Hepatitis E in liver biopsies from patients with acute hepatitis of clinically unexplained origin

Incidence of Hepatitis E Infection in American Patients With Suspected Drug-Induced Liver Injury Is Low and Declining: The DILIN Prospective Study

INTRODUCTION

Hepatitis E virus (HEV) infection rarely causes icteric hepatitis, yet 10%-40% of adult Americans have serological evidence of previous infection. The aim of this study was to investigate the incidence, presentation, and outcome of acute and previous HEV infection in a large cohort of patients with suspected drug-induced liver injury (DILI).

METHODS

Serum samples from 2012 patients enrolled in the DILI Network were tested for anti-HEV immunoglobulin G (IgG). Those with detectable anti-HEV IgG underwent testing for anti-HEV IgM; those with detectable anti-HEV immunoglobulin m (IgM) were tested for HEV RNA.

RESULTS

Anti-HEV IgG was detected in 407 (20%) patients and associated with increasing subject age and earlier year of enrollment. The median age of seropositive subjects was more than a decade higher than seronegative subjects (59.8 vs 48.7 years). The overall prevalence of anti-HEV declined from 22% (2004-2011) to 18% (2012-2019), suggestive of a cohort effect. The frequency of acute hepatitis E (median ALT = 1231 IU/L) also decreased from 3% (2004-2008) to 1.2% (2009-2013) to 0.6% (2014-2019). These results suggest that acute HEV infection is usually subclinical and was much more frequent in this cohort before 2004.

DISCUSSION

Acute HEV infection accounts for less than 1% of suspected American DILI cases and is more frequent in older men. Previous HEV infection is also most commonly seen in older individuals. Clinicians should consider testing for unsuspected acute HEV infection in older adult patients with acute hepatocellular DILI and jaundice.

The impact of hepatitis E infection on hepatic fibrosis in liver transplanted patients for hepatitis C infection

Hepatitis E Virus (HEV) is an infection known worldwide for its asymptomatic and self-limited course in most cases. Some cases progressing to chronicity have been described in immunosuppressed patients, especially in recipients of solid organ transplants. We evaluated laboratory parameters of HEV infection (HEV RNA, anti-HEV IgM and anti-HEV IgG) through enzyme-linked immunosorbent assay (Elisa), confirmed by immunoblotting, in a cohort of 294 patients who received liver transplants at the HCFMUSP (Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo). Laboratory and demographic data were collected from the entirety of the transplanted population. Hepatic biopsies of 122 patients transplanted due liver failure secondary to hepatitis C (HCV), with or without serological or molecular markers of HEV, were analyzed according to METAVIR score. Out of 24 (8.2%) patients tested positive for anti-HEV IgG, six (2%) were positive for anti-HEV IgM and 17 (5.8%) for HEV RNA. Of the patients transplanted because of HCV infection, 95 (77.8%) had received treatment including ribavirin for at least six months before blood sample collection. Among patients transplanted due to HCV cirrhosis who tested positive for anti-HEV IgG, only three (37.5%) showed fibrosis beyond stage 2, while five (41.7%) of the HEV RNA-positive patients had liver fibrosis beyond stage 2. Overall, the prevalence of HEV in the post-hepatic transplant scenario appears to be low, and, at least histologically, seemingly not harmful. We conclude that, although some studies reported a risk of HEV chronification, patients who had their livers transplanted due to HCV and showed serological or molecular markers of HEV did not have higher levels of fibrosis compared to patients who showed no indications of HEV infection at the time of the analysis.

The histologic presentation of hepatitis E reflects patients' immune status and pre-existing liver condition

Infection with the hepatitis E virus (HEV) is one of the main causes of acute hepatitis worldwide. Given that, the histopathology of hepatitis E is relatively poorly characterized, and it is unclear what exactly determines its remarkable variability. The aim of our study was a systematic analysis of hepatitis E histology, especially with regard to the clinical setting. Fifty-two liver samples (48 biopsies, 1 liver explant, 3 autopsy livers) from 41 patients with molecularly proven hepatitis E (28 HEV genotype (gt) 3, three gt 1, one gt 4 and 9 undetermined gt) were systematically evaluated for 33 histopathologic features. Following one approach, the biopsies were assigned to one of five generic histologic patterns. In another approach, they were subjected to hierarchical clustering. We found that 23/41 (56%) patients were immunocompromised, whereas 18 (44%) had no known immunosuppression. Five patients (12%) had pre-existing liver disease (LD). The histopathologic spectrum ranged from almost normal to acute, chronic, and steato-hepatitis to subtotal necrosis, and was thus distributed across all five generic patterns. Hierarchical clustering, however, identified three histopathologic clusters (C1-C3), which segregated along the immune status and pre-existing LD: C1 comprised mostly patients with pre-existing LD; histology mainly reflected the respective LD without pointing to the additional hepatitis E. C2 comprised mostly immunocompetent patients; histology mainly displayed florid hepatitis. C3 comprised mostly immunocompromised patients; histology mainly displayed smoldering hepatitis. Accordingly, C1-C3 differed markedly with respect to their clinical and histopathologic differential diagnoses. Hierarchical clustering suggests three groups with distinct histopathologies, indicating biologically different manifestations of hepatitis E. The association of histopathologic changes with the patient's immune status and pre-existing LD plausibly explains the diversity of hepatitis E histopathology, and suggests that these factors are the crucial underlying determinants. We expect our results to improve patient management by guiding the clinico-pathologic diagnosis of hepatitis E.

Clinicopathologic features and pathologic diagnosis of hepatitis E

Infection with the hepatitis E virus (HEV) is one of the most common causes, if not the most common, of acute hepatitis worldwide. In the last decade, we have learned that, in addition to the endemically and epidemically occurring form of hepatitis E, which is predominantly transmitted by contaminated drinking water and constitutes a significant health problem in resource-poor countries, there is a globally existing form of hepatitis E, which is a zoonosis and as such is primarily transmitted by the consumption of contaminated meat products. Although in most cases hepatitis E is subclinical or mild and self-limiting, pregnant women and patients with liver cirrhosis may have severe, occasionally even fatal disease, and immunocompromised individuals may develop chronic hepatitis E. Considering the substantial global health burden caused by HEV infection, it is surprising how limited our knowledge of hepatitis E pathology still is. In this article, we describe localization studies on HEV infection and discuss their implications for everyday diagnostics. Furthermore, we outline and discuss the spectrum of histologic changes, which can be found in HEV infection in various clinical contexts.

Chronic Hepatitis E is associated with cholangitis

BACKGROUND AND AIMS

Sporadic hepatitis E is an emerging indigenous disease in Europe induced by genotype 3 of the virus. While the disease takes an acute self-limited course in immunocompetent individuals, under immunocompromised conditions chronic hepatitis E might develop. The histology of chronic hepatitis E has not been described in detail systematically.

METHODS

Liver biopsies from 19 immunosuppressed patients with chronic hepatitis E were collected: 17 were organ transplant recipients, one had a CD4-deficiency and one had received steroid therapy because of ulcerative colitis. Biopsies were processed with standard stains. Evaluation of histologic activity and fibrosis was performed according to Ishak. Additionally, immunohistochemistry with antibodies directed against open reading frame 2 and 3 of the virus was performed and liver biopsies were tested for hepatitis E virus RNA.

RESULTS

Biochemical data showed an increase in alanine transaminase, aspartate transaminase, gamma-glutamyl transferase and total bilirubin. Histopathology displayed typical features of chronic hepatitis with mild to moderate activity. The number of polymorphonuclear leucocytes was considerably increased and all patients had a florid cholangitis that presented as a destructive form in five of them. Hepatocytes and bile duct epithelia stained positive for hepatitis E virus by immunohistochemistry.

CONCLUSIONS

Chronic hepatitis E in immunocompromised individuals runs a similar course as hepatitis B and C and shows similar histopathology. However, the presence of destructive cholangitis in some cases accompanied by an increased number of polymorphonuclear leucocytes is markedly different. Immunohistochemically the virus is present in bile duct epithelia, seemingly the cause for cholangitis.

Role of formalin fixed paraffin embedded liver tissues in the diagnosis of viral hepatitis E in patients with undiagnosed acute liver failure

Viral hepatitis E is gaining importance as an emerging worldwide disease. Though viral hepatitis E (HEV) has been attributed as an etiology of acute liver failure (ALF), however its actual incidence and the immunopathogenesis are being under explored. The present study is aimed at detecting HEV in post mortem liver tissues of patients with undiagnosed ALF. Twenty six liver tissues of ALF patients died of unknown etiology are subjected to nested reverse transcriptase PCR with HEV ORF1 gene targeted primers and HEV RNA is detected in 30.4% (7/23) of ALF cases. Out of seven HEV RNA positive cases, three (42.8%) had HEV antigen positivity by immunohistochemistry on liver tissues using HEV ORF2 antibody. Histopathological examination by H&E staining shows multiacinar confluent hepatic necrosis, bile ductular proliferation, bridging hepatic and periportal necrosis in 4, 4, 2 and 1 cases respectively. The isolates were sequenced using RdRp gene specific primers and found to HEV genotype-1. Quantitative TaqMan real time PCR estimated the viral load ranged between 7.77 × 10³ and 1.44 × 10⁷ viral copies/µl. HEV has been associated with 30.4% (7/23) of undiagnosed ALF cases. Immuno-histochemistry along with molecular testing in FFPE biopsies might be useful for the detection of HEV in undiagnosed cases.

First detection of Hepatitis E virus (Orthohepevirus C) in wild brown rats (Rattus norvegicus) from Great Britain

In the United Kingdom, there has been an increase in the number of hepatitis E virus (HEV) infections in people annually since 2010. Most of these are thought to be indigenously acquired Orthohepevirus A genotype 3 (HEV G3), which has been linked to pork production and consumption. However, the dominant subgroup circulating in British pigs differs from that which is found in people; therefore, an alternative, potentially zoonotic, source is suspected as a possible cause of these infections. Rodents, brown rats (Rattus norvegicus) in particular, have been shown to carry HEV, both the swine HEV G3 genotype and Orthohepevirus C, genotype C1 (rat HEV). To investigate the prevalence of HEV in British rodents, liver tissue was taken from 307 rodents collected from pig farms (n = 12) and other locations (n = 10). The RNA from these samples was extracted and tested using a pan‐HEV nested RT‐PCR. Limited histopathology was also performed. In this study, 8/61 (13%, 95% CI, 5–21) of brown rat livers were positive for HEV RNA. Sequencing of amplicons demonstrated all infections to be rat HEV with 87%–92% nucleotide identity to other rat HEV sequences circulating within Europe and China (224 nt ORF‐1). Lesions and necrosis were observed histologically in 2/3 samples examined. No rat HEV RNA was detected in any other species, and no HEV G3 RNA was detected in any rodent in this study. This is the first reported detection of rat HEV in Great Britain. A human case of rat HEV infection has recently been reported in Asia, suggesting that rat HEV could pose a risk to public health.

Genotype specific pathogenicity of hepatitis E virus at the human maternal-fetal interface

Hepatitis E virus (HEV) infection, particularly HEV genotype 1 (HEV-1), can result in fulminant hepatic failure and severe placental diseases, but mechanisms underlying genotype-specific pathogenicity are unclear and appropriate models are lacking. Here, we model HEV-1 infection ex vivo at the maternal-fetal interface using the decidua basalis and fetal placenta, and compare its effects to the less-pathogenic genotype 3 (HEV-3). We demonstrate that HEV-1 replicates more efficiently than HEV-3 both in tissue explants and stromal cells, produces more infectious progeny virions and causes severe tissue alterations. HEV-1 infection dysregulates the secretion of several soluble factors. These alterations to the cytokine microenvironment correlate with viral load and contribute to the tissue damage. Collectively, this study characterizes an ex vivo model for HEV infection and provides insights into HEV-1 pathogenesis during pregnancy that are linked to high viral replication, alteration of the local secretome and induction of tissue injuries.

An Update on the Clinicopathologic Features and Pathologic Diagnosis of Hepatitis E in Liver Specimens

Infection with the hepatitis E virus (HEV) is globally seen a leading cause of hepatitis. Now increasingly recognized also in industrialized countries, hepatitis E constitutes a significant health problem worldwide. The patient's immune status determines the clinical course and histopathology of hepatitis E. In immunocompetent patients, hepatitis E usually follows an asymptomatic or subclinical course, but may also present with acute hepatitis. In contrast, immunocompromised patients may develop chronic hepatitis, and patients with preexisting liver diseases are at risk for liver decompensation with potentially fatal outcome. Whereas pathologists only occasionally encounter liver biopsies from immunocompetent individuals with hepatitis E, they are more likely exposed to biopsies from patients with preexisting liver disease or immunocompromised individuals. Histopathologic hallmarks of hepatitis E in immunocompetent patients comprise lobular disarray, lobular, and portal inflammation, as well as hepatocyte necrosis of varying extend and regeneration. Thus, it is similar to acute non-E viral hepatitis, yet further differential diagnoses include autoimmune hepatitis and drug-induced liver injury. Histopathologic findings of hepatitis E in preexisting liver disease are determined by the underlying pathology, but may be more severe. Histopathologic presentation of hepatitis E in immunocompromised patients is highly variable, ranging from minimal active hepatitis to chronic hepatitis with severe activity and progressive fibrosis. Taken together, the variability of the histologic features depending on the clinical context and the overlap with other liver diseases make the histopathologic diagnosis of hepatitis E challenging. Immunohistochemistry for HEV open reading frame 2 protein and molecular testing for HEV RNA are useful tissue-based ancillary tools.

Acute Viral Hepatitis: Beyond A, B, and C

From the standpoint of the surgical pathologist "hepatitis" is defined as the set of histologic patterns of lesions found in livers infected by hepatotropic viruses, by non-hepatotrophic viruses leading to liver inflammation in the context of systemic infection, or due to an autoimmune disease, drug, or toxin involving the liver. This article is centered on the histologic patterns of injury in acute viral hepatitis, encompassing the hepatotropic viruses A, B, C, D, and E and the "icteric hemorrhagic fevers" (dengue, hantavirus, yellow fever). A brief mention of viruses causing hepatitis in immunosuppressed patients also is presented.

Hepatitis E Virus and the Liver: Clinical Settings and Liver Pathology

Infection with hepatitis E virus (HEV) is a leading cause of acute hepatitis worldwide, now increasingly recognized also in nonendemic regions. Clinical manifestation of hepatitis E includes mostly asymptomatic/subclinical presentations or acute, self-limiting hepatitis, but also potentially fatal liver failure or chronic hepatitis in immunocompromised individuals. Accordingly, hepatitis E histolpathologic patterns range from an unremarkable histology over acute (cholestatic) hepatitis with variable degree of necrosis to chronic hepatitis with fibrosis. Awareness of hepatitis E and its differential diagnoses, knowledge of its clinico-pathologic manifestations and familiarity with its diagnostic tools will enable clinicians and pathologists to competently make this diagnosis.

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.

Unique clinical courses of transfusion-transmitted hepatitis E in patients with immunosuppression

BACKGROUND

The high prevalence of specific immunoglobulin G for hepatitis E virus (HEV) in Japanese people raises the possibility of a high incidence of HEV-viremic blood donors and therefore frequent transfusion-transmitted HEV (TT-HEV).

STUDY DESIGN AND METHODS

TT-HEV cases established in Japan through hemovigilance and those published in the literature were collected. Infectivity of HEV-contaminated blood components and disease severity in relation to immunosuppression were investigated.

RESULTS

Twenty established TT-HEV cases were recorded over the past 17 years. A lookback study verified that five of 10 patients transfused with known HEV-contaminated blood components acquired HEV infection. The minimal infectious dose of HEV through transfusion was 3.6 × 10⁴ IU. Nine of the 19 TT-HEV cases analyzed had hematologic diseases. Only two cases showed the maximal alanine aminotransferase level of more than 1000 U/L. Two patients with hematologic malignancy and two liver transplant recipients had chronic liver injury of moderate severity.

CONCLUSION

The infectivity of HEV-contaminated components was 50%. Immunosuppression likely causes the moderate illness of TT-HEV, but it may lead to the establishment of chronic sequelae. Transfusion recipients, a population that is variably immunosuppressed, are more vulnerable to chronic liver injury as a result of TT-HEV than the general population is as a result of food-borne infection.

Treatment of Hepatitis E

Hepatitis E virus (HEV) infections are the most common cause of acute hepatitis, but they can also take a chronic course. There is no specific therapy for acute hepatitis, and current treatment is supportive. Choosing ribavirin as the first-line therapy for chronic HEV is advisable, especially in solid organ transplant patients. Pegylated interferon-α has been used successfully for treatment of hepatitis E but is associated with major side effects. Cholestasis is one of the most common, but devastating, manifestations in hepatitis E. Current therapy for HEV aims to treat symptoms. Therapy generally involves several measures, such as vitamins for adequate nutrition, albumin and plasma for supporting treatment, symptomatic treatment for cutaneous pruritus, and ursodeoxycholic acid and S-adenosylmethionine, and Traditional Chinese medicine for removing jaundice. Patients with underlying liver disease may develop liver failure. For these patients, supportive treatment is the foundation. Ribavirin has successfully been used to prevent liver transplantation. Prevention and treatment of complications are important for treatment of liver failure. Liver support devices are intended to support liver function until such time as native liver function recovers or until liver transplantation. Liver transplantation is widely considered as irreplaceable and definitive treatment for acute-on-chronic liver failure, particularly for patients who do not improve with supportive measures to sustain life.

Hepatitis e virus detection in liver tissue from patients with suspected drug-induced liver injury

Hepatitis E virus (HEV) infection is increasingly recognized as a cause of acute hepatitis in the industrialized world. We aimed to determine the frequency of acute HEV infection in cases of suspected drug-induced liver injury (DILI), mainly a diagnosis of exclusion. To this aim, formalin-fixed paraffin-embedded (FFPE) liver tissues of all cases routinely processed in our institute during a 2 1/2 years period in which DILI was among the differential diagnoses (157 liver biopsies, 1 liver explant) were subjected to semi-nested RT-PCR for the detection of HEV RNA. Histopathology was re-evaluated on all cases tested positive. HEV RNA was detectable in 3 of 158 cases (2%) tested, comprising autochthonic as well as travel-related infections with genotypes 1, 3, and 4 each found once, respectively. Histopathologic findings comprised one case with subtotal hepatic necrosis and two cases of acute (cholestatic) hepatitis not distinguishable from acute hepatitis of other etiology. Thus, the overall frequency of acute HEV infection as determined by detection of HEV RNA in liver tissue is substantially increased in patients with suspected DILI compared to the healthy population, emphasizing the need to actively look for HEV infection in cases of suspected DILI. Molecular testing for HEV RNA in routinely processed FFPE liver tissues can be applied to cases with undetermined HEV status.

Hepatitis E virus: do locally acquired infections in Australia necessitate laboratory testing in acute hepatitis patients with no overseas travel history?

Hepatitis E virus (HEV) is emerging as a global public health threat. Water-borne HEV outbreaks are common in developing countries and are associated with genotypes 1 and 2. In industrialised countries, sporadic cases of zoonotic transmission associated with genotypes 3 and 4 are increasingly being reported. Transfusion- and transplantation-transmitted HEV have been documented, although ingestion of contaminated food is thought to be the major transmission route. Severe disease is possible and chronic hepatitis infection occurs in solid-organ-transplant recipients and in patients with immunosuppressive disorders. In Australia, HEV cases are mainly travellers returning from disease endemic countries. Indeed, there are few reported cases of locally acquired HEV. Pigs in Australia have been shown to be infected with HEV, which indicates the possibility of zoonotic transmission. The extent of locally acquired infection is not known, however it may be greater than expected and may necessitate laboratory testing in patients reporting no overseas travel.

New foe treated with old guns - supportive role of steroids in the treatment of acute severe hepatitis E

Background

Autochthonous hepatitis E has been observed with growing incidence in industrialized countries. Hepatitis E virus infection causes an acute hepatitis with spontaneous resolution in the majority of cases. However, in individual cases, hepatitis E may lead to life-threatening acute liver failure. In this report, we describe a case of acute liver injury caused by an autochthonous hepatitis E that resolved under steroid treatment. To our knowledge, this is the first case report describing supportive steroid monotherapy for acute liver injury due to hepatitis E.

Case presentation

A 63-year-old Caucasian male presented with acute liver injury of unknown origin. After excluding the most prevalent causes of acute liver injury, liver histology revealed signs of immune-mediated toxic or drug-induced liver injury. Therefore, immunosuppressive treatment with prednisolone was started. After initialization of steroid treatment, polymerase chain reaction analyses of peripheral blood and liver tissue revealed an acute hepatitis E virus infection (genotype 3). Under sustained steroid treatment, acute liver injury improved and hepatitis E infection resolved.

Conclusion

Steroid treatment might be an option to prevent progress of life-threatening liver failure and liver transplantation in patients with hepatitis E-induced acute liver injury and high-grade inflammation.

Hepatitis E virus in patients with acute severe liver injury

AIM: To examine the incidence of hepatitis E (HepE) in individuals with acute liver injury severe enough to warrant treatment at a transplant unit.

METHODS: Hepatitis E virus (HEV) is an emerging pathogen in developed countries causing severe illness, particularly in immunocompromised patients or those with underlying chronic liver disease. HepE infection is often under diagnosed, as clinicians can be reluctant to test patients who have not travelled to regions traditionally considered hyperendemic for HepE. There are few data regarding the significance of HEV in patients with very severe acute liver injury in developed countries. Eighty patients with acute severe liver injury attending the Scottish Liver Transplant unit were tested for HEV and anti-HEV IgG and IgM. Severe acute liver injury was defined as a sudden deterioration in liver function confirmed by abnormal liver function tests and coagulopathy or presence of hepatic encephalopathy. Eighty percent of these patients were diagnosed with paracetomol overdose. No patients had a history of chronic or decompensated chronic liver disease at time of sampling. IgG positive samples were quantified against the World Health Organization anti-HEV IgG standard. Samples were screened for HEV viral RNA by quantitative reverse transcription polymerase chain reaction.

RESULTS: Four cases of hepatitis E were identified. Three of the four cases were only diagnosed on retrospective testing and were initially erroneously ascribed to drug-induced liver injury and decompensated chronic liver disease, with the cause of the decompensation uncertain. One case was caused by HEV genotype 1 in a traveller returning from Asia, the other three were autochthonous and diagnosed on retrospective testing. In two of these cases (where RNA was detected) HEV was found to be genotype 3, the most prevalent genotype in developed countries. Three patients survived, two of whom had been misdiagnosed as having drug induced liver injury. The fourth patient died from sepsis and liver failure precipitated as a result of hepatitis E infection and previously undiagnosed cirrhosis. Histopathology data to date is limited to mainly that seen for endemic HepE. All patients, with the exception of patient 1, demonstrated characteristics of HepE infection, as seen in previously described locally acquired cases.

CONCLUSION: In patients with acute severe liver injury, HEV testing should be part of the initial diagnostic investigation algorithm irrespective of suspected initial diagnosis, age or travel history.