Interleukin-1 polymorphism and expression in hepatitis B virus-mediated disease outcome in India

Correlation of IL-10 and IL18 with the development of liver cirrhosis associated with hepatitis B virus infection: A systematic review

BACKGROUND

Patients who have been infected with the Hepatitis B virus (HBV) are susceptible to developing liver cirrhosis (LC) and hepatocellular carcinoma (HCC). The objective of this systematic review was to comprehensively scrutinize the existing evidence concerning the association between host genetic polymorphisms and HBV-associated LC.

METHODS

We searched databases of PubMed, Scopus, and Web of Science for relevant articles published from building databases to 25 October 2023.

RESULT

We detected 104 relevant articles, relating to 84 individuals genes. Nine genes had the strong evidence of correlation, including IL-10, IL-18, IL-1B, TGF- β, TLR3, STAT4, IL-1RN, Tim3, and IFN receptors. A positive correlation was found for 33 genes but this data had not yet been replicated, 11 genes had limited or mixed evidence of a correlation, and 34 genes indicated no correlation. IL-10 and IL-18 had the most evidence of correlation. There was a notable amount of diversity in both the design and method of studies and data quality.

CONCLUSION

IL-10 and IL-18 had the most evidence of correlation. There was a notable amount of diversity in both the design and method of studies and data quality. It is of necessary to take into account the fundamental mechanism behind these associations and discern those that are confounded by the coexistence of other LC/HCC risk factors and response to therapy. These results are expected to guide future studies on the genetic susceptibility of HBV-related LC/HCC.

Association of Common Polymorphisms in the Interleukin-1 Beta Gene with Hepatocellular Carcinoma in Caucasian Patients with Chronic Hepatitis B

Interleukin-1 beta (IL-1β) promotes liver disease progression and hepatocarcinogenesis in chronic hepatitis B (CHB). Single nucleotide polymorphisms (SNPs) within the promotor region of the IL-1β gene can affect the progression towards liver cirrhosis and hepatocellular carcinoma (HCC). Aims: We aimed to investigate the association of three common IL-1β SNPs with hepatitis B virus (HBV)-related HCC in Caucasian patients. Method: A Caucasian cohort of 99 patients with HBe antigen (Ag)-positive CHB, 255 patients with HBeAg-negative CHB and 278 inactive carriers (IC) were enrolled. 105 patients were diagnosed with liver cirrhosis, and 64 with HCC and cirrhosis. Genotyping of the IL-1β rs1143623, rs1143627 and rs16944 was performed. Results: The rs1143627 TT and rs16944 CC genotypes were more frequent in patients with HCC compared to patients without liver tumours (48% vs. 33%, p = 0.018 and 47% vs. 31%, p = 0.001, respectively). In multivariate analysis, the rs16944 CC genotype was independently associated with HCC (OR = 6.44 [95% CI 1.50-27.59] p = 0.012). The haplotype, including rs1143623 TT and rs16944 CC, was a risk factor for HCC development (OR = 1.55 [95% CI 1.04-2.32] p = 0.031). Conclusions: We identified an association of common IL-1β SNPs with HBV-related HCC in a Caucasian population. The effect was independent of the phases of chronic HBV infection, which are currently regarded as important HCC risk factors.

Association of interleukin-18 genotypes (-607C > A) and (-137 G > C) with the hepatitis B virus disease progression to hepatocellular carcinoma

Chronic infection with HBV has been reported to be associated with the development of HCC. The inflammation mounted by cytokine-mediated immune system plays an important role in the pathogenesis of HBV-associated HCC. IL-18 is a pro-inflammatory cytokine whose role in the development of HBV-associated chronic to malignant disease state has not been much studied. The present study was conceived to determine the role of genetic polymorphisms in IL-18, serum levels of IL-18, and expression level of its signal transducers in the HBV disease progression. A total of 403 subjects were enrolled for this study including 102 healthy subjects and 301 patients with HBV infection in different diseased categories. Polymorphism was determined using PCR-RFLP. Genotypic distributions between the groups were compared using odd's ratio and 95% CI were calculated to express the relative risk. Circulating IL-18 levels were determined by ELISA. Expression levels of pSTAT-1 and pNFƙB was determined by western blotting. In case of IL-18(- 607C > A), the heterozygous genotype (CA) was found to be a protective factor while in case of IL-18(- 137G > C) the heterozygous genotype (GC) acted as a risk factor for disease progression from HBV to HCC. Moreover, serum IL-18 levels were significantly increased during HBV disease progression to HCC as compared to controls. Also the levels of activated signal transducers (pSTAT-1 and pNF-κB) of IL-18 in stimulated PBMCs were significantly increased during HBV to HCC disease progression. These findings suggest that IL-18 has the potential to act as a biomarker of HBV-related disease progression to HCC.

Relationships between IL-1β, TNF-α genetic polymorphisms and HBV infection: A meta-analytical study

BACKGROUND

IL-1β and TNF-α have been demonstrated as pro-inflammatory cytokines to participate in the innate immune response and suppression of HBV infection. However, the exact relationship between IL-1β, TNF-α gene polymorphisms and HBV infection remains unknown. Our study aims to assess the associations between IL-1β, TNF-α gene polymorphisms and HBV infection.

METHODS

A systematic literature search of PubMed and Embase databases was conducted through February 2020, and studies that were included in the present meta-analysis should fulfil the following conditions: (1) case-control studies focusing on the associations between IL-1β, TNF-α polymorphisms and HBV infection; (2) patients in the case group should be tested positive for the HBsAg and/or HBV-DNA without liver cirrhosis or hepatocellular carcinoma; (3) the control group including healthy population or HBV spontaneous clearance population; (4) odds ratios (ORs) and their 95% confidence intervals (CIs) could be calculated based on the allele and genotype frequencies provided in articles. The quality of included studies was assessed according to the Newcastle-Ottawa scale (NOS) assessment system. Pooled ORs and 95% CIs were used to analyze the strength of associations. Subgroup analysis was performed according to ethnicity and control type.

RESULTS

In the present meta-analysis, 49 articles including 10,218 cases and 9,557 controls were enrolled and seven polymorphisms (IL-1β rs16944, rs1143634, TNF-α rs1799724, rs1799964, rs1800629, rs1800630, rs361525) were studied. In overall meta-analysis, significant associations were found in IL-1β rs1143634, TNF-α rs1799724 and TNF-α rs1799964. For subgroup analysis under ethnicity, TNF-α rs1799724 and rs1800630 were markedly related to HBV infection in both Asian and Caucasian populations. In terms of control type subgroup, TNF-α rs1799724, rs1799964, rs1800630 were significantly associated with HBV persistence in HBV spontaneous clearance group.

CONCLUSION

In the present study, we identified that three polymorphisms (IL-1β rs1143634, TNF-α rs1799724, rs1799964) might serve as potential genetic biomarkers in HBV infection.

Serum pentraxin 3 as a biomarker of hepatocellular carcinoma in chronic hepatitis B virus infection

Biomarkers for early diagnosis of hepatocellular carcinoma (HCC) are needed in chronic hepatitis B virus (HBV) infection, a leading cause of HCC. We evaluated whether measurement of serum pentraxin 3 (PTX3) could improve diagnosis of HCC in chronic HBV infection. Data from patients with HBV-related chronic hepatitis (n = 159), cirrhosis (n = 99) and HCC (n = 107), and healthy controls (n = 151) were analyzed. Serum PTX3 concentration was measured by immunoassay. Area under the receiver operating characteristic curve (AUC) was applied to assess diagnostic accuracy. PTX3 levels were significantly higher in HBV patients than in healthy controls (P < 0.001) and in HCC than in chronic hepatitis (P < 0.001) or cirrhosis patients (P < 0.001). PTX3 was an independent risk factor of HCC [odds ratio (OR) 1.617, P < 0.001] and could distinguish HCC in chronic HBV infection [cutoff 9.231 ng/mL, AUC 0.929 with 95% confidence interval (CI) of 0.898-0.953], including α-fetoprotein (AFP) negative [cutoff 8.985 ng/mL, AUC (95%CI) 0.947 (0.908-0.973)] and early-stage HCC [cutoff 9.359 ng/mL, AUC (95%CI) 0.920 (0.885-0.947)]. Combination of PTX3 with AFP improved the discrimination of early HCC from chronic HBV infection [AUC (95%CI) 0.948 (0.918-0.970)]. In short, PTX3 measurement could identify HCC, including AFP-negative and early-stage HCC, in chronic HBV infection.

The autophagy gene ATG16L1 (T300A) variant is associated with the risk and progression of HBV infection

Autophagy pathway genes variants that play crucial roles in immune responses are involved in many diseases but their role in viral diseases is ill-defined. ATG16L1 gene plays a crucial role in the autophagy process. In this study, we have investigated the role of ATG16L1 variant T300A in the risk of HBV infection. rs2241880 (T300A) variant in 551 HBV infected patients (at various stages of infection) and 247 healthy controls were genotyped applying PCR-RFLP. Data analysis revealed that mutant allele G contributes to the risk of hepatitis B infection. Mutant alleles were significantly associated the HBV risk in allelic (OR = 1.31; 95%CI = 1.06-1.63, p = .01) and homozygous (OR = 1.87; 95%CI = 1.17-2.99, p = .009) models. On stratifying HBV infected individuals according to the stage of infection, a significant association was observed in asymptomatic (allelic; OR = 1.52; 95%CI = 1.10-2.09, p = .01 and homozygous; OR = 2.30; 95%CI = 1.22-4.36, p = .01) and chronic (allelic; OR = 1.36; 95%CI = 1.07-1.73, p = .01 and homozygous; OR = 2.07; 95%CI = 1.22-3.53, p = .008) stages of infection. High HBV DNA levels were associated with mutant genotype GG in asymptomatic and chronic carriers. Significantly higher ALT levels were observed in the liver cirrhosis patients with mutant genotypes. In conclusion, our data suggest that rs2241880 mutant allele carriers (allelic and homozygous models) were associated with increased risk of hepatitis B virus infection in North Indian population.

Interleukin IL-1B gene polymorphism in Tunisian patients with chronic hepatitis B infection: Association with replication levels

Approaches based on association studies have proven useful in identifying genetic predictors for many diseases, including susceptibility to chronic hepatitis B. In this study we were interested by the IL-1B genetic variants that have been involved in the immune response and we analyzed their role in the susceptibility to develop chronic hepatitis B in the Tunisian population. IL-1B is a potent proinflammatory cytokine that plays an important role in inflammation of the liver. Polymorphic gene IL-1 (-511, +3954) was analyzed in a total of 476 individuals: 236 patients with chronic hepatitis B from different cities of Tunisia recruited in Pasteur Institute between January 2017 and December 2018 and 240 controls. Genomic DNA was obtained using the standard salting-out method and genotyping was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism. For -511C>T polymorphism a significant association was found between patients and controls when comparing the genotypic (P = 0.007; χ²  = 9.74 and odds ratio [OR] = 0.60; confidence interval [CI] = 0.41-0.89) and allelic (P = 0.001; χ²  = 10.60) frequencies. When the viral load was taken into account a highly significant difference was found (P = 9 × 10^-4 ; χ²  = 10.89). For +3954C>T polymorphism a significant association was found between patients and controls when comparing genotypic (P = 0.0058; χ²  = 7.60 and OR = 1.67; CI = 1.14-2.46) and allelic (P = 0.0029; χ²  = 8.81) frequencies. T allele can be used as a strong marker for hepatitis B virus disease for both polymorphisms.

IL-18 and IL-1β Gene Polymorphisms: The Plausible Risk Factors for Chronic Hepatitis B

Chronic inflammation is the main risk factor for induction of liver cirrhosis and also hepatocellular carcinoma in chronic hepatitis B (CHB) patients. Although our knowledge is growing regarding molecular mechanisms of immune responses against viruses, the main mechanisms that lead to the progression of chronic inflammation and then CHB are yet to be clarified. IL-18 and IL-1β are the members of the IL-1 family and produced in the cytoplasm of a wide range of immune and nonimmune cells and activated by inflammasome pathways. The cytokines play key roles in the pathologies of CHB. IL-18 and IL-1β productions are altered in CHB patients. It has been hypothesized that the polymorphisms within IL-18 and IL-1β genes may be the main reasons for the induction of chronic inflammation in CHB patients. This review article discusses the related investigations regarding the main correlation between the polymorphisms within IL-18 and IL-1β genes and CHB pathogenesis.

Interleukin-1 gene cluster Haplotype analysis in the chronic outcome prediction of the Hepatitis B virus infection

Hepatitis B virus (HBV) infection is well known as an important cause of the chronic liver disease. The screening of the genotype of certain cytokines might be helpful to predict the clinical outcome of an HBV infection. The present study investigates the relationship between the polymorphism and haplotypes of the Interleukin-1 (IL-1) gene family, including IL-1-alpha (IL-1A), IL-1-beta (IL-1B,) and IL-1 receptor antagonist (IL-1RN), with chronic HBV infection. A total of 297 chronic HBV and 333 matched on sex and age control individuals were genotyped using the standard sequence-specific-polymerase chain reaction primer (SSP-PCR) method. Four different haplotype analysis software packages were applied for data interpretation. The results showed excess genotype A1/A1 and A2/A2 at IL-1RN (40.2%, 39.9%), C/T at IL-1A-889 (55.6%), and C/C at IL-1B-511 (41.1%) in controls while A1/A1 at IL-1RN (59.3%), T/T at IL-1B-31 (46.5%), C/T at IL-1B + 3953 (65%), in chronic HBV infection cases. A total of 148 haplotypes were observed overall (96 in the case group and 89 in the control group). The haplotype combination of genotype A1/A1 at IL1-RN along with a C/T for all three IL-1B polymorphic positions and either C/T or T/T at the IL-1A-899 position may increase the probability of the chronic outcome for the HBV infection.

Variations in IL-1R1 Gene Influence Risk for Hepatitis B Virus Infection of Children in a Han Chinese population

BACKGROUND/AIMS

Host genetic factors play an important role in the pathogenesis of hepatitis B virus (HBV) infection. However, the role of Interleukin1Receptor, Type I (IL-1R1) gene in HBV infection and breakthrough infection in children remains unclear. The aim of this study was to investigate the association between SNPs in IL-1 family and HBV infection and breakthrough infection in children.

PATIENTS AND METHODS

A total of 627 Chinese children (274 HBV infected children and 353 controls) ages 6 months to 12 years were recruited from October 2013 to May 2015.Six SNPs were genotyped in IL-1R1, Interleukin-1beta (IL-1B) and Interleukin-18 (IL-18) genes.

RESULTS

A statistically significant association was found between genotype AA in rs3917267 (IL-1R1) and HBV infection in children (OR, 1.740; 95%CI, 1.091-2.774; p=0.020), which was also found at allele A (OR, 1.316;95%CI, 1.050-1.648; p=0.017). Furthermore, rs3917267 was also significantly associated with breakthrough infection of HBV in children born of hepatitis B surface antigen (HBsAg) positive mothers (OR,3.675; 95%CI, 1.160-11.646; P=0.027).

CONCLUSION

Our study confirmed that genetic variant in IL-1R1(rs3917267) has significant association with HBV infection and HBV breakthrough infection in children, which provides new clues for the study of pathogenesis of chronic HBV infection in children.

Hepatitis-related hepatocellular carcinoma: Insights into cytokine gene polymorphisms

Hepatocellular carcinoma (HCC) is a primary liver cancer, which is one of the most prevalent cancers among humans. Many factors are involved in the liver carcinogenesis as lifestyle and environmental factors. Hepatitis virus infections are now recognized as the chief etiology of HCC; however, the precise mechanism is still enigmatic till now. The inflammation triggered by the cytokine-mediated immune response, was reported to be the closest factor of HCC development. Cytokines are immunoregulatory proteins produced by immune cells, functioning as orchestrators of the immune response. Genes of cytokines and their receptors are known to be polymorphic, which give rise to variations in their genes. These variations have a great impact on the expression levels of the secreted cytokines. Therefore, cytokine gene polymorphisms are involved in the molecular mechanisms of several diseases. This piece of work aims to shed much light on the role of cytokine gene polymorphisms as genetic host factor in hepatitis related HCC.

Th1/Th2 cytokines and their genotypes as predictors of hepatitis B virus related hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the predominant type of primary liver cancer, is one of the most serious life-threatening malignancies, worldwide. In majority of the cases, HCC develops after prolonged and persistent chronic liver disease. hepatitis B virus (HBV) or HCV infection is prominent etiological factors, attributing to this condition. It has been well documented that HBV, being the inducer of chronic inflammation, is the main causative agent in causing HCC, particularly in Asian countries. The HBV infection leads to a wide range of clinical symptoms from carrier state to malignancy. Cytokines being immune-modulatory molecules, are the key mediators in the defense mechanism against viral infection. In this regard, this review will detail the substantial role of key Th1: interleukin 1 (IL-1), IL-2, IL-12, tumor necrosis factor-α, interferon-γ; Th2: IL-4, IL-10 and non Th1/Th2: IL-6, transforming growth factor-β1 cytokines genotypes in analyzing the variability in the clinical manifestations in an HBV-afflicted individual, which might finally, culminates into HCC. Since cytokine production is regulated genetically, the cytokine promoter region single-nucleotide polymorphisms induced changes, greatly affects the cytokine production, thus resulting into differential outcome of immune balance.

Use of serum levels of proinflammatory cytokine IL-1alpha in chronic hepatitis B

Background:

The reasons for the chronic viral persistence of hepatitis B virus infection (HBV) are unknown, but are probably related to host immune factors. Cytokines play a significant role in immune defense. Interleukin-1 (IL-1) is a proinflammatory cytokine and some studies have demonstrated that IL-1 production was impaired in patients with chronic infections of hepatitis B virus, implying that IL-1 may play a role in viral clearance, progression of fibrosis and in malignant potential of HBV. In this study, along with routine laboratory tests, has been performed the analysis of serum levels of proinflammatory cytokine IL-1 α in order of better understanding and monitoring of chronic hepatitis B.

Objective:

The aim of this study was to analyze the usefulness of laboratory tests, which are routinely used in the assessment of liver disease with specified immunological parameters in patients with chronic hepatitis B.

Patients and methods:

Total of 60 subjects was divided into two groups: HBV- PCR positive and negative group. The control group of 30 healthy participants was included. Apart from standard laboratory tests, the analysis included serum levels of cytokine IL-1 α.

Results and discussion:

IL-1α had the highest mean concentration in group 1–viral hepatitis C, with PCR positive test (5.73 pg / ml), and then in group 2- viral hepatitis B, PCR negative test (5.39 pg / ml). ANOVA test proves that IL-1α in the healthy group (3) was different from other groups as follows: in relation to group 1 statistical significance level was p <0.001 (F = 32 75 5); in relation to group 2 was also statistically significant at p <0.001 (F = 182 361); Cytokine IL-1 was statistically analyzed separately and compared by group 1 and 2 using Student t-test for independent samples. Statistical significance was observed at p = 0.026. IL-1 α was positively correlated with the duration of the illness (p <0.01) and with serum ALT activity (p <0.01) and serum AST activity (p <0.01). Using multivariate analysis model “Factor Analysis”, was made significant stratification predictive parameters in relation to the cytokine IL-1α, stratified significance is indicated as follows: 1. Age, 2. history of receiving transfusions, 3. ALT, 4. AST, 5. MELD score (negative), 6. Child-Pugh score (Negative).

Conclusion:

IL-1α was significantly elevated in inflammatory conditions of pronounced activity (PCR positive hepatitis). IL-1α may have important role as marker of both inflammation and hepatic injury, particularly in the course of hepatitis B. Results suggest that inflammatory and immune parameters, analyzed together can significantly contribute to the understanding and predicting of chronic liver damage. IL-1 can be used as important parameter of inflammatory activity and fibrosis evaluation and eventually prediction of malignant transformation in chronic liver damage.

IL-6(-572/-597) polymorphism and expression in HBV disease chronicity in an Indian population

OBJECTIVES

This study evaluated the association among IL-6(-572) and IL-6(-597) genotypes, haplotypes, mRNA, and protein levels with hepatitis B virus (HBV)-Hepatocellular carcinoma (HCC) risk in India.

METHODS

For this, 403 participants (153 controls, 61 inactive HBV-carriers, 65 chronic-active HBV patients, 63 HBV-cirrhotics, and 61 HBV-HCC participants) were enrolled in the study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), ELISA, and RT-PCR methods were used for assessing polymorphism, protein, and the mRNA levels, respectively, of IL-6.

RESULTS

The study revealed that the IL-6(-572) GC genotype shared a positive association with hepatitis among controls, and a negative association with cirrhosis and consequent HCC development among carriers. However, the CC genotype shared a significant negative association with cirrhosis among controls and carriers. The IL-6(-597G>A), GA genotype acted as a potential protective factor for hepatitis, cirrhosis, and subsequent HCC development among carriers. The GA and CG haplotypes acted as a vital risk factor for HCC among controls and carriers. On the contrary, the CA haplotype was found to be a potential protective factor for HCC among carriers. Besides, the IL-6 levels significantly increased with cirrhosis development, as compared to carriers and hepatitis subjects.

CONCLUSIONS

These preliminary findings indicate a potential role of IL-6(-572/-597) genotypes in HBV disease pathogenesis in an Indian population.

Association of Interleukin-1β and Gene Polymorphisms with Liver Pathogenesis in Hepatitis B Virus Infection among Eastern Indian Population

BACKGROUND

Interleukin-1β (IL-1β) is an important member of the family of the proinflammatory cytokines that modulate outcome of hepatitis B virus (HBV) infection.

OBJECTIVES

This study was designed to investigate the relationship between the polymorphic genotypes of the interleukin-1β (IL-1β) promoter region and the interleukin-1 receptor antagonist gene (IL-1RN) and disease outcome in HBV-infected individuals.

METHODS

DNA was extracted from 395 study subjects including HBV carriers with varying clinical presentations, as well as healthy controls and spontaneously recovered cases (SRC). Polymorphisms in IL-1β (at position -511) and IL-1RN (variable nucleotide tandem repeats, VNTR) were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR based assay respectively.

RESULTS

Among the study subjects, different IL-1β (at position -511) (CC, CT and TT) and IL-1RN (1/1, 1/2, 2/2 and 1/3) polymorphic genotypes were found at variable proportions. Logistic regression analysis revealed, no notable difference at the level of IL-1β promoter (P = 0.244; OR = 0.78; 95% CI = 0.52-1.18) or IL-1RN genotype polymorphism (P = 0.840; OR = 1.03; 95% CI = 0.78-1.36) among the HBV carriers and controls or SRC cases. Pairwise proportion testing showed, IL-1β -511 genotype CC was significantly higher among asymptomatic carriers (ASC) in comparison with liver cirrhosis (LC) patients (P value = 0.028) and healthy control group (P-value = 0.036). IL-1RN genotype 2/2 was considerably higher in LC group than SRC as well as control group. Combinations of IL-1β (-511) and IL-1RN polymorphisms were associated with disease progression, such as CC-1/2 with ASC and TT-2/2 with LC.

CONCLUSION

IL-1β polymorphisms are found to be associated with disease severity. Different polymorphic combinations are associated with degree of disease severity. Overall this is the first report from Eastern India, which shows association of IL-1β polymorphisms with HBV-related hepatic complications.

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.

IFN-γ (+874) and not TNF-α (-308) is associated with HBV-HCC risk in India

Tumor necrosis factor (TNF)-α and interferon (IFN)-γ, the pro-inflammatory Th1 cytokines are the indispensable coordinators of the inflammatory responses involved in hepatitis B virus (HBV) pathogenesis. This study attempted to evaluate any possible association among TNF-α (-308G>A) and IFN-γ (+874T/A) genotypes, the spontaneous blood and mRNA levels and expression of their major signal transducers, namely STAT1 and NF-кB with hepatitis B virus-induced hepatocellular carcinoma (HCC) susceptibility in India. For this, 398 subjects (146 controls, 68 inactive-HBV-carriers, 64 chronic-active HBV patients, 61 HBV-cirrhotics, and 59 HBV-HCC subjects) were enrolled. Polymerase chain reaction-restriction fragment length polymorphism, allele-specific PCR, enzyme-linked immunosorbent assay, reverse transcriptase-PCR, and Western blot analysis were done for assessing polymorphism, blood levels, mRNA expression, and protein expression of signal transducers, respectively, of TNF-α and IFN-γ. The study revealed no significant association of TNF-α (-308) GA genotype, while a significant negative association of IFN-γ (+874) TA and AA genotypes, in HBV-HCC risk. Moreover, blood levels of TNF-α were significantly elevated as disease progresses to HCC, while IFN-γ levels were raised in HCC patients only. Besides, IFN-γ mRNA levels were significantly elevated in cirrhotics, with no change observed in TNF-α transcript levels. Moreover, NF-кB expression also consistently increased during HCC progression. These observations suggest a vital negative association of IFN-γ (+874) with HBV-HCC risk, with no significant association evident in TNF-α (-308). However, the TNF-α and IFN-γ levels markedly increased in HCC development.

Virus induced inflammation and cancer development

Chronic inflammation as a result of viral infection significantly increases the likelihood of cancer development. A handful of diverse viruses have confirmed roles in cancer development and progression, but the list of suspected oncogenic viruses is continually growing. Viruses induce cancer directly and indirectly, by activating inflammatory signalling pathways and cytokines, stimulating growth of infected cells and inhibiting apoptosis. Although oncogenic viruses induce inflammation by various mechanisms, it is generally mediated by the MAPK, NFκB and STAT3 signalling pathways. This review will explore the unique mechanisms by which different oncogenic viruses induce inflammation to promote cancer initiation and progression.