Basal core promoter and precore mutations among hepatitis B virus circulating in Brazil and its association with severe forms of hepatic diseases

BACKGROUND In Brazil, few studies have investigated the prevalence of infection with the precore (PC) and basal core promoter (BCP) mutants of the hepatitis B virus (HBV). OBJECTIVES This study aimed to analyse the frequency of PC and BCP mutations among patients infected with HBV and to evaluate the association between the variants and advanced hepatic disease. METHODS A total of 161 patients infected with HBV were studied. To identify PC and BCP mutations, a 501-bp fragment of HBV DNA was amplified and sequenced. FINDINGS PC and BCP regions from HBV strains were successfully amplified and sequenced in 129 and 118 cases, respectively. PC and BCP mutations were detected in 61.0% and 80.6% of the cases, respectively. The A1762T/G1764A variant was identified in 36.7% of the patients with grade 1 and 2 liver fibrosis (29/79) and in 81.8% of the patients with grade 3 and 4 liver fibrosis (9/11) (p < 0.01); in 76.9% of the patients with cirrhosis (10/13) and in 38.1% of the patients without cirrhosis (40/105) (p = 0.01); and in 77.8% of the patients with hepatocellular carcinoma (HCC) (7/9) and in 39.4% of the patients without HCC (43/109) (p = 0.03). MAIN CONCLUSIONS A high prevalence of HBV PC and BCP mutants was found. The A1762T/G1764A variant was independently associated with advanced forms of liver fibrosis, hepatic cirrhosis, and HCC.

Analysis on relationship between HBV precore/core promoter region and the liver histological changes in ;HBeAg negative CHB patients / 实用医学杂志

Objective To investigate the relationship between HBV mutations in the precore (PC)/core promoter region and the liver histological changes in HBeAg negative CHB patients. Method A total of 71 HBeAg negative CHB patients with liver biopsy from April 2012 to Dec 2013 were enrolled. DNA was extracted from blood serum, then the HBV S gene and PC/core promoter region were amplified by semi-nested PCR and sequenced. The relationship between significant liver histological changes and viral factors were analyzed by Logistic regression analysis. Results The incidence of significant necroinflammation (15.8% vs. 27.3%, χ2 =1.398, P = 0.237) and significant fibrosis (71.1% vs. 84.4%, χ2= 1.926, P = 0.165) were found to be similar between patients infected with HBV genotype B and genotype C . By Logistic regression analysis including risk factors of age, sex, HBV genotype and mutations (T1753V,A1762T/G1764A,A1846T and G1896A), the A1762T/G1764A mutation in HBV associated with significant necroinflammation (OR = 4.296, P = 0.037), while factors of age, sex, genotype and other mutation were not associated with significant liver histological changes. (all P > 0.05). Conclusion Mutation in PC/core promoter region of HBV may act as a marker to evaluate the liver histological changes.

A novel assay for detecting the mutation of nucleotide 1758-1777 deletion in core promoter region of hepatitis B virus / 解放军医学杂志

Objective Nucleotide (nt) 1758-1777 deletion in core promoter (CP) region of hepatitis B virus (HBV) has been suggested to be associated with disease progression. However, the complicated and less sensitive assay for it limited its use in clinic. The present study was aimed at setting a novel assay for its detection using single-tube nested PCR amplification and real-time PCR melting curve analysis. Methods The PCR primers were designed through analysis of HBV genomic sequences in GenBank, and detection conditions were optimized. HBV CP region from 340 serum samples of chronic hepatitis B patients were amplified and directly sequenced, and fifty samples were randomly selected for cloning and sequencing for analysis of nt 1758-1777 deletion. The wild-type and deletion-type plasmids were extracted from mono-cloning samples. Positive standard of melting curve analysis was set up in light of the results of PCR amplification of two standard plasmids and cloning samples. The new method of assay was used in 340 samples, and the data were verified by the results of pyrosequencing. Results Sixteen (4.7%) samples were positive for the deletion by direct sequencing, and no less than 15% samples in standard plasmids and cloning sequencing showed sequence deletion. The melting temperature (Tm) of deletion-type plasmid and cloning samples containing ≥15% proportion of the deletion sequence was ≥88.3°C, which was determined as positive standard of the novel assay. Forty-seven (13.8%) samples were detected positive for nt 1758-1777 deletion by the novel assay. Among them, deletion ratio was ≥1.0% in 38 samples and <1.0% in 9 samples by pyrosequencing, respectively. The deletion ratio was all <1.0% in 15 negative control samples. The deletion ratio of 1.0% was taken as positive cutoff by pyrosequencing, the novel assay had 80.9% positive consistency and 100% negative consistency, with a Kappa value of 0.671. Conclusions Comparing with direct sequencing, the novel assay significantly increased detection rate of nt 1758-1777 deletion. In combination with pyrosequencing for confirmation, the accuracy and cost-effectiveness of the detection could be significantly improved. The novel assay offers an example for detecting HBV genetic deletions.

Hepatitis B virus genotypes and mutations in the basal core promoter and pre-core/core in chronically infected patients in southern Brazil: a cross-sectional study of HBV genotypes and mutations in chronic carriers

Introduction In Brazil, little data exist regarding the distribution of genotypes in relation to basal core promoter (BCP) and precore/core mutations among chronic hepatitis B virus (HBV) carriers from different regions of the country. The aim of this study was to identify HBV genotypes and the frequency of mutations at the BCP and precore/core region among the prevalent genotypes in chronic carriers from southern Brazil. Methods Nested-polymerase chain reaction (nested-PCR) products amplified from the S-polymerase gene, BCP and precore/core region from 54 samples were sequenced and analyzed. Results Phylogenetic analysis of the S-polymerase gene sequences showed that 66.7% (36/54) of the patients were infected with genotype D (D1, D2, D3), 25.9% (14/54) with genotype A (A1, A2), 5.6% (3/54) with subgenotype C2, and 2% (1/54) with genotype E. A comparison of virological characteristics showed significant differences between genotypes A, C and D. The comparison between HBeAg status and the G1896A stop codon mutation in patients with genotype D revealed a relationship between HBV G1896A precore mutants and genotype D and hepatitis B e antigen (HBeAg) seroconversion. Genotype D had a higher prevalence of the G1896A mutation and the presence of a thymine at position 1858. Genotype A was associated with a higher ...

Detection of hepatitis B virus A1762T/G1764A mutant by amplification refractory mutation system

OBJECTIVE: To study the role of hepatitis B virus with A1762T/G1764A double mutation in liver cirrhosis and hepatocellular carcinoma, and create a sensitive, fast, accurate assay for detection of A1762T/G1764A double mutation. METHODS: We developed an accurate and fast real-time amplification refractory mutation system to detect A1762T/G1764A double mutation. Cloned hepatitis B virus genome was used as a control. Assay sensitivity was determined by serial dilution and mixed template experiments. Specificity was determined by cross experiments with wild and mutant hepatitis B virus. Fifty clinical samples were tested by the real-time amplification refractory mutation system and the results were compared with sequencing. RESULTS: The real-time amplification refractory mutation system had a sensitivity of 100 copies of virus with these mutations, and 0.1% weak population virus with double mutation could be found in mixtures. A total of 50 randomly collected clinical samples were detected by real-time amplification refractory mutation system, and the results were consistent with those by DNA sequencing. Hepatitis B virus genotype C was more prevalent in 39 of 50 samples than genotype B (11 samples), and about 75% of genotype C carried a double mutation compared to 45% of genotype B. However, the percentage of A1762T/G1764A double mutation in hepatitis B e antigen-negative (58.3%) samples was almost the same as in hepatitis B e antigen-positive (61%) samples. CONCLUSION: The real-time amplification refractory mutation system is sensitive and specific for detection of hepatitis B virus double mutation. .

Relationship between hotspot mutations in basic core promoter of hepatitis B virus and familial clustering of hepatocellular carcinoma in Guangxi / 实用医学杂志

Objective To explore the relationship between mutations in basic core promoter (BCP) of hepatitis B virus (HBV) and familial clustering of hepatocellular carcinoma (HCC) in Guangxi. Methods 153 pairs of members with HBsAg-positive were selected and matched from HCC high-incidence families and carcinoma-free families in Guangxi. The BCP genes were amplified and sequenced. Results The hotspot sites of the previous five mutations in BCP were T1762, A1764, G1775, V1753, G1803. In univariant analysis, HBV DNA≥105 copies/mL, T1762, A1764 and V1753 mutations were associated with the HCC high-incidence (P <0.05). The multivariate logistic analysis showed that HBV DNA≥105 copies/mL and A1764 were independent risk factors for it. Conclusion HBV DNA level, the mutations in BCP showed correlations with familial clustering of HCC in Guangxi.

Hepatitis B virus subgenotype C2- and B2-associated mutation patterns may be responsible for liver cirrhosis and hepatocellular carcinoma, respectively

The objective of this study was to examine hepatitis B virus (HBV) subgenotypes and mutations in enhancer II, basal core promoter, and precore regions of HBV in relation to risks of liver cirrhosis (LC) and hepatocellular carcinoma (HCC) in Southeast China. A case-control study was performed, including chronic hepatitis B (CHB; n=125), LC (n=120), and HCC (n=136). HBV was genotyped by multiplex polymerase chain reaction and subgenotyped by restriction fragment length polymorphism. HBV mutations were measured by DNA sequencing. HBV genotype C (68.2%) predominated and genotype B (30.2%) was the second most common. Of these, C2 (67.5%) was the most prevalent subgenotype, and B2 (30.2%) ranked second. Thirteen mutations with a frequency >5% were detected. Seven mutation patterns (C1653T, G1719T, G1730C, T1753C, A1762T, G1764A, and G1799C) were associated with C2, and four patterns (C1810T, A1846T, G1862T, and G1896A) were associated with B2. Six patterns (C1653T, G1730C, T1753C, A1762T, G1764A, and G1799C) were obviously associated with LC, and 10 patterns (C1653T, G1730C, T1753C, A1762T, G1764A, G1799C, C1810T, A1846T, G1862T, and G1896A) were significantly associated with HCC compared with CHB. Four patterns (C1810T, A1846T, G1862T, and G1896A) were significantly associated with HCC compared with LC. Multivariate regression analyses showed that HBV subgenotype C2 and C2-associated mutation patterns (C1653T, T1753C, A1762T, and G1764A) were independent risk factors for LC when CHB was the control, and that B2-associated mutation patterns (C1810T, A1846T, G1862T, and G1896A) were independent risk factors for HCC when LC was the control.

Mutations in Hepatitis B Virus Precore, Core Promoter, and "a" Determinant in Children with Chronic Hepatitis B Virus Infection / 대한소아소화기영양학회지

PURPOSE: The aim of this study was to determine the prevalence, types of variants, and clinical significance of mutations in precore, core promoter, and "a" determinant mutations in children with chronic hepatitis B virus infection. METHODS: Thirty-one patients with chronic hepatitis B virus infection who visited Seoul National University Children's Hospital in Korea between 2004 and 2005 were enrolled in this study. Serum HBV DNA was amplified by polymerase chain reaction (PCR) and the precore/core promoter and "a" determinant sequences were determined. RESULTS: Precore mutations were found in 11 of 27 patients (40.7%), and appeared more frequently in the HBeAg-negative group (p<0.05) compared to the HBeAg-positive group. G1896A was detected most frequently (81.8%). BCP mutations were found in 15 of 27 patients (55.6%) and the TA mutation (A1762T/G1764A) was the most common (86.7%). Mutations in the "a" determinant region were detected in 8 of 28 patients (28.6%), and amino acid changes were detected in 6 of 28 patients (21.4%). Of these mutations, substitutions at amino acid position 126 were found most frequently. CONCLUSION: In children with chronic hepatitis B virus infection, the most common mutations were G1896A in the precore region and TA mutation(A1762T/G1764A) in the core promoter region. Substitutions at amino acid position 126 was the most common mutation in the "a" determinant. Precore mutants were found to be significantly higher in HBeAg-negative patients. The high prevalence of mutations in the "a" determinant and low frequency of G145R were characteristic features. These mutations were not significantly associated with other clinical features except for high aminotransferase concentration in the core promoter variant group.

Cloning and identification of the core promoter of human TSLC1 gene / 基础医学与临床

Objective To clone and to identify the core promoter of human TSLCI used for exploring of transcrip-tion regulatory mechanism.Methods A series of different fragments located in the upstream of translation start site of TSLC1 were amplified from human genomic DNA by PCR,and then constructed into pGL3-Basic luciferase re-porter vector.The activity of different fragments in A549 and NCI-H446 cells was examined by a dual-luciferase as-say after transient transfection,and then the core promoter of TSLC1 was identified.Results Among the different constructs,the fragment of -68 ～ -329 bp located in the upstream of ATG showed the strong activity both in A549 cells and NCI-H446 cells,which played an important role in the transcription of TSLC1.Conclusion The fragment of -68 ～ -329 bp located in the upstream of translation start site of TSLC1 might be the core promoter region.

The association of primary liver cancer with the mutations in basic core promoter and precore genes of hepatitis B virus / 中华临床感染病杂志

Objective To investigate the association of primary liver cancer(PLC)with the mutations of HBV precore and basic core promoter(BCP)genes.Methods The serum markers of hepatitis B and the quantities of serum HBV DNA were detected in 144 HBsAg-positive PLC patients.The precore and BCP gene mutations in patients with HBeAg-negtive and HBV DNA-positive were detected by real-time PCR.One hundred and twenty chronic hepatitis B(CHB)patients were randomly selected to serve as the conol.Results There were 46(3 1.94%)patients with HBeAg-positive and 98(68.06%)patients with HBeAg-negative.In 98 HBeAg-negative patients,56(57.14%)were HBV DNA-positive,in which 43 (76.79%)were with precore 1896 gene mutations,50(89.29%)were with BCP1762/1764 gene mutations.and 38(67.86%)were with both gene mutations.Precore 1896 and BCP1762/1764 gene mutation rates in PLC patients were much higher than those in CHB patients(χ2=9.36 and 5.77,P＜0.05).Conclusion PLC may be associated with the mutations of HBV precore anti BCP genes.

Hepatitis B virus genotypes and mutations affecting HBeAg production: A Malaysian perspective

Infection by hepatitis B virus (HBV) is a major global health-care problem. HBV is an accepted factor in the elevated risks for liver disease such as cirrhosis and development of hepatocellular carcinoma. This problem is particularly prevalent in the Asia-Pacific region which includes Malaysia. During infection, the hepatitis B e antigen (HBeAg) is produced in the hosts. This antigen is an important serological marker for diagnosing chronic hepatitis B. Seroconversion to anti-body (anti-HBe) corresponds to the improvement of disease prognosis. However, certain mutations such as the core promoter dual mutations (A1762G1764→T1762A1764), the codon 15 variants (C1858/ T1858) and the precore stop codon mutations (TGG→TAG) can affect the HBeAg expression. This has diagnostic and clinical implications. Besides that, the HBV can be grouped into eight genotypes (A to H). Moreover, genotypic subtypes and recombinants have been observed as well. Studies have observed that these can differ in their affiliations with the mutations above as well as with disease prognosis.

Correlation of Hepatitis B Virus Basic Promoter Mutation with IL-10,IL-12,TNF-?,IFN-? as well as HBV DNA Contents in Chronic Hepatitis / 中华医院感染学杂志

OBJECTIVE To study the correlation of hepatitis B virus(HBV)basic core promoter(BCP) mutation with the interleukins(IL-10,IL-12),tumor necrosis factor(TNF)-?,interferon(IFN)-?,as well as HBV DNA contents in patients with chronic hepatitis B virus infection.METHODS(1) Project subject: 176 patients(chronic hepatitis B with mild,moderate and severe degree;liver cirrhosis,chronic fulminant and hepatocellular carcinoma(HCC)) with chronic hepatitis B virus infection were studied.(2) Project methods: ① The A to T mutation at nucleotide 1762 and G to A mutation at nucleotide 1764 were determined by the method of polymerase chain reaction(PCR) microplate hybridization ELISA in these patients.② The serum cytokines(IL-10,IL-12,TNF-? and IFN-?) of these patients were measured by specific-ELISA.RESULTS The serum levels of cytokines(IL-10(80.96?30.86 vs 72.11?24.19 mg/L),IL-12(41.33?15.10 vs 35.98?14.47 mg/L),TNF-?(56.04?27.05 vs 38.01?10.49 mg/L),IFN-?(19.81?12.29 vs 16.55?8.99 mg/L))and HBV DNA contents(108.2478?0.9826 vs 105.8876?1.4822copies/ml) in BCP mutant group were significantly higher than that in non-mutant group(P

Single nucleotide polymorphisms of follicle-stimulating hormone receptor promoter and their impacts to the promoter activities.

Women of reproductive ages are varies in their responses to exogenous FSH stimulations. The difference of FSHR genotype due to the polymorphisms in exon 10 is one of its significant factors. To know further whether the core promoter of FSHR is also polymorphic and to know whether those polymorphisms influence the promoter activity, we did polymorphism screening of FSHR promoter to 262 women undergoing IVF/ICSI, followed by functional study to know the impact of polymorphisms to the promoter activity. This study indicated that the core promoter of human FSHR is polymorphic. We found five SNPs at positions –29, –37, –114, –123 and –138 in addition to the variety number of adenines. Polymorphism at position –123 significantly decreased the promoter activity, in contrast, polymorphism at position –37 and –138 significantly increased the promoter activity, whereas polymorphism at position –29, –114 and short adenines stretch did not significantly influence the promoter activity. The differences of the promoter activities due to polymorphisms might change the ovarian sensitivity to FSH.

The Prevalence and Clinical Significance of Precore and Core Promoter Mutations in Korean Patients with hronic Hepatitis B Virus Infection / 대한간학회지

BACKGROUND/AIMS: Precore and core promoter mutations of hepatitis B virus (HBV) have been reported in Korea but their prevalence and clinical significance have not been determined. The aims of this study were to determine the prevalence of precore and core promoter mutations and their relationships to hepatitis B e antigen (HBeAg) status, viral replication level, and severity of liver disease in Korea. METHODS: Among the patients who visited the Liver Diseases Clinics (Chung Ang University Hospital) between December 1998 and August 1999, 150 patients were randomly selected: 50 HBeAg-positive HBV-DNA positive patients by a branched DNA (bDNA) assay, 50 HBeAg-negative bDNA-positive patients, and 50 HBeAg-negative bDNA-negative patients. Serum HBV-DNA was amplified by a polymerase chain reaction (PCR) in these patients and the core promoter/precore HBV sequence was determined in 135 of the patients whose sera were positive for HBV-DNA by PCR. RESULTS: All of the 135 determined HBV-DNA sequences had HBV genotype with T at nucleotide 1858. Precore mutation (A1896) was detected in 95.7% of HBeAg-negative bDNA-positive patients and 94.9% of HBeAg-negative bDNA-negative patients. In HBeAg-positive patients 88% had wild type and 12% had mixture of wild type and A1896 mutant. Core promoter TA mutation (T1762/A1764) was detected in 93.5% of HBeAg-negative bDNA-positive patients, 94.9% of HBeAg-negative bDNA-negative patients and 74% of HBeAg-positive patients. No correlation was found between the presence of precore/core promoter mutations and liver disease severity or HBV-DNA levels. CONCLUSION: Precore stop codon mutation occurred almost invariably, along with HBeAg seroconversion, irrespective of subsequent viral replication levels or disease severity. Core promoter TA mutation was frequent both in the HBeAg-positive patients and HBeAg-negative patients irrespective of viral replication levels or disease severity.

The DPE, a core promoter element for transcription by RNA polymerase II

The core promoter is an important yet often overlooked component in the regulation of transcription by RNA polymerase II. In fact, the core promoter is the ultimate target of action of all of the factors and coregulators that control the transcriptional activity of every gene. In this review, I describe our current knowledge of a downstream core promoter element termed the DPE, which is a TFIID recognition site that is conserved from Drosophila to humans. The DPE is located from +28 to +32 relative to the +1 transcription start site, and is mainly present in core promoters that lack a TATA box motif. Moreover, in Drosophila, the DPE appears to be about as common as the TATA box. There are distinct mechanisms of basal transcription from DPE- versus TATA-dependent core promoters. For instance, NC2/Dr1-Drap1 is a repressor of TATA-dependent transcription and an activator of DPE-dependent transcription. In addition, DPE-specific and TATA-specific transcriptional enhancers have been identified. These findings further indicate that the core promoter is an active participant in the regulation of eukaryotic gene expression.

The DPE, a core promoter element for transcription by RNA polymerase II

The core promoter is an important yet often overlooked component in the regulation of transcription by RNA polymerase II. In fact, the core promoter is the ultimate target of action of all of the factors and coregulators that control the transcriptional activity of every gene. In this review, I describe our current knowledge of a downstream core promoter element termed the DPE, which is a TFIID recognition site that is conserved from Drosophila to humans. The DPE is located from +28 to +32 relative to the +1 transcription start site, and is mainly present in core promoters that lack a TATA box motif. Moreover, in Drosophila, the DPE appears to be about as common as the TATA box. There are distinct mechanisms of basal transcription from DPE- versus TATA-dependent core promoters. For instance, NC2/Dr1-Drap1 is a repressor of TATA-dependent transcription and an activator of DPE-dependent transcription. In addition, DPE-specific and TATA-specific transcriptional enhancers have been identified. These findings further indicate that the core promoter is an active participant in the regulation of eukaryotic gene expression.

The influence of hepatitis B virus basic core promoter/precore mutations on adv ance of liver disease / 中国实用内科杂志

Objective To investigate the relationship between hepatitis B virus (HBV) basic core promoter(BCP)/precore(PreC) mutations and severity of liver dis ease. Methods In 113 patients chronically infected with HBV, do uble mutations in BCP(T1762/A1764) and PreC mutation(A1896) were determined by INNO-LiPA and HB V genotype was determined by S gene sequencing. Results Whether in all patients or in patients infected by single genotype C, compared with AsC, the prevalence of double mutations in BCP(T1762/A1764) was higher in patients with CHB, LC and HCC[(24.1% vs 2.8%,? 2=5.93, P0.05). Conclusions The doubl e mutations in BCP(T1762/A1764 ) may be related to progressive liver disease in patients with chronic HBV infec tion.

Detection of double-position mutation in the basic core promoter of hepatitis B virus with microplate sandwich hybridization / 中华传染病杂志

Objective To investigate 1762T、1764A double position mutation in the Basic Core Promoter(BCP) of hepatitis B virus and reveal its relation to clinical symptoms and HBeAg phenotype. Methods microplate sandwich hybridization technique was used to detect BCP double position mutation. One common capture probe and one mutant specific detector probe as well as one wild type detector probe were synthesized and hybridized with amplified HBV DNA from the sera of hepatitis B patients. The results of hybridization were exhibited with ELISA. Results 147 hepatitis B patients who had been confirmed HBV DNA positive were screened. 51 patients were BCP double position mutation, 42 of which were BCP single position mutation and, 9 were mix mutation(both mutation and wild type were positive). BCP mutant was detected in 36 of 117 with chronic hepatitis and, 8 of which were mix mutants. Moreover, BCP mutant was detected in 7 of 30 with acute hepatitis in 25 of 78 with HBeAg positive were mutant and in 26 of 65 with HBeAg negative were mutant.Conclusions (1) The rate of BCP double position mutation in chronic hepatitis B patients is higher than that in acute hepatitis B patients. (2) BCP mutation may impair HBeAg expression. (3) PCR microplate sandwich hybridization ELISA is a sensitive and efficient method for detecting gene mutations.

The association of hepatitis B virus precore/basic core promoter mutations with genotype and progression of liver disease / 中华消化杂志

Objective To study association of hepatitis B virus(HBV) precore (pre c)/basic core promoter(BCP) mutations with the genotype or the progression of liver disease. Methods The serum samples from 148 patients with HBV-relative diseases were collected, including 31 asymptomatic carriers, 32 with chronic hepatitis B (CHB), 40 with liver cirrhosis(LC) and 45 with hepatocellular carcinoma(HCC). The genes covering HBV pre c and BCP were amplified by nested polymerase chain reaction (nPCR). The PCR products were subjected to direct sequencing and the mutations in pre c 1896 and BCP 1762/1764 were determined by sequence analysis. HBV genotypes were also detected in the sera by restriction fragment length polymorphism based on S-gene PCR products. Results Of 148 serum samples of HBV, 128 were successfully genotyped and sequenced. There were 60 genotype B and 68 genotype C. The mutation in pre c (A1896) was significantly higher in genotype B than in genotype C (48.3% vs 29.34%, P

Clinicopathologic Significance of HBV X, Core promoter, Precore Mutants in Patients with Chronic HBV Infection / 대한간학회지

BACKGROUND/AIMS: There have been much debates on the effects of HBV mutants on the clinical course of HBV-associated chronic liver diseases. The purpose of this study was to define the relationship among HBV mutants, severity of hepatitis and expression patterns of HBcAg METHODS: HBV DNA was extracted from the liver tissue of 31 patients who had been HBsAg positive for more than 6 months. The amplification of X was performed as well as core promoter/precore region of HBV DNA by polymerase chain reaction and then direct sequencing of them. Pathologic severity was classified utilizing Scheuer's scoring system and immunohistochemical staing for HBcAg in hepatocytes was performed. The expression patterns of HBcAg were divided into four types according to expression location of HBcAg: Type I as a nuclear predominant expression of HBcAg; Type II as mixed patterns, combined expression of cytoplasmic and nuclear localization of HBcAg; Type III as a diffuse cytoplasmic expression of HBcAg; and Type II as an inclusive body-like expression in cytoplasm. RESULTS: In investigating the relationship between HBV mutants and clinical findings, ALT, HBV DNA and hepatitis activity index (HAI) in hepatitis with wild HBV were normal to high but those in hepatitis with core promoter or precore mutants were high . There were no statistically significant differences (p=0.062). In terms of the relationship between HBV mutants and the expression pattern of HBcAg, type I, II, IV were noticed in hepatitis with wild HBV but in almost all mutants cases type III, II were noticed (p<0.01). The score of HAI increased as the number of the expression pattern of HBcAg increased from type I to type III or IV(p<0.05). No relationships among the mutation in X region, the mutations in other regions and clinicopathological severity could be found. CONCLUSION: The mutation in X, core promoter and precore region had little association with the severity of hepatitis. And the relationship did not exist between precore mutants and X mutants. The expression pattern of HBcAg could be a useful indicator in determining what stage of chronic hepatitis B is in and whether mutant strains exist.