Association of vitamin-D-related genetic variations and treatment response to pegylated interferon in patients with chronic hepatitis B

Higher TP53BP2 expression is associated with HBsAg loss in peginterferon-α-treated patients with chronic hepatitis B

BACKGROUND & AIMS

HBsAg loss is only observed in a small proportion of patients with chronic hepatitis B (CHB) who undergo interferon treatment. Investigating the host factors crucial for functional cure of CHB can aid in identifying individuals who would benefit from peginterferon-α (Peg-IFNα) therapy.

METHODS

We conducted a genome-wide association study (GWAS) by enrolling 48 patients with CHB who achieved HBsAg loss after Peg-IFNα treatment and 47 patients who didn't. In the validation stage, we included 224 patients, of whom 90 had achieved HBsAg loss, to validate the identified significant single nucleotide polymorphisms. To verify the functional involvement of the candidate genes identified, we performed a series of in vitro and in vivo experiments.

RESULTS

GWAS results indicated a significant association between the rs7519753 C allele and serum HBsAg loss in patients with CHB after Peg-IFNα treatment (p = 4.85 × 10-8, odds ratio = 14.47). This association was also observed in two independent validation cohorts. Expression quantitative trait locus analysis revealed higher hepatic TP53BP2 expression in individuals carrying the rs7519753 C allele (p = 2.90 × 10-6). RNA-sequencing of liver biopsies from patients with CHB after Peg-IFNα treatment revealed that hepatic TP53BP2 levels were significantly higher in the HBsAg loss group compared to the HBsAg persistence group (p = 0.035). In vitro and in vivo experiments demonstrated that loss of TP53BP2 decreased interferon-stimulated gene levels and the anti-HBV effect of IFN-α. Mechanistically, TP53BP2 was found to downregulate SOCS2, thereby facilitating JAK/STAT signaling.

CONCLUSION

The rs7519753 C allele is associated with elevated hepatic TP53BP2 expression and an increased probability of serum HBsAg loss post-Peg-IFNα treatment in patients with CHB. TP53BP2 enhances the response of the hepatocyte to IFN-α by suppressing SOCS2 expression.

IMPACT AND IMPLICATIONS

Chronic hepatitis B (CHB) remains a global public health issue. Although current antiviral therapies are more effective in halting disease progression, only a few patients achieve functional cure for hepatitis B with HBsAg loss, highlighting the urgent need for a cure for CHB. This study revealed that the rs7519753 C allele, which is associated with high expression of hepatic TP53BP2, significantly increases the likelihood of serum HBsAg loss in patients with CHB undergoing Peg-IFNα treatment. This finding not only provides a promising predictor for HBsAg loss but identifies a potential therapeutic target for Peg-IFNα treatment. We believe our results are of great interest to a wide range of stakeholders based on their potential clinical implications.

The association between vitamin D-related gene polymorphisms and hepatitis B virus-related liver cirrhosis

OBJECTIVES

To investigate the relationship between vitamin D-related gene single nucleotide polymorphisms (SNPs) and hepatitis B-related liver cirrhosis.

METHODS

This study included patients with chronic hepatitis B who were admitted to the Liver Research Center of the First Affiliated Hospital of Fujian Medical University from July 2012 to August 2016. SNPs rs1544410 and rs2228570 in the vitamin D receptor gene and rs2282679 in the vitamin D-binding protein gene were detected using the imLDR™ multiple SNP typing kit. Genotype and allele frequencies were compared between groups using the chi-square test or Fisher’s exact test.

RESULTS

A total of 226 patients with hepatitis B virus (HBV) infection were enrolled, including 116 with HBV-related cirrhosis and 110 patients without. The distributions of vitamin D-related gene SNPs in both groups were in accordance with the Hardy–Weinberg equilibrium. There was no significant difference in the frequency or allelic distributions of rs1544410, rs2228570, and rs2282679 between the two groups. Additionally, the SNPs were not associated with the severity of cirrhosis.

CONCLUSION

No significant connection was identified between vitamin D-related SNPs and HBV-related liver cirrhosis.

Genetic variations in the CXCR5 gene decrease the risk of clinical relapse after discontinuation of nucleos(t)ide analogue therapy in patients with chronic hepatitis B

Discontinuation of nucleos(t)ide analogue (NA) therapy in patients with chronic hepatitis B (CHB) remains a global but controversial problem. Clinical outcomes of NA cessation depend on the interplay between viral factors and host immunity. Recent studies have shown that genetic polymorphisms might influence the immune response in chronic HBV infection. A total of 33 single-nucleotide polymorphisms (SNPs) from 16 genes (BCL6, CD40, CD40L, CTLA-4, CXCL13, CXCR5, ICOS, IL-21, HLA-C, NTCP, UBE2L3, STAT4, IFN-λ3, CYP27B1, INST10, and IPS1) were selected and analyzed in 106 CHB patients enrolled in an off-treatment cohort. Significantly unbalanced distributions between patients who experienced clinical relapse and those who did not were found regarding two SNPs, rs676925 in CXCR5 and rs733618 in CTLA-4. Furthermore, the genotype 'GC' of rs676925 were associated with decreased risk of clinical relapse, implicating that rs676925 may serve as a protective factor for HBV control and facilitate a virus-specific immune response. We also compared the expression of CXCR5 in lymphocytes and its ligand CXCL13 in plasma between different genotypes of rs676925. However, no significant differences were observed. In conclusion, this study suggested that the rs676925 'GC' genotype of the CXCR5 gene were associated with decreased risk of clinical relapse after discontinuation of long-term NA therapy in CHB patients.

Updates in the management of hepatitis B in children

Introduction: Universal infant hepatitis B virus (HBV) vaccination program has reduced HBV infection dramatically in vaccinated young generations. Management of chronically infected children is still challenging concerning high viral load with mostly mild diseases, yet with a nonnegligible proportion of advanced diseases, and long-term effect of antivirals. However, with more potent antivirals approved for pediatric patients, to start antivirals earlier in eligible patients may benefit their outcomes. This review aimed to update the current management of chronic hepatitis B in children.Areas covered: This review covered the natural history of chronic HBV infection, management of chronic hepatitis B in children from the past to the present, current consensus on the treatment of chronic hepatitis B in children, controversies in cessation of oral antivirals, and management of special populations such as pregnancy and co-infections.Expert opinions: Without contraindication, peginterferon is recommended for immune-active children ≥ 3 years old. For those intolerant, decompensating or preferring oral therapy, first-line Nucleos(t)ide analogs (NUC), Entecavir or Tenofovir, may be applied. For immune-tolerant or inactive carriers, close monitoring is crucial. When to stop NUCs and novel therapies for HBV cure await further research.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

Association of NTCP polymorphisms with clinical outcome of hepatitis B infection in Thai individuals

BACKGROUND

Single nucleotide polymorphisms (SNPs) in the sodium taurocholate co-transporting polypeptide (NTCP) have been showed to be associated with natural history of hepatitis B virus (HBV) infection. However, it is unclear whether the SNPs are related to the clinical outcome of HBV infection in Thai individuals.

METHODS

The rs2296651 and rs4646287 polymorphisms of NTCP were determined by allelic discrimination using commercial TaqMan probes in blood samples of 1021 Thai individuals. These subjects included 610 patients with chronic HBV infection [CHB, 305 with hepatocellular carcinoma (HCC) and 305 without HCC], 206 subjects with spontaneous HBV clearance and 205 healthy controls who were age and gender-matched.

RESULTS

The frequencies of rs2296651 A minor allele in the CHB group, the HBV clearance group and healthy controls were 7.8, 7.3 and 13.9%, respectively. For rs4646287, the frequencies of T minor allele of the corresponding groups were 10.4, 8.0 and 9.5%, respectively. Compared with healthy controls, the frequencies of rs2296651 GA + AA genotypes were significantly lower in the CHB group (P < 0.001) and in the HBV clearance group (P = 0.001). There was no difference in their distribution between the HBV clearance and CHB groups. Among the CHB group, the distribution of GA + AA genotypes in patients with HCC were significantly lower than in patients without HCC (P = 0.014). The frequencies of HBeAg positivity in patients harboring GG and GA + AA genotypes were 39.8 and 23.5%, respectively (P = 0.004). Among patients with HCC, the mean HBV DNA of the corresponding genotypes were 4.9 ± 1.3 vs. 2.7 ± 1.0 log₁₀ IU/mL, respectively (P < 0.001). There was no difference in genotype and allele frequencies of rs4646287 polymorphism among all studied groups.

CONCLUSIONS

Our results showed that rs2296651 polymorphism was associated with a decreased risk of susceptibility to HBV infection and the development of HCC. These data suggest that the NTCP polymorphism might have an influence on natural history of HBV infection in Thai individuals. This abstract was partly presented at the American Association for the Study of Liver Diseases (AASLD) Meeting 2018, November 9-13, 2018, in San Francisco, CA, USA and was published in Hepatology 2018; 68:1237A-1238A.

Genetic Factors That Affect Spontaneous Clearance of Hepatitis C or B Virus, Response to Treatment, and Disease Progression

Hepatitis C virus (HCV) and hepatitis B virus (HBV) infections can lead to cirrhosis, end-stage liver disease, and hepatocellular carcinoma. Over the past decade, studies of individuals infected with these viruses have established genetic associations with the probability of developing a chronic infection, risk of disease progression, and likelihood of treatment response. We review genetic and genomic methods that have been used to study risk of HBV and HCV infection and patient outcomes. For example, genome-wide association studies have linked a region containing the interferon lambda genes to spontaneous and treatment-induced clearance of HCV. We review the genetic variants associated with HCV and HBV infection, and how these variants affect specific expression or activities of their products. Further studies of these variants could provide insights into risk factors for and mechanisms of chronic infection and disease progression, as well as new strategies for treatment.

VDR rs7975232/ApaI genetic variation predicts sustained HBsAg loss in HBeAg-positive chronic hepatitis B patients treated with pegylated interferon

AIM

To evaluate the predictive value of vitamin D and its metabolic pathway gene polymorphisms in response to pegylated interferon (Peg-IFN) in hepatitis B early antigen (HBeAg)-positive chronic hepatitis B (CHB) patients.

METHODS

One hundred and nineteen HBeAg-positive CHB patients who received Peg-IFN monotherapy for 48 weeks and then were followed-up for another 48 weeks were prospectively enrolled; baseline 25-hydroxy vitamin D (25-(OH)D) and hepatitis B virus serologic marker levels were detected, nine critical single nucleotide polymorphisms within vitamin D metabolism were genotyped.

RESULTS

Forty-five (37.8%), 44 (37.0%), 35 (29.4%), and 11 (9.2%) of the patients achieved virological response (VR), HBeAg loss, combined response (CR), and hepatitis B surface antigen (HBsAg) level < 200 IU/mL at the end of treatment (EOT; week 48), respectively; 42 (35.3%) and six (5.0%) people achieved HBeAg and HBsAg loss at the end of follow-up (EOF; week 96). Baseline HBeAg level was independent predictor of VR (odds ratio [OR], 0.470; 95% confidence interval [CI], 0.294-0.751; P = 0.002), HBeAg loss (OR, 0.395; 95% CI, 0.243-0.643; P < 0.001), CR (OR, 0.392; 95% CI, 0.215-0.714; P = 0.002) at EOT and HBeAg loss at EOF (OR, 0.334; 95% CI, 0.203-0.559; P < 0.001); baseline HBsAg level itself was independent predictor of both HBsAg < 200 IU/mL at EOT (OR, 0.257; 95% CI, 0.103-0.642; P = 0.004) and HBsAg loss at EOF (OR, 0.232; 95% CI, 0.077-0.702; P = 0.010). Age was also independent predictors of HBsAg loss at EOF (OR, 0.775; 95% CI, 0.634-0.948; P = 0.013). Concerning genetic variation of VDR rs7975232/ ApaI, A allele was the genetic independent predictor of VR at EOT (OR, 1.824; 95% CI, 1.024-3.248; P = 0.041) and HBsAg loss at EOF (OR, 3.566; 95% CI, 1.057-12.029; P = 0.040).

CONCLUSIONS

Genetic variation of VDR rs7975232/ ApaI is a pretreatment predictor of sustained HBsAg loss in HBeAg-positive CHB patients with Peg-IFN monotherapy.