Management of individuals with chronic hepatitis B virus infection and persistent normal or mildly elevated aminotransferase levels

No consensus exists with respect to positive hepatitis B virus (HBV) DNA results and persistent normal or mildly elevated alanine aminotransferase (ALT). The aim of this study is to investigate the appropriate management and prognosis of these populations with chronic hepatitis B (CHB). A total of 235 subjects with positive HBV DNA results and persistent normal or mildly elevated ALT were enrolled in this study. Liver biopsy and liver stiffness measurements (LSM) were performed in all participants at baseline. Antiviral therapy was initiated in patients with significant hepatic inflammation (G ≥ 2) and/or fibrosis (S ≥ 2). The patients were divided into entecavir and adefovir groups based on HBV DNA load (>2000 IU/mL vs <2000 IU/mL). The liver biopsies were repeated at 72 weeks for the patients received antiviral therapy. We found that 112 subjects were hepatitis B e antigen (HBeAg) positive, and 123 subjects were negative. The corresponding median ALTs were 46 (39.5-52.5) and 48 (41.5-57.0) U/mL, respectively. G ≥ 2 and/or S ≥ 2 diseases were present in 48.8% (82/168) of the HBeAg-positive and 51.2% (86/168) of HBeAg-negative patients, respectively. In addition, 96 HBeAg-positive and 72 HBeAg-negative patients were divided into entecavir and adefovir groups. Meanwhile, liver biopsies had greater diagnostic accuracy for determining cirrhosis than LSM (0.711 vs 1.0, P < 0.0001). At the end of the study period, undetectable HBV DNA levels and normal ALT levels were observed in CHB-infected patients. Furthermore, the patients showed histologic improvement at 72 weeks compared with baseline measurements (G, 1.72 ± 1.00 vs 0.73 ± 0.88, P = 0.0002; S, 1.484 ± 0.90 vs 0.99 ± 1.13, P < 0.0001). Collectively, liver biopsy enhanced diagnostic accuracy for CHB-infected individuals with persistent normal or mildly elevated aminotransferase levels. Moreover, antiviral therapy can improve or regress the hepatic fibrosis and cirrhosis.     

Anti-pre-S2 antibody response in subjects vaccinated against hepatitis B and in naturally immunized subjects

Serum samples from individuals immunized with a pepsinized or non-pepsinized vaccine and from patients who had recovered from acute hepatitis B or who developed a chronic form of the disease, were analysed for the presence of antibody against the pre-S2 epitope of the hepatitis B virus.Anti-pre-S2 antibody was absent in all but one individual immunized with the pepsinized vaccine. Thirty-eight percent of the subjects who responded by anti-HBs production to the non-pepsinized preparation showed anti-pre-S2 antibody one year after complete vaccination. Among subjects who did not produce anti-HBs after immunization with this vaccine, 1 single individual produced anti-pre-S2 antibody. Anti-preS2 antibody was detectable after one year in 38% of the patients who recovered from acute hepatitis B, but in none of those with chronic hepatitis B. The kinetics of anti-pre-S2 antibody response to a booster injection was also analysed 1 month and 1 year after the 3rd injection and 1 month after the 4th injection of the non-pepsinized vaccine.     

Core antigen and antibody in woodchucks after infection with woodchuck hepatitis virus

The woodchuck hepatitis virus is a naturally occurring hepatitis B-like virus that infects the eastern woodchuck. Direct immunofluorescence staining for woodchuck hepatitis virus core antigen in liver biopsies demonstrated the presence of this antigen in 14 of 17 chronically infected woodchucks, and in 8 of 10 woodchucks undergoing acute infections. Fluorescent localization of woodchuck hepatitis virus core antigen was typically cytoplasmic, and this was confirmed further by electron microscopy. Experimental infection with woodchuck hepatitis virus was achieved in four of four woodchucks inoculated with serum from chronic carrier woodchucks. All infected animals developed a self-limited disease characterized by seroconversion to antibodies against the major viral antigens (core and surface antigens); naturally acquired acute infection demonstrated a similar course. A chimpanzee seronegative for all markers of hepatitis B virus developed a subclinical infection after inoculation with woodchuck hepatitis virus.     

Should homosexuals be vaccinated against hepatitis B virus? Cost and benefit assessment.

The recent introduction of a vaccine against hepatitis B has raised the questions of who should be offered it and what the cost would be of a vaccination programme. An analysis was performed of the financial costs and benefits of such a programme designed to prevent acute hepatitis B in male homosexuals in the United Kingdom. Under various assumptions the total costs of screening and vaccination ranged from 2.2m pounds to 3m pounds for a five year programme and from 3.3m pounds to 4.8m pounds for a 10 year programme. The benefits over the same two periods for the programme, depending on two different assumptions of mortality prevented, ranged 3.9m pounds to 13.7m pounds and from 7m pounds to 24.4m pounds. Thus considerable savings may be made to the national economy by offering vaccination to homosexuals. These savings are obtained after consideration of only the acute aspects of hepatitis B. Had it been possible to determine the costs of the chronic sequelae of this disease the savings, compared with the costs, would have been greatly increased.     

Affinity maturation to improve human monoclonal antibody neutralization potency and breadth against hepatitis C virus

A potent neutralizing antibody to a conserved hepatitis C virus (HCV) epitope might overcome its extreme variability, allowing immunotherapy. The human monoclonal antibody HC-1 recognizes a conformational epitope on the HCV E2 glycoprotein. Previous studies showed that HC-1 neutralizes most HCV genotypes but has modest potency. To improve neutralization, we affinity-matured HC-1 by constructing a library of yeast-displayed HC-1 single chain Fv (scFv) mutants, using for selection an E2 antigen from one of the poorly neutralized HCVpp. We developed an approach by parallel mutagenesis of the heavy chain variable (VH) and κ-chain variable (Vk) genes separately, then combining the optimized VH and Vk mutants. This resulted in the generation of HC-1-related scFv variants exhibiting improved affinities. The best scFv variant had a 92-fold improved affinity. After conversion to IgG1, some of the antibodies exhibited a 30-fold improvement in neutralization activity. Both surface plasmon resonance and solution kinetic exclusion analysis showed that the increase in affinity was largely due to a lowering of the dissociation rate constant, Koff. Neutralization against a panel of HCV pseudoparticles and infectious 2a HCV virus improved with the affinity-matured IgG1 antibodies. Interestingly, some of these antibodies neutralized a viral isolate that was not neutralized by wild-type HC-1. Moreover, propagating 2a HCVcc under the selective pressure of WT HC-1 or affinity-matured HC-1 antibodies yielded no viral escape mutants and, with the affinity-matured IgG1, needed 100-fold less antibody to achieve complete virus elimination. Taken together, these findings suggest that affinity-matured HC-1 antibodies are excellent candidates for therapeutic development.     

Comparison and significance of specific and non-specific cellular immunity in patients with chronic hepatitis B caused by infection with genotypes B or C of hepatitis B virus

The present study was designed to investigate possible relationships between the genotypes of hepa-titis B virus (HBV) and the HBV-specific cytotoxic T lymphocyte (CTL) responses. HBV genotypes, HBV specific CTL HBV DNA and other markers of HBV infection were determined in 138 patients with chronic hepatitis B. The results showed that the patients infected with genotype C (n=62) had a significantly lower HBV-specific CTL response than those who were infected with HBV genotype B (P<0.01). HBV DNA titer was higher in patients infected with HBV genotype C than in those infected with HBV geno-type B (P<0.01). Both alanine aminotransferase (ALT) and total bilirubin (TBIL) were higher in HBV genotype C infected patients than in those infected with genotype B (P<0.01 and <0.05, respectively). These results suggest that compared with CHB patients infected with HBV genotype B, the higher HBV DNA level and more severe liver damages in the patients infected with genotype C of HBV may be as-sociated with genotype C of the virus.     

In vitro production of antibody to hepatitis B core and E antigens by peripheral blood mononuclear cells in patients with chronic hepatitis B virus infection

To evaluate the relative immunogenicity of and the mechanism for production of antibody to hepatitis B core (HBc) and hepatitis B e (HBe) Ag, we investigated the in vitro anti-HBc and anti-HBe production by PBMC from 25 patients with chronic active hepatitis (CAH) (15 with HBeAg and 10 with anti-HBe) and 12 ASC (5 with HBeAg and 7 with anti-HBe) in the presence of PWM, rHBcAg, or purified HBeAg. PWM-stimulated culture produced higher titer anti-HBc (mean % inhibition +/- SD = 73 +/- 23%, p less than 0.001) than anti-HBe (34 +/- 17%). HBcAg stimulation elicited greater anti-HBc response (43 +/- 26%, p less than 0.001) than did HBeAg for anti-HBe (26 +/- 12%). Both HBcAg and HBeAg induced equivalent anti-HBe response. Anti-HBc production in response to HBcAg was higher in CAH patients (51 to 55%) than in asymptomatic carriers of hepatitis B surface Ag (22 to 28%) irrespective of their HBeAg/anti-HBe status, but reflecting serum anti-HBc value. Similar findings were noted in HBeAg-stimulated anti-HBe production for the two patient groups. In HBeAg- and anti-HBe-positive CAH, HBcAG-stimulated anti-HBc production was similar in T (1.4 x 10(6)) and B (0.6 x 10(6)) cells coculture, and B cells (2 x 10(6)) alone culture. However, in the HBeAg-stimulated culture, T plus B cells produced significantly higher titer anti-HBe than B cells alone did. These results indicate that HBcAg has a relatively higher immunogenicity in terms of antibody production as compared to HBeAg. Furthermore, HBcAg was shown to function as a T cell-dependent and -independent Ag, whereas HBeAg is T cell-dependent during chronic hepatitis virus B infection in man.     

Expression of hepatitis B virus S gene in Pichia pastoris and application of the product for detection of anti-HBs antibody

Antibody to hepatitis B surface antigen (HBsAb) is the important serological marker of the hepatitis B virus (HBV) infection. Conventionally, the hepatitis B surface antigen (HBsAg) obtained from the plasma of HBV carriers is used as the diagnostic antigen for detection of HBsAb. This blood-origin antigen has some disadvantages involved in high cost, over-elaborate preparation, risk of infection, et al. In an attempt to explore the suitable recombinant HBsAg for the diagnostic purpose, the HBV S gene was expressed in Pichia pastoris and the product was applied for detection of HBsAb. Hepatitis B virus S gene was inserted into the yeast vector and the expressed product was analyzed by sodium dodecyl sulphate polyacrolamide gel electrophoresis (SDS-PAGE), immunoblot, electronic microscope and enzyme linked immunosorbent assay (ELISA). The preparations of synthesized S protein were applied to detect HBsAb by sandwich ELISA. The S gene encoding the 226 amino acid of HBsAg carrying a hexa-histidine tag at C terminus was successfully expressed in Pichia pastoris. The His-Tagged S protein in this strain was expressed at a level of about 14.5 % of total cell protein. Immunoblot showed the recombinant HBsAg recognized by monoclonal HBsAb and there was no cross reaction between all proteins from the host and normal sera. HBsAb detection indicated that the sensitivity reached 10 mIu (micro international unit)/ml and the specificity was 100 % with HBsAb standard of National Center for Clinical Laboratories. A total of 293 random sera were assayed using recombinant S protein and a commercial HBsAb ELISA kit (produced by blood-origin HBsAg), 35 HBsAb positive sera and 258 HBsAb negative sera were examined. The same results were obtained with two different reagents and there was no significant difference in the value of S/CO between the two reagents. The recombinant HBV S protein with good immunoreactivity and specificity was successfully expressed in Pichia pastoris. The reagent for HBsAb detection prepared by Pichia pastoris-derived S protein showed high sensitivity and specificity for detection of HBsAb standard. And a good correlation was obtained between the reagent produced by recombinant S protein and commercial kit produced by blood-origin HBsAg in random samples.     

慢性乙型肝炎病毒感染自然史中HBsAg和HBsAb共存血清学模式分析

目的分析慢性乙肝病毒感染者HBsAg和HBsAb共存模式中血清学指标、HBV-DNA和肝酶等指标与自然病程的关系,探讨其临床意义。方法回顾性分析2016年重庆医科大学附属第一医院HBsAg和HBsAb双阳性患者的血清学指标、HBV-DNA和ALT、GGT检测结果,并对其感染的自然病程进行分析。结果 2016年该院HBsAg和HBsAb双阳性患者共520例,占全部HBV感染者的2.80%,占总送检标本数的0.42%。可分期的184例双阳性患者中,免疫耐受期47例(25.54%),免疫清除期17例(9.24%),低复制期108例(58.70%),再活动期12例(6.52%),HBsAg、HBsAg/HBsAb比值、HBV-DNA、ALT和GGT水平差异均有统计学意义(P<0.05),低复制期患者HBsAg/HBsAb比值均低于其他患者(P<0.05)。不同分期患者HBsAb、年龄和性别比较差异无统计学意义(P>0.05),且HBsAb水平均较低。284例资料完整HBsAg和HBsAb共存病例中HBV-DNA阳性136例,占47.89%。HBsAg浓度与HBV-DNA载量成正相关(r=0.295,P<0.05),HBsAb浓度与HBV-DNA载量之间没有显著相关性(r=0.04,P>0.05)。结论 HBsAg和HBsAb共存患者并不少见,与性别无关,可发生在各个年龄阶段,以低复制期患者为最多。HBsAg和HBsAb共存患者中HBsAb多以低浓度形式存在,且浓度与自然病程无关。HBsAb的出现并非代表患者体内病毒复制停止,在诊断及治疗HBsAg和HBsAb共存模式的乙肝病毒感染者时仍需结合HBV-DNA载量来判断感染状态。     

自然人群乙型肝炎病毒慢性感染者HBV DNA的流行病学分析

目的了解寿光市自然人群乙型肝炎病毒(hepatitis B virus,HBV)慢性感染者HBV DNA的流行病学特征,为乙型肝炎的防治提供依据。方法采集2012年寿光市3个镇街道居民体检发现的HBs Ag阳性者静脉血5 m L,以实时荧光定量聚合酶链反应(FQ-PCR)法检测血清HBV DNA载量,分析HBV DNA与性别、年龄、有无乙肝/肝癌家族史、密切接触史、输血史等因素的相关性。结果在2 026例HBs Ag阳性感染者中,HBV DNA阳性率为49.41%(1 001/2 026),HBV DNA载量的平均值为6.27×107拷贝/m L。其中男性HBV DNA阳性率为53.28%(585/1 098),女性为44.83%(416/928),差异有统计学意义(χ2=14.370,P<0.01);HBV DNA均值男性为(6.72×107±2.07×108)拷贝/m L,女性为(5.56×107±1.44×108)拷贝/m L,差异无统计学意义(t=0.447,P>0.05)。HBVDNA阳性率与年龄呈负相关(r=-0.983),与HBV感染的主要影响因素乙肝/肝癌家族史、密切接触史、输血史等均无关。结论 HBV DNA阳性率与慢性HBV感染者的性别、年龄有关,与HBV感染的主要影响因素无关。     

Immunology of hepatitis B virus and hepatitis C virus infection

More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and survival strategies. This review assesses recent advances in our understanding of viral hepatitis, contrasts mechanisms of virus-host interaction in acute hepatitis B and hepatitis C, and outlines areas for future studies.     

Prevalence of HIV antigens in cerebrospinal fluid and in serum of patients with both asymptomatic and symptomatic HIV infection]

Prevalence of HIV-Ag in both serum and CSF has been determined in 19 HIV infected patients, including 7 patients without any symptoms or only generalized lymphadenopathy, 5 patients with ARC and 7 patients with AIDS. The results have been correlated with clinically evident neurological disorders. HIV-Ag have been detected in 9 out of 12 patients with ARC (AIDS Related Complex) and AIDS. In 8 of them neurological disorders have been present. Out of the remaining 7 patients in only one HIV-Ag has been detected in CSF (p < 025). No correlation between the presence of HIV antigen in CSF and serum has been noted.     

Cytokine expression during chronic versus occult hepatitis B virus infection in HIV co-infected individuals

Chronic hepatitis B virus infection is characterized by persistent detectable levels of hepatitis B surface antigen (HBsAg) and HBV DNA in the serum. In contrast, HBsAg is not detectable during occult HBV infection, despite the presence of HBV DNA. An altered host immune response could play a role in the development of occult HBV infection; however, potential differences in immune responses among chronic and occult HBV-infected patients have not been evaluated in vivo. In the current study, we evaluated serum levels of regulatory, apoptotic, and fibrotic/anti-fibrotic cytokines/markers as indicators of immune responses in 25 chronic and 12 occult HBV-infected patients. More than half of the patients in both chronic and occult HBV infection groups had IL-2, IL-4, IL-13, and IFN-γ levels below detectable limits. In contrast, most patients had detectable levels of IL-8, IL-10, IP-10, sFas, sFasL, and TGF-β1. Of these, only sFas was significantly different between the two groups, with lower levels observed during occult compared to chronic HBV infection (p = 0.01). As a surrogate marker of apoptotic inhibition, decreased sFas during occult HBV infection suggests that apoptosis occurs at different rates in occult compared to chronic HBV infection and therefore, may contribute to persistence of occult HBV infection.     

Immunoglobulin M antibody to hepatitis B core antigen (IgM anti-HBc) as a marker of interferon therapy in patients with persistent hepatitis B virus infection

Immunoglobulin M antibody to hepatitis B core antigen (IgM anti-HBc) was measured by radioimmunoassay in the sera of 96 HBV carriers. IgM anti-HBc was detected in 17 of 66 patients with chronic active hepatitis and in 4 of 11 with liver cirrhosis. This antibody was not present in asymptomatic carriers or in patients with chronic persistent hepatitis. Testing of sequential samples revealed that the presence of IgM anti-HBc indicated active replication of HBV and at the same time an immune response to the virus. The relationship between IgM anti-HBc and the response to interferon (IFN) therapy was also studied. Results showed that IgM anti-HBc is a useful marker of the efficacy of interferon therapy.     

Detection of a new antibody system reacting with Dane particles in hepatitis B virus infection.

Antibodies in the serum reacting with antigens on the surface of radiolabelled Dane particles distinct from hepatitis B surface and core antigens (HBsAg and HBcAg) were detected, using a double antibody precipitation assay, in 12 out of 15 patients early in the course of acute type B hepatitis and at the time of disappearance of circulating Dane particles. No such antibody activity was found in 15 of the 16 patients with HBsAg-positive chronic active hepatitis, 13 of whom had complete Dane particles in the serum. In a group of 16 asymptomatic HBsAg carriers (without Dane particles in serum) antibody activity was shown in nine. This demonstration of antibodies precipitating Dane particles may be relevant to the clearance of circulating hepatitis B virions and the termination of infection in acute type B hepatitis. Their absence in all but one of the cases of chronic active hepatitis might explain why the virus infection persists in this group of patients.