Association of polymorphisms in interleukin-18 and interleukin-28B genes with outcomes of hepatitis B virus infections: a meta-analysis

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.

Association between IL28B Polymorphisms and Outcomes of Hepatitis B Virus Infection: A meta-analysis

BACKGROUND

Interleukin (IL) 28B polymorphisms encoding pro-inflammatory and anti-inflammatory cytokines trigger diverse clinical outcome of hepatitis virus infection. However, there is controversy concerning the association of IL28B polymorphisms with the outcome of hepatitis B virus (HBV) infection, with several studies obtaining inconsistent results. We performed a meta-analysis to evaluate the role of 3 single nucleotide polymorphisms (SNPs) rs12979860, rs12980275 and rs8099917 in the progression of HBV infection, overall and by ethnicity.

METHODS

Searched PubMed, Embase and Wiley Online Library electronic databases using 'interleukin 28B', 'IL 28B', 'IL 28B polymorphism', 'hepatitis B virus', 'HBV', and performed meta- analysis for rs12979860, rs12980275 and rs8099917 in Asian and Caucasian populations under the dominant recessive and allele model.

RESULTS

Eighteen studies were found in total and used for this meta-analysis, including 5587 cases and 4295 controls. The IL28B polymorphism rs12979860 had no association with HBV persistence (CC vs CT + TT: OR = 0.86, 95% CI = 0.76-1.00; TT vs CT + CC: OR = 1.14, 95% CI = 0.76-1.70; T vs C: OR = 1.03, 95% CI = 0.94-1.13). Similarly, neither rs12980275 nor rs8099917 had associations with HBV persistence (rs12980275 in AA vs AG + AA: OR = 1.15, 95% CI = 0.96-1.38; rs8099917 in TT vs GT + GG: OR = 1.15, 95% CI = 0.96-1.39). There was also no significant association of IL28B polymorphisms with persistent HBV infection in Asians or Chinese. There was no evidence of an association of rs12979860 with the HBV-related hepatocellular carcinoma susceptibility (T vs C: OR = 1.53, 95% CI = 0.96-2.43).

CONCLUSION

IL28B polymorphisms had no association with the outcome of HBV infection overall, nor in the Asians and the Chinese. These 3 SNPs might not be relevant to the development of HBV infection.

Role of IL-18 Gene Promoter Polymorphisms, Serum IL-18 Levels, and Risk of Hepatitis B Virus-related Liver Disease in the Guangxi Zhuang Population: a Retrospective Case-Control Study

BACKGROUND

The aim of this study was to assess the relationship between IL-18 gene polymorphisms and HBV-related diseases and whether these polymorphisms influence its expression in the Guangxi Zhuang population.

MATERIALS AND METHODS

We enrolled 129 chronic HBV infected (CHB) patients, 86 HBV-related liver cirrhosis (LC) patients and 160 healthy controls in our study. Polymerase chain reaction-restriction fragment length polymorphism methods were used to detect IL-18 gene -607C/A, -137G/C polymorphisms, and an ELISA kit was employed to determine serum IL-18 levels.

RESULTS

No correlation was found between the -607C/A polymorphism and risk of HBV-related disease. For the -137G/C polymorphism, the GC genotype and C allele were associated with a significantly lower risk of CHB (95%CI: 0.32-0.95, p=0.034 and 95%CI: 0.35-0.91, p=0.018) and HBV-related LC (95%CI: 0.24-0.89, p=0.022 and 95%CI: 0.28-0.90, p=0.021). A similar decreased risk was also found with the A-607C-137 haplotype. With respect to IL-18 expression, it was significantly lower in both patient groups, but no association was noted between the two polymorphisms in the IL-18 gene and its expression.

CONCLUSIONS

Our study indicated that the -137C allele in the IL-18 gene may be a protective factor for HBV-related disease, and serum IL-18 level may be inversely associated with CHB and HBV-related LC.

Genetic, metabolic and environmental factors involved in the development of liver cirrhosis in Mexico

Liver cirrhosis (LC) is a chronic illness caused by inflammatory responses and progressive fibrosis. Globally, the most common causes of chronic liver disease include persistent alcohol abuse, followed by viral hepatitis infections and nonalcoholic fatty liver disease. However, regardless of the etiological factors, the susceptibility and degree of liver damage may be influenced by genetic polymorphisms that are associated with distinct ethnic and cultural backgrounds. Consequently, metabolic genes are influenced by variable environmental lifestyle factors, such as diet, physical inactivity, and emotional stress, which are associated with regional differences among populations. This Topic Highlight will focus on the genetic and environmental factors that may influence the metabolism of alcohol and nutrients in the setting of distinct etiologies of liver disease. The interaction between genes and environment in the current-day admixed population, Mestizo and Native Mexican, will be described. Additionally, genes involved in immune regulation, insulin sensitivity, oxidative stress and extracellular matrix deposition may modulate the degree of severity. In conclusion, LC is a complex disease. The onset, progression, and clinical outcome of LC among the Mexican population are influenced by specific genetic and environmental factors. Among these are an admixed genome with a heterogenic distribution of European, Amerindian and African ancestry; a high score of alcohol consumption; viral infections; a hepatopathogenic diet; and a high prevalence of obesity. The variance in risk factors among populations suggests that intervention strategies directed towards the prevention and management of LC should be tailored according to such population-based features.

Precore/Core promoter variants to predict significant fibrosis in both HBeAg positive and negative chronic hepatitis B

BACKGROUND & AIMS

Assessing fibrosis is essential in patients with chronic hepatitis B (CHB). The objective was to investigate the relationship between fibrosis, host and viral factors to identify non-invasive markers of significant fibrosis in a large cohort of unselected, well-characterized, treatment-naïve CHB patients.

METHODS

Three hundred and seventy-seven HBsAg-positive patients (97 HBeAg-positive and 280 HBeAg-negative, genotypes A to E) who had liver biopsy were consecutively included. Host and viral factors (ALT, HBsAg and HBV-DNA levels, HBV genotype and precore (PC)/basal core promoter (BCP) variants) were determined on the day of the biopsy. Fibrosis stage was assessed using METAVIR score.

RESULTS

Thirty-nine percent of the patients had significant fibrosis (METAVIR F ≥ 2). On univariate analysis, the stages of fibrosis F ≥ 2 were associated with older age (P < 0.0001), male gender (P = 0.01), higher ALT and HBV-DNA levels (P < 0.0001 and P = 0.0003, respectively), the presence of BCP (P < 0.0001) and BCP/PC variants (P < 0.0001). On multivariate analysis, age (P < 0.0001), the presence of HBV variants (P < 0.0001), HBV-DNA level (P = 0.0006) and ALT level (P = 0.02) were independently associated with significant fibrosis. The diagnostic accuracy of the combination (age, ALT, HBV-DNA, HBV variants) in predicting fibrosis F ≥ 2 was evidenced by a c-index of 0.76 (CI 95% 0.71-0.81).

CONCLUSIONS

We identified strong independent risk factors (age, ALT, HBV-DNA, HBV variants) predicting significant fibrosis (F ≥ 2) independently of HBeAg status in patients with CHB. Patients with BCP variants have a higher risk of severe liver disease. The detection of these mutants may help to predict significant fibrosis (F ≥ 2).

A meta-analysis of the association between IL28B polymorphisms and infection susceptibility of hepatitis B virus in Asian population

BACKGROUND

Several association studies with small sample sizes of two SNPs in IL28BB (rs12979860 and rs8099917) showed inconsistent results, so in this study, we aim to evaluate the association between the two SNPs and infection susceptibility of Hepatitis B Virus (HBV) in Asian population, especially in Chinese population by meta-analysis.

METHODS

Search the relevant published papers and perform meta-analysis respectively on IL28B (rs12979860 and rs8099917) in Asian population and Chinese population under an additive genetic model by STATA11.0.

RESULTS

The pooled odds ratios (OR) of rs12979860 are 0.79 (95% CI, 0.53-1.18; P = 0.25, I(2) = 63.2%) and 1.62 (95% CI, 1.04-2.51; P = 0.033, I(2) = 54.3%) respectively in Asian population and Chinese population analysis. The pooled OR of rs8099917 are 1.05 (95% CI, 0.93-1.19; P = 0.44, I(2) = 43.3%) and 0.97 (95% CI, 0.84-1.23; P = 0.726, I(2) = 15.6%) respectively in Asian population and Chinese population analysis.

CONCLUSION

Our study demonstrated that T allele of rs12979680 can increase the risk of HBV infection in Chinese population but not Asian population under an additive genetic model. There is no association between rs8099917 and HBV infection in Chinese population and Asian population.