Virological differences between patients infected with subtypes Ba and Bj of hepatitis B virus genotype B

BACKGROUND: Hepatitis B virus (HBV) genotype B is classified into subtype Ba with the recombination with genotype C in the precore region plus core gene and subtype Bj without recombination. Virological and clinical differences between infections with subtypes Ba and Bj, however, are yet to be determined. METHODS: During 1976 through 2001, 224 patients visited Toranomon Hospital in Tokyo, Japan who were infected with HBV genotype B. Subtypes of genotype B were determined by sequencing HBV-DNA recovered from sera for detecting recombination with genotype C. RESULTS: Subtype Ba was detected in 53 patients (24%) and Bj in 167 (75%); subtypes were not able to be determined in the remaining four (1%). The only virological difference was that detection of hepatitis B e antigen at the presentation was more frequent in the patients infected with subtype Ba than those with Bj (63% vs 33%, P = 0.016). There were no differences in the distribution of liver disease of various forms between the patients infected with subtypes Ba and Bj at presentation. No differences were noted, either, in the development of liver cirrhosis or hepatocellular carcinoma, or the loss of hepatitis B surface antigen from serum, between the patients infected with subtypes Ba and Bj during follow up of up to 26 years. CONCLUSIONS: Although there were some virological differences between the patients infected with subtypes Ba and Bj of HBV genotype B, they do not seem to influence the long-term clinical outcome.     

Analysis of hepatitis B surface antigen (HBsAg) using high‐sensitivity HBsAg assays in hepatitis B virus carriers in whom HBsAg seroclearance was confirmed by conventional assays

Aim

We investigated the utility of high‐sensitivity hepatitis B surface antigen (HBsAg) assays compared with conventional HBsAg assays.

Methods

Using serum samples from 114 hepatitis B virus (HBV) carriers in whom HBsAg seroclearance was confirmed by conventional HBsAg assays (cut‐off value, 0.05 IU/mL), the amount of HBsAg was re‐examined by high‐sensitivity HBsAg assays (cut‐off value, 0.005 IU/mL). Cases negative for HBsAg in both assays were defined as consistent cases, and cases positive for HBsAg in the high‐sensitivity HBsAg assay only were defined as discrepant cases.

Results

There were 55 (48.2%) discrepant cases, and the range of HBsAg titers determined by high‐sensitivity HBsAg assays was 0.005–0.056 IU/mL. Multivariate analysis showed that the presence of nucleos(t)ide analog therapy, liver cirrhosis, and negative anti‐HBs contributed to the discrepancies between the two assays. Cumulative anti‐HBs positivity rates among discrepant cases were 12.7%, 17.2%, 38.8%, and 43.9% at baseline, 1 year, 3 years, and 5 years, respectively, whereas the corresponding rates among consistent cases were 50.8%, 56.0%, 61.7%, and 68.0%, respectively. Hepatitis B virus DNA negativity rates were 56.4% and 81.4% at baseline, 51.3% and 83.3% at 1 year, and 36.8% and 95.7% at 3 years, among discrepant and consistent cases, respectively. Hepatitis B surface antigen reversion was observed only in discrepant cases.

Conclusions

Re‐examination by high‐sensitivity HBsAg assays revealed that HBsAg was positive in approximately 50% of cases. Cumulative anti‐HBs seroconversion rates and HBV‐DNA seroclearance rates were lower in these cases, suggesting a population at risk for HBsAg reversion.     

利用单个细胞RT-PCR法克隆全人源性HBV单克隆抗体的探讨

目的建立外周血单个抗体分泌细胞分离和单个细胞RT-PCR系统,高效快速克隆高度特异性、全人源性的HBV单克隆抗体。方法选择3例HBV感染恢复期患者,从外周血中富集B淋巴细胞,加入HBcAg Peptide pool活化B淋巴细胞,流式分选出记忆性抗体分泌细胞(CD19~+CD10~-IgG~+CD27~+),通过有限稀释法获得单个细胞,单细胞RT-PCR反转出cDNA,巢式PCR扩增抗体重链恒定区序列片段,将PCR产物纯化并克隆至pEASY~-T1 simple克隆载体,进行测序鉴定。结果 ELISA结果显示,3例HBV感染恢复期患者血浆中均检测到较高水平IgG,与健康志愿者相比,差异均有统计学意义(P值均0.05)。流式结果显示,B淋巴细胞比例均高于94%,且均可分离出记忆性抗体分泌细胞。从分离的抗体分泌细胞中挑选出24个含有1个形态完好的细胞,经鉴定,其中有14个扩增成功,且条带在200 bp左右,与预期片段大小相符。对抗体重链序列分析显示成功扩增出抗体恒定区片段。结论成功构建了单个抗体分泌细胞分离和单个细胞RT-PCR系统,获得了抗体重链序列,为后期全人源性乙型肝炎单克隆抗体的高通量生产打下了坚实的基础。     

Detection of hepatitis B surface antigen by a monoclonal radioimmunoassay in the serum of alcoholic patients

The presence of HBV infection has been retrospectively assessed using monoclonal radioimmunoassay (M-RIA) in the sera of 269 alcoholics. There were three subjects with normal liver, 92 had steatosis, 32 had fibrosis, 15 had acute alcoholic steatosis and 127 had cirrhosis. The HBsAg M-RIA was performed by the sandwich method using high affinity IgG and IgM monoclonal antibodies. The M-RIA was more sensitive for detection of HBV when compared with conventional RIA, the former detecting 15 out of 269, the latter detecting five out of 269 (5.6% and 1.9% respectively; P= 0.02). Among the 264 patients negative for conventional RIA, the prevalence of a positive M-RIA test was no different between patients who lacked HBV related antibodies (seven out of 196; 3.6%) compared with patients with at least one antibody (three out of 68; 4.4%). The prevalence of HBsAg detected by M-RIA was higher in alcoholic patients with cirrhosis (9.4%) compared with patients without cirrhosis (2.1%; P < 0.01). These results suggest that all alcoholic patients could have a low production, or an abnormal expression, of HBV or could be infected by an hepatitis B variant virus. HBV or an hepatitis B variant virus could have in some cases a causative role in the pathogenesis of cirrhosis.     

Novel hepatitis B virus surface antigen mutations associated with occult genotype B hepatitis B virus infection affect HBsAg detection

The causative factors of occult hepatitis B infection are complicated and not yet been fully elucidated. Mutations in hepatitis B virus (HBV) S gene are one of the factors may contributing to occult infection. In this study, 89 blood donors with genotype B occult HBV infection were investigated. Fifty‐seven hepatitis B surface antigen (HBsAg)‐positive/HBV DNA‐positive blood donors served as control group for comparison. Occult HBV‐related mutations with a high incidence (P < .05) in the S gene were identified. To further verify these occult infection‐related mutations, a conservative full‐gene expression vector of HBV B genotype (pHBV1.3B) was constructed. Then, the mutant plasmids on the basis of pHBV1.3B were constructed and transfected into HepG2 cells. Extracellular as well as intracellular HBsAg was analysed by electrochemical luminescence and cellular immunohistochemistry. Ten occult infection‐related mutations (E2G, Q101R, K122R, M133T, D144E, G145R, V168A, S174N, L175S and I226S) were significantly more frequent in the occult infection group (P < .05). Five of the ten mutations (E2G, D144E, G145R, V168A and S174N) strongly decreased extracellular HBsAg level (P < .05) in the transfection system. Notably, the E2G mutation had the most significant impact on the ratio of extracellular HBsAg (3.8% vs pHBV1.3B) and intracellular HBsAg (239.3% vs pHBV1.3B) (P < .05), and the fluorescence density of E2G mutant HBsAg was significantly higher than that of pHBV1.3B (P < .0001). Hence, ten mutations were associated with genotype B occult HBV infection; E2G and V168A were novel mutations which we confirmed significantly affect HBsAg detection. E2G might cause HBsAg secretion impairment that results in intracellular accumulation and a decrease in HBsAg secretion.     

Identification of a hepatitis B virus S gene mutant in lamivudine-treated patients experiencing HBsAg seroclearance

BACKGROUND & AIMS: Seroclearance of hepatitis B virus (HBV) surface antigen (HBsAg) is a rare event in chronic hepatitis B patients receiving lamivudine therapy. It is generally believed to be a benevolent sign, implicating clearance of viremia. The aim of this study is to examine the authenticity of this dogma. METHODS: In a 5-year period, 11 patients treated with lamivudine experienced seroclearance of HBsAg. The clinical data were examined. The HBV S gene sequences derived from the patient's serum samples before and after seroclearance of HBsAg were analyzed. RESULTS: Serum HBV-DNA could be detected by nested polymerase chain reaction (PCR) in all 11 patients, by 1-step PCR in 8, and by Cobas Amplicor HBV-DNA test (>200 copies/mL) in 5. A mutation hot spot, P120A in the S gene, was identified in 6 of the 11 patients. Site-directed mutagenesis experiments indicated that the Ausria-II RIA test failed to detect this mutant. Decreased sensitivity of detection was also observed when other monoclonal antibodies were applied. CONCLUSIONS: Seroclearance of HBsAg during lamivudine therapy may not indicate viral clearance. Specifically, it may be caused by a point mutation in the S gene, which results in detection failure. In such patients, further verification and follow-up using a sensitive HBV-DNA test are advised.     

Development of monoclonal antibodies to target the large surface protein of hepatitis B virus and their use in therapeutic and diagnostic applications

Over 250 million people are living with chronic infection caused by the hepatitis B virus (HBV). HBV has three surface proteins, namely small (SHBs), medium (MHBs) and large (LHBs), and they play different roles in the virus life cycle. The approved hepatitis B vaccine only contains the SHBs protein and many studies have focused on characterising the functional domains in SHBs. Although the LHBs protein is less studied, recent studies have shown that it plays important roles in mediating viral entry, replication and assembly. Over the years, there have been major advancements in monoclonal antibody (mAb) discovery tools and multiple mAbs have been developed to specifically target the preS1 domain in LHBs. We summarise the HBV infection systems and antibody discovery strategies that have been utilised by various research groups to assess the potential use of anti-preS1 mAbs as therapeutic antibodies against HBV or in the development of new diagnostic assays.     

Molecular epidemiology of hepatitis B virus in Indonesia

The S-gene sequences of hepatitis B virus (HBV) from 22 carriers in several islands of Indonesia were amplified by polymerase chain reaction, and XbaI-SpeI fragments corresponding to nucleotides 93-529 (437 base pairs) in the S gene were sequenced. The 22 sequences, along with the 5 reported sequences from Indonesia, were compared with each other, and with the corresponding sequences of 20 clones from other countries including China, France, Great Britain, Japan, Kenya, Papua New Guinea, Philippines, USA and USSR. When the 27 HBV DNA clones of various subtypes from Indonesia were classified by the homology in the nucleotide sequence into the five genotypes, twelve belonged to genotype B (subtype adw 7 and ayw 5), 13 to genotype C (adw 1, adr 10, ayr 1 and ar 1), and 2 to genotype D (ayw); none belonged to genotype A or E. Different subtypes of clones in the same genotype indicated that point mutations inducing d-to-y or w-to-r phenotypic changes would be common among Indonesian carriers. Comparison of the translation products of XbaI-SpeI fragments, now available for 47 HBV DNA clones of different genotypes (A 4; B 14; C 21; D 7; E 1), identified several amino acids characteristic to or influenced by the five genotypes as well as those highly conserved by clones of different genotypes.     

Incidence of hepatocellular carcinoma among individuals with hepatitis B virus infection identified using an automated data algorithm

The purpose of this study was to develop an algorithm for identifying patients with chronic hepatitis B virus (HBV) using automated data sources from two US health systems and evaluate the algorithm's performance by quantifying the incidence of hepatocellular carcinoma (HCC) among chronic HBV patients. To allow comparisons with estimates from automated databases that may not contain all data elements used in this algorithm, we created three definitions of chronic HBV infection and used these definitions to create three overlapping cohorts. We compared the incidence of HCC in each cohort with the incidence of HCC in a matched general population comparison cohort with no evidence of HBV. Patients who met the most stringent criteria for chronic HBV infection (based on the standard definition of 6 months of infection using repeat laboratory tests and record review) were 146 times more likely to develop HCC than matched comparison patients (adjusted hazard ratio = 146.5, 95% CI: 74.0-289.8). Those not meeting the stringent criteria, but who met the criterion of at least one positive hepatitis B surface antigen test were 30 times more likely to develop HCC than comparison patients (adjusted hazard ratio = 29.8, 95% CI: 16.5-53.6). Finally, patients who met the criterion based on at least one HBV diagnosis were 38 times more likely to develop HCC than matched comparison patients (adjusted hazard ratio = 37.8, 95% CI: 25.9-55.1). The magnitude of the relative increase in HCC risk seen using different criteria used to define HBV infection indicate that these automated data algorithms can identify patients with chronic HBV infection.     

HBsAg-negative hepatitis B virus infections in hepatitis C virus-associated hepatocellular carcinoma

This study was conducted to evaluate reports that hepatitis B virus (HBV) DNA sequences can be found in the serum and/or tumour tissue from some hepatocellular carcinoma (HCC) patients who have no detectable hepatitis B surface antigen (HBsAg) in their sera. Such HBV infections would be highly atypical, because prospective studies have shown a clear succession of specific serologic markers during and after most HBV infections. As most HBsAg-negative HCC patients in Japan have hepatitis C virus (HCV) infections, the present study was conducted to determine whether some of these patients actually have unrecognized HBV infections. Thirty newly diagnosed HCC patients from Kurume, Japan, with antibody to the hepatitis C virus (anti-HCV) were studied. None of the 30 had HBsAg detectable in their serum. Of 22 for whom test results for antibodies to the hepatitis B core antigen (anti-HBc) and antibodies to HBsAg (anti-HBs) were available, 14 (64%) had anti-HBc and anti-HBs, four (18%) had anti-HBc alone, and four (18%) had no HBV markers. Nested polymerase chain reaction was used to detect the HBV surface (S), core (C), polymerase (P) and core promoter gene sequences in the HCC tissues and in the adjacent nontumorous liver tissues. HBV DNA was detected in HCC and/or adjacent nontumorous liver in 22 of 30 (73%) patients [detected in both HCC and nontumorous liver in 19/30 patients (63%)]. Among the 22 patients with detectable HBV DNA, more than one HBV gene was detected in 10 (46%). Among the four patients whose sera were negative for all HBV markers, three had HBV DNA in either HCC and nontumorous liver (two cases) or only in the nontumorous liver (one case); HBV DNA could not be detected in tissues from the fourth patient. In 18 of 21 (86%) patients with detectable HBV core promoter sequences, mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found. No deletions were detected in the core promoter gene region of the type reported to be associated with some cases of HBsAg-negative HBV infection. Thus, HBV DNA was detectable in 22 (73%) HBsAg-negative, anti-HCV-positive HCCs, including three (10%) who were also negative for anti-HBc and anti-HBs. HBV mutations at both nucleotides 1762 (A-GT) and 1764 (G-A) in the core promoter region were found in the majority of cases, mutations that have previously been reported in HBV that is integrated in HCC DNA. In serologic surveys to determine etiologic associations of HCC, patients such as those in this study would have been incorrectly designated as having 'HCV-associated HCC,' whereas the data in this study suggest that HBV could have played a role in the development of their HCCs.     

唐山地区乙肝患者HBsAg滴度、HBV DNA水平与乙肝基因突变位点的关系研究

目的:研究唐山地区乙型肝炎(乙肝)患者乙肝表面抗原(HBsAg)滴度、乙肝病毒基因(HBV DNA)水平与乙肝基因突变位点的关系。方法:选择2018年1月—2020年12月唐山地区150例乙肝患者作为研究对象,测定HBsAg滴度和血清HBV DNA水平,通过基因测序分析突变情况,并据此分为突变组与未突变组,比较不同基因突变位点患者的HBsAg滴度、HBV DNA水平,使用线性回归分析唐山地区乙肝患者HBsAg滴度、HBV DNA水平与乙肝基因突变位点的关系。结果:本研究150例乙肝患者中,有62例患者发生了基因突变,基因突变发生率为41.33%(62/150)。其中,rtM204I/V位点基因突变占比最高,为27.42%(17/62),rtL180M次之,为22.58%(14/62);rtL180M+rtM204I/V、rtA181T+rtN236T基因突变患者HBsAg滴度、HBV DNA水平高于rtM204I/V、rtL180M、rtN236T基因突变患者,差异有统计学意义(P<0.05);经Pearson相关性分析结果显示,基因突变乙肝患者HBsAg滴度、HBV DNA水平...     

Infection with hepatitis B virus genotype A in Tokyo, Japan during 1976 through 2001

Background Because genotype A of hepatitis B virus (HBV) is not indigenous, there have been only few data on infection with it in Japan.Methods We examined clinical and virological features of the 66 Japanese patients who admitted Toranomon Hospital in Tokyo, Japan, between 1976 and 2001, who were found to have HBV/A infection. HBV genotype A was classified into subtype A (European type) and A (South African type) by phylogenetic analysis of the preS1 and preS2 regions, and the S gene sequences.Results Of the 66 patients infected with HBV/A, 14 (21%) were asymptomatic carriers, 26 (39%) presented with acute hepatitis, 22 (33%) with chronic hepatitis, and 4 (6%) with liver cirrhosis. HBV/A infection persisted for more than 6 months in 5 of the 26 (19%) patients with acute hepatitis. The frequency of acute hepatitis in patients infected with HBV/A was higher after than before 1991 (2/22 [9%] vs 24/44 [55%]; P < 0.0001). The frequency of nucleotide 1858 of T was higher in asymptomatic carriers than in patients with acute hepatitis in whom infection was resolved (5/14 [36%] vs 0/21 [0%]; P = 0.008). Of the 57 patients for whom subtypes of genotype A were determined, subtype A was identified in 53 (93%) and subtype A in only 4 (7%). All patients infected with subtype A were persistently infected with HBV.Conclusions HBV/A infection has become more frequent during recent years, predominantly presenting as acute hepatitis, and subtype A is uncommon in the Tokyo metropolitan area.     

Changes in levels of hepatitis B virus markers in patients positive for low-titer hepatitis B surface antigen

Aim: Recently, patients positive for the low-titer hepatitis B surface antigen (HBsAg) have been found occasionally owing to the increase in the accuracy of detection methods. The aim of this study is to clarify the clinical status of acute hepatitis B virus (HBV) infection in patients positive for low-titer HBsAg. Method: Eight patients, who were positive for HBsAg at low titers and diagnosed as having acute HBV infection, were enrolled in this study. Assays of HBsAg, hepatitis B core antibody (anti-HBc), hepatitis B e-antigen (HBeAg), hepatitis B e-antibody (anti-HBe), hepatitis B surface antibody (anti-HBs) and HBV DNA, and biochemical tests were basically conducted every 4 weeks for at least 24 weeks. Result: The average cut-off index of HBsAg was 8.7 ± 9.6 (range, 1.0–25.7). All the patients were negative for anti-HBc, HBeAg, anti-HBe and HBV DNA on their initial visit. The genotype of HBV could be determined in four patients: two were infected with genotype B/HBV, one was infected with genotype A/HBV, and the remaining patient was infected with genotype C/HBV. Although HBsAg clearance was observed within 4 months in all the patients, none of the other HBV markers seroconverted during the observation period. Conclusion: HBV infection terminating with seronegativity for HBV markers may occur in transient HBV infection.     

HBsAg与抗-HBs同时阳性的慢性乙型肝炎患者临床特点分析

目的分析HBsAg与抗-HBs同时阳性的现象及其临床特点,并探讨其产生的原因。方法收集2011年2月-2014年2月东南大学附属第二医院体检者2260例,其中被诊断为慢性乙型肝炎的患者830例。采用化学发光微粒子免疫分析法筛选HBsAg与抗-HBs同时阳性的患者188例,分为HBeAg阳性组(n=101)和HBeAg阴性组(n=87)。同时选取200例HBsAg阳性、抗-HBs阴性者作为对照,其中HBeAg阳性组80例,HBeAg阴性组120例。检测HBV血清学标志物、肝功能、病毒载量并结合临床进行分析。计数资料组间比较采用χ2检验。结果 HBV血清学标志物在HBsAg与抗-HBs双阳性情况下共有5种模式,其中以HBsAg、抗-HBs、HBeAg及抗-HBc阳性,且抗-HBe阴性多见,占47.9%(90/188),肝功能指标总异常率为69.1%(130/188),HBV DNA总阳性率为56.9%(107/188)。HBeAg阳性的2组HBV DNA均存在高水平复制,其中HBsAg与抗-HBs双阳性组HBV DNA阳性率与对照组比较,差异无统计学意义(χ2=2.632,P0.05);HBeAg阴性组中,HBsAg与抗-HBs双阳性组HBV DNA定量1×105IU/ml的比例与对照组比较,差异有统计学意义(χ2=10.740,P0.05)。对HBV S区进行测序分析发现,测序的80例HBsAg与抗-HBs双阳性患者中有27例患者的HBV S区发生变异,突变率33.7%,且S区变异位点主要有P29L、S61L、P62L、I126T/S、Q129N、M133K、F134L、G145R/K、L175S和L186H等。结论 HBsAg与抗-HBs同时阳性者在乙型肝炎患者中有一定比例,其主要原因可能是病毒株变异所致。这种情况并不代表疾病好转,且抗-HBs出现并不一定能完全有效清除HBsAg,病毒DNA往往存在持续复制,需引起重视。     

Preparation and application of monoclonal antibodies against hepatitis C virus nonstructural proteins

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

AIM: To investigate the clinical significance and presence of mutations in the surface (S) and overlapping polymerase gene of hepatitis B patients with coexisting HBsAg and anti-HBs. METHODS: Twenty-three patients with chronic hepatitis B were studied. Of the 23 patients, 11 were both positive for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV surface antigen (anti-HBs), 12 were negative for anti-HBs while positive for HBsAg. DNA was extracted from 200μL serum of the patients. Nucleotide of the surface and overlapping polymerase gene from HBV-infected patients was amplified by PCR, and the PCR products were sequenced. RESULTS: Forty-one mutations were found within the surface gene protein of HBV in 15 patients (10 with coexisting HBsAg and anti-HBs). Six (14.6%) out of 41 mutations were located at "α" determinant region in 5 patients (4 positive for HBsAg and anti-HBs). Eleven mutations (26.8%) occurred in the downstream or upstream of "α" determinant region. Lamivudine (LMV)-selected mutations were found in three patients who developed anti-HBs, which occurred in amino acid positions (196, 198, 199) of the surface protein and in YMDD motif (M204I/V) of the polymerase protein simultaneously. Presence of these mutations did not relate to changes in ALT and HBV DNA levels. CONCLUSION: Besides mutations in the "α" determinant region, mutations at downstream or upstream of the "α" determinant region may contribute to the development of anti-HBs. These mutations do not block the replicating competency of HBV in the presence of high titer of anti-HBs.     

Progressive and sufficient decrease of hepatitis B core antibody can predict the disappearance of hepatitis B virus DNA in Japanese patients with hepatitis B surface antigen clearance

The aim of this study was to elucidate the relationships among serum levels of hepatitis B virus (HBV) DNA, periods after hepatitis B surface (HBs) antigen clearance, and the titer of hepatitis B core (HBc) antibody in 200-fold diluted serum. Twelve patients who had clearance of HBs antigen from serum were studied. Five patients had not received any treatment (group A), and seven had received prednisolone withdrawal therapy. The patients in groups A and B were followed up for 86 months and 108 months (median), respectively. Serum HBV was measured by the nested polymerase chain reaction method. In both groups, serum HBV tended to become gradually undetectable after HBs antigen clearance. The positive rate of HBV in the sera 5 years or more after HBs antigen clearance was significantly lower than that in the sera at less than 5 years, both in group A (P = 0.004) and group B (P = 0.010). In both groups, the titer of HBs tended to decline every year after HBs antigen clearance. HBV was still detectable in the sera of some patients for a long period of time after they showed seroconversion to HBs antibody. The results suggest that detection of HBV was difficult in sera with an HBc titer of 30% or lower and at more than 5 years after HBs antigen clearance in both groups. It is important to note that HBV DNA rarely exists in the serum, even when HBs antigen and HBc are both negative. Received: November 22, 1999 / Accepted: April 28, 2000     

HBV持续感染及其机制的研究进展

HBV属嗜肝DNA病毒科,可引起人类急性和慢性肝炎,甚至肝硬化、肝癌。目前的抗病毒药物因不能彻底清除肝细胞内HBV,故很难达到治愈的效果。近年来,HBV持续感染的机制受到广泛关注,主要涉及宿主与病毒两方面,从病毒方面展开,主要阐述了cccDNA、HBV颗粒和HBV自身组分维持HBV持续感染的相关研究进展。     

Therapeutic implications of hepatitis B virus genotypes.

BACKGROUND/AIMS: Hepatitis B virus (HBV) is a global health problem. In addition to the implementation of universal hepatitis B vaccination, effective and individualized treatment of chronic hepatitis B to prevent progression into end-stage liver diseases and hepatocellular carcinoma is still needed. HBV has been designated eight genotypes (A-H) based on genome sequence divergence. The epidemiology of HBV genotypes and their implications on the responses to antiviral therapy have become increasingly recognized in both Asian and Western countries. METHODS: Published data are thus reviewed. Results: Each genotype has its distinct geographical and ethnic distribution. Genotypes A and D occur frequently in Africa, Europe, and India, while genotypes B and C are prevalent in Asia. Genotype E is restricted to West Africa, and genotype F is found in Central and South America. The distribution of genotypes G and H is less clear. Accumulating evidence indicates a better sustained response to conventional interferon in patients with genotype B than those with C, and in patients with genotype A than those with D. In contrast, conflicting results exist regarding the response to pegylated interferon. On the other hand, the therapeutic responses to nucleoside/nucleotide analogues are comparable among patients with different HBV genotypes. The impact of HBV subgenotypes, mixed genotype infections, and recombinants of different genotypes on the response to antiviral treatments awaits further examinations. CONCLUSION: Remarkable clinical and pathogenic differences do exist among HBV genotypes; however, researches on molecular and virologic mechanisms underlying the clinical phenotypes of different HBV genotypes are urgently needed.     

HBsAg和HBsAb双阳性检测结果的初步分析

目的对临床检测中少见的HBsAg和HBsAb双阳性结果进行分析,寻找可能的产生原因。方法对3家医院初筛HBsAg和HBsAb双阳性的81份血标本进行同种和不同种试剂盒复检,并检测HBsAg145位氨基酸变异（G145R变异）、HBVDNA基因型和血清型分析。结果81份双阳性标本经复检有30例（37％）仍然为双阳性;对30例复检双阳性标本应用不同试剂盒再次检测,HBsAg／HBsAb仍为双阳性者18例（22．2％）;18例双阳性标本G145R检测全部为阴性;其中8例HBV DNA阳性血清的基因型分布为B型2例和C型6例,血清型分布为adw2例、adr5例和ayr1例,与9份对照血清的检测结果比无显著性差异。结论HBsAg和HBsAb双阳性检测结果大多数与操作或试剂的质量有关,少数可能为S基因变异或不同血清型的再次感染等有关。