Sustained virologic response with ribavirin in chronic hepatitis E virus infection in heart transplantation

Hepatitis E Virus: What More Do We Need to Know?

Hepatitis E virus (HEV) infection is typically a self-limiting, acute illness that spreads through the gastrointestinal tract but replicates in the liver. However, chronic infections are possible in immunocompromised individuals. The HEV virion has two shapes: exosome-like membrane-associated quasi-enveloped virions (eHEV) found in circulating blood or in the supernatant of infected cell cultures and non-enveloped virions ("naked") found in infected hosts' feces and bile to mediate inter-host transmission. Although HEV is mainly spread via enteric routes, it is unclear how it penetrates the gut wall to reach the portal bloodstream. Both virion types are infectious, but they infect cells in different ways. To develop personalized treatment/prevention strategies and reduce HEV impact on public health, it is necessary to decipher the entry mechanism for both virion types using robust cell culture and animal models. The contemporary knowledge of the cell entry mechanism for these two HEV virions as possible therapeutic target candidates is summarized in this narrative review.

The different replication between nonenveloped and quasi-enveloped hepatitis E virus

Hepatitis E virus (HEV) is the major pathogen of viral hepatitis. However, the understanding of the HEV life cycle is limited. In the present study, cells were separately infected with nonenveloped HEV (derived from feces or bile) or quasi-enveloped HEV (derived from the cell culture after serial passages, eHEV) and observed by confocal fluorescence microscopy to investigate the life cycle of HEV. HEV finished its binding and entry into host cells at first 6 h postinoculation (hpi). Cells inoculated with eHEV showed less infectivity than cells inoculated with nonenveloped HEV. Newly synthesized progeny virions were released into the supernatant of cell cultures from 48 hpi. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis results showed that the supernatant's progeny viruses were infectious even after five serial passages. These results show the significant difference between nonenveloped HEV and eHEV, which will provide novel insights into the HEV replication cycle. The efficient cell culture of HEV will promote the development of anti-HEV drugs and vaccines.

Current Paradigm of Hepatitis E Virus Among Pediatric and Adult Patients

Hepatitis E virus (HEV) infection is a polymorphic condition, present throughout the world and involving children and adults. Multiple studies over the last decade have contributed to a better understanding of the natural evolution of this infection in various population groups, several reservoirs and transmission routes being identified. To date, acute or chronic HEV-induced hepatitis has in some cases remained underdiagnosed due to the lower accuracy of serological tests and due to the evolutionary possibility with extrahepatic manifestations. Implementation of diagnostic tests based on nucleic acid analysis has increased the detection rate of this disease. The epidemiological and clinical features of HEV hepatitis differ depending on the geographical areas studied. HEV infection is usually a self-limiting condition in immunocompetent patients, but in certain categories of vulnerable patients it can induce a sudden evolution toward acute liver failure (pregnant women) or chronicity (immunosuppressed patients, post-transplant, hematological, or malignant diseases). In acute HEV infections in most cases supportive treatment is sufficient. In patients who develop chronic hepatitis with HEV, dose reduction of immunosuppressive medication should be the first therapeutic step, especially in patients with transplant. In case of unfavorable response, the initiation of antiviral therapy is recommended. In this review, the authors summarized the essential published data related to the epidemiological, clinical, paraclinical, and therapeutic aspects of HEV infection in adult and pediatric patients.

Ribavirin as a First Treatment Approach for Hepatitis E Virus Infection in Transplant Recipient Patients

The hepatitis E virus (HEV) is the major cause of acute hepatitis of viral origin worldwide. Despite its usual course as an asymptomatic self-limited hepatitis, there are highly susceptible populations, such as those with underlying immunosuppression, which could develop chronic hepatitis. In this situation, implementation of therapy is mandatory in the sense to facilitate viral clearance. Currently, there are no specific drugs approved for HEV infection, but ribavirin (RBV), the drug of choice, is used for off-label treatment. Here, we present two cases of chronic HEV infection in transplant patients, reviewing and discussing the therapeutic approach available in the literature. The use of RBV for the treatment of an HEV infection in organ transplant patients seems to be effective. The recommendation of 12 weeks of therapy is adequate in terms of efficacy. Nevertheless, there are important issues that urgently need to be assessed, such as optimal duration of therapy and drug dosage.

Efficacy and safety of ribavirin therapy for chronic hepatitis E after kidney transplantation

Hepatitis E virus (HEV) infection has been recognized as an acute condition. However, recent reports have shown that immunocompromised patients, such as those receiving solid-organ transplantation, can develop chronic hepatitis with HEV infection. We report two cases of chronic hepatitis E after kidney transplantation (KT) who were successfully treated with ribavirin monotherapy. Several years after KT, both patients had sustained elevations in the levels of liver enzymes for a period of more than 6 months. Both patients had HEV infection, genotype 3a. Histological studies showed infiltration of inflammatory cells without fibrosis. Treatment included ribavirin monotherapy at a dosage of 600 mg daily for 3 months. One month after therapy initiation, HEV-RNA turned to negative, and remained negative at 24 weeks after ribavirin therapy without severe complications. Although the treatment of chronic hepatitis E is not fully established, ribavirin therapy can be a safe and effective treatment for chronic hepatitis E.

Acute hepatitis E virus infection causing acute liver failure requiring living-donor liver transplantation in a non-pregnant immunocompetent woman

We report a rare case of acute liver failure from acute hepatitis E virus (HEV) in a non-pregnant woman without comorbidities who survived after liver transplantation. The source was likely consumption of partially cooked pig liver. HEV genotype 3 is the second most common genotype causing acute hepatitis E in developed countries. Fulminant hepatitis E rarely occurs without a risk factor, as in our patient. Vigilant monitoring for chronic hepatitis E in post-transplant immunocompromised patients is needed.

The relationship between serology of hepatitis E virus with liver and kidney function in kidney transplant patients

Although hepatitis E virus (HEV) is well known to cause acute hepatitis, there are reports showing that HEV may also be responsible for progression of acute to chronic hepatitis and liver cirrhosis in patients receiving organ transplantation. In this study, we aimed to evaluate the prevalence of HEV in patients with kidney transplantation. In this study, 110 patients with kidney transplantation were recruited, and anti-HEV IgG, creatinine, alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and estimated glomerular filtration rate (eGFR) in the first, third and sixth months after renal transplantation were measured. The mean serum anti-HEV IgG titers in the study participants was 1.36 (range 0.23 to 6.3). Twenty-three patients were found to be seropositive for HEV Ab defined as anti-HEV IgG titer > 1.1. The difference in liver and renal function tests (creatinine, eGFR, AST, ALT and ALP) at different intervals was not significant between patients with HEV Ab titers higher and lower than 1.1 (p > 0.05). However, an inverse correlation was observed between HEV Ab and eGFR values in the first (p = 0.047, r = -0.21), third (p = 0.04, r = -0.20) and sixth (p = 0.04, r = -0.22) months after renal transplantation in patients with HEV Ab < 1.1 but not in the subgroup with HEV Ab > 1.1. Also, a significant correlation between age and HEV Ab levels was found in the entire study population (p = 0.001, r = 0.33). Our findings showed a high prevalence of seropositivity for anti-HEV IgG in patients receiving renal transplants. However, liver and renal functions were not found to be significantly different seropositive and seronegative patients by up to 6 months post-transplantation.

Hepatitis E: latest developments in knowledge

Hepatitis E, caused by Hepatitis E virus (HEV), is a highly prevalent disease in developing countries. In developed nations, autochthonous HEV infections seem to be an emergent disease. Its clinical manifestations and epidemiology are well known for endemic countries. It has been confirmed that hepatitis E is a zoonosis and that parenteral transmission can also occur. The molecular mechanisms of HEV replication are not fully understood, mostly because there are no efficient cell culture systems. HEV can cause chronic hepatitis in organ transplant recipients and immunocompetent patients. Cases with fulminant hepatitis and other extrahepatic manifestations have also been reported. The diagnosis is based on serological studies and detection of HEV RNA in blood and feces. Treatment with ribavirin and/or pegylated-IFN-α have proven to be successful in some cases. The recently approved/marketed vaccine is a good option in order to prevent this infection.

An Early Viral Response Predicts the Virological Response to Ribavirin in Hepatitis E Virus Organ Transplant Patients

BACKGROUND

Ribavirin is efficient at treating chronic hepatitis E virus infection in solid-organ transplant patients. However, the early kinetics of viral replication under therapy and the impact of immunosuppressant regimens on viral replication are unknown: thus, determining the aim of our study.

METHODS

Thirty-five patients with a solid-organ transplant and chronic hepatitis E virus infection were given ribavirin for 3 months. The hepatitis E virus (HEV) RNA concentrations were determined before treatment, at days 7, 15, and 21 and at months 1, 2, and 3 during therapy and after ribavirin cessation.

RESULTS

A sustained virological response (SVR) occurred in 63%. Decreased viral concentration within the first week post-ribavirin therapy was an independent predictive factor for SVR, and a decreased HEV concentration of 0.5 log copies/mL or greater had an 88% positive predictive value. No correlation between ribavirin trough level on day 7 or at month 2 with a virological response or an SVR was observed. Before therapy, HEV RNA concentration was significantly greater in patients receiving mechanistic target of rapamycin inhibitor-based immunosuppression compared to patients given calcineurin inhibitors. The use of mycophenolic acid did not impact on the response to ribavirin.

CONCLUSION

An early response to ribavirin can be used to define the optimal duration of therapy in the setting of HEV infection.

Antiviral therapy in chronic hepatitis E: a systematic review

Hepatitis E viral infection can lead to a chronic infection in immunocompromised patients, resulting in progressive liver disease and cirrhosis. Isolated cases have shown that treatment with ribavirin or pegylated interferon-α can result in viral eradication. This systematic review evaluated efficacy and safety of both treatments in chronic hepatitis E. A systematic literature search was performed on PubMed, Web of Science and clinicaltrials.gov for articles and abstracts. The keywords '"Hepatitis E" or HEV' AND 'ribavirin or Rebetol or Copegus' OR 'pegylated interferon OR peginterferon' were combined. The primary outcome was sustained viral response (SVR). Secondary endpoints include rapid viral response (RVR), relapse rates and side effects. Twenty-four studies matched our criteria, representing a total of 105 ribavirin-treated and 8 pegylated interferon-treated patients. The majority of patients had a solid organ transplant. Sixty-four per cent of ribavirin-treated patients achieved a SVR at 6 months after treatment cessation compared to 2/8 peginterferon-treated patients. Ribavirin was relatively well tolerated with the main side effect being anaemia, requiring dose reduction in 28% of patients. Peginterferon leads to acute transplant rejection in 2/8 patients. Ribavirin monotherapy appears to be an effective and safe treatment in all immunocompromised patients with chronic hepatitis E. The use of pegylated interferon in transplant patients may lead to transplant rejection and is not recommended. Therefore, ribavirin should be the antiviral treatment of choice in chronic hepatitis E.

Phylogenetic demonstration of hepatitis E infection transmitted by pork meat ingestion

Hepatitis E virus (HEV) is responsible for a small number of acute hepatitis in developed countries. In this setting, HEV infection seems to be a zoonosis, although this has not been completely demonstrated. High morbidity and mortality associated with severe acute infections have been described, as well as the possible role of ribavirin therapy in those cases. We describe a case of acute hepatitis after pork meat ingestion in a patient with Waldeström macroglobulinemia with immunoglobulin A deficiency. Acute hepatitis E was diagnosed based on positive IgM anti-HEV antibodies and HEV RNA detected by real-time PCR. Because of clinical and analytical worsening, ribavirin was initiated, achieving sustained virologic response after 12 weeks of treatment. The phylogenetic analysis revealed the same HEV strain genotype 3 in both plasma and consumed meat samples, proving the zoonotic transmission. Regarding immunocompromised patients, acute hepatitis E can be associated to high morbidity and mortality rate, so dietetic recommendations may be needed to avoid the virus transmission.

Hepatitis E virus: chronic infection, extra-hepatic manifestations, and treatment

Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. It is an underdiagnosed disease because of the use of low-sensitivity serological assays; however, diagnostics tools, including nucleic-acid tests, have improved. HEV infection is usually an acute self-limiting disease, but causes chronic infection with rapidly progressive cirrhosis in adult and pediatric organ-transplant-patients. HEV infection evolves to chronic hepatitis in nearly 60% of HEV-infection solid-organ-transplant patients. HEV can also cause extra-hepatic manifestations, such as neurological symptoms and kidney injury. Reducing immunosuppression in transplant patients can lead to HEV clearance in one-third of patients with chronic hepatitis. The use of anti-viral therapies, such as pegylated-interferon and ribavirin, has been found to efficaciously treat HEV infection.

Hepatitis viruses and liver transplantation: evolving trends in antiviral management

Viral hepatitis is both a leading indication for liver transplant (LT) and an important cause of posttransplant graft loss and mortality. Treatment and prevention of hepatitis B virus in LT recipients, with the observed corresponding improvement in post-LT outcomes, is among the great success stories in transplantation. By comparison, treatment of hepatitis C virus with safe and effective regimens is only just becoming a reality. Chronic hepatitis E virus infection in LT recipients represents a newly described phenomenon that can also lead to graft loss; early diagnosis and treatment may be key in the management of these patients.

Hepatitis E virus infection

Hepatitis E virus (HEV) infection is a worldwide disease. An improved understanding of the natural history of HEV infection has been achieved within the last decade. Several reservoirs and transmission modes have been identified. Hepatitis E is an underdiagnosed disease, in part due to the use of serological assays with low sensitivity. However, diagnostic tools, including nucleic acid-based tests, have been improved. The epidemiology and clinical features of hepatitis E differ between developing and developed countries. HEV infection is usually an acute self-limiting disease, but in developed countries it causes chronic infection with rapidly progressive cirrhosis in organ transplant recipients, patients with hematological malignancy requiring chemotherapy, and individuals with HIV. HEV also causes extrahepatic manifestations, including a number of neurological syndromes and renal injury. Acute infection usually requires no treatment, but chronic infection should be treated by reducing immunosuppression in transplant patients and/or the use of antiviral therapy. In this comprehensive review, we summarize the current knowledge about the virus itself, as well as the epidemiology, diagnostics, natural history, and management of HEV infection in developing and developed countries.

Transmission, diagnosis, and management of hepatitis E: an update

Hepatitis E virus (HEV) infection is an important public health concern in many developing countries, causing waterborne outbreaks as well as sporadic autochthonous hepatitis. HEV is mainly transmitted by the fecal–oral route in endemic areas through drinking of contaminated water. However, zoonotic transmission from animal reservoirs to humans has also been suggested. Three additional routes of HEV transmission have been proposed to occur: blood borne, human to human, and vertical transmission from mother to child. Acute HEV infection is usually diagnosed by detecting specific anti-HEV antibodies. However, the performance of the available assays in different settings is not optimal. Analysis of HEV ribonucleic acid in biologic specimens such as stools, serum, and liver biopsy by using nucleic acid amplification techniques is also employed. Nonetheless, additional consensus regarding the best technologies suitable for serosurveys and diagnosis of acute HEV infection is also needed. This review article summarizes the current status of HEV infection end epidemiology with particular emphasis in transmission, diagnosis, and clinical management.

Ribavirin for chronic hepatitis E virus infection in transplant recipients

BACKGROUND

There is no established therapy for hepatitis E virus (HEV) infection. The aim of this retrospective, multicenter case series was to assess the effects of ribavirin as monotherapy for solid-organ transplant recipients with prolonged HEV viremia.

METHODS

We examined the records of 59 patients who had received a solid-organ transplant (37 kidney-transplant recipients, 10 liver-transplant recipients, 5 heart-transplant recipients, 5 kidney and pancreas-transplant recipients, and 2 lung-transplant recipients). Ribavirin therapy was initiated a median of 9 months (range, 1 to 82) after the diagnosis of HEV infection at a median dose of 600 mg per day (range, 29 to 1200), which was equivalent to 8.1 mg per kilogram of body weight per day (range, 0.6 to 16.3). Patients received ribavirin for a median of 3 months (range, 1 to 18); 66% of the patients received ribavirin for 3 months or less.

RESULTS

All the patients had HEV viremia when ribavirin was initiated (all 54 in whom genotyping was performed had HEV genotype 3). At the end of therapy, HEV clearance was observed in 95% of the patients. A recurrence of HEV replication occurred in 10 patients after ribavirin was stopped. A sustained virologic response, defined as an undetectable serum HEV RNA level at least 6 months after cessation of ribavirin therapy, occurred in 46 of the 59 patients (78%). A sustained virologic response was also observed in 4 patients who had a recurrence and were re-treated for a longer period. A higher lymphocyte count when ribavirin therapy was initiated was associated with a greater likelihood of a sustained virologic response. Anemia was the main identified side effect and required a reduction in ribavirin dose in 29% of the patients, the use of erythropoietin in 54%, and blood transfusions in 12%.

CONCLUSIONS

This retrospective, multicenter study showed that ribavirin as monotherapy may be effective in the treatment of chronic HEV infection; a 3-month course seemed to be an appropriate duration of therapy for most patients.

Chronic hepatitis E: a review of the literature

In 1978, the first case of hepatitis E was identified as non-A, non-B hepatitis. Hepatitis E virus (HEV) infection is believed to be one of the common causes of enterically transmitted acute hepatitis in developing countries and is rare in developed countries, except in patients with a history of travel. However, an increasing number of chronic HEV infection cases have recently been reported in developed countries. In these countries, immunosuppressed patients with HEV infection, such as organ transplant recipients, human immunodeficiency virus (HIV)-infected patients or patients with haematological malignancies, could develop chronic hepatitis E (CHE) infection. Approximately 60% of HEV infections in immunocompromised patients after solid organ transplantation evolve to CHE without antiviral treatment. Clinical manifestations of CHE are often nonspecific symptoms. Many patients with CHE infection are asymptomatic, but some have jaundice, fatigue, abdominal pain, fever and asthenia. Several extrahepatic manifestations have also been reported. Although chronic HEV infection can result in progressive severe liver failure and cirrhosis, diagnosis is often controversial because of the lack of specific diagnostic criteria. Many CHE cases are diagnosed by HEV RNA-positive serum or stool for >6 months. Immunosuppressive drugs, interferon-alpha and ribavirin have been used for treatment. Diagnostic reverse-transcription polymerase chain reaction is useful for estimating treatment efficacy. Preventive measures for HEV infection have been discussed, while systematic guidelines have not yet been reported.

Hepatitis E infection in liver transplant recipients

Hepatitis E virus (HEV) infection (genotype 3) has been described in developed countries as a cause of chronic hepatitis in recipients of solid organ transplantation (SOT), with the first cases reported in 2008. Immunosuppression seems to play a major role in the pathogenesis of chronic infections. The current gold standard for the diagnosis of HEV infection is the detection of HEV RNA in serum, stools, or both. In liver transplant recipients, HEV infection is considered an uncommon disease; however, a high index of suspicion is needed for patients with graft hepatitis of an unclear etiology. Liver transplant recipients seem more likely to develop chronic HEV after an acute infection, and there is accelerated progression to advanced fibrosis and cirrhosis. A decrease in immunosuppression is considered the first line of treatment, and pegylated interferon can be considered the second line of treatment for liver transplant recipients. At the present time, there are not enough data to recommend treatment with ribavirin for adult liver transplant recipients, although this has been tried in other SOT populations.

Autochthonous hepatitis e virus infections: a new transfusion-associated risk?

Hepatitis E virus (HEV) has been recognized since 2004 as a transfusion-transmissible infectious agent, and recent epidemiological data suggest that it may pose a safety threat to the blood supply. It has recently become obvious that hepatitis E is endemic in industrialized countries, and that more infections are autochthonous than travel-associated. Epidemiological and phylogenetic analysis suggests that HEV infection has to be considered as a zoonosis and that viral transmission from animals (pigs, wild animals) occurs through food or direct contact. The seroprevalence and incidence of HEV in the general population and blood donors in European countries indicate an underestimated risk for transfusion transmissions. Recently reported cases of transfusion transmission of HEV infection, and detection of viremic, asymptomatic blood donors in nucleic acid amplification technique screening programs give an indication of the importance of this virus. Diagnostic assays for detection of anti-HEV antibodies, HEV antigens and RNA are discussed. Recent studies support the idea that active immunization can prevent hepatitis E, highlighting the need for vaccination programs. Here we review current knowledge of HEV and its epidemiology, blood transmission and prevention of this disease with emphasis on blood supply.

Hepatitis E: An emerging infection in high income countries

Hepatitis E virus (HEV) genotype 3 is the most recently characterized hepatotropic virus and is increasingly being recognized as the cause of unexplained liver disease in many western countries. Although asymptomatic in most cases, HEV GT3 may be responsible for a wide range of illnesses, from mild to fulminant acute hepatitis, and also chronic hepatitis in immunocompromised patients. Extrahepatic manifestations have been occasionally described. Anti-HEV antibody detection by immunoassays is hampered by moderate test accuracy particularly in immunocompromised hosts while a WHO international standard for molecular detection of HEV RNA by RT-PCR has recently been introduced. This review describes the basic virology, epidemiology, clinical virology and treatment of HEV GT3 infections in high income countries.

Hepatitis E: when to treat and how to treat

HEV generally causes a self-limited acute infection and treatment remains supportive. However, severe hepatitis or fulminant hepatic failure may occur, more so during pregnancy. It is an important cause of acute-on-chronic liver failure in endemic areas. Chronic HEV infection and progressive disease has been reported in recipients of solid organ transplants, haematological malignancies, HIV patients and those on haemodialysis. Clearance of HEV may occur after reducing immunosuppressive therapy, especially those targeting T-cells, in about one third of cases. Antiviral therapy should be considered for patients for whom immunosuppressive therapy cannot be reduced and for those who do not achieve viral clearance after reducing immunosuppression. For the patients with severe infection, fulminant hepatic failure and acute-on-chronic infection, ribavirin monotherapy should be considered to expedite the viral clearance and recovery. Although ribavirin therapy is contraindicated in pregnancy owing to teratogenicity, the risks of untreated HEV to the mother and fetus are high and treatment may be offered. A twelve-week course of pegylated interferon, ribavirin or a combination of the two agents leads to viral clearance in about two-thirds of patients with chronic hepatitis E. Three- to twelve-month treatment with pegylated interferon clears virus in liver transplant recipients and patients on haemodialysis. In kidney and heart transplant patients where interferon may lead to organ rejection, ribavirin may be given.

Hepatitis E virus infection as a new probable cause of de novo membranous nephropathy after kidney transplantation

Hepatitis E virus (HEV) has been identified as a cause of chronic viral hepatitis in immunocompromised patients. Some glomerular diseases were found to be associated with this infection. We report the first case, to our knowledge, of a kidney transplant recipient who developed an HEV infection and de novo membranous nephropathy (MN) concomitantly. The patient displayed a hepatic cytolysis first and a nephrotic syndrome occurred 3 months later. HEV infection was diagnosed upon positive polymerase chain reaction on plasma and stool samples, and renal allograft biopsy revealed de novo MN. Typical causes of MN were definitively excluded. A 3-month course of ribavirin monotherapy allowed the patient to mount a sustained viral response that was rapidly followed by complete remission of the nephrotic syndrome. The chronology of the onset and remission of both diseases is highly suggestive of a causal relationship between hepatitis E and MN.

Hepatitis E virus infection in a liver transplant recipient in the United States: a case report

BACKGROUND

Chronic infection with hepatitis E virus (HEV) has recently been recognized in immunocompromised or immunosuppressed individuals.

CASE REPORT

We report a case of concurrent HEV and human herpes virus-6 (HHV-6) infection, documented by serum HEV RNA and HHV-6 DNA, in an orthotopic liver transplant (OLT) recipient in the United States, where HEV genotype 3 infection, although prevalent, is considered to be self-limited and almost always asymptomatic. The coinfection was accompanied by elevated serum aminotransaminases, liver biopsies demonstrating chronic hepatitis, and the presence of HEV RNA in the tissue. After lowering of immunosuppressive therapy and 2 courses of valganciclovir, sequential clearance of the viruses and normalization of the serum aminotransaminases were observed.

CONCLUSIONS

HEV infection can lead to chronic hepatitis in OLT recipients, and evaluation of this virus should be considered in immunosuppressed individuals with unexplained liver test abnormalities.

Hepatitis E: current status

Acute hepatitis E is a very common disease in developing countries, to the point that, according to World Health Organization estimates, one third of the world's population has been exposed to HEV. It also causes outbreaks in refugee camps or after natural disasters such as floods or earthquakes. Sporadic cases of acute hepatitis have been observed in practically all European countries and other developed geographical areas, not only in travelers from endemic countries but also in people with no risk factors. But, lately, new aspects of this infection are appearing in industrialized countries such as the possibility of the disease becoming chronic in transplant patients, the immunocompromised in general, and even in patients with previous liver disease who are immunocompetent. In this comprehensive review, we summarize the current knowledge on HEV infection.

Epidemiology and management of chronic hepatitis E infection in solid organ transplantation: a comprehensive literature review

Hepatitis E virus (HEV) infection has emerged as a global public health issue. Although it often causes an acute and self-limiting infection with low mortality rates in the western world, it bears a high risk of developing chronic hepatitis in immunocompromised patients with substantial mortality rates. Organ transplant recipients who receive immunosuppressive medication to prevent rejection are thought to be the main population at risk for chronic hepatitis E. Therefore, there is an urgent need to properly evaluate the clinical impact of HEV in these patients. This article aims to review the prevalence, infection course, and management of HEV infection after solid organ transplantation by performing a comprehensive literature review. In addition, an in-depth emphasis of this clinical issue and a discussion of future development are also presented.

Clinical implications of chronic hepatitis E virus infection in heart transplant recipients

BACKGROUND

Recent reports have shown that hepatitis E virus (HEV) infection can become chronic in solid-organ transplant recipients, but few studies have systematically investigated the clinical consequences of this chronic HEV infection in solid-organ transplant (SOT) recipients.

METHODS

We have undertaken an in-depth study of 6 chronic HEV-infected heart transplant recipients to gain further insight into the clinical, biochemical and virologic presentation of this disorder.

RESULTS

In 6 patients (2.3%) chronic HEV infection, genotype 3, was identified. Immunosuppression in these patients was tacrolimus-based, combined with either everolimus or prednisolone and/or mycophenolate mofetil. Median follow-up after case detection was 26 months (range 21 to 40 months). All chronic HEV cases had elevated liver enzyme values. IgM antibodies at presentation were positive in 2 of 6 (33%) patients. Liver histology in 4 of 6 (67%) patients showed advanced fibrosis within 2 years after infection. One patient spontaneously cleared the HEV infection: 1 after dose reduction of immunosuppressive therapy and 3 during ribavirin therapy. One patient has yet to clear the virus and remains on ribavirin therapy.

CONCLUSIONS

Chronic HEV infection in heart transplant (HTx) recipients may lead to rapid fibrosis of the liver. We advise additional HEV RNA screening in solid-organ transplant recipients with elevated liver enzymes, because antibody production is often delayed, as demonstrated in these patients. Dose reduction of immunosuppressive therapy should be the first intervention strategy to achieve viral clearance in chronic HEV-infected immunocompromised patients. Ribavirin treatment should be considered in cases of chronic HEV.

Chronic hepatitis e virus infection and treatment

It is now well accepted that hepatitis E virus (HEV) infection can induce chronic hepatitis and cirrhosis in immunosuppressed patients. Chronic genotype-3 HEV infections were first reported in patients with a solid-organ transplant. Thereafter, cases of chronic HEV infection have been reported in patients with hematological disease and in those who are human immunodeficiency virus (HIV)-positive. HEV-associated extra-hepatic manifestations, including neurological symptoms, kidney injuries, and hematological disorders, have been also reported. In transplant patients, reducing the dosage of immunosuppressive drugs allows the virus to be cleared in some patients. In the remaining patients, as well as hematological patients and patients who are HIV-positive, anti-viral therapies, such as pegylated interferon and ribavirin, have been found to be efficient in eradicating HEV infection. This review summarizes our current knowledge of chronic HEV infection, its treatment, and the extra-hepatic manifestations induced by HEV.

Hepatitis E virus infection

PURPOSE OF REVIEW

The spectrum of hepatitis E virus (HEV) infection has changed over the past 2 years, especially in the developed world. Herein, we review the progress made in studying the epidemiology, hepatic, and extrahepatic manifestations, and the treatment of HEV infection, over the past 2 years.

RECENT FINDINGS

HEV infection is an underdiagnosed disease because of the use of low-sensitivity serological assays. In addition to the four known genotypes, other new genotypes have also been recently described. HEV infection is not only a self-limiting disease but it can also evolve to chronic hepatitis and cirrhosis in organ transplant patients, hematological patients receiving chemotherapy, and HIV patients. HEV can also cause extrahepatic manifestations, such as neurological symptoms, kidney injury, and hematological disorders. Pegylated interferon and ribavirin have been found to effectively treat HEV infection.

SUMMARY

HEV is a worldwide disease that can cause hepatic and extrahepatic manifestations.

Intervention strategies for emerging viruses: use of antivirals

Today, small molecule antiviral drugs are available for the treatment of infections with herpesviruses, HIV, HBV and HCV as well as with influenza viruses. Ribavirin, a broad-spectrum (but aspecific) antiviral, has been approved for the treatment of infections with respiratory syncytial virus, HCV and Lassa virus. Yet, for many other viruses that cause life-threatening infections [most of which are considered emerging and/or neglected] there are no drugs available. Ideally, potent and broad-spectrum (i.e., pan-genus or pan-family virus activity) antiviral drugs should be developed whereby one drug could be used for the treatment of a number of such viral infections. We here review recent evolutions in the search for inhibitors of emerging and neglected RNA viruses.

Hepatitis B and E co-primary infections in an HIV-1-infected patient

We report an autochthonous hepatitis E virus (HEV)-hepatitis B virus co-primary infection in a 41-year-old man having sex with men and infected with human immunodeficiency virus (HIV). This case prompts testing for HEV in HIV-infected patients with acute hepatitis even if primary infection with another hepatitis virus is diagnosed.

Infection with hepatitis E virus in kidney transplant recipients in southeastern France

Hepatitis E virus (HEV) is an emerging cause of acute hepatitis in Europe, particularly in southern France, and HEV is a new causative agent of chronic hepatitis and cirrhosis in immunocompromised patients. However, the data regarding HEV infection after kidney transplantation are still scarce with respect to the clinical issues that have been raised, and no study has specifically focused on kidney transplant recipients. This study described the clinical features and outcomes of HEV infections in a cohort of kidney transplant recipients living in southeastern France. The epidemiological, clinical, and virological characteristics of HEV infections diagnosed by PCR over a 53-month period were retrospectively analyzed in a cohort of 1,350 kidney transplant recipients monitored at the Marseille University Hospital. Sixteen HEV infections were diagnosed, all of which were autochthonous and involved genotype 3 viruses (HEV-3). Chronic infections occurred in 80% of these patients and resolved in half of the cases after a median time of 39 months. The rate of HEV clearance was 54% after a decrease in the dose of immunosuppressants. One patient developed liver cirrhosis 14 months after infection and experienced acute rejection after a decrease in the dose of immunosuppressants. Autochthonous HEV-3 infections in kidney transplant recipients progress to chronicity in most cases and might be complicated by early liver cirrhosis. Chronic HEV infection can resolve following the reduction of immunosuppressive therapy, but ribavirin may be required if reduction of the immunosuppressant dose is not associated with HEV clearance or is inappropriate for the patient management.

[Hepatitis E: molecular virology, epidemiology and pathogenesis]

Hepatitis E represents a significant proportion of enteric transmitted liver diseases and poses a major public health problem, mainly associated with epidemics due to contamination of water supplies, especially in developing countries. Hepatitis E virus (HEV) is responsible for self-limiting acute liver oral-faecal infections. In industrialised countries, acute hepatitis E is sporadic, detected in travellers from endemic areas but also in sporadic cases with no risk factors. HEV is a non-enveloped virus with a single-stranded RNA genome classified into 4 genotypes and a single serotype. Genotypes 1 and 2 only infect humans, and are predominant in the developing countries, while 3 and 4 are predominant in industrialised countries, and also infect other species of mammals, especially pigs, and multiple evidence classifies HEV as a zoonotic agent. Some HEV chronic infections have recently been reported in kidney and liver transplant patients. The mortality rate of HEV infection is greater than hepatitis A. In addition to faecal-oral transmission, parenteral transmission of HEV has also been reported. Several vaccines are currently in development. The severity of this infection in some groups of patients, especially pregnant women, and the occurrence of chronic hepatitis, even with progression to cirrhosis, have raised interest in the application of interferon and/or ribavirin therapy.

Chronic hepatitis e in heart transplant recipients

Chronic courses of hepatitis E virus (HEV) infections have been described in immunosuppressed patients. We aimed to study the role of HEV infections in heart transplant recipients (HTR). 274 HTR were prospectively screened for HEV infection using an anti-HEV-IgG ELISA and HEV-PCR. In addition, 137 patients undergoing cardiac surgery (non-HTR) and 537 healthy subjects were studied cross-sectionally. The anti-HEV-IgG seroprevalence was 11% in HTR, 7% in non-HTR and 2% in healthy controls (HTR vs. healthy controls p<0.0001; non-HTR vs. healthy controls p<0.01). Anti-HEV tested positive in 4.0% in control cohorts of other immunocompromised patients (n = 474). Four HTR (1.5%) were chronically infected with HEV as shown by HEV-PCR and all four patients had liver transaminases of >200 IU/L and histological or clinical evidence of advanced liver disease. In three patients ribavirin treatment was successful with a sustained biochemical and virological response while treatment failed in one cirrhotic patient after ribavirin dose reduction. Heart transplant recipients and patients undergoing cardiac surgery have an increased risk for HEV infections. Chronic hepatitis E may explain elevated liver enzymes in heart transplant recipients. Treatment of HEV infection with ribavirin is effective but the optimal dose and duration of ribavirin therapy remains to be determined.

Prevalence of hepatitis E virus infection in pediatric solid organ transplant recipients--a single-center experience

HEV infection appears to be an emerging disease in industrialized countries. The aim of this study was to evaluate the prevalence of HEV infection in pediatric solid organ transplant recipients. One hundred and twenty-four pediatric recipients of liver (n = 41) or kidney (n = 83) transplants aged between one and 18 yr were screened for anti-HEV IgG antibodies. Patients were tested for fecal HEV RNA excretion if they showed anti-HEV seropositivity. As a control group, 108 immunocompetent pediatric patients without liver disease aged between three and 18 yr were screened for anti-HEV IgG. HEV seroprevalence was 2.4% in renal Tx (2/83), 4.9% in liver Tx patients (2/41), and 3.2% overall (4/124). Three of these four patients were HEV RNA-negative. In one renal transplant patient, HEV genotype 3 RNA excretion persisted and liver enzymes were elevated, indicating chronic hepatitis. In the control group, eight patients (7.4%) were HEV IgG-positive without biochemical evidence of hepatitis. The prevalence of HEV infection in pediatric renal or liver transplant recipients is not higher compared with immunocompetent children. Chronic HEV infection with long-term carriage of the virus may develop in pediatric transplant recipients. Autochthonous HEV infection needs to be considered in uncertain cases of hepatitis in immunosuppressed as well as immunocompetent children.

Hepatitis E virus: what transplant physicians should know

Hepatitis E virus (HEV) infection is an underdiagnosed disease in the developed world. In pediatric and adult organ transplant patients HEV infection can cause chronic hepatitis, which can lead to cirrhosis. Extra-hepatic manifestations, such as neurological symptoms and kidney injury, have been also reported in transplant patients. In this comprehensive minireview, we summarize the current knowledge on HEV infection in transplant patients, that is, its prevalence, incidence, natural history and therapy.

Ribavirin therapy for hepatitis E virus-induced acute on chronic liver failure: a preliminary report

Hepatitis E virus (HEV) is a common cause of acute on chronic liver failure (ACLF) in HEV hyperendemic regions with high mortality. Treatment for HEV-induced ACLF is currently not available. Recently, efficacy of ribavirin in genotype 3 chronic hepatitis E patients has been reported; however, whether ribavirin is effective in genotype 1 HEV infection is not yet known. The present study includes four patients with HEV-induced ACLF treated with ribavirin in a genotype 1 HEV hyperendemic region. Diagnosis of ACLF was made by conventional criteria and HEV as the cause of ACLF was confirmed by detection of HEV RNA by reverse transcriptase PCR. Ribavirin dose ranged from 200 to 600 mg/day and was used for a median duration of 12 (range 3-24) weeks. All patients had undetectable HEV in 3-8 weeks, survived and none had serious adverse effects. This preliminary observation from a single centre indicates that ribavirin may be an effective therapeutic agent for HEV-induced ACLF and a randomized control trial is needed to establish its efficacy.

Progress in research of chronic hepatitis E

Hepatitis E caused by hepatitis E virus (HEV) has long been considered as an acute self-limiting disease. But in recent years, cases which progress to chronic liver disease mainly in immunocompromised patients have been detected, such as organ transplant recipients and patients with human immunodeficiency virus infection. Studies indicate that chronic HEV hepatitis may result in cirrhosis and end-stage liver disease. Since clearance of the virus depends on the development of specific immunity, lowering the immunosuppressive medication is generally recommended. Ribavirin, interferon-alpha-2a and interferon-alpha-2b were found to be effective in patients with chronic HEV infection.