Hepatitis E virus and chronic hepatitis in organ-transplant recipients

[How to investigate and diagnose autochthonous hepatitis E?]

In developed countries, HEV infection was still recently considered as rare, and as an imported disease from endemic areas by travellers. Hepatitis E virus is now recognized mainly as an autochthonous disease in these countries. Although the source and the route of contamination remain uncertain, several cases of food-borne (zoonotic transmission) and blood-borne transmission have been recently reported. The mortality rates in industrialized countries seems to be higher than in endemic areas, since the infection occurs more frequently in elderly people with underlying chronic liver disease (mortality rate approaching 70% in this subgroup of patients). By contrast, whereas mortality rate rises by 20% during pregnancy in developing countries, no death in pregnant woman from developed countries secondary to an autochthonous case has been reported so far. Lastly, HEV infection may be a cause of chronic hepatitis in immunocompromised patients (mostly in solid organ-transplant recipients) which can evolve to cirrhosis.

Full-genome nucleotide sequence and analysis of a Chinese swine hepatitis E virus isolate of genotype 4 identified in the Guangxi Zhuang autonomous region: evidence of zoonotic risk from swine to human in South China

BACKGROUND

Hepatitis E virus (HEV) is one of the leading causes of the enteric-transmitted acute hepatitis. Many studies have found high identities between human and animal HEV isolates using partial sequence comparison analysis.

AIMS

To determine and phylogenetically analyse the complete genome of the swGX40 isolate from the Guangxi Zhuang autonomous region.

METHODS

The overlapping fragments of HEV isolate swGX40 were amplified with reverse transcription-nested polymerase chain reaction (PCR) and the 5' and 3' ends of viral genome were amplified with rapid amplification of cDNA ends. The PCR products were cloned and sequenced. The sequence and phylogenetic analysis of swGX40 were performed.

RESULTS

The full genome of the swGX40 strain consisted of 7233 nucleotides, excluding the poly (A) tail of 36 residues. There are three open reading frames (ORFs), encoding 1705, 674 and 114 amino acids (aa) respectively. The full-genomic sequencing showed that the swGX40 strain shared similarity with all known HEV genotype 1, 2 and 3 isolates by 73.4-76.5% and with an identity of 83.1-91.2% among genotype 4 HEV isolates. The partial ORF2 sequencing (249 nt) showed that swGX40 shared a high nucleotide identity of 94 and 97% with the Chinese human strain LZ-105 and the Vietnamese human strain HE-JVN-1 respectively.

CONCLUSIONS

The swine isolate swGX40 was closely related to the human isolate LZ-105, both of which were collected from Liuzhou, the same district in the Guangxi Zhuang autonomous region. This molecular biological evidence strongly supported the zoonosis hypothesis of hepatitis E.

Epidemiology of hepatitis E: current status

Hepatitis E, caused by infection with hepatitis E virus (HEV), is a common cause of acute hepatitis in areas with poor sanitation. The virus has four genotypes with one serotype: genotypes 1 and 2 exclusively infect humans, whereas genotypes 3 and 4 also infect other animals, particularly pigs. In endemic areas, both large outbreaks of acute hepatitis as well as sporadic cases occur frequently. These cases are usually due to genotype 1 or 2 HEV and are predominantly caused by fecal-oral transmission, usually through contamination of drinking water; contaminated food, materno-fetal (vertical spread) and parenteral routes are less common modes of infection. The acute hepatitis caused by this virus has the highest attack rates in young adults and the disease is particularly severe among pregnant women. HEV superinfection can occur among persons with pre-existing chronic liver disease. In non-endemic regions, locally acquired disease was believed to be extremely uncommon. However, in recent years, an increasing number of cases, due mostly due to genotype 3 or 4 HEV, have been recognized. These are more often elderly men who have other coexisting illnesses, and appear to be related to zoonotic transmission from pigs, wild boars and deer, either food-borne or otherwise. Also, chronic infection with genotype 3 HEV has been reported among immunosuppressed persons in these regions. A subunit vaccine has been shown to be effective in preventing clinical disease, but is not yet commercially available. Our understanding of hepatitis E epidemiology has undergone major changes in recent years, and the future may hold even more surprises.

Late protocol liver biopsies in the liver allograft: a neglected investigation?

As outcomes from liver transplantation have improved, attention has focused on long-term outcomes: patient and graft survival is affected by many factors, including the consequences of both overimmunosuppression (eg, renal failure and cancer) and underimmunosuppression (eg, rejection). The use of protocol (rather than event-driven) biopsies of the liver allograft, except for those grafted for HCV infection, has been largely abandoned. The aim of this study was to determine if protocol biopsies can improve the management of liver allograft recipients. A retrospective analysis of liver allograft recipients who had undergone protocol liver biopsies between 2000 and 2006 was performed. One hundred seventy-eight patients with normal liver tests (alcoholic liver disease, 49; autoimmune hepatitis, 20; and primary biliary cirrhosis, 107) who had undergone 235 protocol biopsies were identified. No significant complication from the biopsy was recorded. Liver histology was reported as normal or nearly normal in only 57 (24%). Chronic hepatitis (not obviously related to disease recurrence) was present in 78 (33%). Interpreted in the light of the calculated creatinine clearance, the biopsy findings indicated that overall immunosuppression (IMS) should be maintained or increased with standard calcineurin inhibitor (CNI)-based IMS in 25% of cases, that overall IMS should be reduced in 15% of cases, and that overall IMS should be maintained or increased by the substitution of non-nephrotoxic agents for CNIs in 9% of cases. The histological findings led to a documented change in IMS in 76 (32%) (increased IMS, 11; decreased IMS, 58; and switch from CNI, 7). In conclusion, protocol liver biopsy provides important histological information about graft function that is not available from standard liver tests and safely allows modification of IMS to ensure that long-term side effects of drug therapy (eg, renal failure) are minimized while graft function is sustained. Liver Transpl 15:931-938, 2009. (c) 2009 AASLD.

Clinical course and duration of viremia in vertically transmitted hepatitis E virus (HEV) infection in babies born to HEV-infected mothers

Infection with the hepatitis E virus (HEV) causes a self-limiting acute hepatitis. However, prolonged viremia and chronic hepatitis has been reported in organ transplant recipients. Vertically transmitted HEV infection is known to cause acute hepatitis in newborn babies. The clinical course and duration of viremia in vertically transmitted HEV infection in neonates in not known. We studied 19 babies born to HEV infected mothers. Babies were studied at birth and on a monthly basis to evaluate clinical profile, pattern of antibody response and duration of viremia in those infected with HEV. Fifteen (78.9%) babies had evidence of vertically transmitted HEV infection at birth (IgM anti-HEV positive in 12 and HEV RNA reactive in 10) and three had short-lasting IgG anti-HEV positivity because of trans-placental antibody transmission. Seven HEV-infected babies had icteric hepatitis, five had anicteric hepatitis and three had high serum bilirubin with normal liver enzymes. Seven babies died in first week of birth (prematurity 1, icteric HEV 3, anicteric HEV 2 and hyperbilirubinemia 1). Nine babies survived and were followed up for clinical, biochemical, serological course and duration of viremia. Five of 9 babies who survived were HEV RNA positive. HEV RNA was not detectable by 4 weeks of birth in three babies, by 8 weeks in one and by 32 weeks in one. All surviving babies had self-limiting disease and none had prolonged viremia. Thus HEV infection is commonly transmitted from mother-to-foetus and causes high neonatal mortality. HEV infection in survivors is self-limiting with short lasting viremia.

National mortality rates from chronic liver disease and consumption of alcohol and pig meat

A correlation between national pig-meat consumption and mortality rates from chronic liver disease (CLD) across developed countries was reported in 1985. One possible mechanism explaining this may be hepatitis E infection spread via pig meat. We aimed to re-examine the original association in more recent international data. Regression models were used to estimate associations between national pig-meat consumption and CLD mortality, adjusting for confounders. Data on CLD mortality, alcohol consumption, hepatitis B virus (HBV) and hepatitis C virus (HCV) seroprevalence for 18 developed countries (1990-2000) were obtained from WHO databases. Data on national pig-meat and beef consumption were obtained from the UN database. Univariate regression showed that alcohol and pig-meat consumption were associated with mortality from CLD, but beef consumption, HBV and HCV seroprevalence were not. A 1 litre per capita increase in alcohol consumption was associated with an increase in mortality from CLD in excess of 1.6 deaths/100,000 population. A 10 kg higher national annual average per capita consumption of pork meat was associated with an increase in mortality from CLD of between 4 and 5 deaths/100,000 population. Multivariate regression showed that alcohol, pig-meat consumption and HBV seroprevalence were independently associated with mortality from CLD, but HCV seroprevalence was not. Pig-meat consumption remained independently associated with mortality from CLD in developed countries in the 1990-2000 period. Further work is needed to establish the mechanism.

Fever in returned travellers presenting in the United Kingdom: recommendations for investigation and initial management

International travel is increasing. Most physicians and general practitioners will encounter returned travellers with fever and the majority of travel-related infection is associated with travel to the tropics. In those returning from the tropics malaria must always be excluded, and HIV considered, from all settings. Common causes of non-malarial fever include from Africa rickettsial diseases, amoebic liver abscess and Katayama syndrome; from South and South East Asia, enteric fever and arboviral infection; from the Middle East, brucellosis and from the Horn of Africa visceral leishmaniasis. Other rare but important diseases from particular geographical areas include leptospirosis, trypanosomiasis and viral haemorrhagic fever. North and South America, Europe and Australia also have infections which are geographically concentrated. Empirical treatment may have to be started based on epidemiological probability of infection whilst waiting for results to return. The evidence base for much of the management of tropical infections is limited. These recommendations provide a pragmatic approach to the initial diagnosis and management of fever in returned travellers, based on evidence where it is available and on consensus of expert opinion where it is not. With early diagnosis and treatment the majority of patients with a potentially fatal infection related to travel will make a rapid and full recovery.

Requirement of protocol biopsy before and after complete cessation of immunosuppression after liver transplantation

BACKGROUND

Operational tolerance is defined as long-term acceptance of a transplanted organ after complete cessation of immunosuppression (IS), but may not always protect against antigen-dependent changes in graft morphology.

METHOD

IS free patients after living-donor liver transplantation (LDLT) underwent protocol biopsy (tolerance group [Gr-Tol]) and were evaluated for rejection and fibrosis. The degree of fibrosis was compared with those in the patients on maintenance IS group (Gr-IS) and the base line normal liver group (Gr-BS). When bridging fibrosis or progression of fibrosis was observed, IS was reintroduced or increased in Gr-Tol or in the patients in the weaning process.

RESULTS

Neither acute nor chronic rejection was observed. The degree of fibrosis, however, was significantly greater in Gr-Tol than those in Gr-IS and Gr-BS. In Gr-Tol, the number of graft infiltrating FOXP3 cells was significantly increased, the interval between LDLT and biopsy plus the donor age was significantly longer, and recipient age at LDLT was significantly younger, compared with those in Gr-IS. However, none of these three parameters correlated with the degree of fibrosis. In 7 of 11 patients in whom IS was reintroduced or increased, the improvement of fibrosis was observed by the subsequent biopsy.

CONCLUSION

Grafts of operationally tolerant patients after LDLT did not exhibit acute or chronic rejection, but they exhibited fibrosis. It remains elusive whether fibrosis observed in tolerant grafts is antigen dependent. The finding that after [corrected] the reintroduction or the increase of IS fibrosis was improved supported the possibility that fibrosis in operationally tolerant patients was antigen dependent.

[Sexually transmissible hepatitis viruses]

The transmission of hepatitis viruses as a result of sexual activity is a common problem in medical practice. A system of stages is proposed to diagnose viral hepatitis. Testing for anti-HBc, HBsAg, anti-HAV and anti-HCV is sufficient for initial screening. Depending on the circumstances, this may be followed by further tests for HBV, HCV and HAV. If initial screening provides no evidence, further tests for HEV, Epstein-Barr virus, cytomegalovirus or other agents are conducted.

Update on viral hepatitis: 2008

PURPOSE OF REVIEW

The present review is a concise review of recent developments in the field of viral hepatitis, based on publications between December 2007 and November 2008.

RECENT FINDINGS

The incidence of acute hepatitis A and B infection has declined significantly, especially among children less than 15 years of age. Five oral antiviral agents have been approved for the treatment of chronic hepatitis B. Telbivudine is more potent than lamivudine but is associated with a high rate of antiviral resistance compared with entecavir or tenofovir. De-novo combination of lamivudine and adefovir reduces the rate of antiviral resistance compared with lamivudine monotherapy. Individualizing dose and duration of pegylated interferon and ribavirin according to on-treatment virologic response may improve sustained virologic response rates. Several specifically targeted antiviral therapies notably protease and polymerase inhibitors are promising but must be used in combination with pegylated interferon and ribavirin. Hepatitis E virus has been reported to result in chronic hepatitis in transplant patients.

SUMMARY

Multiple treatment options are available for hepatitis B but long-term treatment is required. Several specifically targeted antiviral therapies have shown promise. In the meantime, individualizing dose and duration of pegylated interferon and ribavirin might improve sustained virologic response rates in patients with hepatitis C.

Molecular biology and pathogenesis of hepatitis E virus

The hepatitis E virus (HEV) is a small RNA virus and the etiological agent for hepatitis E, a form of acute viral hepatitis. The virus has a feco-oral transmission cycle and is transmitted through environmental contamination, mainly through drinking water. Recent studies on the isolation of HEV-like viruses from animal species also suggest zoonotic transfer of the virus. The absence of small animal models of infection and efficient cell culture systems has precluded virological studies on the replication cycle and pathogenesis of HEV. A vaccine against HEV has undergone successful clinical testing and diagnostic tests are available. This review describes HEV epidemiology, clinical presentation, pathogenesis, molecular virology and the host response to HEV infection. The focus is on published literature in the past decade.

Hepatitis E virus genotype 3 diversity, France

We characterized 42 hepatitis E virus (HEV) genotype 3 strains from infected patients in France in 3 parts of the genome and sequenced the full-length HEV genotype 3f genome found in Europe. These strains are closely related to swine strains in Europe, which suggests zoonotic transmission of HEV in France.

Serum autoantibodies against cytochrome P450 2E1 (CYP2E1) predict severity of necroinflammation of recurrent hepatitis C

We previously reported that autoantibodies against cytochrome P4502E1 (CYP2E1) are frequent in patients with chronic hepatitis C. As autoimmune reactions are increasingly detected after orthotopic liver transplantation (OLT), this study investigates prevalence and significance of anti-CYP2E1 autoantibodies in 46 patients with post-OLT recurrent hepatitis C. IgG against recombinant human CYP2E1 above the control threshold was detected in 19 out 46 (41%) sera collected immediately before OLT and in 15 out 46 (33%) sera collected at the time of the 12 months follow-up liver biopsy. Although anti-CYP2E1 reactivity was not modified by OLT, the patients with persistently elevated anti-CYP2E1 IgG (n = 12; 26%) showed significantly higher prevalence of recurrent hepatitis with severe necroinflammation and fibrosis than those persistently negative or positive only either before or after OLT. Moreover, the probability of developing severe necroinflammation was significantly higher in persistently anti-CYP2E1-positive subjects. Multivariate regression and Cox analysis confirmed that the persistence of anti-CYP2E1 IgG, together with a history of acute cellular rejection and donor age >50 years, was an independent risk factor for developing recurrent hepatitis C with severe necroinflammation. We propose that autoimmune reactions involving CYP2E1 might contribute to hepatic damage in a subgroup of transplanted patients with recurrent hepatitis C.

Hepatitis E vaccine: current status and future prospects

HEV, a positive ssRNA and nonenveloped virus, is endemic in many developing countries and one of the most frequent causes of acute hepatitis after fecal–oral transmission. Pregnant women are at particular risk for a fatal course of disease, including maternal and fetal mortality. Recent reports indicate that HEV genotype 3, possibly related to zoonotic transmission, may cause chronic hepatitis in some immunosuppressed organ transplant patients. Various approaches have been conducted to develop HEV vaccines, but only one candidate, a recombinant HEV (rHEV) vaccine generated from Spodoptera frugiperda-9 cells by baculoviruses expressing the HEV capsid antigen, has reached clinical Phase I and II trials so far. These trials suggest that the rHEV vaccine is safe and can prevent clinically overt acute hepatitis E in high-risk populations. We herein review the different approaches in HEV-vaccine development and critically discuss the current status and future directions of the rHEV vaccine used in clinical trials.

Acute hepatitis E virus infection in an HIV-infected person in the United States

Background

Hepatitis E virus (HEV) is an enterically transmitted cause of viral hepatitis rarely noted without international travel.

Objective

To report the first case of an HIV-infected man with acute hepatitis due to HEV infection who had not traveled outside the United States.

Phylogenetic and case-control study on hepatitis E virus infection in Germany

BACKGROUND

Hepatitis E is a classic water-borne disease in developing countries. In Germany, hepatitis E virus (HEV) infections are notifiable. The number of non-travel-associated infections has increased in recent years, but the route of transmission in most is unknown. Our objective was to determine risk factors for autochthonous HEV infections in Germany.

METHODS

Cases of HEV met clinical definitions and were confirmed by laboratory analysis (defined as detection of HEV by polymerase chain reaction [PCR] or immunoglobulin M by serologic testing). PCR products from blood or stool samples were genotyped for phylogenetic analysis. A case-control study included case subjects with autochthonous HEV infection and matched control subjects who were randomly recruited from a population-based telephone list.

RESULTS

From May 2006 through August 2007, 76 of 96 persons for whom HEV infection had been reported to the routine surveillance system were interviewed. Sixty-six persons had disease that fulfilled the inclusion criteria: 45 (68%) had autochthonous infection, and 21 (32%) had travel-associated disease. Genotypes 3 or 4 were present in 15 of 15 persons with autochthonous infection, and genotype 1 was present in 8 of 9 persons with travel-associated infection. In conditional logistic regression involving 45 case subjects and 135 control subjects, consumption of offal (41% vs. 19%; odds ratio [OR], 2.7; 95% confidence interval [CI], 1.2-6.2) and wild-boar meat (20% vs. 7%; OR, 4.3; 95% CI, 1.2-15.9) were independently associated with autochthonous HEV infection.

CONCLUSION

Hepatitis E is endemic in Germany and likely exists as a food-borne zoonosis. Implicated meat products should be investigated to provide recommendations for preventive measures.

Emerging and Re-emerging Infectious Diseases

Emerging infectious diseases (EIDs) are characterized by a new or an increased occurrence within the last few decades. They include the following categories Emerging diagnosis of infectious diseases: old diseases that are newly classified as infectious diseases because of the discovery of a responsible infectious agent.

Hepatitis E: an emerging infection in developed countries

Hepatitis E is endemic in many developing countries where it causes substantial morbidity. In industrialised countries, it is considered rare, and largely confined to travellers returning from endemic areas. However, there is now a growing body of evidence that challenges this notion. Autochthonous hepatitis E in developed countries is far more common than previously recognised, and might be more common than hepatitis A. Hepatitis E has a predilection for older men in whom it causes substantial morbidity and mortality. The disease has a poor prognosis in the context of pre-existing chronic liver disease, and is frequently misdiagnosed as drug-induced liver injury. The source and route of infection remain uncertain, but it might be a porcine zoonosis. Patients with unexplained hepatitis should be tested for hepatitis E, whatever their age or travel history.

Hepatitis E virus is highly prevalent among pregnant women in Gabon, central Africa, with different patterns between rural and urban areas

Hepatitis E virus (HEV) is highly endemic in several African countries with high mortality rate among pregnant women. Nothing is known about the circulation of this virus in central Africa. We evaluated therefore the prevalence of anti-HEV IgG in samples collected from pregnant women living in the five main cities of Gabon, central Africa. We found that 14.1% (119/840) of pregnant women had anti-HEV IgG. The prevalence differed between regions and between age groups. In 391 newly collected samples from the region where the highest prevalence was found, a significant difference (p < 0.05) in seroprevalence was found between rural (6.4%) and urban (13.5%) areas. These data provide evidence of a high prevalence of HEV in Gabon, providing indirect evidence of past contact with this virus.

Hepatitis E virus as a newly identified cause of acute viral hepatitis during human immunodeficiency virus infection

The recent description of chronic hepatitis E in organ transplant recipients deserves increased awareness in the context of hepatitis E virus (HEV) infection in immunocompromised individuals. Reported here is what is apparently the first PCR-documented case of acute hepatitis E in a human immunodeficiency virus (HIV)-1-infected patient. The CD4(+) T-lymphocyte count was 246/mm(3). The IgM anti-HEV antibody and HEV RNA tests results from serum were positive. Hepatitis was benign, and chronic HEV infection was ruled out. The HEV genotype was 3f. The patient did not report recent travel abroad. HEV should be tested in HIV-infected individuals presenting with acute hepatitis. HEV RNA detection is useful in diagnosing HEV infection and in monitoring recovery.

Hepatitis E: a complex and global disease

Thirty years after its discovery, the hepatitis E virus (HEV) continues to represent a major public health problem in developing countries. In developed countries, it has emerged as a significant cause of non-travel-associated acute hepatitis. HEV infects a wide range of mammalian species and a key reservoir worldwide appears to be swine. Genomic sequence similarity between some human HEV genotypes and swine HEV strains has been identified and we know that humans can acquire HEV infection from animals. Although for the most part the clinical course of HEV infection is asymptomatic or mild, significant risk of serious disease exists in pregnant women and those with chronic liver disease. In addition, there are data on the threat of chronic infections in immunocompromised patients. Beyond management of exposure by public health measures, recent data support that active immunisation can prevent hepatitis E, highlighting the need for vaccination programmes. Here we review the current knowledge on HEV, its epidemiology, and the management and prevention of human disease.

Acute hepatitis E in south-west France over a 5-year period

BACKGROUND

Hepatitis E was found in people living in industrialized countries who had not travelled to highly endemic areas.

OBJECTIVES

To study the cases of acute hepatitis E confirmed thanks to viral genomic detection over a 5 years period in south-west France.

STUDY DESIGN

62 cases of hepatitis E were identified between 2003 and 2007. Their demographic, clinical, and virological features were analyzed.

RESULTS

Cases of acute hepatitis E occurred regularly throughout this period. No seasonal variation was found. Patients, usually male (sex ratio=1.95), were adults living in both urban and rural areas. Sixty (96.8%) patients had not travelled abroad during the 6 months before diagnosis. Clinical manifestations ranged from asymptomatic infection to severe hepatitis. HEV was genotyped in 55 specimens. All the patients who had not travelled abroad were infected with genotype 3.

CONCLUSION

The incidence of hepatitis E in south-west France was stable from 2003 to 2007, 96.8% of the cases were autochthonous. There was an age-related increase in the disease and patients tended to be men. The predominant genotype and subtype was 3f. However, contaminations pathways involved in hepatitis E in our area remain to clarify.

Hepatitis E virus

PURPOSE OF REVIEW

Hepatitis E is an emerging infectious disease. This review will focus on recent advances in the zoonotic transmission, global distribution and control of hepatitis E.

RECENT FINDINGS

Hepatitis E virus infection is known to cause waterborne epidemics and sporadic infections in developing countries. Recently, there have been several reports on zoonotic foodborne autochthonous infections of hepatitis E in developed countries. Hepatitis E typically causes self-limited acute infection. Recent reports have documented hepatitis E virus causing chronic hepatitis and cirrhosis in patients after solid organ transplantation. High incidence and severity of hepatitis E in pregnant women have been re-confirmed. The reason for high mortality in pregnant women remains ill understood. A recombinant hepatitis E vaccine has been evaluated in a phase 2, randomized, placebo-controlled trial in Nepal and was found to be well tolerated and efficacious.

SUMMARY

There has been considerable advance in understanding the epidemiology of hepatitis E virus infections in western countries. The occurrence of chronic hepatitis in organ transplant recipients opens a new chapter in hepatitis E epidemiology. The report on an efficacious and well tolerated recombinant vaccine gives hope for control of the disease in the near future.

Hepatitis E and pregnancy: understanding the pathogenesis

Hepatitis E virus (HEV) is a single-stranded RNA virus that causes large-scale epidemics of acute viral hepatitis, particularly in developing countries. In men and non-pregnant women, the disease is usually self-limited and has a case-fatality rate of less than <0.1%. However, in pregnant women, particularly from certain geographical areas in India, HEV infection is more severe, often leading to fulminant hepatic failure and death in a significant proportion of patients. In contrast, reports from Egypt, Europe and the USA have shown that the course and severity of viral hepatitis during pregnancy is not different from that in non-pregnant women. The reasons for this geographical difference are not clear. The high mortality rate in pregnancy has been thought to be secondary to the associated hormonal (oestrogen and progesterone) changes during pregnancy and consequent immunological changes. These immunological changes include downregulation of the p65 component of nuclear factor (NF-kappaB) with a predominant T-helper type 2 (Th2) bias in the T-cell response along with host susceptibility factors, mediated by human leucocyte antigen expression. Thus far, researchers were unable to explain the high HEV morbidity in pregnancy, why it is different from other hepatitis viruses such as hepatitis A with similar epidemiological features and the reason behind the difference in HEV morbidity in pregnant women in different geographical regions. The recent developments in understanding the immune response to HEV have encouraged us to review the possible mechanisms for these differences. Further research in the immunology of HEV and pregnancy is required to conquer this disease in the near future.

Hepatitis E and pregnancy: understanding the pathogenesis

Hepatitis E virus (HEV) is a single-stranded RNA virus that causes large-scale epidemics of acute viral hepatitis, particularly in developing countries. In men and non-pregnant women, the disease is usually self-limited and has a case-fatality rate of less than <0.1%. However, in pregnant women, particularly from certain geographical areas in India, HEV infection is more severe, often leading to fulminant hepatic failure and death in a significant proportion of patients. In contrast, reports from Egypt, Europe and the USA have shown that the course and severity of viral hepatitis during pregnancy is not different from that in non-pregnant women. The reasons for this geographical difference are not clear. The high mortality rate in pregnancy has been thought to be secondary to the associated hormonal (oestrogen and progesterone) changes during pregnancy and consequent immunological changes. These immunological changes include downregulation of the p65 component of nuclear factor (NF-kappaB) with a predominant T-helper type 2 (Th2) bias in the T-cell response along with host susceptibility factors, mediated by human leucocyte antigen expression. Thus far, researchers were unable to explain the high HEV morbidity in pregnancy, why it is different from other hepatitis viruses such as hepatitis A with similar epidemiological features and the reason behind the difference in HEV morbidity in pregnant women in different geographical regions. The recent developments in understanding the immune response to HEV have encouraged us to review the possible mechanisms for these differences. Further research in the immunology of HEV and pregnancy is required to conquer this disease in the near future.

Time trend of the prevalence of hepatitis E antibodies among farmers and blood donors: a potential zoonosis in Denmark

BACKGROUND

Antibody to hepatitis E virus (anti-HEV) is prevalent in Western countries, where clinical hepatitis E is rarely reported. The aim of this study was to determine the prevalence of anti-HEV among Danish blood donors and Danish farmers. In addition, we compared the prevalence among 2 sets of serum samples obtained from blood donors 20 years apart.

METHODS

Samples from 291 Danish farmers and 169 blood donors that were collected in 1983 and samples from 461 blood donors that were collected in 2003 were tested for anti-HEV. Relevant information on HEV exposure was collected by self-administered questionnaire.

RESULTS

Anti-HEV testing was performed on samples after 20 years of storage at -20 degrees C. The prevalence of anti-HEV was 50.4% among farmers and 32.9% among donors in 1983 and 20.6% among donors in 2003 (P < .05). Presence of anti-HEV was significantly correlated with increasing age in all 3 groups (P < .05). Among donors who had serum samples obtained in 2003, age, contact with horses, and the presence of antibody to hepatitis A virus were associated with the presence of anti-HEV in multivariate analysis. Among farmers, only age was independently associated with the presence of anti-HEV.

CONCLUSION

Anti-HEV was highly prevalent among Danes but has decreased in prevalence over the past 50 years. Our study supports the hypothesis that HEV infection in Denmark may be an asymptomatic zoonotic infection.

Etiology and prognosis of fulminant hepatitis in adults

1. Establishing the cause of fulminant hepatitis is an important step in the management of acute liver failure, so that specific therapy can be initiated and any contraindications to liver transplantation can be eliminated. 2. The etiology of fulminant hepatitis varies in different countries and at different times. A viral etiology (in particular hepatitis B virus) is now less frequent, and paracetamol-induced fulminant hepatic failure is more common. 3. Many patients have miscellaneous causes of fulminant hepatitis. It is important to establish the main clinical and biological characteristics for specific management. 4. Assessment of the prognosis of fulminant hepatitis is important for distinguishing patients requiring liver transplantation from those whose will improve spontaneously. Prognosis depends on several factors, including the gold standard, the King's College Hospital criteria and Clichy's criteria.

Hepatitis E: does it cause chronic hepatitis?

Hepatitis E virus (HEV) is considered an agent responsible for acute hepatitis that does not progress to chronic hepatitis. We identified 14 cases of acute HEV infection in three patients receiving liver transplants, nine receiving kidney transplants, and two receiving kidney and pancreas transplants. All patients were positive for serum HEV RNA. Chronic hepatitis developed in eight patients, as confirmed by persistently elevated aminotransferase levels, serum HEV RNA, and histologic features of chronic hepatitis. The time from transplantation to diagnosis was significantly shorter and the total counts of lymphocytes and of CD2, CD3, and CD4 T cells were significantly lower in patients in whom chronic disease developed.

Monoclonal antibodies raised against the ORF3 protein of hepatitis E virus (HEV) can capture HEV particles in culture supernatant and serum but not those in feces

Ten murine monoclonal antibodies (MAbs) against a synthetic peptide corresponding to the well-conserved, C-terminal 24-amino acid portion of ORF3 protein of hepatitis E virus (HEV) were produced and characterized. Immunofluorescent assays using the anti-ORF3 MAbs revealed accumulation of ORF3 protein in the cytoplasm of PLC/PRF/5 cells transfected with ORF3-expressing plasmid or inoculated with cell-culture-generated HEV. The anti-ORF3 MAbs could capture HEV particles in culture medium and serum at variable efficiency of up to 61 and 49%, respectively, but not those in feces. By sandwiching between immobilized and enzyme-labeled anti-ORF3 MAbs in ELISA, ORF3 antigen was detected in the culture media with an HEV RNA titer of >10(6) copies/ml and increased in parallel with the increase in HEV load. HEV progenies in the culture supernatant, with ORF3 protein on the surface, banded at a low buoyant density of 1.15 g/cm(3) in sucrose. A representative anti-ORF3 MAb (TA0536) could partially neutralize the infection of cell-culture-generated HEV in a cell culture system. These results indicate that ORF3 protein, at least its C-terminal portion, is present on the surface of HEV virions released from infected cells and support a previously proposed assumption that ORF3 protein is associated with virus release from infected cells.

Hepatitis E virus-related cirrhosis in kidney- and kidney-pancreas-transplant recipients

Hepatitis E virus (HEV) infection was thought to be responsible for acute hepatitis that did not become chronic. However, we have recently reported that HEV infection can evolve to chronic hepatitis, at least in solid-organ transplant patients. We report on two cases of rapidly progressive of HEV-related cirrhosis that occurred in two organ-transplant patients. Case 1: A kidney-pancreas-transplant patient developed acute HEV hepatitis 60 months after transplantation, which evolved to chronicity as defined by persisting elevated liver-enzyme levels and positive serum HEV RNA. At 22 months after the acute phase, she presented with cirrhosis and portal hypertension, that is ascites and esophagus varices. Case 2: A kidney-transplant patient developed acute hepatitis 36 months after transplantation, which persisted and remained unexplained for 38 months. Then, HEV RNA was searched for in their serum and stools, and was found to be positive in both. Retrospective analysis of available stored serum, mainly the serum obtained at the acute phase, confirmed the diagnosis of chronic hepatitis E. In both cases, a liver biopsy showed cirrhosis. We conclude that HEV infection cannot only evolve to chronic hepatitis, but can also be responsible for rapidly progressing cirrhosis in organ-transplant patients.