Chronic Hepatitis E: A Review of the Literature
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.
The first case of hepatitis E was identified as non-A, non-B hepatitis in 1978. Hepatitis E virus (HEV) infection, which is believed to be one of the common causes of enterically transmitted acute hepatitis in developing countries, is rare in developed countries, except in patients with a history of travel. However, recent studies show that an increasing number of HEV infection cases have been reported in developed countries. Patients with chronic hepatitis E (CHE) in developed countries are those who are immunosuppressed, such as organ transplant recipients, patients with human immunodeficiency virus (HIV) infection or patients with haematological malignancies. Hence, such immunocompromised situations have been pointed out to be risk factors for CHE infection with potentially poor prognosis. In case of immunocompromised patients, HEV infection can evolve to chronic hepatitis. In particular, in some organ transplant recipients, CHE may rapidly progress to liver failure. This has been attributed to the lack of attention to HEV infection among physicians in developed countries wherein this disease has not been commonly prevalent in the past. Thus, clinicians in developed countries must be alert to these patients because this disease in developed countries is more severe than that reported in developing countries. Furthermore, 15% of patients with HEV infection develop hepatic or non-hepatic complications. Despite the fact that diagnosis is still challenging, approaches and management of the disease are improving. Recent research suggests an association between HEV genotype 3 in immunosuppressed patients and rapid progression to cirrhosis and end-stage liver disease (ESLD), and evidence of successful treatment with ribavirin and pegylated interferon (IFN)-alpha-2b has emerged. Appropriate serological examinations are essential for accurate diagnosis, including detection of IgM and IgG antibodies to HEV for diagnosing recent infection and HEV RNA testing. This manuscript provides a review of CHE infection from the microbiological aspect through overall disease management.
Abstract and Introduction
Abstract
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.
Introduction
The first case of hepatitis E was identified as non-A, non-B hepatitis in 1978. Hepatitis E virus (HEV) infection, which is believed to be one of the common causes of enterically transmitted acute hepatitis in developing countries, is rare in developed countries, except in patients with a history of travel. However, recent studies show that an increasing number of HEV infection cases have been reported in developed countries. Patients with chronic hepatitis E (CHE) in developed countries are those who are immunosuppressed, such as organ transplant recipients, patients with human immunodeficiency virus (HIV) infection or patients with haematological malignancies. Hence, such immunocompromised situations have been pointed out to be risk factors for CHE infection with potentially poor prognosis. In case of immunocompromised patients, HEV infection can evolve to chronic hepatitis. In particular, in some organ transplant recipients, CHE may rapidly progress to liver failure. This has been attributed to the lack of attention to HEV infection among physicians in developed countries wherein this disease has not been commonly prevalent in the past. Thus, clinicians in developed countries must be alert to these patients because this disease in developed countries is more severe than that reported in developing countries. Furthermore, 15% of patients with HEV infection develop hepatic or non-hepatic complications. Despite the fact that diagnosis is still challenging, approaches and management of the disease are improving. Recent research suggests an association between HEV genotype 3 in immunosuppressed patients and rapid progression to cirrhosis and end-stage liver disease (ESLD), and evidence of successful treatment with ribavirin and pegylated interferon (IFN)-alpha-2b has emerged. Appropriate serological examinations are essential for accurate diagnosis, including detection of IgM and IgG antibodies to HEV for diagnosing recent infection and HEV RNA testing. This manuscript provides a review of CHE infection from the microbiological aspect through overall disease management.
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