Hepatitis B virus genotypes and clinical manifestation among hepatitis B carriers in Thailand

BACKGROUND: Hepatitis B virus (HBV) genotypes have distinct geographic distributions. The aim of the present study was to evaluate the distribution of HBV genotypes and their clinical relevance in Thailand. METHODS: Hepatitis B virus genotypes among 107 hepatitis B carriers residing in Thailand were evaluated using serologic and genetic methods. They were clinically classified into asymptomatic carriers with normal serum alanine transaminase (ALT) levels and patients with chronic liver disease, such as those with chronic hepatitis (CH), liver cirrhosis (LC) and hepatocellular carcinoma (HCC). RESULTS: Hepatitis B virus genotype distribution among the 107 patients was 25.2% for genotype B, 72.0% for genotype C and 2.8% for genotype D. The serum ALT levels, HBV-DNA and hepatitis B e antigen positivity were significantly higher in carriers infected with genotype C HBV than in those infected with genotype B (P < 0.05). The proportion of genotype B HBV was higher in asymptomatic carriers than in patients with CH and those who developed liver disease, such as LC and HCC (45.5, 16.9 and 25.0%, respectively; P < 0.05). In contrast, the proportion of genotype C HBV was higher in patients who developed liver disease and CH than in asymptomatic carriers (68.7, 83.0 and 50.0%, respectively; P < 0.05). Phylogenetic analysis based on entire genome sequences revealed three HBV isolates, which were classified into a subgroup of genotype C in isolates from South-East Asian countries. CONCLUSIONS: Genotypes B and C are the predominant types among hepatitis B carriers residing in Thailand and those genotypes influence the clinical manifestation in carriers with chronic hepatitis B infection.     

慢性乙型肝炎和肝硬化患者血清HBV基因型分析

目的 分析慢性乙型肝炎和肝硬化患者血清乙型肝炎病毒(HBV)分型分布情况。方法 2015年6月～2018年5月南京中医药大学附属南京市第二医院就诊的慢性乙型肝炎患者261例,乙型肝炎肝硬化患者30例,肝细胞癌4例,采用测序法检测血清HBV基因型。结果 在295例HBV感染者中,有132例(44.7%)为B型感染,161例(54.6%)为C型感染,2例(0.7%)为D型感染;慢性乙型肝炎患者与肝硬化患者血清TBIL、ALT和AST水平比较差异均无统计学意义(P>0.05);肝硬化患者血清肝纤维化指标(P<0.05)、血清HBV DNA载量(P<0.05)和血清HBeAg阳性率(x²=5.798,P<0.05)均显著高于慢性乙型肝炎患者;乙型肝炎肝硬化患者和肝细胞癌患者C型感染比例均显著高于慢性乙型肝炎患者,差异具有统计学意义(P<0.05)结论 慢性乙型肝炎和肝硬化患者HBV感染以B基因型和C基因型为主,而肝硬化患者以C型感染居多,提示C型感染患者可能比B型患者更容易出现严重的肝损伤,并产生严重的临床结局。     

HBV genotypes in India: do they influence disease severity?

Aims:  Association of HBV genotypes (especially A and D) with severity of liver disease is controversial. We studied the influence of HBV genotypes on liver disease severity among Indian patients.
Methods:  We selected 247 HBV infected patients (42 acute hepatitis, 87 carriers, 44 chronic hepatitis B [CHB], 35 liver cirrhosis [LC] and 40 hepatocellular carcinoma [HCC]). Genotyping of stored sera was performed using genotype-specific enzyme-linked immunosorbent assay (ELISA) and restriction fragment length polymorphism (RFLP). The distribution of genotypes in disease states of differing clinical, histological and biochemical severity were compared.
Results:  The most common genotype was D (162/237, 68.3%), followed by A (61, 25.7%) and C (14, 5.9%). The distribution of HBV genotypes between patients with acute hepatitis and CHB (carriers + CHB + LC + HCC), or between carriers and disease states (CHB + LC + HCC), or between mild chronic infection (carriers + CHB) and complications of chronic HBV infection (LC + HCC) was similar. Eighty-seven patients had liver biopsy; the median histological activity index (HAI) and fibrosis stage at baseline were similar between genotype groups (four [1–9] genotype A [ n  = 28]), three (2–4) genotype C ( n  = 4) and four (1–10) genotype D ( n  = 55); P  = 0.33 for HAI score; (0.5 [0–6] genotype A, 0.5 [0–4] genotype C and 1 [0–6] genotype D; P  = 0.92 for fibrosis stage). The response to therapy was similar between the genotypes.
Conclusion:  Clinical, histological severity and therapeutic responses are similar among patients with HBV genotypes A and D.     

肝癌患者血清中乙型肝炎病毒基因分型及临床意义

目的:探讨血清中乙型肝炎病毒(HBV)基因型及HBV DNA水平与肝细胞癌的关系。方法:应用巢式聚合酶链反应扩增乙型肝炎病毒与基因,用末端标记方法对PCR产物标记并直接测序,测序结果和GenBank中登录的标准基因型序列相比较,应用荧光定量PCR法检测HBV DNA水平。对61例肝癌、65例慢性乙型肝炎、10例乙型肝炎病毒携带者进行了检测。结果:136例中B基因型59例(43.4%)、C基因型77例(56.6%),随着病情加重,C基因型比例逐渐增高;不同基因型HBV感染的肝癌患者间HBV DNA水平差异有显著意义,P<0.05;在慢性乙型肝炎患者中,HBV DNA水平差异无显著性意义。结论:本地区乙型肝炎病毒以B、C基因型为主,乙型肝炎病毒C基因型及高水平的HBV DNA感染与肝癌的发生相关。     

湖北地区乙型肝炎病毒基因型分布与临床的相关性

目的 了解湖北地区乙型肝炎病毒(HBV)基因型的分布及其与临床的相关性。 方法 选择湖北地区HBV DNA阳性的慢性HBV感染者190例,其中乙型肝炎表面抗原(HBsAg)携带者52例、慢性乙型肝炎56例、重型肝炎32例、肝硬化22例、原发性肝癌28例,应用多对型特异性引物-聚合酶链反应检测HBV的基因型。 结果 多对HBV型特异性引物法可快速准确鉴定HBV的基因型。190份HBV DNA阳性血清标本中,B基因型140例(73.7％),C基因型42例(22.1％),BC混合型8例(4.2％),未发现A、D和E基因型;B基因型在重型肝炎和肝癌患者中占绝对优势,分别为87.5％和89.3％,显著高于HBsAg携带者的67.3％;B基因型患者血清丙氨酸氨基转移酶水平(253.1±306.7)U／L高于C基因型患者的(154.1±192.9)U／L,差异有统计学意义(P<0.05);除HBsAg携带者外的慢性HBV感染者中,B基因型患者血清抗-HBe阳性率50.5％(53／105)显著高于C基因型的18.5％(5／27),P<0.01。 结论 多对型特异性引物同时进行聚合酶链反应的基因分型方法可用于HBV基因型的流行病学调查;湖北地区存在HBV的B、C和BC混合基因型,B型为本地区的优势基因型并在严重肝病和肝癌中的比例较高,基因型的分布可能有较大的地区差异。     

The clinical implications of hepatitis B virus genotype: Recent advances

Outcomes of chronic hepatitis B virus (HBV) infection are heterogeneous. Estimates of annual incidence of cirrhosis and hepatocellular carcinoma (HCC) are 2-10% and 1-3%, respectively. Several viral factors, including HBV genotype, viral load and specific viral mutations, have been associated with disease progression. Among these, HBV genotype is not only predictive of clinical outcomes but has also been associated with response to interferon treatment. Currently, at least 10 HBV genotypes and several subtypes have been identified; they have distinct geographic distribution. Acute infection with genotypes A and D results in higher rates of chronicity than genotypes B and C. Compared to genotype A and B cases, patients with genotypes C and D have lower rates of spontaneous hepatitis B e antigen (HBeAg) seroconversion; when this occurs, it tends to be delayed. HBV genotype C has a higher frequency of basal core promoter (BCP) A1762T/G1764A mutation, pre-S deletion and is associated with higher viral load than genotype B. Similarly, genotype D has a higher prevalence of BCP A1762T/G1764A mutation than genotype A. These observations suggest important pathogenic differences between HBV genotypes. These may contribute to more severe liver disease, including cirrhosis and HCC with genotypes C and D HBV infection. In addition, genotype A and B patients have better responses to interferon-based therapy than genotypes C and D, but there are few consistent differences for direct HBV antivirals. In conclusion, genotyping of chronic HBV infections can help practicing physicians identify those at risk of disease progression and determine optimal anti-viral therapy.     

Hepatitis B viral genotypes: clinical relevance and molecular characteristics

Hepatitis B virus (HBV) infection is a global health problem and the clinical outcome of chronic HBV infection depends on the frequency and severity of hepatitis flares in the immune clearance phase. Currently, four subtypes and seven genotypes of HBV are identified and most have specific geographic distributions. The impact of HBV genotypes on the clinical outcome of chronic HBV infection has been partially clarified. In Taiwan, genotype C is associated with more severe liver disease and genotype B is associated with the development of hepatocellular carcinoma (HCC) in young non-cirrhotic patients. In contrast, genotype B has a relatively good prognosis in Japan and China and is rarely associated with the development of HCC. Similarly, genotype D is associated with more severe liver disease than genotype A in India and may predict occurrence of HCC in young patients. Although superinfection of HBV on top of hepatitis B carriers occurs in Taiwan, it is rarely associated with acute exacerbations. As to the response to antiviral treatment, genotypes C and D are associated with a lower response rate to interferon therapy compared with genotypes B and A. In addition, the subtype adw is reported to be associated with a higher risk of lamivudine resistance than ayw. In HBV subtype adw-infected HCC patients, genotype B responds better to embolization therapy and has a lower rate of HCC recurrence than genotype C. In summary, pathogenic and therapeutic differences do exist among HBV genotypes and determining the genotype in patients with chronic HBV infection would help gain further information for etiologic, clinical, virologic and anthropologic investigations. Further studies to clarify the molecular virological factors that contribute to these differences are awaited.     

Influence of hepatitis B virus genotypes on the progression of chronic type B liver disease

To investigate the hepatitis B virus (HBV) genotype-related differences in the progression of liver disease, 585 patients with chronic HBV infection including 258 with histologically verified chronic liver disease (CLD) and 74 with hepatocellular carcinoma (HCC) were examined. The mean ages of both patients with advanced fibrosis (F3 or F4) and with HCC were significantly older in genotype B than in genotype C patients (P =.018, P =.024, respectively). Both the hepatitis B e antigen (HBeAg) negativity rate at biopsy and the cumulative HBe seroconversion rate in patients with CLD were significantly higher in genotype B patients than genotype C patients (P <.01, P =.022, respectively). Multivariate analysis revealed that genotype B, presence of precore mutation, high ALT levels, and severe histologic activity were independent factors for HBe seroconversion. Among all the biopsy-proven CLD patients, the ratio of patients with advanced fibrosis in genotype B was significantly lower than that in genotype C (4/30 vs. 74/224, respectively; P =.034). This difference was more remarkable in younger patients (< or =45 years; 1/25 vs. 47/180, respectively; P =.020), and there was no difference in older patients (>45 years). The distribution of each genotype between CLD and HCC was very similar (B and C: 11.2% and 87.0% vs. 10.8% and 89.2%, respectively). In conclusion, our results suggest that, although the patients with genotype B experience earlier HBe seroconversion, slower progression of liver fibrosis, and slower development of HCC, the life-long risk of progression to advanced fibrosis and development of HCC may not differ among genotypes B- and C-related chronic liver disease.     

乙型肝炎病毒基因型检测及其临床应用

目的:探讨HBV基因型的检测及其在临床上的应用.方法:用微板核酸分子杂交-ELISA方法检测468例HBV DNA阳性的慢性乙型肝炎患者血清HBV基因型.分析HBV基因型与病毒复制、基本C基因启动子(BCP)变异、肝病病情轻重、干扰素疗效的关系.结果:深圳地区HBV基因型以B和C基因型为主,分别占25.0%和64.9%;C基因型的HBeAg阳性率(68.8%)高于B基因型的HBeAg阳性率(35.0%)(P＜0.01);C基因型的血清HBV DNA水平也明显高于B基因型(1g 6.74 copies/ml vs. 1g 5.44 copies/ml, P＜0.01);轻中度慢性肝炎以B基因型为主,而重度慢性肝炎以C基因型为主;B基因型对干扰素的有效应答率为47.2%,C基因型的有效应答率为28.9%,两组比较差异有显著性意义(P＜0.05).结论:HBV基因分型有助于临床判断病情、估计预后及抗病毒治疗疗效预测.     

Basal core promoter mutations of hepatitis B virus increase the risk of hepatocellular carcinoma in hepatitis B carriers

BACKGROUND & AIMS: Hepatitis B viral (HBV) genotype C is associated with the development of hepatocellular carcinoma (HCC) compared with genotype B; however, the virologic factors contributing to the pathogenic differences remain unknown. We investigated the prevalence of T1762/A1764 basal core promoter mutant in a cohort of 250 genotype B- or C-infected HBV carriers with different stages of liver disease to clarify a possible role for this mutant in hepatocarcinogenesis. METHODS: The sequences of basal core promoter of HBV genome were determined in 60 inactive HBV carriers and 190 patients with histologically verified chronic liver disease and HCC. RESULTS: Genotype C has a higher prevalence of T1762/A1764 mutation than genotype B (odds ratio, 5.18; 95% confidence interval [CI], 2.59-10.37; P < 0.001). The likelihood of T1762/A1764 mutation parallels the progression of liver disease, from 3% in inactive carriers to 64% in HCC patients (odds ratio, 20.04; 95% CI, 7.25-55.41; P < 0.001). By multiple logistic regression analysis, patients with T1762/A1764 mutation were significantly associated with the development of HCC than those without (odds ratio, 10.60; 95% CI, 4.92-22.86; P < 0.001), and the risk was observed for both genotypes B and C. In addition, the prevalence of T1762/A1764 mutation in younger HCC patients was comparable with older HCC patients but was significantly higher than that in age-matched inactive carriers, irrespective of genotypes. CONCLUSIONS: Our data suggest that HBV carriers with T1762/A1764 basal core promoter mutant are at increased risk for HCC and that this mutant may contribute to the pathogenesis of HBV infection.     

Hepatitis B virus subgenotypes and basal core promoter mutations in Indonesia

AIM： To identify the distribution of hepatitis B virus （HBV） subgenotype and basal core promoter （BCP） mutations among patients with HBV-associated liver disease in Indonesia.
METHODS： Patients with chronic hepatitis （CH, n =61）, liver cirrhosis （LC, n = 62）, and hepatocellular carcinoma （HCC, n = 48） were included in this study. HBV subgenotype was identified based on S or preS gene sequence, and mutations in the HBx gene including the overlapping BCP region were examined by direct sequencing.
RESULTS： HBV genotype B （subgenotypes B2, B3, B4, 85 and B7） the major genotype in the samples, accounted for 75.4%, 71.0% and 75.0% of CH, LC and HCC patients, respectively, while the genotype C （subgenotypes C1, C2 and C3） was detected in 24.6%, 29.0%, and 25.0% of CH, LC, and HCC patients, respectively. Subgenotypes B3 （84.9%） and C1 （82.2%） were the main subgenotype in HBV genotype B and C, respectively. Serotype adw2 （84.9%） and adrq＋ （89.4%） were the most prevalent in HBV genotype B and C, respectively. Double mutation （A1762T/G1764A） in the BCP was significantly higher in LC （59.7%） and HCC （54.2%） than in CH （19.7%）, suggesting that this mutation was associated with severity of liver disease. The T1753V was also higher in LC （46.8%）, but lower in HCC （22.9%） and CH （18.0%）, suggesting that this mutation may be an indicator of cirrhosis.
CONCLUSION： HBV genotype B/B3 and C/C1 are the major genotypes in Indonesia. Mutations in BCP, such as A1762T/G1764A and T1753V, might have an association with manifestations of liver disease.     

Hepatitis B genotypes correlate with clinical outcomes in patients with chronic hepatitis B

BACKGROUND & AIMS: Six genotypes (A-F) of hepatitis B virus (HBV) have been identified; however, the genotype-related differences in the pathogenicity of HBV remain unknown. Therefore, we investigated the prevalence of HBV genotypes in Taiwan and the association between distinct genotypes and severity of liver disease in a cross-sectional study. METHODS: Using a molecular method, HBV genotypes were determined in 100 asymptomatic carriers and in 170 patients with histologically verified chronic liver disease and hepatocellular carcinoma (HCC). RESULTS: All genotypes except genotype E were identified in Taiwan, and genotypes B and C were predominant. Genotype C was prevalent in patients with cirrhosis and in those with HCC who were older than 50 years compared with age-matched asymptomatic carriers (60% vs. 23%, P < 0.001, and 41% vs. 15%, P = 0.005, respectively). Genotype B was significantly more common in patients with HCC aged less than 50 years compared with age-matched asymptomatic carriers (80% vs. 52%, P = 0.03). This predominance was more marked in younger patients with HCC (90% in those aged 相似文献   

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.     

Clinicopathological differences between hepatitis B viral genotype B- and C-related resectable hepatocellular carcinoma

Clinical and pathogenic differences exist between hepatitis B viral (HBV) genotypes B and C, and genotype C has a higher risk of hepatocellular carcinoma (HCC) development than genotype B. The aim of this study was to investigate whether HBV genotypes B and C influence the clinicopathological features of patients with resectable HCC. Stored serum samples from 193 patients with resectable HBV-related HCC were tested for HBV genotypes by a molecular method. Of 193 patients undergoing resection of HCC, 107 (55%) and 86 (45%) were infected with genotypes B and C, respectively. Compared with genotype C patients, genotype B patients were less likely to be associated with liver cirrhosis (33%vs 51%, P = 0.01). Pathologically, genotype B patients had a higher rate of solitary tumour (94%vs 86%, P = 0.048) and more satellite nodules (22%vs 12%, P = 0.05) than genotype C patients. Our results indicate that genotype B-related HCC is less associated with liver cirrhosis and has a higher frequency of solitary tumour as well as more satellite nodules than genotype C-related HCC. These characteristics may contribute to the recurrence patterns and prognosis of HBV-related HCC in patients with genotype B or C infection.     

Hepatitis B virus genotypes in chronic liver disease patients from New Delhi, India

INTRODUCTION Approximately, two billion people in the world have been infected by Hepatitis B virus (HBV), 350 million of whom are chronic carriers of the virus[1,2]. Worldwide HBV isolates have been classified into eight genotypes: A, B, C, D, E, F, G an…     

Hepatitis B virus subgenotype A1 predominates in liver disease patients from Kerala,India

AIM:To molecularly characterize hepatitis B virus(HBV)isolates from Kerala and to relate them to the clinical manifestation of infection.METHODS:Sera and clinical data were collected from91 patients diagnosed with chronic HBV infection and HBV-related hepatocellular carcinoma(HCC).HBV from44 HCC,22 cirrhotic and 25 chronic hepatitis patients were genotyped by sequencing of the complete S region or by restriction fragment length polymorphism assays.The basic core promoter/precore region was sequenced.The complete surface DNA sequences were assembled and aligned manually,and then compared with the sequences of HBV of genotypes(A-J)from GenBank.The evolutionary history was inferred using the Neighbor-Joining method and the evolutionary distances computed using the Kimura 2-parameter method.Bootstrapping was performed using 1000 replicates.The TaqMan BS-1 probe was used to quantify HBV DNA at a lower detection limit of approximately20 IU/mL.Continuous variables were compared using an independent Student’s t test.Theχ2test or Fisher’s exact test was used to compare categorical variables.The differences were considered statistically significant at P<0.05.RESULTS:Irrespective of disease status,the predominant genotype was A(72%);95%belonging to subgenotype A1,followed by genotypes D(27%)and C(1%).HCC patients infected with subgenotype A1were significantly younger than those infected with D.Mutation A1762T/G1764A was significantly associated with HCC in both genotypes A and D.Mutation G1862T was more frequent in subgenotype A1(P<0.0001),and in combination with A1762T/G1764A,it was significantly associated with HBV from HCC patients.Mutation C1766T/T1768A was significantly associated with genotype A(P=0.05)and HCC(P=0.03).The preS2start codon M1T/I mutation was unique to genotype A strains(15.6%)from all disease groups and occurred at a higher frequency in isolates from HCC patients(P=0.076).A higher frequency of preS deletion mutants(33.3%)was observed in genotype A from HCC compared with non-HCC patients,but     

Genotype C hepatitis B virus infection is associated with an increased risk of hepatocellular carcinoma

BACKGROUND: Identification of risk factors for the development of hepatocellular carcinoma (HCC) is important for HCC surveillance in chronic hepatitis B virus (HBV) infection. Our aim was to study the independent risk factors and effect of HBV genotypes on HCC development in a prospective longitudinal cohort of chronic hepatitis B patients. PATIENTS AND METHODS: Chronic hepatitis B patients recruited since 1997 were prospectively followed up for the development of HCC. HCC was diagnosed by a combination of alpha fetoprotein, imaging, and histology. Liver cirrhosis was defined as ultrasonic features of cirrhosis together with hypersplenism, ascites, varices, and/or encephalopathy. RESULTS: In total, 426 patients were followed up for 1664 person years; median 225 (range 12-295) weeks. Forty nine (11%) patients had underlying clinical liver cirrhosis. A total of 242 (57%) and 179 (42%) patients had HBV genotypes C and B, respectively. Twenty five patients developed HCC in a median follow up of 121 (range 14-236) weeks. The overall incidence of HCC was 1502 cases per 100 000 person years. On multivariate analysis, clinical liver cirrhosis and HBV genotype C infection were independently associated with HCC development, with an adjusted relative risk of 10.24 (95% confidence interval (CI) 4.39-23.89; p<0.001) and 2.84 (95% CI 1.05-7.72; p = 0.040), respectively. Patient age, sex, hepatitis B e antigen (HBeAg) status, alanine aminotransferase (ALT) levels, and basal core promoter mutations did not predict HCC development. Patients infected with HBV genotype C tended to have persistently positive HBeAg or fluctuating HBeAg status and higher ALT levels during the follow up period. CONCLUSION: Genotype C HBV infection is an independent risk factor for HCC development in addition to liver cirrhosis.     

Profile, spectrum and significance of HBV genotypes in chronic liver disease patients in the Indian subcontinent

BACKGROUND AND AIM: Certain hepatitis B virus (HBV) genotypes have been alleged to be associated with the development of cirrhosis and hepatocellular carcinoma (HCC), and the response to interferon therapy in Taiwanese patients. We undertook to study the prevalence and significance of HBV genotypes in the Indian subcontinent. METHODS: One hundred and thirty histopathologically proven chronic HBV-infected patients, including 52 incidentally detected asymptomatic hepatitis B surface antigen (HBsAg)-positive subjects (IDAHS) with chronic HBV infection (group I), 48 cirrhotics (group II) and 30 hepatocellular carcinoma (HCC; group III) patients were studied. Hepatitis B virus genotypes were determined by using restriction fragment length polymorphism, and direct sequencing of the s gene including the 'a' determinant region. RESULTS: Only genotypes A (46%) and D (48%) were found in the chronic HBV-infected patients. A mixed infection with genotypes A and D was seen in 6% of patients. Genotype A was found in 42, 48 and 50%, and genotype D in 48, 50 and 47% of group I, II and III patients, respectively (P = NS). The patients who had mixed genotypes were significantly younger (P < 0.05). In group I (IDAHS) patients infected with genotype D, none had a histological activity index (HAI) of < four. Genotype D was significantly more common in group I patients with HAI > 4 as compared to genotype A (53 vs 32%, P < 0.05). Similarly, genotype D was associated with more severe liver diseases (61 vs 30%, P < 0.05). Genotype D was more prevalent in HCC patients of < 40 years of age, as compared to IDAHS (63 vs 44%, P = 0.06). CONCLUSIONS: (i) Hepatitis B virus genotypes A and D are prevalent in chronic liver disease patients of Indian origin; and (ii) HBV genotype D is associated with more severe diseases and may predict the occurrence of HCC in young patients.     

Geographic distribution, virologic and clinical characteristics of hepatitis B virus genotypes in China

The significance of hepatitis B virus (HBV) genotypes for the heterogeneity of chronic HBV infection and severity of liver disease is not well understood. The aim of this study was to determine the distribution and virologic characteristics of HBV genotypes in China and possible association with the diversity of liver disease. The study includes 1096 chronic HBV carriers from nine provinces in China. We collected clinical and laboratory data and analysed the HBV strains in sera by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and nucleotide sequencing techniques. The most common HBV genotypes were B (41%) and C (53%), while genotypes A and D were also found. A North-South divide was identified in genotype B and C distribution - genotype C was predominant in northern China, while genotype B was more prevalent in southern provinces. Patients with genotype B were younger than those with genotype C, and had a lower prevalence of HBeAg - 65%vs 72%, respectively (P = 0.03). However, the severity of liver disease did not differ significantly between patients infected with genotype B or C - neither when comparing liver function tests (1024 patients), nor hepatic inflammation and fibrosis (264 patients). Amongst 47 patients with genotype D (by PCR-RFLP), 37 (79%) were infected with a new subtype (designated Dc), having a recombination fragment from genotype C precore/core region. This is the first large-scale HBV genotype study from China and convincing documentation of the North-to-South gradient of genotypes C vs B in this country. HBV DNA recombination over the surface and precore/core genes increases the diversity of HBV strains and may have diagnostic and clinical implications.     

Is There Any Value to Hepatitis B Virus Genotype Analysis?

Hepatitis B may cause a varying spectrum of diseases ranging from an asymptomatic or mild anicteric acute illness, to severe or fulminant hepatitis. Similarly, the outcome of chronic hepatitis B is variable. Viral factors associated with outcome of chronic hepatitis B virus (HBV) infection include hepatitis B e antigen status, HBV DNA, genotype, and HBV variants. HBV genotypes and subgenotypes have been associated with differences in clinical and virological characteristics, indicating that they may play a role in the virus-host relationship. A total of ten hepatitis B virus genotypes have been defined with a distinct geographical distribution. Hitherto, genotypes A, B, C and D have been studied most extensively. The HBV genotype appears to influence not only the natural history of HBV related liver disease but also the response to HBV treatment. HBV genotypes are also linked with both core promoter and BCP mutations. Progression to chronic infection appears to occur more frequently following acute infection with genotypes A and D than with the other studied genotypes. Genotypes A and B appear to have higher rates of spontaneous HBeAg seroconversion. More advanced liver disease and progression to HCC is more often seen in chronic infection with genotypes C and D in contrast to genotypes A and B. More specifically, genotypes A1, C, B2–B5 and H appear to be associated with more serious complications than genotypes A2, B1 and B6. These observations suggest important pathogenic differences between HBV genotypes. Genotypes A and B have higher response rates to interferon based therapy than genotypes C and D. Knowledge of HBV genotype enables clinicians to identify those patients at increased risk of disease progression whilst aiding the selection of appropriate antiviral therapy. Genotyping and monoclonal subtyping can provide useful information for epidemiological studies. In conclusion, genotyping of chronic HBV infections can help practicing physicians identify those at risk of disease progression and determine optimal anti-viral therapy.