Key role of hepatitis B virus mutation in chronic hepatitis B development to hepatocellular carcinoma

Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). The HBV mutations, which include point mutation, deletion, insertion and truncation mutation of HBV gene in 4 open reading frames (S, C, P, X), are closely associated with HCC pathogenesis. Some mutations accumulated during chronic HBV infection could be regarded as a biomarker to predict the occurrence of HCC. The detection of the mutations in clinical practice could be helpful for defining better preventive and therapeutic strategies and, moreover, predicting the progression of liver disease.     

Hepatitis B virus pre-S2 start codon mutations in Indonesian liver disease patients

AIM: To identify the prevalence of pre-S2 start codon mutations and to assess their association with liver disease progression. METHODS: The mutations were identified by direct sequencing from 73 asymptomatic carriers, 66 chronic hepatitis (CH), 66 liver cirrhosis (LC) and 63 hepatocellular carcinoma (HCC) patients. Statistical significances were determined using Fisher's exact test, χ 2 test, and t -test analyses whenever appropriate. Pre-S mutation as a risk factor for advanced liver disease was estimated by unconditional logistic regression model adjusted with age, sex, and hepatitis B e antigen (HBeAg). P 0.05 was considered significant. RESULTS: Mutation of the hepatitis B virus (HBV) pre-S2 start codon was found in 59 samples from 268 subjects (22.0%), with higher prevalence in patients with cirrhosis 27/66 (40.9%) followed by HCC 18/63 (28.6%), chronic hepatitis 12/66 (18.2%) and asymptomatic carriers 2/73 (2.7%) (P 0.001). Logistic regression analysis showed that pre-S2 start codon mutation was an independent factor for progressive liver disease. Other mutations, at T130, Q132, and A138, were also associated with LC and HCC, although this was not statistically significant when adjusted for age, sex, and HBeAg. The prevalence of pre-S2 start codon mutation was higher in HBV/B than in HBV/C (23.0% vs 19.1%), whilst the prevalence of T130, Q132, and A138 mutation was higher in HBV/C than in HBV/B. The prevalence of pre-S2 start codon mutation was higher in LC (38.9%) and HCC (40.0%) than CH (5.6%) in HBeAg(+) group, but it was similar between CH, LC and HCC in HBeAg(-) group. CONCLUSION: Pre-S2 start codon mutation was higher in Indonesian patients compared to other Asian countries, and its prevalence was associated with advanced liver disease, particularly in HBeAg(+) patients.     

Mutations in <Emphasis Type="Italic">preS</Emphasis> genes of genotype C hepatitis B virus in patients with chronic hepatitis B and hepatocellular carcinoma

Background Hepatitis B virus (HBV) preS mutations are frequently isolated from patients with severe forms of liver disease. Meanwhile, genotype C has been shown to cause more serious liver disease than genotype B. This study assesses the frequency of preS mutation in Chinese patients with genotype C chronic HBV infection and its relation to liver damage. Methods Seventy-nine persistently infected patients (25 asymptomatic carriers, 28 with chronic hepatitis, and 26 with hepatocellular carcinoma) with genotype C HBV were analyzed. Levels of HBV DNA, hepatitis B e antigen (HBeAg), alanine aminotransferase, and aspartate transaminase and mutations in the preS region were determined. Results The correlations of preS deletion with disease progression were distinct: preS deletion mutations were more commonly found in the hepatocellular carcinoma (HCC) group than in the chronic hepatitis B (CHB) or asymptomatic carrier (ASC) groups, with the frequencies of 38.46% (10/26) in the HCC, 7.14% (2/28) in the CHB, and 4.00% (1/25) in the ASC (P = 0.001) groups. The HBeAg-positive rate and HBV DNA levels were comparable between patients with the preS mutation and those without. Conclusions PreS deletion mutations of genotype C HBV might play a role in HBV-related hepatocarcinogenesis.     

Mutations in pre-core and basic core promoter regions of hepatitis B virus in chronic hepatitis B patients

AIM: To investigate the frequency of mutations in precore(pre-C) and basic core promoter(BCP) regions of hepatitis B virus(HBV) from Shanxi Province, and the association between mutations and disease related indexes.METHODS: One hundred chronic hepatitis B patients treated at Shanxi Province Hospital of Traditional Chinese Medicine were included in this study. PCRreverse dot blot hybridization and mismatch amplification mutation assay(MAMA)-PCR were used to detect the mutations in the HBV pre-C and BCP regions. HBV DNA content and liver function were compared between patients with mutant HBV pre-C and BCP loci and those with wild-type loci. The consistency between PCR-reverse dot blot hybridization and MAMA-PCR for detecting mutations in the HBV pre-C and BCP regions was assessed.RESULTS: Of the 100 serum samples detected, 9.38% had single mutations in the pre-C region, 29.17% had single mutations in the BCP region, 41.67% had mutations in both BCP and pre-C regions, and 19.79% had wild-type loci. The rates of BCP and pre-C mutations were 65.7% and 34.3%, respectively, in hepatitis B e antigen(HBe Ag) positive patients, and 84.6% and 96.2%, respectively, in HBe Ag negative patients. The rate of pre-C mutations was significantly higher in HBe Ag negative patients than in HBe Ag positive patients(χ~2 = 26.62, P = 0.00), but there was no significant difference in the distribution of mutations in the BCP region between HBeAg positive and negative patients(χ~2 = 2.43, P = 0.12). The presence of mutations in the pre-C(Wilcoxon W = 1802.5, P = 0.00) and BCP regions(Wilcoxon W = 2906.5, P = 0.00) was more common in patients with low HBV DNA content. Both AST and GGT were significantly higher in patients with mutant pre-C and BCP loci than in those with wild-type loci(P 0.05). PCR-reverse dot blot hybridization and MAMA-PCR for detection of mutations in the BCP and pre-C regions had good consistency, and the Kappa values obtained were 0.91 and 0.58, respectively.CONCLUSION: HBe Ag negative patients tend to have HBV pre-C mutations. However, these mutations do not cause increased DNA copies, but associate with damage of liver function.     

HBsAg, HBeAg and HBV DNA level changes and precore/basal core promoter mutations in the natural history of chronic hepatitis B in Indonesian patients

Introduction

Chronic hepatitis B (CHB) is a state of complex interactions between the hepatitis B virus (HBV) and host. We studied the changes in hepatitis B surface antigen (HBsAg), hepatitis B ‘e’ antigen (HBeAg) and HBV DNA levels, considering the implications of HBV genotype, basal core promoter (BCP) A1762T/G1764A and precore G1896A mutations in CHB.

Methods

One hundred fifty-two treatment-naïve CHB patients were classified into immune-tolerant (IT), immune-clearance (IC), low/non-replicative (LR) and ‘e’-negative hepatitis B (ENH) phases, based on HBeAg status, HBV DNA and ALT levels. HBV DNA was detected and quantified by polymerase chain reaction, then analyzed by sequencing. HBsAg and HBeAg levels were measured serologically.

Results

HBsAg and HBV DNA levels varied between CHB phases, with HBsAg highest in IT and lowest in LR, and HBV DNA high in IT and IC, and lowest in LR. Both markers increased in ENH. Correlation between HBsAg and HBV DNA was significant in IT and IC, modest in ENH, but missing in LR. HBeAg and HBV DNA levels were dissociated in HBeAg-positive patients. Genotypes B and C were similarly distributed, with precore mutations higher in HBeAg-negative patients and BCP mutations comparable in all phases. Temporal association between HBeAg seroconversion and an increase of BCP/precore mutations was observed.

Conclusion

HBsAg and HBV DNA levels were high and correlated in early CHB phases and dissociated after HBeAg seroconversion, indicating different controls affecting HBV replication and HBsAg production. Selection of BCP/precore mutants may affect disease course and explain the HBeAg–HBV DNA dissociation, a precaution for clinical application of quantitative HBeAg.     

Association of Mutations in the Basal Core Promoter and Pre-core Regions of the Hepatitis B Viral Genome and Longitudinal Changes in HBV Level in HBeAg Negative Individuals: Results From a Cohort Study in Northern Iran

Background:

Although certain HBV mutations are known to affect the expression of Hepatitis e antigen, their association with HBV viral level or clinical outcomes is less clear.

Objectives:

We evaluated associations between different mutations in the Basal Core promoter (BCP) and Pre-core (PC) regions of HBV genome and subsequent changes in HBV viral DNA level over seven years in a population of untreated HBeAg negative chronic hepatitis B (CHB) participants in Northeast of Iran.

Materials and Methods:

Participants in the current study were drawn from the Golestan Hepatitis B Cohort Study (GHBCS), a cohort of approximately 2590 HBsAg positive subjects (living in Gonbad city) embedded in the Golestan Cohort Study (GCS). At baseline, HBsAg was measured in all participants and revealed 2590 HBsAg positive cases. We randomly selected 304 participants who their blood sample were taken at both baseline and seven years later in follow-up and had not been treated for HBV during this time. HBV viral load were assessed at baseline and at year 7. The BCP and PC regions of the HBV DNA, at baseline, were amplified via hemi-nested PCR and sequenced by cycle sequencing. At year 7, liver stiffness was assessed by fibroscan; also, other parameters of liver disease were assessed following standard clinical protocols. Associations were assessed via tabulation, chi-square, t-tests and logistic regression. P values < 0.05 were considered statistically significant and all tests were two-sided.

Results:

Among 304 HBsAg positive participants, 99 had detectable HBV DNA at study baseline. Of these, 61.6% had PC mutations (48.5% A1896 and 25.2% G1899). In contrast to other mutations, A1896 was associated with a higher proportion of detectable HBV DNA at year 7 (39.6%) compared to patients with the wild type (13.7%) (OR: 4.36, CI95% = 1.63-11.70; P Value = 0.002). Although participants with the A1896 mutation had higher year-7 HBV viral load than participants with G1896 (2.30 ± 1.66 IU/mL vs. 1.76 ± 1 IU/mL among patients with detectable HBV; P value = 0.052), no association was observed with either serum level ALT or liver stiffness. Interestingly, mutations in the basal core promoter (BCP) region had no significant effect on virus DNA detection.

Conclusions:

In this population with chronic HBeAg negative hepatitis B, an association was observed between the G1896A mutation in the Pre-core region of HBV and subsequent level of HBV DNA seven years later, which indicated that mutations in this region of HBV genome may contribute to disease progression in these patients and play an important role in HBV natural course of disease.     

Resistant mutants induced by adefovir dipivoxil in hepatitis B virus isolates

AIM:To investigate the loci of adefovir dipivoxil(ADV)-induced resistance in hepatitis B virus(HBV)isolates and optimize the management of ADV-treated patients.METHODS:Between June 2008 and August 2010,a cross-sectional control study was conducted comprising 79 patients with chronic HBV infection-related liver disease who had been administered ADV monotherapy.Patients underwent liver imaging.Serum DNA extracts were analyzed for HBV DNA levels,genotypes,and serology markers,and deep sequencing of the HBV P gene was performed.RESULTS:ADV-resistant patients were found either with a single mutated locus,or with coexisting mutated loci.The most prevalent mutations were rt A181T,rt V214A,and rt N236T.Twenty-six patients had more than two mutated loci.The mutants were distributed among the patients without any significant affinity for gender,age,end-stage of liver disease,complications of non-alcoholic fatty liver disease,or HBV DNA levels.Patients with the rt A181T mutant were primarily infected with genotype C and e-antigen negative HBV,while patients with the rt N236T mutant were primarily infected by genotype B HBV(χ2=6.004,7.159;P=0.023,0.007).The duration of treatment with ADV was shorter in the single mutant group compared with the multi-mutant group(t=2.426,P=0.018).CONCLUSION:Drug-resistant HBV mutants are complex and diverse.Patients should receive the standard and first-line antiviral treatment,strictly comply with medication dosage,and avoid short-term withdrawal.     

Relationship between hepatocellular carcinoma and hepatitis B virus genotype with spontaneous YMDD mutations

AIM: To investigate the relationship between hepatitis B virus (HBV) genotype with spontaneous YMDD mu-tations and hepatocellular carcinoma (HCC) in HBV-related cirrhosis. METHODS: We investigated 264 liver cirrhosis pa-tients who were not treated with antiviral drugs, in-cluding 81 patients with HCC. YMDD mutations were detected by fluorescent hybridization bioprobe poly-merase chain reaction (PCR) and melting curve assay using the Diagnosis Kit for HBV YMDD Mutation. Serum HBV genotypes were detected by real-time PCR using genotype-specific TaqMan probes. Statistical analysis was performed according to data type using the t test, χ2 test and unconditional logistic regression analysis. RESULTS: In the HCC group, genotype C strains, spon-taneous YMDD mutations, and genotype C strains with YMDD mutations were detected in 33 (40.74%), 13 (16.05%) and 11 (13.58%) patients, respectively. In the liver cirrhosis (LC) group, HBV genotype C strains,spontaneous YMDD mutations, and genotype C strains with YMDD mutations were detected in 33 (18.03%), 7 (3.83%) and 2 (1.09%) patients, respectively. The dif-ferences in genotype C strains, spontaneous YMDD mu-tations, and genotype C strains with YMDD mutations between the two groups were statistically significant (χ2=15.441, P=0.000; χ2=11.983, P=0.001; P=0.000). In the HCC and LC groups, there were seven patients infected by genotype B strains with YMDD mutations and 13 by genotype C strains with YMDD mutations. Further research revealed that HCC oc-curred in 2 patients infected by genotype B strains with YMDD mutations and 11 infected by genotype C strains with YMDD mutations. The difference was statistically significant (P=0.000). Unconditional logistic regres-sion analysis revealed that patients infected by geno-type C strains with spontaneous YMDD mutations had a 7.775-fold higher risk for the development of HBV-related HCC than patients infected by other type HBV strains (P=0.013, 95%CI: 1.540-39.264). CONCLUSION: Genotype C strains with spontaneous YMDD mutations ar     

Natural YMDD-motif mutants affect clinical course of lamivudine in chronic hepatitis B

AIM:To investigate the prevalence of nature tyrosinemethionine-aspartic acid-aspartic acid motif mutations in chronic hepatitis B(CHB)patients and to evaluate the efficacy of lamivudine.METHODS:A total of 1268 CHB patients were recruited from the outpatient and inpatient departments of six centers.Tyrosine-methionine-aspartic acid-aspartic acid(YMDD)mutations were analyzed using the hepatitis B virus(HBV)drug resistance line probe assay.Forty voluntary patients were selected from those with positive or negative natural YMDD mutations to undergo treatment with lamivudine.RESULTS:YMDD mutations were detected in 288(22.71%)of the 1268 CHB patients.Multivariate analysis revealed that the patients’HBV DNA level(P=0.0282)and hepatitis B e antigen status(P=0.0133)were also associated with natural YMDD mutations.The rates of normalization of alanine aminotransferase levels and HBV DNA nondetection at 6,24,36,and 48 wk were compared between the patients with natural YMDD mutations and those without,and the differences were not significant.However,there was a significant difference in the cumulative emergence rates of virological breakthrough at 48 wk in the patients with natural YMDD mutations and those without(32.5%vs 12.5%,P=0.032).CONCLUSION:Naturally occurring YMDD mutationsare detectable in a large proportion of CHB patients;breakthrough hepatitis tended to occur in patients with natural YMDD mutations.     

Prognostic Significance of Serum Galectin-3 Levels in Patients with Hepatocellular Cancer and Chronic Viral Hepatitis

Background/Aim:

Galectins affect diverse physiological and pathophysiological processes such as development, inflammation, and tumor growth. We aimed to compare serum galectin-3 levels in three patient groups with chronic hepatitis B and C virus (HBV, HCV), cirrhosis secondary to HBV or HCV, and hepatocellular carcinoma (HCC) secondary to HBV or HCV and evaluate the role of galectin-3 during HCC progression.

Patients and Methods:

Nineteen patients with hepatocellular cancer, 22 patients with cirrhosis, and 24 patients with chronic hepatitis B and C were included in this study. Serum galectin-3 levels in different liver diseases were assessed by enzyme-linked immunosorbent assay.

Results:

The mean galectin-3 levels were 4.61 ng/mL (±2.32) in HCC patients, 5.68 ng/mL (±2,2) in cirrhotic patients, 1.98 ng/mL (±1.50) in chronic viral hepatitis group. There were no statistical differences between HCC and cirrhotic patients (P = 0.5), but lower in chronic hepatitis group statistically compared with cirrhosis and HCC (P < 0.001, P = 0.002, respectively). In case of cirrhotic patients, galectin-3 levels were significantly higher in patients with cirrhosis secondary to HCV compared with HBV (P = 0.03). When we evaluated galectin-3 levels in HCC patients, it was found to be 3.92 ng/mL in HCC secondary to hepatitis B and 5.37 ng/mL in HCC secondary to hepatitis C.

Conclusion:

Serum galectin-3 levels in patients with chronic HBV or HCV may guide us about progression to cirrhosis or HCC and prognosis of the disease. Especially, galectin-3 levels may be more pronounced in case of HCV.     

Plasmatic KRAS Kinetics for the Prediction of Treatment Response and Progression in Patients With KRAS-mutant Lung Adenocarcinoma

IntroductionKRAS is the most common driver mutation in lung cancer. ctDNA-based assessment offers advantages over tumor as a minimally invasive method able to capture tumor heterogeneity. Monitoring KRAS mutational load in ctDNA may be useful in the management of the patients.MethodsConsecutive patients diagnosed with KRAS mutant lung adenocarcinoma in the tumor biopsy were included in this study. Plasma samples were obtained at different time points during the course of the disease. KRAS mutations in plasma were quantified using digital PCR and correlated with mutations in tumor and with radiological response and progression.ResultsTwo hundred and forty-five plasma samples from 56 patients were analyzed. The rate of detection of KRAS mutations in plasma in our previously characterized KRAS-mutant cases was 82% overall, reaching 96% in cases with more than 1 metastatic location. The dynamics of KRAS mutational load predicted response in 93% and progression in 63% of cases, 33 and 50 days respectively in advance of radiological evaluation. Progression-free survival for patients in whom ctDNA was not detectable in plasma after treatment initiation was significantly longer than for those in whom ctDNA remained detectable (7.7 versus 3.2 months; HR: 0.44, p = 0.004).ConclusionsThe detection of KRAS mutations in ctDNA showed a good correlation with that in tumor biopsy and, in most cases, predicted tumor response and progression to chemotherapy in advance of radiographic evaluation. The liquid biopsies for ctDNA-based molecular analyses are a reliable tool for KRAS testing in clinical practice.     

Mutations of pre-core and basal core promoter before and after hepatitis B e antigen seroconversion

AIM: To investigate the role of pre-core and basal core promoter(BCP) mutations before and after hepatitis Be antigen(HBe Ag) seroconversion.METHODS: The proportion of pre-core(G1896A) and basal core promoter(A1762T and G1764A) mutant viruses and serum levels of hepatitis B virus(HBV) DNA, hepatitis B surface antigen(HBs Ag), and HB core-related antigen were analyzed in chronic hepatitis B patients before and after HBe Ag seroconversion(n = 25), in those who were persistently HBe Ag positive(n = 18), and in those who were persistently anti-HBe positive(n = 43). All patients were infected with HBV genotype C and were followed for a median of 9 years.RESULTS: Although the pre-core mutant became predominant(24% to 65%, P = 0.022) in the HBe Ag seroconversion group during follow-up, the proportion of the basal core promoter mutation did not change. Median HBV viral markers were significantly higher in patients without the mutations in an HBe Ag positive status(HBV DNA: P = 0.003; HBs Ag: P < 0.001; HB core-related antigen: P = 0.001). In contrast, HBV DNA(P = 0.012) and HBs Ag(P = 0.041) levels were significantly higher in patients with the pre-core mutation in an anti-HBe positive status.CONCLUSION: There is an opposite association of the pre-core mutation with viral load before and after HBe Ag seroconversion in patients with HBV infection.     

A 13-year longitudinal study of the impact of double mutations in the core promoter region of hepatitis B virus on HBeAg seroconversion and disease progression in patients with genotype C chronic active hepatitis

The pathogenic role of core promoter (CP) mutations (T1762/A1764) of hepatitis B virus (HBV) in hepatitis B e antigen (HBeAg) seroconversion or disease progression remains unclear. We investigated the clinical relevance of these mutants over a long-term follow-up period of up to 15 years. In this longitudinal cohort study, 29 HBeAg-positive patients with biopsy-proved chronic active hepatitis without cirrhosis were regularly monitored for >10 years. The viral isolates were characterized, using the frozen liver tissue obtained on the day of biopsy. Long-term outcomes were compared between patients with and without CP mutations of HBV at baseline. HBV genotyping showed that 100% of study subjects were infected with genotype C HBV. During a median follow-up period of 12.5 years, patients without double CP mutations of HBV at baseline showed a tendency towards achieving an earlier HBeAg seroconversion than those with (6.9 vs 9.4 years, P = 0.062) double CP mutations. Double CP mutations at baseline were also significantly associated with the eventual development of cirrhosis or hepatocellular carcinoma (P = 0.013), whereas the absence of double CP mutations predicted inactive carrier status at the last follow-up (P = 0.027). At 10 years, liver-related tests were also significantly better in patients without double CP mutations of HBV than in those with these mutations, as reflected by higher platelet counts and albumin levels (P = 0.036 and P = 0.044, respectively). Double T1762/A1764 mutations are significantly related to liver deterioration in HBeAg-positive genotype C active hepatitis patients. A longer period of immune clearance coupled with delayed HBeAg seroconversion appears to contribute to disease progression in patients harbouring these mutations in the CP region of HBV.     

Association of Pre-S/S and Polymerase Mutations with Acute and Chronic Hepatitis B Virus Infections in Patients from Rio de Janeiro,Brazil

Several hepatitis B virus (HBV)-related factors, including the viral load, genotype, and genomic mutations, have been linked to the development of liver diseases. Therefore, in this study we aimed to investigate the influence of HBV genetic variability during acute and chronic infection phases. A real-time nested PCR was used to detect HBV DNA in all samples (acute, n = 22; chronic, n = 49). All samples were sequenced for phylogenetic and mutation analyses. Genotype A, sub-genotype A1, was the most common genotype in the study population. A total of 190 mutations were found in the pre-S/S gene area and the acute profile revealed a greater number of nucleotide mutations (p < 0.05). However, both profiles contained nucleotide mutations linked to immune escape and an increased risk of hepatocellular carcinomas (acute, A7T; chronic, A7Q). Furthermore, 17 amino acid substitutions were identified in the viral polymerase region, including the drug resistance mutations lamivudine and entecavir (rtL180M), with statistically significant differences between the mutant and wild type strains. Owing to the natural occurrence of these mutations, it is important to screen for resistance mutations before beginning therapy.     

Single nucleotide polymorphisms in CXCR1 gene and its association with hepatitis B infected patients in Saudi Arabia

Background/Aim. This study aims to investigate whether the SNPs of CXCR1 gene, could predict the likelihood of viral persistence and/or disease progression.Material and methods. We investigated the association of two different SNPs (rs2234671, and rs142978743) in 598 normal healthy controls and 662 HBV patients from a Saudi ethnic population. The HBV patients were categorized into inactive carriers (n = 428), active carriers (n = 162), cirrhosis (n = 54) and Cirrhosis-HCC (n = 18) sub-groups. Genetic variants in CXCR1 were determined by polymerase chain reaction (PCR)-based DNA direct sequencing.Results. The frequency of the risk allele ‘C’ for the SNP, rs2234671 was found to be insignificant when the patient group was compared to the uninfected control group, however, a significant distribution of the allele ‘C’ of rs2234671 was observed among active HBV carriers + cirrhosis + cirrhosis - HCC vs. inactive HBV carriers with an OR = 1.631 (95% C.I. 1.016-2.616) and p = 0.032. However, no significant association was observed for rs142978743 when the distribution of risk allele was analyzed among the different patient groups (i.e. inactive carriers, active carriers, cirrhosis and HCC). Furthermore, the most common haplotype, Haplo-1 (AG), was found to have an insignificant frequency distribution between HBV cases and controls, while the same haplotype was found to be significantly distributed when active carriers + cirrhosis + cirrhosis - HCC patients were compared to inactive HBV carriers with a frequency of 0.938 and p = 0.0315. Haplo-2 (AC) was also found to be significantly associated with a frequency of 0.058 and p = 0.0163.Conclusion. The CXCR1 polymorphism, rs2234671 was found to be associated with chronic HBV infection and may play a role in disease activity.     

Genetic alterations in the S gene of hepatitis B virus in patients with acute hepatitis B,chronic hepatitis B and hepatitis B liver cirrhosis before and after liver transplantation

Abstract: Background: Several studies have shown that hepatitis B immunoglobulin (HBIG) imposes a selection pressure on the hepatitis B virus (HBV) S gene, and that the emergence of mutations in this region would make reinfection after orthotopic liver transplantation (OLT) possible. Aims: This study was undertaken to analyze the presence of HBV S-gene mutations in the different stages of HBV infection and the relationship between HBIG therapy and the emergence of mutations in liver transplant recipients. Methods: The frequency and location of mutations in the coding region of the HBV S gene were studied by PCR and direct sequencing in 30 patients (7 with acute self-limited hepatitis B, 16 with chronic hepatitis B and 7 recipients of (OLT) for HBV-related end stage liver disease who became reinfected). Results: The average number of ammo acid changes was higher in patients with a more advanced stage of disease, 0.57 mutations/100 positions in acute hepatitis B and 1.57 in chronic hepatitis B (1.28 in HBeAg-positive and 1.8 in anti-HBe-positive patients). The average number of substitutions in the transplanted patients was 2.7 before OLT and 3 after OLT. No amino acid substitutions were detected in the “a” determinant of HBsAg in acute hepatitis B, however, 8 substitutions were observed in 6 chronic patients. In 3 OLT patients, 4 substitutions were observed in samples before and after OLT. One of these patients, who had protective levels of anti-HBs, showed 3 additional new amino acid substitutions after OLT, suggesting escape mutant selection by the effect of HBIG therapy. No changes were observed between the consensus sequences obtained several years before and after transplantation, indicating consensus sequence stability. Conclusion: These results show that there is an accumulation of HBV S-gene mutations in HBV-related end-stage liver disease. Prophylaxis with HBIG mainly obtained from acute self-limited hepatitis patients who have a highly homogeneous viral population, may be one factor underlying the reinfection after liver transplantation.     

A new core promoter mutation and premature stop codon in the S gene in HBV strains from Iranian patients with cirrhosis

Summary. In order to define hepatitis B virus (HBV) mutational patterns in Iran, nucleotide sequences obtained from 91 patients and encompassing the precore, basal core promoter (BCP) and surface (S) regions, were compared. The patients were grouped as asymptomatic carriers, chronic active hepatitis or cirrhotic patients. Genotypes and mutations were determined by sequencing and phylogenetic analysis. All strains belonged to genotype D, and most of them to subgenotype D1. All but two strains specified ayw2, one ayw3 and one adw2 determinants. Two deletions of 8‐ or 20‐bp were found in the X region in eight strains, six from patients with chronic active hepatitis. Eight of 21 strains from patients with cirrhosis harboured unusual mutations such as a stop codon at position 69 in the S region or a previously not described mutation in the BCP region (¹⁷⁶¹TC/ATTTG¹⁷⁶⁶). All patients infected by strains with the stop codon mutation had detectable HBsAg and high viral load. The accumulation of mutations found in the BCP and S regions in HBV strains from patients with chronic active hepatitis and cirrhosis may predict disease progression in Iranian HBsAg carriers.     

Detection of Q129H Immune Escape Mutation in Apparently Healthy Hepatitis B Virus Carriers in Southwestern Nigeria

As the global effort to eradicate hepatitis B continues, immune escape mutations (IEMs) and drug resistance mutations (DRMs) affecting its diagnosis, treatment, and prevention are compromising this goal. However, knowledge about the prevalence and circulation of these mutations in Nigeria is scarce. Serum samples (n = 199) from apparently healthy prospective blood donors, pregnant women, and individuals presenting with fever in southwestern Nigeria were analyzed for the presence of IEMs and DRMs by means of nested PCR in the HBV S (HBs) and HBV polymerase (Pol) genes, followed by phylogenetic and mutational analyses. In total, 25.1% (n = 50/199) of samples were positive for HBV, as measured by PCR. In 41 samples (20.6%), both fragments could be amplified, whereas the HBs gene and the Pol gene fragment alone were detected in 0.5% (n = 1/199) and 4% (n = 8/199) of samples, respectively. Sequences were successfully obtained for all 42 HBs gene fragments but for only 31/49 Pol gene fragments (totaling 73 sequences from 44 individuals). All sequences were identified as HBV genotype E. IEMs were present in 18.2% (n = 8/44) of the sequences of HBV-positive individuals with available sequences. IEM Q129H was detected in eight out of the 44 (18.2%) HBV isolates sequenced in this study; however, no DRMs were observed. This study confirms the circulation of HBV IEMs and reports the presence of Q129H IEM for the first time in Nigeria. Intensified research on the dynamics of IEM is necessary in order to enhance the elimination of HBV.     

Hepatitis B e antigen‐suppressing mutations enhance the replication efficiency of adefovir‐resistant hepatitis B virus strains

Summary. Hepatitis B e antigen (HBeAg) negative hepatitis B virus (HBV) infections caused by precore (PC) or basal core promoter (BCP) mutations are associated with disease progression and complications. PC or BCP mutations may enhance the replication capacity of distinct drug‐resistance‐associated polymerase mutations, but their effect on adefovir‐resistant HBV mutants is unclear. Importantly, BCP mutations were an independent risk factor for virological breakthrough in lamivudine‐resistant patients treated with adefovir. We aimed at addressing the functional consequences of PC and BCP mutations on the replication and drug susceptibility of adefovir‐resistant HBV mutants. Therefore, HBV constructs with wild type (WT) or adefovir‐resistant rtN236T, rtA181V and rtA181T mutations, with or without concomitant PC or BCP mutations, were analysed in vitro using molecular assays. The adefovir‐resistant polymerase mutations rtN236T, rtA181V and rtA181T showed a drastically reduced viral replication compared with WT. Interestingly, additional PC or BCP mutations enhanced the reduced replication efficacy of adefovir‐resistant constructs and restored HBV replication to WT level. HBV rtA181T mutants displayed abolished hepatitis B surface antigen (HBsAg) secretion, owing to a sW172* stop codon in the overlapping envelope gene. All rtN236T‐ or rtA181V/T‐containing constructs, regardless of concomitant PC or BCP mutations, were resistant to adefovir, but remained susceptible to telbivudine, entecavir and tenofovir. In conclusion, adefovir drug resistance mutations reduced viral replication, which can be significantly increased by additional HBeAg‐suppressing PC or BCP mutations. Because increased HBV replication in HBeAg‐negative patients has been associated with an unfavourable clinical course, close monitoring appears indispensable during adefovir treatment in HBeAg‐negative patients.