A low rate of hepatitis B virus vaccine breakthrough infections in Mongolia

A nation-wide hepatitis B virus (HBV) immunization program of all newborn babies was launched in Mongolia in 1991. However, the continuation of clinical icteric viral hepatitis infections in children led to the investigation to determine whether HBV breakthrough infections were occurring and if any were due to hepatitis B surface antigen (HBsAg) mutants. Hepatitis A virus (HAV) infections accounted for most of these cases with 3% of the jaundiced children shown to have acute hepatitis B. Hepatitis B vaccine protection was 93% against HBV infection and 97% against HBV carriage. A G145A "escape mutant" was found in one HBV carrier child only. Anti-HBs levels, however, were low with 85% having titers less than 100 IU/L, 46% of whom had levels less than 10 IU/L. The results from this study demonstrate that the HBV immunization program in Mongolia provides an effective level of protection. However, continued surveillance of breakthrough infections and close monitoring of "vaccine escape" mutants is required.     

Control of HBV and HDV infection in an isolated Pacific Island: 1. Pattern of infection

Hepatitis B virus (HBV) and hepatitis delta virus (HDV) infections are known to be hyperendemic in Nauru. Because of the consequences of chronic HBV infection, the Nauruan Government has commenced a program that aims to reduce and eventually eliminate hepatitis B infection by immunizing susceptible adults and children on the island and every newborn baby. At the outset of this program, a national seroepidemiological survey was undertaken. Eighty-eight percent of the population were tested, of whom 69.1% had markers of HBV infection. Evidence of superinfection with HDV was found in 22.7% of HBV carriers, with the highest prevalence in adolescents and young adults. All seronegative individuals were offered three doses of plasma derived hepatitis B vaccine. A post-vaccination survey of 64% of those vaccinated showed that 98% had developed circulating antibodies.     

HBV疫苗接种后高、低、无应答个体B细胞特征的研究进展

乙型肝炎病毒(hepatitis B virus,HBV)感染一直以来都是世界范围内严重的公共卫生问题,可导致急、慢性肝脏疾病以及多种并发症。接种HBV疫苗诱导机体B细胞分泌保护性的乙型肝炎病毒表面抗体(hepatitis B surface antibody,HBsAb)是预防HBV感染最重要的措施。研究表明不同个体对HBV疫苗应答的效应不一致,可分为超高/高、正常/中等、低/无应答,对其产生机制的研究可为高滴度HBsAb制备、HBV感染防治等提供参考。本文将对HBV疫苗接种后不同应答效应个体B细胞特征和机制的研究概况与进展进行综述。     

Update on diagnosis, management, and prevention of hepatitis B virus infection

Acute and chronic hepatitis B virus (HBV) infection is a leading cause of liver disease worldwide. It is estimated that approximately 350 million people worldwide have chronic HBV infection and that 1 million persons die each year from HBV-related chronic liver disease. In the past decade, significant progress in the understanding of the molecular virology and pathogenesis of HBV infection has been made. In addition, effective treatment modalities have been developed for persons with chronic infection. Worldwide, prevention of HBV transmission has become a high priority. In 1992, the Global Advisory Group to the World Health Organization recommended that all countries integrate hepatitis B vaccine into national immunization programs by 1997. Currently, 80 countries have done so and several others are planning to. Many countries have reported dramatic reductions in the prevalence of chronic HBV infection among children born since the hepatitis B vaccine was introduced into infant immunization schedules. Recent reports from Taiwan indicate a reduction in the incidence of liver cancer among children as a result of widespread hepatitis B vaccination programs.     

湖州地区乙肝疫苗免疫失败儿童乙肝病毒S基因“a"决定簇变异分析

目的 了解湖州地区乙肝疫苗免疫失败儿童病毒S基因型变异情况.方法 应用聚合酶链反应(PCR)方法对29例HBV-DNA阳性乙肝疫苗免疫失败儿童乙肝病毒S基因进行扩增,PCR扩增产物进行序列分析.结果 29例样本中测序结果显示,B基因型26例,C基因型3例,有9例样本在S区“a”决定簇发生变异,变异主要存在“a”决定簇内127、129、131、133、141、142、144等氨基酸位点.结论 湖州地区乙肝疫苗免疫失败儿童在“a”决定簇区确实存在变异,可能是发生免疫失败的原因,但并未形成明显优势变异株.     

Advances in immunomodulating therapy of HBV infection

Patients with chronic hepatitis B virus (HBV) infection have a higher risk of developing liver cirrhosis and hepatocellular carcinoma. Interferon-alpha, lamivudine and adefovir dipivoxil are the three approved treatment for chronic HBV infection and offers the only means of preventing the development of these complications. However, the efficacy of these agents, in terms of loss of Hepatitis B e antigen with or without seroconversion to Hepatitis B e antibody, normalization of serum alanine transaminase levels, loss of serum HBV DNA, and improvement in liver histology can only be achieved in 20-30% of those treated. Long-term treatment with either lamivudine or adefovir dipivoxil can result in the development of drug resistant mutants leading to an increased length of treatment with additional nucleoside analogues. These limitations of the current antiviral therapies underline the need for alternative therapies. Specific and nonspecific immunotherapeutic strategies to restore effective virus-specific T cell responses in those with chronic HBV infection offers an interesting alternative approach. These immunotherapeutic therapies include the adoptive transfer of HBV immunity, pegylated interferon and therapeutic vaccine therapies.     

Hepatitis B precore protein: pathogenic potential and therapeutic promise

Hepatitis B virus (HBV), a small and economically packaged double-stranded DNA virus, represents an enormous global health care burden. In spite of an effective vaccine, HBV is endemic in many countries. Chronic hepatitis B (CHB) results in the development of significant clinical outcomes such as liver disease and hepatocellular carcinoma (HCC), which are associated with high mortality rates. HBV is a non-cytopathic virus, with the host's immune response responsible for the associated liver damage. Indeed, HBV appears to be a master of manipulating and modulating the immune response to achieve persistent and chronic infection. The HBV precore protein or hepatitis B e antigen (HBeAg) is a key viral protein involved in these processes, for instance though the down-regulation of the innate immune response. The development of new therapies that target viral proteins, such as HBeAg, which regulates of the immune system, may offer a new wave of potential therapeutics to circumvent progression to CHB and liver disease.     

秦皇岛市5739名孕产妇乙肝五项定量检测结果分析

目的 讨论2013年本院建卡孕产妇的乙肝流行情况,以及各个年龄组乙肝表面抗体的含量,及时接种乙肝疫苗,为孕产妇的乙肝防护提供数据支持.方法 采集孕产妇空腹静脉血,采用荧光免疫分析法（TRFIA）进行乙肝五项定量检测.结果 乙肝表面抗体的阳性率为51.93％,高免疫应答阳性率平均为30.49％,低免疫应答阳性率平均为21.43％.结论 在孕妇中存在着一定比例的HBV感染者和易感者,进行乙肝定量检测能够更好地反应机体乙肝感染动态免疫情况,预防HBV感染,阻断母婴传播,对优生优育、提高人口素质有重要意义.     

慢性乙肝患儿HBV基因型与乙肝病毒大蛋白关系探讨

目的 探讨慢性乙型肝炎患儿HBV基因型与乙肝病毒大蛋白的关系.方法 采用实时荧光PCR法和ELISA法分别检测138例处于乙肝病毒活动期的慢性乙型肝炎患儿血清中的HBV DNA和乙肝病毒大蛋白并鉴定其基因型.结果 乙肝病毒大蛋白吸光度与HBV DNA载量存在正相关（r=0.85,P＜0.05）;HBV基因B型与HBV基因C型的ALT水平、乙肝病毒大蛋白吸光度和HBVDNA载量差异无统计学意义（P＞0.05,P＞0.05,P＞0.05）.结论 乙肝病毒大蛋白水平与HBVDNA载量具有良好的正相关性,表明乙肝病毒活动期的慢性乙肝患者体内乙肝病毒大蛋白与病毒复制程度密切相关,乙肝病毒基因型与乙肝病毒大蛋白无关.     

Prevalence of parenterally transmitted hepatitis viruses in clinically diagnosed cases of hepatitis

Hepatitis B virus (HBV) is the most important causative agent of blood borne hepatitis in humans. Hepatitis D Virus (HDV) infection occurs either as a coinfection or superinfection in HBV carriers. Hepatitis C virus (HCV) is the major cause of transfusion non-A, non-B hepatitis and continues to be a major cause of human liver disease throughout the world. The present study was conducted on 70 clinically diagnosed cases of viral hepatitis to study the prevalence of parenterally transmitted viral hepatitis. The serum samples were tested for HBsAg, HBeAg, IgM anti-HBc, anti-HBe, anti-HCV and anti-HDV using separate ELISA kits. Of the 70 serum samples tested, 28 (40%) were positive for HBsAg out of which 3 (4.28%) were positive for HBeAg also. Five (7.1%) of the HBsAg positive cases tested positive for IgM anti-HBc also. HBsAg alone was found in 17 (24.28%) cases. The prevalence of anti-HCV was 3 (4.28%) in 70 cases. Thus early screening of clinically diagnosed cases of viral hepatitis is essential for establishing diagnosis and treatment to prevent long term sequelae.     

Prevalence and significance of HBeAg and isolated anti-HBc in several institutions for the mentally retarded in the autonomous community of madrid

Hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBsAg (antiHBs) are excellent markers for HBV infection and its immunity. A total of 414 patients, 312 Down syndrome and 102 non-Down's syndrome, were studied, and 142 were residents of an institution (RI), whereas 272 were in nonresidential care (NRC). Of the total, 28 (6.8%) were HBsAg positive, and of these, 16 (57.1%) had a positive test for the Hepatitis Be antigen (HBeAg). Proportionately more Down syndrome chronic carriers of HBsAg acquired the persistent Hepatitis Be antigen (HBeAg) than non-Down syndrome patients 15 (65.2%) vs. 1 (20%). The presence of HBeAg was correlated with abnormal liver function and high titres of HBsAg. Testing for the IgM antibody to the hepatitis B core antigen (IgM AntiHBc) facilitated the identification of acute and chronic hepatitis infection in both RI and NRC individuals. The significance of isolated antiHBc seropositivity in Down syndrome patients remains unclear. It is not certain whether the isolated antiHBc seropositivity represents chronic “low levels” of HBV, past infection, or false-positive tests, and whether this test should be employed as a vaccine screening test. Am. J. Hum. Biol. 9:29–33 © 1997 Wiley-Liss, Inc.     

Prophylaxis and therapy of hepatitis B after liver transplantation

About 25% of all liver transplantations in USA are performed for liver disease due to viral hepatitis, 25% of them related to hepatitis B. It is also known that 90%-100% of transplanted persons with proven replicative stage of hepatitis B [HBeAg (+), HBV DNA (+)] develop reinfection of the transplanted liver in the absence of prophylaxis. This percentage is lower (30%-50%) in patients with nonreplicative stage of infection [HBeAg (-), HBV DNA (-)]. The consequence of most transplant infections is death due to the transplanted organ failure. The prophylaxis of infection is possible, however a combination of intravenous hepatitis B hyperimmune gammaglobulin and lamivudin may be too expensive for some transplantation centers in less developed countries. The aim of this article is to recommend prophylaxis and treatment of recurrent hepatitis B in persons with transplanted liver using data of the Consensus Conference on Hepatitis B in Geneva 2002, Canadian Consensus Group for Hepatitis (CASL) and EASL International Consensus Conference on Hepatitis B that should be available for patients in Croatia.     

Serum hepatitis B virus-DNA in chronic hepatitis B and delta infection

Hepatitis B-associated delta agent, a defective RNA virus requiring helper functions of hepatitis B virus (HBV), has been shown to interfere with HBV replication. Low titers of serum hepatitis B surface antigen, absence of hepatitis B e antigen, and low levels of stainable hepatitis B core antigen in liver cells usually seen in chronic delta infection are indirect evidences of such an interference. Measurement of serum HBV-DNA by hybridization with phosphorus 32-labeled HBV-clone DNA is the most sensitive method currently available to detect HBV replication. Using this method, we found that only two of 13 patients with chronic delta infection showed serum HBV-DNA positivity in comparison with seven of 14 patients who had chronic hepatitis B without delta infection. These two groups were matched for hepatitis B e antigen status and liver histopathology. Thus, we report direct evidence of delta agent interfering with the replication of the helper (HBV) virus.     

不同剂量乙肝疫苗与HBIG联合免疫阻断HBV母婴传播的效果对比

目的 探讨10 μg和20 μg乙肝疫苗与HBIG联合免疫阻断HBV母婴传播的效果.方法 124例HBsAg阳性孕妇所生的婴儿随机分为两组,即10 μg乙肝疫苗组和20 μg乙肝疫苗组.婴儿于出生6h内及30 d分别注射200 IU HBIG,同时分别于出生24 h内、1个月及6个月注射3次10 μg或20 μg重组酵母乙肝疫苗.检测婴儿出生时以及1岁时血清HBV标志物.结果 两组新生儿血清HBsAg、HBeAg及抗-HBe阳性率与滴度之间差别均无统计学意义（P＞0.05）.所有新生儿血清HBV DNA水平均小于检测下限（500 U/ml）.出生12个月时,所有124例婴儿血清HBsAg和HBeAg检测结果均为阴性;血清HBV DNA水平均在检测下限以下;10 μg和20 μg乙肝疫苗组血清抗-HBs阳性率分别为90.3％和96.8％,差异无统计学意义（P＞0.05）;抗-HBs水平分别为325.5±342.2 mIU/ml和463.7±353.3 mIU/ml,后者显著高于前者（P=0.01）.而且,20 μg乙肝疫苗组产生高应答抗-HBs（＞ 100 mIU/ml）的比例显著高于10μg乙肝疫苗组（P =0.035）.结论 20 μg乙肝疫苗联合HBIG方案阻断HBV母婴传播的效果优于10 μg乙肝疫苗联合HBIG方案.     

Delta hepatitis: molecular biology and clinical and epidemiological features.

Hepatitis delta virus, discovered in 1977, requires the help of hepatitis B virus to replicate in hepatocytes and is an important cause of acute, fulminant, and chronic liver disease in many regions of the world. Because of the helper function of hepatitis delta virus, infection with it occurs either as a coinfection with hepatitis B or as a superinfection of a carrier of hepatitis B surface antigen. Although the mechanisms of transmission are similar to those of hepatitis B virus, the patterns of transmission of delta virus vary widely around the world. In regions of the world in which hepatitis delta virus infection is not endemic, the disease is confined to groups at high risk of acquiring hepatitis B infection and high-risk hepatitis B carriers. Because of the propensity of this viral infection to cause fulminant as well as chronic liver disease, continued incursion of hepatitis delta virus into areas of the world where persistent hepatitis B infection is endemic will have serious implications. Prevention depends on the widespread use of hepatitis B vaccine. This review focuses on the molecular biology and the clinical and epidemiologic features of this important viral infection.     

Quantitative detection of serum HBV DNA levels employing a new S gene based cPCR assay

Summary. Hepatitis B virus (HBV) infection is a major public health problem and a leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma. Worldwide, there are about 350 million carriers of this pathogen and India bears the second highest carrier pool in the world. Early diagnosis and measurement of viral load in hepatitis B patients is very helpful for the better management of this disease. The existing methods for viral quantification are either cumbersome or expensive. Since viral replication correlate well with HBV DNA levels a new sensitive, reliable and cost effective competitive PCR assay has been developed for quantifying the viral load in the serum of hepatitis B patients. The S gene based cPCR assay was able to detect as low as 100 genome equivalent/ml of HBV DNA from human serum and was applied to determine viral load among inactive and chronic hepatitis B carriers demonstrating the usefulness of the developed test.     

Pattern of T cell activation in absence of protective immunity against hepatitis B virus. Review

Hepatitis B is an important cause of morbidity and mortality around the world. One-third of the world's population has been estimated to be infected with hepatitis B virus (HBV). A significant amount of evidence suggests that both humoral and cellular immune responses are important to eliminate the virus and that, cellular immunity is involved in the pathogenesis of the disease. Vaccination with HBsAg is considered as the main strategy for effective control of the infection and viral transmission. However, approximately 5-10% of immunized individuals fail to elicit detectable specific antibodies and remain at risk for hepatitis B infection. In this work we have reviewed the current status in the pathogenesis of the disease and the mechanisms described to explain nonresponsiveness to the vaccine as well. Since nonresponders to the vaccine are at risk for the infection, a common mechanism to explain the absence or inappropriate immune response to virus components is proposed. Within the suggested model an impaired activation of T lymphocytes against viral antigens, both in nonresponders to vaccination and chronically infected patients, is described. These observations could be consistent with potential differences in the MHC/Ag presentation; therefore contributing to our understanding of the altered T helper response as an underlying mechanism for the lack of protective immunity against VHB.     

Significance of isolated anti-HBc seropositivity by ELISA: implications and the role of radioimmunoassay.

Hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBsAg (anti-HBs) are excellent markers for HBV infection and its immunity. The significance of isolated antibody to HBV core antigen (anti-HBc) seropositivity is not certain. To elucidate this, sera from 638 Chinese adult subjects, aged 18-52 years, seronegative for both HBsAg and anti-HBs, were tested for anti-HBc. Fifty-one (8%) were found to have an isolated anti-HBc seropositivity by ELISA, and all were negative for IgM-anti-HBc. The anti-HBc persisted in all subjects who attended follow-up for hepatitis B vaccination (n = 48) for a period of 8 months. These 48 subjects received 3 doses of hepatitis B vaccine (HB-VAX, 10 micrograms or 20 micrograms) at 0, 1, and 6 months: 72.9% developed a primary anti-HBs response (suggestive of a false-positive anti-HBc seropositivity), 4.2% developed an anamnestic or secondary anti-HBs response, and 22.9% did not develop an anti-HBs response. Increasing the cutoff point of the ELISA or reconfirmation with radioimmunoassay (RIA) reduced only a minor half of the false positives. This low specificity of anti-HBc ELISA/RIA, together with the high rate of anti-HBs response to hepatitis B vaccine, indicates that subjects with isolated anti-HBc seropositivity should be included in vaccination programs.     

DNA: DNA hybridization method for the diagnosis of hepatitis B infection

Hepatitis B viral (HBV) DNA was detected in a hepatoma cell line which produces hepatitis B surface antigen (HBsAg) and in patients with acute hepatitis B. The serum of one patient with acute hepatitis B was found to be infectious when injected i.v. into a chimpanzee up to a dilution of 10(-8). Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) were detectable in the same serum sample by radioimmunoassay up to a dilution of 10(-5) and of 10(-3), respectively. Using DNA: DNA hybridization on nitrocellulose membranes, HBV DNA sequences were detectable up to 10(-8) dilution corresponding to the infectivity level. Based on this finding, it appears that DNA: DNA hybridization is the most sensitive method for detecting hepatitis B virus (HBV) infection. In situations with low virus levels it may be the only indicator of the presence of infectious hepatitis B virus. The use of a tritium-labelled probe makes the method economical and adaptable to hospital laboratories.