Relationship between HBV genotypes and anti-viral therapeutic efficacy of interferon-alpha

BACKGROUND: Much evidence demonstrates that the genotypes of hepatitis B virus (HBV) present differences in pathogenicity and outcomes owing to differences in genetic structure. This study aimed to investigate the influences of HBV genotypes on the anti-viral therapeutic efficacy of interferon-α (IFN-α) in chronic hepatitis B patients, and to determine the relationship between HBV genotypes and levels of viral replication or gene variations. METHODS: The chronic hepatitis B patients who were treated with IFN-α were selected randomly. Anti-viral therapeutic efficacy was monitored in these patients. The HBV genotypes were detected by PCR microplate hybridization ELISA. The levels of serum HBV-DNA were determined by fluorescence quantitative PCR. HBV gene variation at pre-C and basic core promoter (BCP) regions were assayed by gene chip technology. RESULTS: Genotypes B and C were predominant in 94 chronic hepatitis B patients. A, E and F genotypes were not found in these patients. The HBV-DNA levels of genotype C and mixed genotypes were significantly higher than those of genotype B. The response to IFN-α in patients with genotype B was markedly better than in those with genotypes C and D, and the complete response to IFN-α was only observed in genotype B. The response to IFN-α in patients with mixed genotypes was the least sensitive. The negative transition of HBeAg was correlated with variations in the HBV pre-C and BCP regions in patientswith partial or no response to IFN-α. The variation rates of HBV pre-C and BCP regions were clearly higher in genotype C than in genotype B. CONCLUSIONS: The results suggest that HBV genotype is correlated with the serum levels of HBV-DNA, HBV gene variations and therapeutic efficacy of IFN-α. The regular detection of HBV genotypes in the clinic will be of benefit for disease prognosis and planning of anti-viral therapeutic strategies.     

Hepatitis B virus genotypes,phylogeny and occult infection in a region with a high incidence of hepatocellular carcinoma in China

AIM:To determine the genotypes and phylogeny of hepatitis B viruses(HBVs)in asymptomatic HBV carriers,and the prevalence of occult HBV infection in Long An County,Guangxi Zhuang Autonomous Region,an area with a high incidence of hepatocellular carcinoma. METHODS:A nested polymerase chain reaction(nPCR) was used for detection of HBV DNA in serum samples from 36 blood donors with asympmatic HBV infection,and in serum samples from 52 HBsAg negative family members of the children who did not receive hepatitis B vaccination in Long An County.PCR products were sequenced,and the genotype of each HBV sequence was determined by comparison with sequences of known genotypes in the GenBank and EMBL nucleotide databases using the BLAST programme.Phylogenetic trees were constructed by the quartet maximum likelihood analysis using the TreePuzzle software. RESULTS:Twenty(55.56%)of 36 HBV asymptomatic carriers were positive for HBV DNA.They were all genotype C by comparison with sequences of known genotypes in the GenBank and EMBL nucleotide databases.The full-length HBV DNA sequence isolated from the sample No.624 contained 3 215 bases.No interesting mutations were found in this isolate.The homology analysis showed that this strain was closer to the Vietnamese HBV genotype C strain,with a homology of 97%,compared its relation to the same genotype of HBV isolated in Shanghai.Six(11.5%) of the 52 HBsAg negative family members were positive for HBV DNA.A point mutation was found in the sample No.37,resulting in the substitution of amino acid glycine to arginine in the"a"determinant.Other samples with positive HBV DNA did not have any unusual amino acid substitutions in or around the"a"determinant,and were attributed to the wild-type HBV. CONCLUSION:The HBVs isolated from asymptomatic carriers of Long An County were all identified as genotype C,and the prevalence of occult HBV infection in the population of the county is as high as 11.5%.It is suggested that genotype C and persistent occult HBV infection may play an important role in the development of HCC in the county.     

Hepatitis B virus genotypes, phylogeny and occult infection in a region with a high incidence of hepatocellular carcinoma in China

AIM: To determine the genotypes and phylogeny of hepatitis B viruses (HBVs) in asymptomatic HBV carriers, and the prevalence of occult HBV infection in Long An County, Guangxi Zhuang Autonomous Region, an area with a high incidence of hepatocellular carcinoma. METHODS. A nested polymerase chain reaction (nPCR) was used for detection of HBV DNA in serum samples from 36 blood donors with asympmatic HBV infection, and in serum samples from 52 HBsAg negative family members of the children who did not receive hepatitis B vaccination in Long An County. PCR products were sequenced, and the genotype of each HBV sequence was determined by comparison with sequences of known genotypes in the GenBank and EMBL nucleotide databases using the BLAST programme. Phylogenetic trees were constructed by the quartet maximum likelihood analysis using the TreePuzzle software. RESULTS: Twenty (55.56%) of 36 HBV asymptomatic carriers were positive for HBV DNA. They were all genotype C by comparison with sequences of known genotypes in the GenBank and EMBL nucleotide databases. The full-length HBV DNA sequence isolated from the sample No. 624 contained 3215 bases. No interesting mutations were found in this isolate. The homology analysis showed that this strain was closer to the Vietnamese HBV genotype C strain, with a homology of 97%, compared its relation to the same genotype of HBV isolated in Shanghai. Six (11.5%) of the 52 HBsAg negative family members were positive for HBV DNA. A point mutation was found in the sample No. 37, resulting in the substitution of amino acid glycine to arginine in the “a” determinant. Other samples with positive HBV DNA did not have any unusual amino acid substitutions in or around the “a” determinant, and were attributed to the wild-type HBV. CONCLUSION: The HBVs isolated from asymptomatic carriers of Long An County were all identified as genotype C, and the prevalence of occult HBV infection in the population of the county is as high as 11.5%. It is suggested that genotype C and persistent occult HBV infection may play an important role in the development of HCC in the county.     

Genotype and phylogenetic characterization of hepatitis B virus among multi-ethnic cohort in Hawaii

AIM:Hepatitis B virus(HBV)genomes in carriers fromHawaii have not been evaluated previously.The aim of thepresent study was to evaluate the distribution of HBVgenotypes and their clinical relevance in Hawaii.METHODS:Genotyping of HBV among 61 multi-ethniccarriers in Hawaii was performed by genetic methods.Three complete genomes and 61 core promoter/precoreregions of HBV were sequenced directly.RESULTS:HBV genotype distribution among the 61 carrierswas 23.0% for genotype A,14.7% for genotype B and 62.3%for genotype C.Genotypes A,B and C were obtained fromthe carriers whose ethnicities were Filipino and Caucasian,Southeast Asian,and various Asian and Micronesian,respectively.All cases of genotype B were composed ofrecombinant strains with genotype C in the precore pluscore region named genotype Ba.HBeAg was detected morefrequently in genotype C than in genotype B(68.4% vs33.3%,P<0.05)and basal core promoter(BCP)mutation(T1762/A1764)was more frequently found in genotype Cthan in genotype B.Twelve of the 38 genotype C strainspossessed C at nucleotide(nt)position 1858(C-1858).However there was no significant difference in clinicalcharacteristics between C-1858 and T-1858 variants.Basedon complete genome sequences,phylogenetic analysisrevealed one patient of Micronesian ethnicity as having C-1858 clustered with two isolates from Polynesia with T-1858.In addition,two strains from Asian ethnicities were clusteredwith known isolates in carriers from Southeast Asia.CONCLUSION:Genotypes A,B and C are predominanttypes among multi-ethnic HBV carriers in Hawaii,anddistribution of HBV genotypes is dependent on the ethnicbackground of the carriers in Hawaii.     

Influence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B

AIM: To investigate the influence of HLA-DRB1 alleles and HBV genotypes on interferon-α therapy for chronic hepatitis B. METHODS: HLA-DRB1*03, *07, *09, *12, *15 alleles were determined using polymerase chain reaction/sequence specific primer (PCR/SSP) technique in 126 patients with chronic hepatitis B and 76 normal control subjects in Shandong Province, and HBV genotypes were determined by nested-PCR analysis using type-specific primers in 126 patients. RESULTS: The positivity of HLA-DRB1*07 allele in chronic hepatitis B group was significantly higher than that in normal control group (X2=6.33, P<0.025, RR=2.37). Among the 126 patients, genotype B was found in 38 (30.2%), genotype C in 69 (54.8%), and mixed genotype (B+C) in 19 (15.0%), genotypes D-F were not found. Among the 46 DRB1*07(+) patients, 7 were responders and 39 were non-responders among them (X2=6.71, P<0.05). The positivity of HLA-DRB1*07 and prevalence of HBV genotype C were significantly higher in non-responders than in responders. CONCLUSION: High positivities of HLA-DRBI *07 allele and HBV genotype C are closely associated with the lower response to interferon-α therapy for chronic hepatitis B.     

Clinical, virologic and phylogenetic features of hepatitis B infection in Iranian patients

AIM： To characterize the clinical, serologic and virologic features of hepatitis B virus （HBV） infection in Iranian patients with different stages of liver disease.
METHODS： Sixty two patients comprising of 12 inactive carriers, 30 chronic hepatitis patients, 13 patients with liver cirrhosis and 7 patients with hepatocellular carcinoma （HCC） were enrolled in the study. The HBV S, C and basal core promoter （BCP） regions were amplified and sequenced, and the clinical, serologic, phylogenetic and virologic characteristics were investigated.
RESULTS： The study group consisted of 16 HBeAgpositive and 46 HBeAg-negative patients. Anti-HBepositive patients were older and had higher levels of ALT, ASL and bilirubin compared to HBeAg-positive patients. Phylogenetic analysis revealed that all patients were infected with genotype D （mostly ayw2）. The G1896A precore （PC） mutant was detected in 58.1% patients. HBeAg-negative patients showed a higher rate of PC mutant compared to HBeAg-positive patients （2,2 = 9.682, P = 0.003）. The majority of patients with HCC were HBeAg-negative and were infected with PC mutant variants. There was no significant difference in the occurrence of BCP mutation between the two groups, while the rate of BCP plus PC mutants was higher in HBeAg-negative patients （2,2 = 4.308, P = 0.04）. In the HBV S region, the genetic variability was low, and the marked substitution was P120T/S, with a rate of 9.7% （n = 6）.
CONCLUSION： In conclusion, HBV/D is the predominant genotype in Iran, and the nucleotide variability in the BCP and PC regions may play a role in HBV disease outcome in HBeAg-negative patients.     

Treatment responses in Asians and Caucasians with chronic hepatitis C infection

AIM：To conduct a multicentre retrospective review of virological response rates in Asians infected with genotype 1 chronic hepatitis C（CHC） treated with combination interferon and ribavirin and then to compare their responses to that among Caucasians.
METHODS：Asian patients infected with genotype 1 CHC treated at 4 Australian centres between 2001 to 2005 were identified through hospital databases.Baseline demographic characteristics,biochemical,virological and histological data and details of treatment were collected.Sustained virological responses（SVR） in this cohort were then compared to that in Caucasian subjects,matched by genotype,age,gender and the stage of hepatic fibrosis.
RESULTS：A total of 108 Asians with genotype 1 CHC were identified.The end of treatment response（ETR） for the cohort was 79% while the SVR was 67%.Due to the relatively advanced age of the Asian cohort,only sixty-four subjects could be matched with Caucasians.The ETR among matched Asians and Caucasians was 81% and 56% respectively（P=0.003）,while the SVR rates were 73% and 36%（P 〈0.001） respectively.This difference remained significant after adjusting for other predictive variables.
CONCLUSION： Genotype 1 CHC in Asian subjects is associated with higher rates of virological response compared to that in Caucasians.     

Relationship between interleukin 18 polymorphisms and susceptibility to chronic hepatitis B virus infection

AIM:To identify the relationship between the tagging single nucleotide polymorphism sites(tagSNPs)of the Interleukin-18(IL-18)gene and genetic susceptibility to chronic hepatitis B virus infection in Chinese patients.METHODS:Five hundred and one cases of chronic hep-atitis B virus(HBV)infection and 301 HBV natural clearance controls were studied.Two tagSNPs in the IL-18 gene(rs1946518A/C and rs574424C/G)were genotyped by the Multiplex Snapshot technique.The genotype and allele frequencies were calculated and analyzed.RESULTS:In the genotypes of rs1946518,the AA type was present at a higher frequency in the patients compared to those in the controls.Odds ratio(OR)of theAA genotype for the comparison with that of the AC and the CC genotype was 1.537(95%confidence intervals(CI):1.116-2.218,P=0.009<0.025).In pheno-types,the allele C at rs1946518 was of a significantly lower frequency in the patients with chronic hepatitis B than that in the controls(P=0.017<0.025).OR of the allele A for the comparison with that of the allele C was 1.279(95%CI:1.045-1.567).As for the rs574424 genotypes,no significant difference in this genotype distribution or in this allele frequency between the patients and the control subjects was observed.No significant difference in the haplotype frequencies between the patients with chronic hepatitis B and HBV natural clearance individuals was displayed.CONCLUSION:The data suggest that genotype AA and the allele A of the IL-18 at position rs1946518 are closely associated with the resistance to chronic hepatitis B and may be the dangerous gene.However,no statistical association was found between polymorphisms of rs574424 for IL-18 and hepatitis B.     

Preliminary report of hepatitis B virus genotype prevalence in Iran

AIM: To determine the prevalence of hepatitis B virus (HBV) genotypes in Iranian hepatitis B surface antigen (HBsAg) carriers, chronic hepatitis B and cirrhotic patients. METHODS: A total of 109 HBsAg-positive patients were included in this study. HBV genotypes were determined by using INNO-LiPA methodology which is based on the reverse hybridization principle. RESULTS: The distribution of patients with different stages of liver disease was as follows: 95 (86.4%) chronic hepatitis, 11 (10%) liver cirrhosis, and 3 (2.7%) inactive carrier. Of the chronic hepatitis and liver cirrhosis patients, 26.4% were HBeAg-positive while 70% were HBeAg-negative. Genotype D was the only detected type found in all patients. CONCLUSION: Classifying HBV into genotypes has to be cost-effective and clinically relevant. Our study indicates that HBV genotype D prevails in the Mediterranean area, Near and Middle East, and South Asia. Continued efforts for understanding HBV genotype through international co-operation will reveal further virological differences of the genotypes and their clinical relevance.     

Hepatitis B virus genotypes and hepatocellular carcinoma in Thailand

AIM: The role of hepatitis B virus (HBV) genotypes on the clinical features and prognosis of patients with hepatocellular carcinoma (HCC) is currently unknown. The aim of the present study was to evaluate the distribution of HBV genotypes and their clinical relevance in Thai patients. METHODS: HBV genotypes were determined by PCR-RFLP in stored sera of 93 asymptomatic carriers, 103 patients with chronic hepatitis, 60 patients with cirrhosis and 76 patients with HCC. The clinical data were analyzed in relation to the HBV genotype. RESULTS: HBV genotypes C and B were predominant in Thailand, accounting for 73% and 21%, respectively. The distributions of genotypes B and C were similar in HCC patients compared to the other groups. Genotype C was significantly more common in HCC patients who were under 40 years old than genotype B (18% vs 0%, P= 0.03), but was significantly less common in patients older than 60 years (26% vs 56.5%, P= 0.01). The positive rate of hepatitis B e antigen (HBeAg) in patients with genotype C was significantly higher than that in patients with genotype B (71.6% vs 44.4%, P= 0.03 in chronic hepatitis; 56.8% vs 11.1%, P= 0.01 in cirrhosis). There were no differences between HCC patients with genotypes B and C regarding tumor staging by CLIP criteria and the overall median survival. Multivariate analyses showed that HBV genotype was not an independent prognostic factor of survival in HCC patients. CONCLUSION: Patients with genotype C had a higher positive rate of HBeAg and exhibited earlier progression of cirrhosis and HCC than those with genotype B. However, there were no differences in the risk of developing HCC and its prognosis between patients with these genotypes.     

慢性乙型肝炎病毒基因型与BCP区变异的临床研究

为了研究乙型肝炎病毒 (HBV)基因型与C基因启动子 (BCP)基因变异的关系 ,对 6 9例慢性乙型肝炎患者分别用聚合酶链反应 (PCR)—限制性片段长度多态性 (RFLP)技术和PCR微板核酸分子杂交技术 ,进行基因分型及HBVBCP基因变异检测。在 6 9例慢性乙型肝炎患者中 ,各基因型发生的BCP区A176 2T/G176 4A双突变分别为C型 18例 (4 3 9% )B型 3例 (16 7% )D型 2例 (2 0 % )。C型的BCP双突变率明显高于B型 ,两者相比有显著性差异(P <0 0 5 )。故可以认为乙型肝炎病毒基因型与BCP区双突变存在有一定的相关性。推测A176 2T/G176 4A双突变可能是造成C型患者比B型存在更严重肝损害的原因之一     

Molecular and serological characterization of hepatitis B virus genotype A and D infected blood donors in Poland

Summary. Hepatitis B virus (HBV) genotypes have distinct geographical distributions and influence severity of clinical outcome and response to antiviral therapies. HBV polymorphism in HBV surface antigen (HBsAg) positive first time blood donors from Poland was examined. HBV serological markers and HBV DNA were tested in 170 samples. Whole genome (n = 53) or specific region sequences: pre‐S/S and basic core promoter/precore (BCP/PC) region (91 and 154 samples, respectively) were phylogenetically analyzed. The median age of infected donors was 21 years. Anti‐HBs, anti‐HBe and hepatitis B e antigen were detected in 5%, 92.4% and 10.5% of tested donors, respectively. The HBV DNA load ranged between unquantifiable and 3.1 × 10¹⁰ IU/mL (median: 4.10 × 10³ IU/mL). Genotypes A2 (81.2%) and D (18.8%) co‐circulated. Phylogenetic analyses revealed differences between the genotypes. Viral load and level of HBsAg tended to be lower in genotype D. The median HBsAg/HBV DNA ratio expressed in IU/mL was one for both genotypes, but very low or very high ratios appeared more frequent in genotype D infections. Higher amino acid variability in the surface proteins (median: 4%vs 1.5%; P = 0.01) and in the major hydrophilic region was observed in genotype D (P = 0.01). BCP/PC region analysis revealed the double mutation 1762T/1764A in 49/125 (39.2%) genotype A2 and 6/29 (20.7%) genotype D strains (P = 0.08). Mutations in PC and BCP regions correlated neither with HBsAg nor HBV DNA levels. HBV genotype A2 is dominant in HBsAg positive donors in Poland. Minority genotype D strains are significantly more substituted than genotype A2 strains potentially affecting the course of infection.     

Distribution of hepatitis B virus genotypes： Phylogenetic analysis and virological characteristics of Genotype C circulating among HBV carriers in Kolkata, Eastern India

INTRODUCTION Hepatitis B virus (HBV) belongs to the Hepadnaviridae family of enveloped viruses with double-stranded DNA genome of nearly 3200 bp lengths. The HBV genome consists of four major overlapping open reading frames named surface (S), core (C), po…     

Mutations of Basal Core Promoter and Precore Regions in Hepatitis B Virus Genotypes B and C

Background:

Mutations in basal core promoter (BCP) and precore regions of hepatitis B virus (HBV) are associated with course and treatment outcomes of chronic HBV infection. While BCP and precore mutation analysis have been carried out in adult patients between different genotypes, this analysis has rarely been performed for chronically infected children.

Objectives:

The aim of this study was to assess the mutation profiles of BCP and precore regions in different HBV genotypes in chronically infected children.

Patients and Methods:

A cohort of 245 children and 92 adults with chronic HBV infection was included in this study. BCP and precore regions were analyzed by PCR amplification and sequenced.

Results:

Ten nucleotide positions, including nt1679, nt1721, nt1753, nt1757, nt1758, nt1762, nt1764, nt1775, nt1856 and nt1858 in BCP/precore regions of HBV genome, showed obviously higher frequencies of mutation in genotype C subjects than in genotype B subjects among children, while there were only three positions, including nt1679, nt1758 and nt1775 showing higher mutation frequencies in genotype C subjects than in genotype B subjects in adults. Several combined mutations were obviously highly distributed in children with chronic HBV genotype C infection, such as G1721A/A1775G/T1858C triple mutation; a novel combined mutation type, exclusively detected in children with chronic HBV genotype C infection. In addition, G1721A/A1775G/T1858C combined mutation was associated with higher viral load and lower age distribution.

Conclusions:

The mutation ratio difference between genotypes B and C in children was higher than that of adults and several combined mutations were exclusively detected in children with chronic HBV genotype C infection associated with higher viral load.     

Correlation of hepatitis B virus (HBV) genotypes and mutations in basal core promoter/precore with clinical features of chronic HBV infection.

BACKGROUND/AIMS: To investigate the correlation of hepatitis B virus (HBV) genotypes and basal core promoter (BCP) and precore (PC) mutations in patients with chronic hepatitis B. METHODS: HBV genotyping, nucleotide mutation, serum HBV DNA level and serological markers were analyzed in 121 patients with chronic HBV infection using INNO-LiPA HBV genotyping, polymerase chain reaction (PCR) product-based sequencing, fluorescence quantitative PCR and enzyme-linked immunosorbent assays respectively. RESULTS: Forty (33.0%), 77 (63.6%), two (1.7%) and two (1.7%) patients had genotypes B, C, B/C and D infections respectively. Significant differences were found in serum HBV DNA levels (log10 copies/ml: 6.18 vs. 5.61, P=0.042) and mutations at nucleotide (nt) 1762/1764 (71.4% vs. 42.5%, P=0.002) between genotypes C- and B-infected patients. There were significant differences in the mean age, serum biochemical parameter levels and mutation rates in BCP/PC among hepatitis e antigen (HBeAg)-positive and -negative chronic hepatitis B (CHB) and liver cirrhosis (LC) groups. CONCLUSION: Genotypes C and B are predominant in China, and the frequent nt 1762/1764 mutation, which occurs commonly in HBeAg-negative CHB, especially in genotype C patients, may be associated with the progress of chronic HBV infection.     

Frequency and distribution of hepatitis B virus genotypes among eastern Indian voluntary blood donors: Association with precore and basal core promoter mutations

Aim:  To screen hepatitis B virus (HBV) genotypes and associated basal core promoter (BCP; T1762/A1764) and precore (PreC; A1896) mutations among the HBV surface antigen (HBsAg) positive voluntary blood donors in eastern India.
Methods:  HBV genotypes, BCP and PreC mutations of 141 HBsAg positive voluntary blood donors were determined by the restriction fragment length polymorphism (RFLP) method and a phylogenetic tree was constructed from surface (S) gene region sequences of representative HBsAg positive donors to confirm the results.
Results:  HBV/D was the most predominant (79, 56.0%) genotype followed by HBV/C (33, 23.4%) and HBV/A (29, 20.6%). HBV/C infected blood donors are mostly young (18–25 years). The occurrence of BCP mutation was found to be significantly higher in HBV/C (24, 72.7%) than in HBV/A (7, 24.1%, P  < 0.001) and HBV/D (17, 21.5%, P  < 0.001), whereas PreC mutation was more frequent in HBV/D (28, 35.4%) than in HBV/C (9, 27.3%). However, the simultaneous presence of BCP and PreC mutations was more common in HBV/C (8/33, 24.2%), followed by HBV/D (6/79, 7.6%).
Conclusion:  In addition to HBV/D and HBV/A, a significant proportion of HBV/C (23.4%) was also present among the voluntary blood donors from eastern India, most frequently in the 18–25 year age group. BCP mutation was more common in HBV/C infected donors.     

Molecular and serological characterization of hepatitis B virus in deferred Ghanaian blood donors with and without elevated alanine aminotransferase

Candidate blood donors in Ghana are frequent carriers of hepatitis B virus (HBV). A comparative study of 117 donor samples including 46 with alanine aminotransferase (ALT) > or = 60 IU/L and 71 with < or =40 IU/L level was undertaken. S and the basic core promoter-precore regions (BCP/PC) sequencing was used to identify genotypes and variants relevant to HBV natural history, respectively. Age, viral load, HBe status were correlated with molecular data. HBV genotype E (87%) was dominant with little genotypes A (10%) and D (3%). Comparing individuals with or without liver disease, an association between liver disease and older age (P = 0.004) and higher viral load (P = 0.002) whether as a whole population or only genotype E was found. Compared with a commercial assay, BCP/PC sequencing had lower sensitivity to detect mixtures of wild-type and variant viruses but detected BCP deletions. BCP 1762/1764 variants were positively correlated with older age (P < 0.0001) and elevated ALT levels (P = 0.01). PC 1896 stop codon was marginally correlated with viral load (P = 0.09). HBV genotype E infection natural history appears different from genotypes B and C prevalent in Asia. Donors with liver disease being older, with higher viral load and higher BCP variant proportion may be at higher risk of cirrhosis and hepatocellular carcinoma.     

HBV基因型和HBV核心启动子双点突变与肝损伤的关系探讨

目的 了解HBV基因型在荆州地区的流行病学状况；探讨HBV基因型和HBV核心启动子双点突变与肝损伤的相关性。方法 采用PCR微板核酸杂交-ELISA技术，对临床诊断为不同程度的乙型肝炎患者血清中的HBV DNA进行基因分型和核心启动子双点突变检测。结果本地区基因型以B型和D型为主，分别为31．4％和24．4％。其它为：A型3．5％，C型18．6％，B、C混合型11．6％，B、D混合型10．5％。结论 HBV基因型在本地区分布有其独特之处，HBV核心启动子双点突变在C型发生频率高于B型，有显著性差异，但与D型比较无显著性差异。HBV基因型及HBV核心启动子双点突变与肝损伤彼此间无明显相关性。肝损作可能主要与机体免疫等相关，HBV变异仅起次要作用。     

Mutations in the basic core promoter region of hepatitis B virus. Relationship with precore variants and HBV genotypes in a Spanish population of HBV carriers

BACKGROUND/AIMS: To determine the prevalence and significance of hepatitis B virus (HBV) basic core promoter (BCP) mutations and to establish their relationship with precore (preC) mutations, HBV genotypes and HBV-DNA levels. METHODS: BCP and preC mutations and genotypes were determined by sequencing. RESULTS: Genomic analysis was performed in 129 (71%) of 182 patients. BCP mutations were detected in 83% of 18 HBeAg-negative (e-) chronic hepatitis B (CHB) patients with fluctuating ALT levels, and in 76% of 58 e- CHB with elevated ALT. The prevalence was lower and similar, 55% in 30 HBeAg-positive CHB (e+ CHB) with elevated ALT and in 23 e- inactive carriers. Frequency of preC mutations was higher in e- CHB (80%) than in e- inactive carriers (65%). Among e- CHB, patients with elevated ALT and preC mutations at nt 1896 showed highest HBV-DNA, regardless of BCP mutations. BCP mutations were similar in genotypes A and D, while preC mutations were most common in genotype D (82 vs. 40%). Simultaneous presence of the main BCP (1762, 1764) and preC (1896, 1899) mutations was associated with the degree of histological injury. CONCLUSIONS: Combined BCP and preC mutational and genotype analysis provides clinically relevant information in the study of HBV infection.     

Genotyping 238 HBV strains using type-specific primer PCR combined with type-specific nucleotide analysis]

OBJECTIVE: To establish a set of suitable and reliable methods for HBV genotyping and to study the distribution of HBV genotypes. METHODS: Type-specific nucleotides were searched through alignment of S genes (more than 1000 sequences) listed in GenBank. Then, type-specific primers were designed and type-specific primer PCR was used to genotype the 238 HBV strains. S genes of the untyped strains were further amplified and sequenced to find out their genotypes with type-specific nucleotide analysis. RESULTS: All the 238 HBV strains were genotyped. 159 (66.8%) cases were genotype B, 69 (28.9%) were genotype C, 6 (2.5%) were mixtures of genotypes B and C and 4 (1.6%) were mixtures of genotypes B and D. No genotypes of A, E, F, G, and H were found. CONCLUSION: Genotypes B and C are the most common types for HBV strains. Mixtures of genotypes B and C or genotypes B and D coinfection rarely existed. There is no relationship between the gender of the patients and HBV genotypes (X2 = 0.794, P more than 0.05).