rs2430561) between patients with BD and normal controls. The T allele was found to be significantly more common among patients with BD than in controls. Additionally, significant differences in scores on the Young Mania Rating Scale (YMRS) were found between the three genotypes of this polymorphism.

CONCLUSIONS

Our results suggest that the IFN-γ +874A/T polymorphism may have important effects related to susceptibility to BD and that the T allele may be associated with an increased risk of developing BD.

Interleukin-4 -590T/C polymorphism influences the susceptibility to nonsmall cell lung cancer

Lung cancer is the leading cause of cancer mortality worldwide. Nonsmall cell lung cancer (NSCLC) accounts for most of these cases. Interleukin 4 (IL-4) is a typical pleiotropic T helper 2 cytokine and plays crucial roles in tumor immunology. IL-4 gene -590T/C polymorphism has been shown to be associated with different autoimmune diseases and cancers. The present study evaluated the correlation between this polymorphism and the susceptibility to NSCLC in the Chinese population. The IL-4 variant -590T/C was detected by polymerase chain reaction-restriction fragment length polymorphism in 1072 NSCLC cases and 1126 age-matched healthy controls. Data were analyzed using the Chi-square test. Results showed that frequencies of IL-4 -590 TC, CC genotype, and -590 C allele were significantly lower in patients with NSCLC than in healthy controls (odds ratio [OR]=0.77, 95% confidence interval [CI] 0.64-0.93, p=0.006; OR=0.54, 95% CI 0.38-0.76, p=0.0004; and OR=0.72, 95% CI 0.62-0.83, p=1.1 × 10(-5), respectively). Our data suggest that the -590T/C polymorphism of the IL-4 gene is associated with a decreased susceptibility to NSCLC.

Interleukin 4-590T/C polymorphism and susceptibility to leprosy

BACKGROUND

Leprosy is a chronic infectious disease caused by Mycobacterium leprae. Cell-mediated (Th1) immune response and humoral (Th2) immune response play different roles in leprosy infection. Interleukin 4 (IL-4) is a typical Th2 cytokine. It is a critical mediator of the Th1/Th2 balance.

OBJECTIVE

The objective of this study is to investigate the association between IL-4 gene -590T/C polymorphism and the susceptibility to leprosy in a Chinese population.

METHODS

The IL-4 variant -590T/C was detected by polymerase chain reaction-restriction fragment length polymorphism in 432 leprosy cases and 465 age-matched healthy controls. Data were analyzed using the chi-square test.

RESULTS

Frequencies of the IL-4-590TC and CC genotypes and the -590C allele were significantly lower in patients with leprosy than in healthy controls (odds ratio [OR]=0.74, 95% confidence interval [CI] 0.55-0.99, p=0.044; OR=0.46, 95% CI 0.25-0.84, p=0.010; and OR=0.68, 95% CI 0.54-0.86, p=0.001, respectively).

CONCLUSIONS

Our data suggest that the -590T/C polymorphism of the IL-4 gene is associated with decreased susceptibility of leprosy.

Association of interleukin-8 gene polymorphisms and haplotypes with oral lichen planus in a Chinese population

Interleukin-8 (IL-8), a CXC chemokine with multiple biological functions, plays an important role in the pathogenesis of oral lichen planus (OLP). The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) of IL-8 gene with OLP in a Chinese population. Four SNPs of the IL-8 gene at positions -845 T/C (rs2227532), -738 T/A, -251 A/T (rs4073) and +781 C/T (rs2227306) were analyzed in 109 patients with OLP and 101 normal controls using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The data revealed that the -251 AA genotype and -251 A allele frequency was significantly lower in the erosive OLP (eOLP) group than in the control group (P = 0.012 and P = 0.031, respectively). Haplotype analysis revealed that the -251 A/+781 C haplotype frequency was lower in the eOLP group than in the control group (P = 0.029) while the -251 T/+781 C haplotype frequency was higher in the eOLP patients than in the healthy controls (P = 0.028). The study suggests that the IL-8 polymorphisms may be associated with the severity of OLP in this Chinese cohort.

Transient liver hypoxia after liver hilus dearterialization

Lichen planus (LP) is a chronic inflammatory disorder that most often affects middle-aged adults. LP can involve the skin or mucous membranes including the oral, vulvovaginal, esophageal, laryngeal, and conjunctival mucosa. It has different variants based on the morphology of the lesions and the site of involvement. The literature suggests that certain presentations of the disease such as esophageal or ophthalmological involvement are underdiagnosed. The burden of the disease is higher in some variants including hypertrophic LP and erosive oral LP, which may have a more chronic pattern. LP can significantly affect the quality of life of patients as well. Drugs or contact allergens can cause lichenoid reactions as the main differential diagnosis of LP. LP is a T-cell mediated immunologic disease but the responsible antigen remains unidentified. In this paper, we review the history, epidemiology, and clinical subtypes of LP. We also review the histopathologic aspects of the disease, differential diagnoses, immunopathogenesis, and the clinical and genetic correlations.