One hundred and ninety-two weeks treatment of entecavir maleate for Chinese chronic hepatitis B predominantly genotyped B or C

BACKGROUND

Entecavir (ETV) is a potent and selective nucleotide analog with significant activity against hepatitis B virus (HBV). ETV maleate is a derivative compound of ETV and was reported to have an efficacy and safety profile that is comparable to ETV (Baraclude) when used in Chinese patients with chronic hepatitis B (CHB) in phase III clinical trials (Clinical Trials.gov number, NCT01926288) at weeks 48, 96, and 144.

AIM

To investigate the antiviral potency and safety of ETV maleate at week 192 in Chinese CHB patients predominantly genotyped B or C.

METHODS

In this double-blind study, we randomly assigned patients to receive 0.5 mg/d ETV (Group A) or ETV maleate (Group B) (ratio, 1:1), each with a placebo tablet for 48 wk. Then, all patients received open-label treatment with 0.5 mg/d ETV maleate starting at week 49. The primary efficacy endpoint was the reduction in HBV DNA levels from baseline. Secondary endpoints included the proportion of patients with undetectable HBV DNA (< 20 IU/mL), serologic response, serum alanine aminotransferase (ALT) normalization and development of resistance mutations.

RESULTS

Two hundred eighteen patients who were hepatitis B e antigen (HBeAg) positive and 57 who were HBeAg negative were analyzed and predominantly presented with genotype B (49.82%) or C (48.73%). For the HBeAg-positive CHB patients, the mean HBV DNA level decrease (6.61 Log₁₀ IU/mL vs 6.69 Log₁₀ IU/mL, P > 0.05), viral suppression with HBV DNA < 20 IU/mL (83.33% vs 79.17%, P > 0.05) and HBeAg seroconversion (28.77% vs 20.00%, P > 0.05) occurred similarly between Groups A and B at week 192. However, there was a significant difference in the proportion of patients with normal ALT levels (91.14% vs 78.38%, P < 0.05). For the HBeAg-negative CHB patients, no significant difference was found between Groups A and B at week 192 in terms of reductions in HBV DNA levels from baseline (6.05 Log₁₀ IU/mL vs 6.03 Log₁₀ IU/mL, P > 0.05), percentages of patients who achieved undetectable HBV DNA (100% vs 100%, P > 0.05) and rates of ALT normalization (95.65% vs 100.00%, P > 0.05). Safety and adverse event profiles were similar between Groups A and B. Two HBeAg-positive patients in Group A and 5 in Group B developed genotypic resistance to ETV.

CONCLUSION

Long-term ETV maleate treatment for up to 192 wk is effective and safe in Chinese CHB patients predominantly genotyped as B or C.

240-week entecavir maleate treatment in Chinese chronic hepatitis B predominantly genotype B or C

This study aimed to evaluate the efficacy and safety of entecavir(ETV) versus ETV maleate in Chinese patients with chronic hepatitis B(CHB). This was a randomized, double-blind, double-dummy, controlled, multicentre study. Patients were randomly assigned to receive 48 weeks of treatment with 0.5 mg/day ETV (group A) or 0.5 mg/day ETV maleate (group B), then, all patients received treatment with 0.5 mg/day ETV maleate from week 49 onwards. Patients were regularly followed up. Serum hepatitis B virus (HBV) markers were detected. Adverse events (AE) were recorded. The primary endpoint was the decline in HBV DNA in each group at the end of treatment. Secondary endpoints included the rate of HBV DNA below the lower limit of detection (LLOD) (20 I U/ml) at the end of treatment, the rate of hepatitis B e antigen (HBeAg) loss, the rate of HBeAg seroconversion and serum alanine aminotransferase (ALT) normalization. One hundred and thirty-seven (71 in group A) patients with HBeAg-positive CHB and 46 (21 in group A) patients with HBeAg-negative CHB completed the 240-week treatment and follow-up. Baseline characteristics were well balanced between the two groups. For the HBeAg-positive CHB patients, the mean HBV DNA level had similarly decreased from baseline in both groups (A: by 6.67 log₁₀ IU/ml vs. B: by 6.74 log₁₀ IU/ml; p &gt; .05) at Week 240. Patients who achieved undetectable levels of serum HBV DNA (&lt;20 IU/ml) at Week 240 were similar between groups (A:91.55% vs. B:87.88%; p &gt; .05). Both groups achieved similar HBeAg seroconversion rates at week 240 (A:26.98% vs. B:20.97%; p &gt; .05). Both groups achieved similar normalization of ALT (A:87.32% vs. B:83.61%; p &gt; .05) at Week 240 (p &gt; .05). For the HBeAg-negative CHB patients, the mean HBV DNA level had similarly decreased from baseline in both groups (A: by 6.05 log₁₀ IU/ml vs. B: by 6.10 log₁₀ IU/ml; p &gt; .05) at Week 240. Patients who achieved undetectable levels of serum HBV DNA at Week 240 were similar between groups (A:100% vs. B:100%). Both groups achieved similar normalization rates (A:90.91% vs. B: 95.45%; p &gt; .05) of ALT at Week 240 (p &gt; .05). In conclusion, long-term ETV maleate treatment was safe and efficient in Chinese CHB predominantly of genotype B or C.

T-Cell Receptor β Chain and B-Cell Receptor Repertoires in Chronic Hepatitis B Patients with Coexisting HBsAg and Anti-HBs

Antibodies in response to antigens are related to the immune repertoire of T- and B-cell receptors. However, some patients with chronic hepatitis B (CHB) have coexisting HBsAg and anti-HBsAg antibodies (anti-HBs) that cannot neutralize HBV. We attempted to investigate the repertoires that produce this response in CHB patients. The T-cell receptor β chain (TRB) and B-cell receptor (BCR) repertoires of peripheral blood genomic DNA were analyzed using MiXCR. T-cell receptor (TCR) cluster analysis was carried out by clusTCR, and motifs prediction was selected by Multiple Em for Motif Elicitation (MEME). A total of 76 subjects were enrolled, including 26 HBsAg and anti-HBs coexisting patients with CHB (DP group), 25 anti-HBs single-positive healthy people (SP group), and 25 CHB patients (CHB group). The clone length of BCR in 39, 90 was significantly different among these groups (p = 0.005, 0.036). The motif “CASSLG” in the DP group was significantly higher than SP and CHB groups and may relate to coexistence, and the motif “GAGPLT” was only shown in the SP group and may relate to anti-HB expression. These provide important insights into vaccine development and CHB treatment.

The Emerging Role of Branched-Chain Amino Acids in Liver Diseases

Chronic liver diseases pose a substantial health burden worldwide, with approximately two million deaths each year. Branched-chain amino acids (BCAAs)-valine, leucine, and isoleucine-are a group of essential amino acids that are essential for human health. Despite the necessity of a dietary intake of BCAA, emerging data indicate the undeniable correlation between elevated circulating BCAA levels and chronic liver diseases, including non-alcoholic fatty liver diseases (NAFLD), cirrhosis, and hepatocellular carcinoma (HCC). Moreover, circulatory BCAAs were positively associated with a higher cholesterol level, liver fat content, and insulin resistance (IR). However, BCAA supplementation was found to provide positive outcomes in cirrhosis and HCC patients. This review will attempt to address the contradictory claims found in the literature, with a special focus on BCAAs' distribution, key signaling pathways, and the modulation of gut microbiota. This should provide a better understanding of BCAAs' possible contribution to liver health.

Human immune repertoire in hepatitis B virus infection

Hepatitis B virus (HBV) infection is a public health threat that affects 257 million people worldwide and can progress to liver cirrhosis, liver failure, and hepatocellular carcinoma. The HBV antigen- induced adaptive immune response plays an important role in HBV clearance. Immune repertoire sequencing (IRS) has been used to investigate the molecular mechanisms behind the immune system, find novel ways to treat HBV infection, and evaluate the genetic responses and immune characteristics of individuals infected by HBV or immunized by HBV vaccine. This review summarizes the human immune repertoire analysis methodology, and the application of the IRS in the prediction of HBV infection progression, treatment, and vaccination.

Clinical Aspects of Gut Microbiota in Hepatocellular Carcinoma Management

Liver cancer, predominantly hepatocellular carcinoma (HCC), is the third leading cause of cancer-related deaths worldwide. Emerging data highlight the importance of gut homeostasis in the pathogenesis of HCC. Clinical and translational studies revealed the patterns of dysbiosis in HCC patients and their potential role for HCC diagnosis. Research on underlying mechanisms of dysbiosis in HCC development pointed out the direction for improving the treatment and prevention. Despite missing clinical studies, animal models showed that modulation of the gut microbiota by probiotics may become a new way to treat or prevent HCC development.

Genome-wide association study identifies new loci associated with risk of HBV infection and disease progression

BACKGROUND

Recent studies have identified susceptibility genes of HBV clearance, chronic hepatitis B, liver cirrhosis, hepatocellular carcinoma, and showed the host genetic factors play an important role in these HBV-related outcomes.

METHODS

Collected samples from different outcomes of HBV infection and performed genotyping by Affymetrix 500 k SNP Array. GCTA tool, PLINK, and Bonferroni method were applied for analysis of genotyping and disease progression. ANOVA was used to evaluate the significance of the association between biomarkers and genotypes in healthy controls. PoMo, FST, Vcftools and Rehh package were used for building the racial tree and population analysis. FST statistics accesses 0.15 was used as a threshold to detect the signature of selection.

RESULTS

There are 1031 participants passed quality control from 1104 participants, including 275 HBV clearance, 92 asymptomatic persistence infection (ASPI), 93 chronic hepatitis B (CHB), 188 HBV-related decompensated cirrhosis (DC), 214 HBV-related hepatocellular carcinoma (HCC) and 169 healthy controls (HC). In the case-control study, one novel locus significantly associated with CHB (SNP: rs1264473, Gene: GRHL2, P = 1.57 × 10-6) and HCC (SNP: rs2833856, Gene: EVA1C, P = 1.62 × 10-6; SNP: rs4661093, Gene: ETV3, P = 2.26 × 10-6). In the trend study across progressive stages post HBV infection, one novel locus (SNP: rs1537862, Gene: LACE1, P = 1.85 × 10-6), and three MHC loci (HLA-DRB1, HLA-DPB1, HLA-DPA2) showed significant increased progressive risk from ASPI to CHB. Underlying the evolutionary study of HBV-related genes in public database, the derived allele of two HBV clearance related loci, rs3077 and rs9277542, are under strong selection in European population.

CONCLUSIONS

In this study, we identified several novel candidate genes associated with individual HBV infectious outcomes, progressive stages, and liver enzymes. Two SNPs that show selective significance (HLA-DPA1, HLA-DPB1) in non-East Asian (European, American, South Asian) versus East Asian, indicating that host genetic factors contribute to the ethnic disparities of susceptibility of HBV infection. Taken together, these findings provided a new insight into the role of host genetic factors in HBV related outcomes and progression.

Human genetic susceptibility to hepatitis B virus infection

Hepatitis B virus (HBV) infection is still a serious health threat worldwide. The outcomes of HBV infection consist of spontaneous HBV clearance and chronic HBV infection. Multiple factors contribute to the disparity of HBV infection outcomes, including host factors, viral factors and environmental factors. The present review comprehends the current researches mainly focusing on the relationships between genetic determinants, including single nucleotide polymorphisms (SNPs) and haplotypes, and susceptibility of HBV infection, namely chronic (persistent) HBV infection and HBV clearance. A number of determinants in the chromosomes, including mutations in human leukocyte antigens (HLAs), cytokines genes, toll-like receptors (TLRs), and other genes are related to the human susceptibility to HBV infection. Among the above variants, some of those in HLAs have been studied and replicated in multiple-ethnic populations and came to consistent conclusions, while some others are novel and need to be evaluated further.

New Gene Variants Associated with the Risk of Chronic HBV Infection

Some patients with chronic hepatitis B virus (HBV) infection failed to clear HBV, even persistently continue to produce antibodies to HBV. Here we performed a two stage genome wide association study in a cohort of Chinese patients designed to discover single nucleotide variants that associate with HBV infection and clearance of HBV. The first stage involved genome wide exome sequencing of 101 cases (HBsAg plus anti-HBs positive) compared with 102 control patients (anti-HBs positive, HBsAg negative). Over 80% of individual sequences displayed 20 × sequence coverage. Adapters, uncertain bases > 10% or low-quality base calls (> 50%) were filtered and compared to the human reference genome hg19. In the second stage, 579 chronic HBV infected cases and 439 HBV clearance controls were sequenced with selected genes from the first stage. Although there were no significant associated gene variants in the first stage, two significant gene associations were discovered when the two stages were assessed in a combined analysis. One association showed rs506121-"T" allele [within the dedicator of cytokinesis 8 (DOCK8) gene] was higher in chronic HBV infection group than that in clearance group (P = 0.002, OR = 0.77, 95% CI [0.65, 0.91]). The second association involved rs2071676-A allele within the Carbonic anhydrase (CA9) gene that was significantly elevated in chronic HBV infection group compared to the clearance group (P = 0.0003, OR = 1.35, 95% CI [1.15, 1.58]). Upon replication these gene associations would suggest the influence of DOCK8 and CA9 as potential risk genetic factors in the persistence of HBV infection.

The Loss-of-Function S267F Variant in HBV Receptor NTCP Reduces Human Risk for HBV Infection and Disease Progression

Background

Sodium taurocholate cotransporting polypeptide (NTCP, SLC10A1) is a hepatocyte receptor for hepatitis B virus (HBV) infection. The natural NTCP S267F variant causes loss of NTCP HBV receptor function. We assessed the association of S267F with HBV resistance, HBV infection clearance, and HBV-related cirrhosis and hepatocellular carcinoma (HCC).

Methods

We tested the effects of S267F in 1117 Han Chinese patients with various HBV infection outcomes using multivariate logistic regression analysis.

Results

The frequency of S267F (T allele) was higher in HBV-resistant healthy controls (n = 179, 4.0%) compared to HBV-infected patients (n = 648, 1.5%); odds ratio (OR) 0.32 (95% confidence interval [CI] 0.15-0.68; P = .003; dominant model). 267F variant genotypes were also associated with reduced risk for cirrhosis (n = 192, 0.5%) and HCC (n = 258, 1.0%) compared to those with chronic HBV infection (n = 202, 3.0%); OR 0.15 (95% CI, 0.03-0.70) and OR 0.21 (95% CI, 0.062-0.72), respectively. There was no association of the S267F variant with spontaneous HBV clearance.

Conclusion

The S267F variant for the HBV cell-entry receptor NTCP was associated with increased resistance to HBV infection and decreased risk for cirrhosis and liver cancer among those with chronic HBV infection.

MRGPRX4 is a bile acid receptor for human cholestatic itch

Patients with liver diseases often suffer from chronic itch, yet the pruritogen(s) and receptor(s) remain largely elusive. Here, we identify bile acids as natural ligands for MRGPRX4. MRGPRX4 is expressed in human dorsal root ganglion (hDRG) neurons and co-expresses with itch receptor HRH1. Bile acids elicited Ca²⁺ responses in cultured hDRG neurons, and bile acids or a MRGPRX4 specific agonist induced itch in human subjects. However, a specific agonist for another bile acid receptor TGR5 failed to induce itch in human subjects and we find that human TGR5 is not expressed in hDRG neurons. Finally, we show positive correlation between cholestatic itch and plasma bile acids level in itchy patients and the elevated bile acids is sufficient to activate MRGPRX4. Taken together, our data strongly suggest that MRGPRX4 is a novel bile acid receptor that likely underlies cholestatic itch in human, providing a promising new drug target for anti-itch therapies.

Identified OAS3 gene variants associated with coexistence of HBsAg and anti-HBs in chronic HBV infection

The underlying mechanism of coexistence of hepatitis B surface antigen (HBsAg) and hepatitis B surface antigen antibody (anti-HBs) is still controversial. To identify the host genetic factors related to this unusual clinical phenomenon, a two-stage study was conducted in the Chinese Han population. In the first stage, we performed a case-control (1:1) age- and gender-matched study of 101 cases with concurrent HBsAg and anti-HBs and 102 controls with negative HBsAg and positive anti-HBs using whole exome sequencing. In the second validation stage, we directly sequence the 16 exons on the OAS3 gene in two dependent cohorts of 48 cases and 200 controls. Although, in the first stage, a genome-wide association study of 58,563 polymorphism variants in 101 cases and 102 controls found no significant loci (P-value ≤ .05/58563), and neither locus achieved a conservative genome-wide significance threshold (P-value ≤ 5e-08), gene-based burden analysis showed that OAS3 gene rare variants were associated with the coexistence of HBsAg and anti-HBs. (P-value = 4.127e-06 ≤ 0.05/6994). A total of 16 rare variants were screened out from 21 cases and 3 controls. In the second validation stage, one case with a stop-gained rare variant was identified. Fisher's exact test of all 149 cases and 302 controls showed that the rare coding sequence mutations were more frequent in cases vs controls (P-value = 7.299e-09, OR = 17.27, 95% CI [5.01-58.72]). Protein-coding rare variations on the OAS3 gene are associated with the coexistence of HBsAg and anti-HBs in patients with chronic HBV infection in Chinese Han population.

Entecavir maleate versus entecavir in Chinese chronic hepatitis B predominantly genotype B or C: Results at week 144

Reports on the efficacy and safety of long-term entecavir treatment in chronic hepatitis B (CHB) predominantly genotype B or C are insufficient. This study presents the efficacy and safety of entecavir maleate in Chinese CHB patients. Patients were randomly assigned to receive 48-week treatment with either 0.5 mg/day entecavir (group A) or 0.5 mg/day entecavir maleate (group B), and then all patients received treatment with 0.5 mg/day entecavir maleate from week 49. Two hundred and seventy-five patients with CHB (HBeAg-positive: 218) were analysed, predominantly (98.5%) with genotype B or C. Baseline characteristics were balanced. For the HBeAg-positive CHB patients, the mean HBV DNA level decreased similarly (A: by 6.36 log₁₀ IU/mL vs B: by 6.31 log₁₀ IU/mL) between groups at week 144. The percentages of patients who achieved undetectable HBV DNA were similar (A: 70.59% vs B: 66.67%) between groups. Similar HBeAg loss rates (A: 43.53% vs B: 40.23%; P>.05) and HBeAg seroconversion rates (A: 21.52% vs B: 21.18%) were achieved. For the HBeAg-negative CHB patients, similar reductions in HBV DNA levels from baseline (A: by 6.13 log₁₀ IU/mL vs B: by 5.65 log₁₀ IU/mL) and percentages of patients who achieved undetectable HBV DNA (A: 100% vs B: 100%) were achieved. The overall incidence of adverse events was comparable between groups. In conclusions, 48-week administration of entecavir maleate and entecavir showed similar efficacy and safety in Chinese patients with CHB. Long-term entecavir maleate treatment was effective and safe in CHB patients.

Efficacy and safety of combined directly acting antivirals for treatment of Chinese chronic hepatitis C patients in a real-world setting

AIM

To assess the efficacy and safety of combined directly acting antivirals (DAAs) for the treatment of Chinese chronic hepatitis C (CHC) patients in a real-world setting.

METHODS

Hospitalized CHC patients who were treated with DAAs at Peking University First Hospital between January 2015 and December 2016 were enrolled. Samples and clinical data were collected at 0 wk, 2 wk, 4 wk, 8 wk, 12 wk, or 24 wk during DAAs treatment and at 4 wk, 12 wk, and 24 wk after the end of treatment.

RESULTS

Fifty-four patients who underwent DAAs treatment were included in our study, of whom 83.3% (45/54) achieved rapid virological response at 2 wk after treatment initiation (RVR 2) and 94.4% (51/54) achieved sustained virological response at 24 wk after the end of treatment (SVR 24). Serum creatinine and uric acid levels at the end of treatment were significantly increased compared with baseline levels (83.6 ± 17.9 vs 88.8 ± 19.4, P₀₁ < 0.001; 320.8 ± 76.3 vs 354.5 ± 87.6, P₀₁ < 0.001), and no significant improvements were observed at 24w after the end of treatment (83.6 ± 17.9 vs 86.8 ± 19.1, P₀₂ = 0.039; 320.8 ± 76.3 vs 345.9 ± 89.4, P₀₂ = 0.001). The total frequency of adverse events (AEs) during treatment was 33.3% (18/54), with major AEs being fatigue (16.7%), headache (7.4%), anorexia (7.4%), and insomnia (5.6%).

CONCLUSION

Though based in a small cohort of patients, the abnormal changes in renal function indices and relative high frequency of AEs during combined DAAs treatment should be taken as a note of caution.

Clinical Features of Chronic Hepatitis B in Treatment-naive Asian Patients With Positive HBeAg and Coexisting Precore and/or Basal Core Promoter Mutations

BACKGROUND

Precore or/and basal core promoter (PC/BCP) mutations are frequently detected in hepatitis B e antigen (HBeAg)-negative patients, but little is known about their clinical significance in HBeAg-positive patients.

AIM

To characterize and report the clinical features of treatment-naive chronic hepatitis B patients who are HBeAg positive and harbor PC and/or BCP mutations.

PATIENTS AND METHODS

Consecutive treatment-naive patients with chronic hepatitis B between 2004 and 2014 were enrolled. Clinical characteristics were compared based on the stratification of HBeAg status and the presence of PC/BCP mutations. In addition, subset analysis in HBeAg-positive cohort was performed to compare clinical features of patients with and without PC/BCP mutations RESULTS:: Of the 267 patients enrolled from 3 centers, 177 were HBeAg positive and 90 HBeAg negative. When compared with HBeAg-negative patients, HBeAg-positive patients were significantly younger in mean age (37.93 vs. 44.40; P<0.001), had higher levels of median ALT (51 vs. 30.5 U/mL; P<0.001), higher levels of mean HBV DNA (7.50±1.48 vs. 5.10±1.44 log10 copies/mL; P<0.001), and lower frequency of detectable PC/BCP mutations (60.45% vs. 93.33%; P<0.001), but had significantly higher frequency of BCP when mutations were detected (37.85% vs. 22.22%; P=0.013). Among HBeAg-positive patients, when compared with patients with wild type, those with PC/BCP mutations were significantly older (30.63 vs. 42.71; P<0.001), had higher median ALT levels (29.5 vs. 73 U/mL; P<0.001), but there was no significant association with mean HBV DNA levels (7.96 vs. 7.20 log10 copies/mL; P=0.865) or HBV genotype (P=1.000). In the multivariate analysis, only age and ALT were independently associated with PC/BCP mutations in HBeAg-positive patients, but there was no association with HBV genotype or DNA.

CONCLUSIONS

PC/BCP mutants were frequent (up to 60%) in treatment-naive HBeAg-positive patients and were associated with distinct clinical characteristics when compared with patients with wild type or HBeAg negative. Future large studies are needed to substantiate the long-term clinical outcomes when PC/BCP mutations are detected in HBeAg-positive patients as it may impact the natural history or treatment response in such patients.

Baseline hepatitis B core antibody predicts treatment response in chronic hepatitis B patients receiving long-term entecavir

Studies regarding the clinical significance of quantitative hepatitis B core antibody (anti-HBc) in patients with chronic hepatitis B receiving first-line nucleos(t)ide analogues is limited. The aim of this study was to determine the performance of anti-HBc as a predictor for hepatitis B e antigen (HBeAg) seroconversion in HBeAg-positive CHB patients treated with entecavir. This was a retrospective cohort study consisting of 139 Chinese patients enrolled in a multicenter clinical trial treated with entecavir or entecavir maleate for up to 240 weeks. Anti-HBc evaluation was conducted for all the available samples using a newly developed double-sandwich anti-HBc immunoassay. At week 240, 35 (25.2%) patients achieved a serological response (HBeAg seroconversion) and these patients at week 240 had significantly higher levels of anti-HBc (P<.01). We defined 4.65 log₁₀  IU·mL^-1 , with a maximum sum of sensitivity and specificity, as the optimal cut-off value of baseline anti-HBc level to predict seroconversion. Patients with baseline anti-HBc ≥4.65 log₁₀  IU·mL^-1 had 28.0% (26/93) and 35.5% (33/93) chance of seroconversion at weeks 144 and 240, respectively. The baseline anti-HBc level was the strongest predictor for seroconversion at week 144 (OR: 5.78, 95% confidence interval [CI]: 2.05-16.34, P=.001). The baseline anti-HBc level was a strong predictor for seroconversion at week 240 (OR: 5.36, 95% CI: 2.17-13.25, P<.001). Hence, baseline anti-HBc titre is a useful predictor of long-term entecavir therapy efficacy in HBeAg-positive CHB patients, which could be used to optimize antiviral therapy.

Human genes involved in hepatitis B virus infection

Persistent hepatitis B virus (HBV) infection is a significant public health problem because it is a major cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). Roughly one-third of the world population has been infected with HBV and there are about 350 million (5%-6%) persistent carriers. HBV causes 80% of all liver cancer cases and is the second most important carcinogen, after smoking tobacco. There is an approximate 90% risk of becoming a persistent carrier following perinatal infection in infants born to e antigen positive carrier mothers and a 30% risk in pre-school children. Only 5%-10% of adults become persistent carriers following infection. Of individuals persistently infected with HBV, 10%-30% will develop liver cirrhosis and HCC. These highly variable outcomes in both clearance rates and disease outcomes in persistently infected individuals cannot be fully explained by differences in immunological, viral or environmental factors. Thus, differences in host genetic factors may affect the natural history of hepatitis B.

Prevalence and significance of Hepatitis B reverse transcriptase mutants in different disease stages of untreated patients

AIMS

Hepatitis B virus (HBV) reverse transcriptase (RT) mutants, which have not been well characterized according to different disease stages. This study aimed to characterize the profiles of naturally occurring mutations in the HBV RT region and their associated clinical outcomes.

METHODS

HBV RT region mutations and genotypes were determined by PCR-direct sequencing and compared with p-distance model.

RESULTS

Among 467 consecutive eligible patients (262 chronic hepatitis B patients, 105 cirrhotic patients and 100 hepatocellular carcinoma patients), the nucleos(t)ide analogues-related mutations (rtI169T, rtV173L, rtL180M, rtA181T, rtS202C, rtM204I/V, rtN236T) were found. The p-distance value reached a peak in the age of 20-30 years in the CHB patients and in the age of 40-45 years in the cirrhotic patients and hepatocellular carcinoma patients. The naturally occurring mutation, rtS106C mutation was higher in chronic hepatitis B patients (14/100, 14.0%) and cirrhotic patients (14/100, 14.0%) than that in hepatocellular carcinoma patients (4/100, 4.0%, P = 0.013). And the rtD134E/G/N/S mutations were also higher in chronic hepatitis B patients (22/100, 22.0%) and cirrhotic patients (21/100, 21.0%) than that in hepatocellular carcinoma patients (10/100, 10.0%, P = 0.021 and P = 0.032 respectively). The mutation frequencies in A-B interdomain were higher in cirrhotic patients (101/1900, 5.3%) than that in hepatocellular carcinoma patients (68/1900, 3.6%) (P = 0.009).

CONCLUSIONS

The nucleos(t)ide analogues-related mutations do exist in treatment naive patients with different disease stages. rtS106C, rtD134E/G/N/S and A-B interdomain mutations may be associated with necro-inflammation, immune response and cirrhosis development at ages older than 40.

Role of hepatitis B virus base core and precore/core promoter mutations on hepatocellular carcinoma in untreated older genotype C Chinese patients

The aim of the study was to investigate the prevalence of mutations of basal core promoter (BCP) and precore (PreC) region of hepatitis B virus (HBV) and their association with hepatocellular carcinoma. A total of 341 untreated older HBV patients were divided into three groups: chronic hepatitis B (CHB, 185), cirrhotic hepatocellular carcinoma (LC-HCC, 113) and non-cirrhotic hepatocellular carcinoma (non-LC-HCC, 43). HBV BCP and PreC mutations and genotypes were determined by direct sequencing. Using univariate analysis, age (≥ 45 years), single mutations including A1896 and A1899 and multiple mutations T1762/A1764 + A1896, T1762/A1764 + A1899 and T1762/A1764 + A1896 + A1899 were more frequently detected in LC-HCC and non-LC-HCC patients than in CHB patients. BCP T1762/A1764 mutations were highly detected in LC-HCC patients than in CHB patients. Multivariate logistic regression analysis (adjusted for age and gender) revealed that among HBeAg-positive patients, BCP T1762/A1764 mutations (OR, 5.975; P = 0.05), PreC A1899 mutation (OR, 4.180; P = 0.013) and multiple mutations T1762/A1764 + A1899 (OR, 6.408; P = 0.006) were independently associated with the development of LC-HCC; PreC A1899 mutation (OR, 7.347; P = 0.034) was also independently associated with the development of non-LC-HCC. On the other hand, among HBeAg-negative patients, PreC A1896 mutation (OR, 5.176; P = 0.002) and multiple mutations T1762/A1764 + A1896 (OR, 4.149; P = 0.007) were independently associated with the development of non-LC-HCC. These results indicated that older age (≥ 45 years) was associated with LC-HCC and non-LC-HCC development. BCP T1762/A1764 mutations and PreC A1899 mutation were associated with the LC-HCC development in HBeAg-positive patients. PreC A1896 mutation was associated with the non-LC-HCC development in HBeAg-negative patients.

A population-based study to investigate host genetic factors associated with hepatitis B infection and pathogenesis in the Chinese population

Background

Hepatitis B virus (HBV) infection is a significant public health problem that may lead to chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). Approximately 30% of the world's population has been infected with HBV and approximately 350 million (5–6%) are persistent carriers. More than 120 million Chinese are infected with HBV. The role of host genetic factors and their interactions with environmental factors leading to chronic HBV infection and its complications are not well understood. We believe that a better understanding of these factors and interactions will lead to more effective diagnostic and therapeutic options.

Methods/Design

This is a population-based, case-control study protocol to enroll 2200 Han Chinese from medical centers in northern and western China. Adult subjects in the following groups are being enrolled: healthy donors (n = 200), HBV infected persons achieving virus clearance (n = 400), asymptomatic HBV persistent carriers (n = 400), chronic hepatitis B cases (n = 400), decompensated liver cirrhosis with HBV infection cases (n = 400), and hepatocellular carcinoma with HBV infection cases (n = 400). In addition, for haplotype inference and quality control of sample handling and genotyping results, children of 1000 cases will be asked to provide a buccal sample for DNA extraction. With the exception of adult patients presenting with liver cirrhosis or HCC, all other cases and controls will be 40 years or older at enrollment. A questionnaire is being administered to capture dietary and environmental risk factors. Both candidate-gene and genome-wide association approaches will be used to assess the role of single genetic factors and higher order interactions with other genetic or environmental factors in HBV diseases.

Conclusion

This study is designed and powered to detect single gene effects as well as gene-gene and environmental-gene interactions. The identification of allelic polymorphisms in genes involved in the pathway leading to chronic viral infection, liver cirrhosis and, ultimately, hepatocellular carcinoma would provide insights to those factors leading to HBV replication, liver inflammation, fibrosis, and the carcinogenic process. An understanding of the contribution of host genetic factors and their interactions may inform public health policy, improve diagnostics and clinical management, and provide targets for drug development.

Mutations in surface and polymerase gene of chronic hepatitis B patients with coexisting HBsAg and anti-HBs

AIM: To investigate the clinical significance and presence of mutations in the surface (S) and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs.

METHODS: Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, 11 were both positive for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV surface antigen (anti-HBs), 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200 μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced.

RESULTS: Forty-one mutations were found within the surface gene protein of HBV in 15 patients (10 with coexisting HBsAg and anti-HBs). Six (14.6%) out of 41 mutations were located at “α” determinant region in 5 patients (4 positive for HBsAg and anti-HBs). Eleven mutations (26.8%) occurred in the downstream or upstream of “α” determinant region. Lamivudine (LMV)-selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions (196, 198, 199) of the surface protein and in YMDD motif (M204I/V) of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels.

CONCLUSION: Besides mutations in the “α” deter-minant region, mutations at downstream or upstream of the “α” determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.