The role of Epstein-Barr virus in acute and chronic hepatitis

HSP70 contributes to pathogenesis of fulminant hepatitis induced by coronavirus

Fulminant viral hepatitis (FH) represents a significant clinical challenge, with its pathogenesis not yet fully elucidated. Heat shock protein (HSP)70, a molecular chaperone protein with a broad range of cytoprotective functions, is upregulated in response to stress. However, the role of HSP70 in FH remains to be investigated. Notably, HSP70 expression is upregulated in the livers of coronavirus-infected mice and patients. Therefore, we investigated the mechanistic role of HSP70 in coronavirus-associated FH pathogenesis. FH was induced in HSP70-deficient (HSP70 KO) mice or in WT mice treated with the HSP70 inhibitor VER155008 when infected with the mouse hepatitis virus strain A59 (MHV-A59). MHV-A59-infected HSP70 KO mice exhibited significantly reduced liver damage and mortality. This effect was attributed to decreased infiltration of monocyte-macrophages and neutrophils in the liver of HSP70 KO mice, resulting in lower levels of inflammatory cytokines such as IL-1β, TNFα, and IL-6, and a reduced viral load. Moreover, treatment with the HSP70 inhibitor VER155008 protected mice from MHV-A59-induced liver damage and FH mortality. In summary, HSP70 promotes coronavirus-induced FH pathogenesis by enhancing the infiltration of monocyte-macrophages and neutrophils and promoting the secretion of inflammatory cytokines. Therefore, HSP70 is a potential therapeutic target in viral FH intervention.

Fas/FasL and Complement Activation are Associated with Chronic Active Epstein-Barr Virus Hepatitis

BACKGROUND AND AIMS

Chronic active Epstein-Barr virus hepatitis (CAEBVH) is a rare and highly lethal disease characterized by hepatitis and hepatomegaly. This study aimed to investigate the clinicopathological features and pathogenic mechanisms of CAEBVH.

METHODS

Ten patients with confirmed Epstein-Barr virus hepatitis infection were enrolled. The clinicopathological characteristics of these patients were summarized and analyzed. Flow cytometry was utilized to detect peripheral blood immune cell phenotypes and whole exome sequencing was used to explore pathogenic genetic mechanisms. Lastly, immunohistochemical staining was employed to verify pathogenic mechanisms.

RESULTS

Clinical features observed in all Epstein-Barr virus hepatitis patients included fever (7/10), splenomegaly (10/10), hepatomegaly (9/10), abnormal liver function (8/10), and CD8+ T cell lymphopenia (6/7). Hematoxylin and eosin staining revealed lymphocytic infiltration in the liver. Positive Epstein-Barr virus-encoded small RNA in-situ hybridization (EBER-ISH) of lymphocytes of liver tissues was noted. Whole exome sequencing indicated that cytotoxic T lymphocytes and the complement system were involved. The expression of CD8, Fas, FasL, and Caspase-8 expression as well as apoptotic markers was enhanced in the Epstein-Barr virus hepatitis group relative to the controls (p<0.05). Lastly, Complement 1q and complement 3d expression, were higher in CAEBVH patients relative to controls (p<0.05).

CONCLUSIONS

CAEBVH patients developed fever, hepatosplenomegaly, and lymphadenopathy. Histopathological changes were a diffuse lymphocytic sinusoidal infiltrate with EBER-ISH positivity. Fas/FasL and complement activation were involved in CAEBVH patients.

Infectious mononucleosis is associated with an increased incidence of NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of liver cirrhosis and hepatocellular carcinoma worldwide. Although various genetic and lifestyle-related risk factors have been identified, its pathophysiology has not yet been fully unravelled. While acute EBV infection in the setting of infectious mononucleosis can lead to acute hepatitis, the long-term hepatic sequelae of infectious mononucleosis are still poorly understood.

METHODS

This retrospective cohort study included 13,859 patients with and 13,859 matched individuals without infectious mononucleosis from the Disease Analyzer database (IQVIA). Multivariable Cox regression analyses were used to evaluate the association between infectious mononucleosis and NAFLD.

RESULTS

Within 10 years of the index date, 2.64% of patients with infectious mononucleosis and 1.78% of individuals without infectious mononucleosis had been diagnosed with NAFLD (p < .001). The incidence of NAFLD was 263.9 cases per 100,000 person-years among individuals with infectious mononucleosis and 164.5 cases per 100,000 person-years among those without. Multivariable regression analyses indicated that infectious mononucleosis was significantly associated with the incidence of NAFLD (HR: 1.73) both among women (HR: 1.73) and among men (HR: 1.70). In age-stratified analyses, the association between infectious mononucleosis and NAFLD was most pronounced for the groups aged between 41 and 50 years (HR: 2.94) and >50 years (HR: 2.68).

CONCLUSION

Infectious mononucleosis is significantly associated with the incidence of NAFLD in a large cohort from Germany. These findings suggest a pathophysiological involvement of EBV in the development of NAFLD and could stimulate research efforts to better understand the pathophysiology of this emerging global medical burden.

The value of bile acid spectrum in the evaluation of hepatic injury in children with infectious mononucleosis caused by Epstein Barr virus infection

Background

Infectious mononucleosis (IM) is an acute infectious disease, caused by Epstein-Barr virus (EBV) infection, which can invade various systemic systems, among which hepatic injury is the most common. In this study, ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to detect serum bile acid spectrum in IM children quantitatively, and to investigate its role in the early assessment of hepatic injury.

Methods

This case-control study was conducted at Yuhuan People's Hospital. A total of 60 IM children and 30 healthy children were included in the study. Among 60 children with IM, 30 had hepatic injury, and 30 without hepatic injury. The clinical and laboratory data were analyzed, and the serum bile acid spectrum and lymphocyte subsets were evaluated in the three groups.

Results

There were statistically significant differences in cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), lithocholic acid (LCA), glycochenodeoxycholic acid (GCDCA), glycodeoxycholic acid(GDCA), glycolithocholic acid (GLCA), taurocholic acid (TCA), taurochenodeoxycholic acid (TCDCA), taurodeoxycholic acid (TDCA), ursodeoxycholic acid (UDCA), glycoursodeoxycholic acid (GUDCA), tauroursodeoxycholic acid(TUDCA), percentage of NK cells, CD4+ and CD8+ in IM hepatic injury group, without hepatic injury group, and the healthy control group (P < 0.05). The percentage of NK cells was positively correlated with TCA (P < 0.05); it was negatively correlated with CDCA, DCA, LCA, GCDCA, GDCA, GLCA, TDCA, UDCA, GUDCA, TUDCA (P < 0.05). CD4+ was positively correlated with CA, TCA and TCDCA (P < 0.05); it was negatively correlated with CDCA, DCA, LCA, GCDCA, GDCA, GLCA, TDCA, UDCA, GUDCA and TUDCA (P < 0.05). CD8+ was positively correlated with CDCA, DCA, LCA, GCDCA, GDCA, GLCA, TDCA, UDCA, GUDCA and TUDCA (P < 0.05); it was negatively correlated with CA, TCA and TCDCA (P < 0.05). ROC curve analysis showed that CD8+, GDCA and GLCA had high predictive value for hepatic injury in IM patients.

Conclusions

UPLC-MS/MS method can sensitively detect the changes in serum bile acid spectrum before hepatic injury in children with IM, which is helpful for early assessment of hepatic injury in children with IM. The changes in lymphocyte subsets in IM children are related to some bile acid subfractions, which may be related to IM hepatic injury.

Cholestatic Hepatitis Secondary to Epstein–Barr Virus Infection in Children: Case Series and Review of the Literature

Objective Cholestatic hepatitis (CH) secondary to Epstein–Barr virus (EBV) infection is a rare clinical condition in children and adolescents, which was reported in 5% of patients. Herein, we aimed to present our pediatric cases of EBV-induced CH with a comprehensive review of previously reported patients.

Methods Three cases of EBV-induced CH diagnosed in our department were included in the study. EBV diagnosis was established with positive viral capsid antigen immunoglobulin M and immunoglobulin G. A search of English literature on pediatric cases with EBV-induced CH was conducted on common search engines (PubMed and GoogleScholar).

Results We report three novel cases (aged 6, 15, and 16 years) presented with infectious mononucleosis and jaundice. The physical examination revealed mild hepatomegaly in all of them. In our cases, a total of 21 pediatric patients with EBV-induced CH were reported until now (52.4% male), with a median age of 15 (1–18) years. Regarding all patients, the most common symptoms were fever (94.1%) and jaundice (84.6%). In laboratory results, aspartate aminotransferase [308 (62–2,148) IU/L], alanine aminotransferase [312 (79–899) IU/L], and γ-glutamyl transpeptidase [328.9 ± 198.6 IU/L] levels were elevated. Hyperbilirubinaemia was observed in all cases with a median direct bilirubin level of 3.9 (1.9–21.8) mg/dL. A thickened gallbladder wall was the most common (50%) finding in the abdominal ultrasonography of the cases. Most of the reported patients recovered under supportive treatment without any further morbidity.

Conclusions Although EBV-induced CH is an atypical presentation for children, it should be considered in the differential diagnosis of cholestasis. Supportive therapies are the mainstay of treatment in most of these cases.

Newer developments in viral hepatitis: Looking beyond hepatotropic viruses

Viral hepatitis in the entirety of its clinical spectrum is vast and most discussion are often restricted to hepatotropic viral infections, including hepatitis virus (A to E). With the advent of more advanced diagnostic techniques, it has now become possible to diagnose patients with non-hepatotropic viral infection in patients with hepatitis. Majority of these viruses belong to the Herpes family, with characteristic feature of latency. With the increase in the rate of liver transplantation globally, especially for the indication of acute hepatitis, it becomes even more relevant to identify non hepatotropic viral infection as the primary hepatic insult. Immunosuppression post-transplant is an established cause of reactivation of a number of viral infections that could then indirectly cause hepatic injury. Antiviral agents may be utilized for treatment of most of these infections, although data supporting their role is derived primarily from case reports. There are no current guidelines to manage patients suspected to have viral hepatitis secondary to non-hepatotropic viral infection, a gap that needs to be addressed. In this review article, the authors analyze the common non hepatotropic viral infections contributing to viral hepatitis, with emphasis on recent advances on diagnosis, management and role of liver transplantation.

Epstein-Barr virus-induced sickle hepatopathy

Sickle hepatopathy comprises a spectrum of disorders that vary in severity. Intravascular sickling and sinusoidal occlusion are the principal drivers of sickle hepatopathy, but infection or autoimmunity can act as triggers. We describe two cases of acute sickle hepatopathy initiated by primary Epstein-Barr virus (EBV) infection, a previously unreported association. The first case entailed a 14-year-old girl with hemoglobin SC (HbSC) disease who developed hepatic sequestration crisis that responded to a simple transfusion of erythrocytes. The second case was that of a 16-year-old boy with HbSC disease who experienced life-threatening intrahepatic cholestasis with multiorgan failure.

Jaundice as a Rare Manifestation of Epstein-Barr Virus Primary Infection

Epstein-Barr virus (EBV) primary infection usually presents with classic symptoms of infectious mononucleosis (IM) like fever, lymphadenopathies and tonsillopharyngitis. Liver damage is frequently mild and self-limited and there are only a few cases of severe EBV-induced cholestatic hepatitis and jaundice reported in the literature. The authors present the case of a 22-year-old woman who was admitted with acute fever and jaundice. Physical examination revealed posterior cervical lymphadenopathies and painful hepatosplenomegaly. Laboratorial findings suggested an obstructive cause for jaundice but ultrasound and magnetic resonance cholangiopancreatography excluded biliary duct pathology. Heterophile antibodies were negative but EBV-specific antibodies revealed isolated positive viral capsid antigen (VCA) immunoglobin (Ig) M suggesting the diagnosis of early phase of EBV primary infection. The diagnosis of EBV-induced cholestatic hepatitis was confirmed after identification of EBV deoxyribonucleic acid (DNA) in blood and by liver biopsy. Supportive management was provided and, despite an initial clinical deterioration, the patient had a favorable outcome. EBV is a virus with a high prevalence worldwide, mainly subclinical, and jaundice is a rare manifestation of the infection. Although the majority of the patients recover without sequelae, progression to liver failure has been described and a careful assessment for complications is mandatory. Therefore, EBV infection should be included in the comprehensive differential diagnosis of jaundice in all age groups.

Human Herpesviruses Increase the Severity of Hepatitis

Simple Summary

More than 300 million people worldwide suffer from hepatitis B or hepatitis C and more than 1 million people die each year from cirrhosis and liver cancer. In some cases, the nature of hepatitis remains unclear. The purpose of this research was to assess the prevalence of human herpesviruses (cytomegalovirus, Epstein–Barr virus, and herpesvirus type 6) in patients with hepatitis, and to examine their effect on the disease severity. In the clinical materials of 377 patients with acute or chronic hepatitis, DNA of these three herpesviruses was detected in the blood in 13.5% of patients with viral hepatitis B or C and in 10.1% of patients with hepatitis of unspecified etiology. The cirrhosis was diagnosed in patients with herpesviruses 3 times more often than in patients without them. In patients with hepatitis C, the incidence of herpesviruses was higher in the tissue samples of liver biopsies (38.7%) than in the blood. Clinical and virological indicators of hepatitis were considerably higher in the patients with coinfection. Since in patients with hepatitis the presence of herpesviruses is associated with a more severe course of the disease, the detection, and herpesvirus DNA monitoring will help to adjust the course of therapy.

Abstract

Acute and chronic liver diseases are a major global public health problem; nevertheless, the etiology of 12–30% of cases remains obscure. The purpose of this research was to study the incidence of human herpesviruses (HHVs) cytomegalovirus, Epstein–Barr virus (EBV), and HHV-6 in patients with hepatitis and to examine the effect of HHV on the disease severity. We studied the clinical materials of 259 patients with hepatitis treated in Infectious Clinic n.1 (Moscow) and the archived materials of 118 patients with hepatitis C. HHV DNA was detected in the whole blood in 13.5% of patients with hepatitis B or C and in 10.1% of patients with hepatitis of unspecified etiology. EBV demonstrated the highest incidence (58.1%). Cirrhosis was diagnosed in 50% of patients with HHV and in 15.6% of patients without HHV. In patients with hepatitis C, the frequency of HHV was higher in liver biopsy (38.7%) compared to blood. The clinical and virological indicators of hepatitis were considerably higher in patients with coinfection. Conclusion: HHV detected in patients with viral hepatitis has been associated with a significant effect on the severity of the disease, and we suggest monitoring HHV DNA in patients with severe hepatitis and/or poor response to antiviral drugs.

Pediatric hematolymphoid pathology in the gastrointestinal tract

Hematolymphoid processes involving the gastrointestinal tract in the pediatric and adolescent young adult (AYA) populations include processes occurring primarily within the gastrointestinal tract as well as systemic diseases with predilection for gastrointestinal involvement. Here, we present a focused review of reactive and neoplastic entities occurring in the pediatric and AYA age groups.

Clinicopathologic findings of chronic active Epstein-Barr virus infection in adults: A single-center retrospective study in China

Chronic active Epstein-Barr virus (CAEBV) infection is a rare disease with a high mortality rate. Our study aimed to summarize the clinicopathological characteristics of CAEBV infection in adults and improve knowledge of the disease. Data for 19 adult patients with CAEBV confirmed at our hospital from January 2010 to December 2019 were collected retrospectively. There were 14 males and 5 females, and the median age was 33 years (range 14-83). The main clinical manifestations included recurrent fever (84.2%, 16/19), splenomegaly (89.5%, 17/19), hepatomegaly (73.6%, 14/19), lymphadenopathy (42.1%, 8/19), abnormal liver function (78.9%, 15/19), hemopenia (94.7%, 18/19), and hemophagocytosis (52.6%, 10/19). A total of 22 specimens were collected from 19 patients for histopathology. Most of the biopsy specimens showed lymphocyte infiltration. Immunohistochemical staining and EBV-encoded small RNA (EBER) in situ hybridization were performed for 14 of the 22 samples. CD3 and CD20 staining were positive, with more CD3-positive cells than CD20-positive cells (100%, 14/14), and EBER in situ hybridization was positive in most cases (85.7%, 12/14). More than half of TCR gene rearrangement tests showed monoclonal rearrangement (66.6%, 4/6). Mortality was high, with most CAEBV patients dying during the period from diagnosis to the end of follow-up (12/19, 63%); the median survival time was only 20.75 months. Based on limited data, we consider that CAEBV is a disease with different ages of onset and is a complex and heterogeneous syndrome with features of both immunodeficiency and malignant neoplasms. Furthermore, the prognosis of adult-onset CAEBV appears to be very poor.

The Serum Mac-2-binding Protein Glycosylation Isomer Dynamics in Acute Liver Injury

Objective We aimed to examine the dynamics of serum Wisteria floribunda agglutinin-positive human Mac-2-binding protein glycosylation isomer (M2BPGi) in patients with acute liver injury. Methods Serum M2BPGi levels at the time of the diagnosis (n=77) and normalization of the serum alanine aminotransferase (ALT) level (n=26) were examined retrospectively. The difference in the serum M2BPGi level according to the etiology, and the correlations with other laboratory parameters were evaluated. Results The serum M2BPGi level at the time of the diagnosis was increased in 59 of 77 patients [2.3 cutoff index (COI); range, 0.31-11.1 COI] and was significantly decreased at the time of serum ALT normalization (0.68 COI; range, 0.15-1.87 COI; p<0.0001). The serum M2BPGi level was positively correlated with the duration for which serum ALT normalization was achieved (n=46, Spearman rho=0.53, p<0.0001). A multivariate analysis identified total bilirubin (T-bil), albumin, ALT, alkaline phosphatase, and etiology (e.g., drug-induced liver injury or etiology unknown) as independent factors for increased serum M2BPGi. In patients with infectious mononucleosis, the serum M2BPGi level was higher relative to the degree of increase of serum ALT or T-bil levels in comparison to other etiologies. Conclusion The serum M2BPGi level in patients with acute liver injury reflects the magnitude and duration of liver injury. However, it should be noted that the degree of increase of serum M2BPGi in patients with acute liver injury may differ according to the etiology.

Epstein-Barr Virus and Cytomegalovirus Infections of the Liver

Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections are common and are associated with a variety of liver manifestations. EBV and CMV infections, in immunocompetent hosts, commonly manifest as acute hepatitis, with severity varying from asymptomatic, self-limited icteric hepatitis to acute liver failure. Atypical manifestations, such as cholestasis, chronic hepatitis, precipitation of acute-on-chronic liver failure, and autoimmune hepatitis, are reported with EBV infection, whereas cholestasis, portal vein thrombosis, and Budd-Chiari syndrome are reported with CMV infection. In the setting of liver transplantation, CMV is the most common infectious complication and carries significant morbidity; EBV is the major cause of post-transplant lymphoproliferative disorders.

Epstein-Barr virus and its association with disease - a review of relevance to general practice

BACKGROUND

General practitioners encounter the vast majority of patients with Epstein-Barr virus-related disease, i.e. infectious mononucleosis in children and adolescents. With the expanding knowledge regarding the multifaceted role of Epstein-Barr virus in both benign and malignant disease we chose to focus this review on Epstein-Barr virus-related conditions with relevance to the general practitioners. A PubMed and Google Scholar literature search was performed using PubMed's MeSH terms of relevance to Epstein-Barr virus/infectious mononucleosis in regard to complications and associated conditions.

MAIN TEXT

In the present review, these included three early complications; hepatitis, splenic rupture and airway compromise, as well as possible late conditions; lymphoproliferative cancers, multiple sclerosis, rheumatoid arthritis, and chronic active Epstein-Barr virus infection. This review thus highlights recent advances in the understanding of Epstein-Barr virus pathogenesis, focusing on management, acute complications, referral indications and potentially associated conditions.

CONCLUSIONS

Hepatitis is a common and self-limiting early complication to infectious mononucleosis and should be monitored with liver tests in more symptomatic cases. Splenic rupture is rare. Most cases are seen within 3 weeks after diagnosis of infectious mononucleosis and may occur spontaneously. There is no consensus on the safe return to physical activities, and ultrasonic assessment of spleen size may provide the best estimate of risk. Airway compromise due to tonsil enlargement is encountered in a minority of patients and should be treated with systemic corticosteroids during hospitalization. Association between lymphoproliferative cancers, especially Hodgkin lymphoma and Burkitt lymphoma, and infectious mononucleosis are well-established. Epstein-Barr virus infection/infectious mononucleosis as a risk factor for multiple sclerosis has been documented and may be linked to genetic susceptibility. Chronic active Epstein-Barr virus infection is rare. However, a general practitioner should be aware of this as a differential diagnosis in patients with persisting symptoms of infectious mononucleosis for more than 3 months.

Organ-Specific Expression of IL-1 Receptor Results in Severe Liver Injury in Type I Interferon Receptor Deficient Mice

Upon treatment with polyinosinic:polycytidylic acid [poly(I:C)], an artificial double-stranded RNA, type I interferon receptor-deficient (IFNAR^−/−) mice develop severe liver injury seen by enhanced alanine aminotransferase (ALT) activity in the serum that is not observed in their wildtype (WT) counterparts. Recently, we showed that liver injury is mediated by an imbalanced expression of interleukin (IL)-1β and its receptor antagonist (IL1-RA) in the absence of type I IFN. Here we show that despite comparable expression levels of IL-1β in livers and spleens, spleens of poly(I:C)-treated IFNAR^−/− mice show no signs of injury. In vitro analyses of hepatocytes and splenocytes revealed that poly(I:C) had no direct toxic effect on hepatocytes. Furthermore, expression levels of cytokines involved in other models for liver damage or protection such as interferon (IFN)-γ, transforming growth factor (TGF)-β, IL-6, IL-10, IL-17, and IL-22 were comparable for both organs in WT and IFNAR^−/− mice upon treatment. Moreover, flow cytometric analyses showed that the composition of different immune cells in livers and spleens were not altered upon injection of poly(I:C). Finally, we demonstrated that the receptor binding IL-1β, IL1R1, is specifically expressed in livers but not spleens of WT and IFNAR^−/− mice. Accordingly, mice double-deficient for IFNAR and IL1R1 developed no liver injury upon poly(I:C) treatment and showed ALT activities comparable to those of WT mice. Collectively, liver injury is mediated by the organ-specific expression of IL1R1 in the liver.

Novel Therapeutics for Epstein⁻Barr Virus

Epstein–Barr virus (EBV) is a human γ-herpesvirus that infects up to 95% of the adult population. Primary EBV infection usually occurs during childhood and is generally asymptomatic, though the virus can cause infectious mononucleosis in 35–50% of the cases when infection occurs later in life. EBV infects mainly B-cells and epithelial cells, establishing latency in resting memory B-cells and possibly also in epithelial cells. EBV is recognized as an oncogenic virus but in immunocompetent hosts, EBV reactivation is controlled by the immune response preventing transformation in vivo. Under immunosuppression, regardless of the cause, the immune system can lose control of EBV replication, which may result in the appearance of neoplasms. The primary malignancies related to EBV are B-cell lymphomas and nasopharyngeal carcinoma, which reflects the primary cell targets of viral infection in vivo. Although a number of antivirals were proven to inhibit EBV replication in vitro, they had limited success in the clinic and to date no antiviral drug has been approved for the treatment of EBV infections. We review here the antiviral drugs that have been evaluated in the clinic to treat EBV infections and discuss novel molecules with anti-EBV activity under investigation as well as new strategies to treat EBV-related diseases.

Epstein-Barr Virus Hepatitis: A Review of Clinicopathologic Features and Differential Diagnosis

Context.—

The liver is frequently affected by Epstein-Barr virus (EBV) infection, but involvement is commonly subclinical and self-limited. Severe and potentially fatal EBV hepatitis has also been occasionally reported in immunocompromised patients and, even more rarely, in immunocompetent individuals.

Objective.—

To provide a review of the clinicopathologic findings of EBV hepatitis, with a focus on microscopic features and ancillary testing with a brief discussion of the differential diagnosis.

Data Sources.—

Analysis of the pertinent literature (PubMed) and clinical practice experience based on institutional materials.

Conclusions.—

Characteristic microscopic findings in EBV hepatitis include a diffuse lymphocytic sinusoidal infiltrate in a “string of beads” pattern, expansion of portal tracts by a predominantly lymphocytic infiltrate, and intact lobular architecture. In situ hybridization of EBV-encoded RNA is a helpful ancillary test. Correlation of clinical history, laboratory findings, and histopathologic features is essential to distinguish EBV hepatitis from autoimmune liver diseases, transplant rejection, lymphomas, and drug-induced liver injury.

Hepatitis caused by herpes viruses: A review

Herpes virus hepatitis varies in presentation, ranging from asymptomatic to acute liver failure, in both immunocompetent and immunocompromised individuals. Hepatitis caused by the Herpesviridae family is uncommon and usually results in mild disease. It is also often self-limiting, although in certain populations especially immunosuppressed patients, it can cause severe infections, leading to acute to fulminant hepatic failure. In addition, some isolated cases of fulminant disease in immunocompetent individuals have been reported. As the presentation is frequently non-specific, it is important to maintain a high level of suspicion for these viral etiologies and start empiric therapy with antiviral agents as soon as possible. Liver transplantation is the last resort. Mortality remains high in fulminant hepatic failure caused by Herpesviridae without liver transplantation. Here we review the literatures on hepatitis caused by three members of the Herpesviridae family, cytomegalovirus, Epstein-Barr virus and herpes simplex virus to discuss the epidemiology, diagnostic methods, clinical features and current management, and also to determine which aspects need to be investigated in further detail. Herpesviridae-mediated acute liver failure is rare but is associated with a poor prognosis, even after early treatment.

Antiviral Drugs for EBV

Epstein–Barr virus (EBV) infects up to 95% of the adult human population, with primary infection typically occurring during childhood and usually asymptomatic. However, EBV can cause infectious mononucleosis in approximately 35–50% cases when infection occurs during adolescence and early adulthood. Epstein–Barr virus is also associated with several B-cell malignancies including Burkitt lymphoma, Hodgkin lymphoma, and post-transplant lymphoproliferative disease. A number of antiviral drugs have proven to be effective inhibitors of EBV replication, yet have resulted in limited success clinically, and none of them has been approved for treatment of EBV infections.

Murine γ-Herpesvirus 68 Induces Severe Lung Inflammation in IL-27-Deficient Mice with Liver Dysfunction Preventable by Oral Neomycin

IL-27 is an immunoregulatory cytokine consisting of p28 and EBI3. Its receptor also has two subunits, WSX1 and gp130. Although IL-27 promotes Th1 differentiation in naive T cells, it also induces IL-10 expression in effector Th1 cells to curtail excessive immune responses. By using p28-deficient mice and WSX1-deficient mice (collectively called IL-27-deficient mice), we examined the role of IL-27 in primary infection by murine γ-herpesvirus 68 (MHV68), a murine model of EBV. Upon airway infection with MHV68, IL-27-deficient mice had more aggravated lung inflammation than wild-type mice, although MHV68 infection per se was better controlled in IL-27-deficient mice. Although epithelial cells and alveolar macrophages were primarily infected by MHV68, interstitial macrophages and dendritic cells were the major producers of IL-27. The lung inflammation of IL-27-deficient mice was characterized by more IFN-γ-producing CD8+ T cells and fewer IL-10-producing CD8+ T cells than that of wild-type mice. An infectious mononucleosis-like disease was also aggravated in IL-27-deficient mice, with prominent splenomegaly and severe hepatitis. Infiltration of IFN-γ-producing effector cells and upregulation of the CXCR3 ligand chemokines CXCL9, CXCL10, and CXCL11 were noted in the liver of MHV68-infected mice. Oral neomycin effectively ameliorated hepatitis, with decreased production of these chemokines in the liver, suggesting that the intestinal microbiota plays a role in liver inflammation through upregulation of these chemokines. Collectively, IL-27 is essential for the generation of IL-10-producing effector cells in primary infection by MHV68. Our findings may also provide new insight into the mechanism of hepatitis associated with infectious mononucleosis.

Type I interferon receptor signaling delays Kupffer cell replenishment during acute fulminant viral hepatitis

BACKGROUND & AIM

Virus-induced fulminant hepatitis is a major cause of acute liver failure. During acute viral hepatitis the impact of type I interferon (IFN-I) on myeloid cells, including liver-resident Kupffer cells (KC), is only partially understood. Herein, we dissected the impact of locally induced IFN-I responses on myeloid cell function and hepatocytes during acute liver inflammation.

METHODS

Two different DNA-encoded viruses, vaccinia virus (VACV) and murine cytomegalovirus (MCMV), were studied. In vivo imaging was applied to visualize local IFN-β induction and IFN-I receptor (IFNAR) triggering in VACV-infected reporter mice. Furthermore, mice with a cell type-selective IFNAR ablation were analyzed to dissect the role of IFNAR signaling in myeloid cells and hepatocytes. Experiments with Cx3cr1^+/gfp mice revealed the origin of reconstituted KC. Finally, mixed bone marrow chimeric mice were studied to specifically analyze the effect of IFNAR triggering on liver infiltrating monocytes.

RESULTS

VACV infection induced local IFN-β responses, which lead to IFNAR signaling primarily within the liver. IFNAR triggering was needed to control the infection and prevent fulminant hepatitis. The severity of liver inflammation was independent of IFNAR triggering of hepatocytes, whereas IFNAR triggering of myeloid cells protected from excessive inflammation. Upon VACV or MCMV infection KC disappeared, whereas infiltrating monocytes differentiated to KC afterwards. During IFNAR triggering such replenished monocyte-derived KC comprised more IFNAR-deficient than -competent cells in mixed bone marrow chimeric mice, whereas after the decline of IFNAR triggering both subsets showed an even distribution.

CONCLUSION

Upon VACV infection IFNAR triggering of myeloid cells, but not of hepatocytes, critically modulates acute viral hepatitis. During infection with DNA-encoded viruses IFNAR triggering of liver-infiltrating blood monocytes delays the development of monocyte-derived KC, pointing towards new therapeutic strategies for acute viral hepatitis.

LAY SUMMARY

Viral infection can cause fulminant hepatitis, which in turn is a major cause of acute liver failure. Herein, we aimed to study the role of type 1 interferon responses in acute viral hepatitis. We identified that during infection with DNA-encoded viruses, type 1 interferon receptor triggering of blood monocytes delays the development of monocyte-derived Kupffer cells. This points to new therapeutic strategies for acute viral hepatitis.

Hepatitis due to Epstein-Barr virus and cytomegalovirus: clinical features and outcomes

OBJECTIVE

To determine the frequency of cytomegalovirus (CMV) and Epstein-Barr virus (EBV) hepatitis among those with acute CMV and EBV infection in a population based setting and to compare these two types of hepatitis and analyze the outcomes.

METHODS

A retrospective search was undertaken on all patients with IgM antibodies to CMV and EBV during the period of 2006-2015 in the virological database of the University Hospital of Iceland covering the metropolitan area of Reykjavík (population 202,255). Patients with available liver tests at the University Hospital and/or admitted to this institution were included and relevant clinical data obtained from medical records.

RESULT

Overall, 190 patients had acute EBV infection during the study period and 118 patients were diagnosed with acute CMV. Overall, 82% of patients with acute EBV infection had hepatitis, males 43%, median age 17 years, 15% had jaundice and 26% hospitalized. Among those with acute CMV infection, 69% had elevated liver tests, 63% males, median age 33 years, 9% had jaundice and also 26% hospitalized. Overall, 17% of those with CMV hepatitis were immunosuppressed, 6% were pregnant and 4% developed Guillain-Barré syndrome following the infection.

CONCLUSION

A high proportion of patients with acute CMV and EBV developed hepatitis and jaundice, most of those patients have good prognosis. Patients with CMV hepatitis were more often immunosuppressed, required hospitalization or were pregnant in comparison with patients with EBV hepatitis.

Chronic active Epstein-Barr virus infection associated with hemophagocytic syndrome and extra-nodal natural killer/T-cell lymphoma in an 18-year-old girl: A case report

RATIONALE

Chronic active Epstein-Barr virus infection (CAEBV) associated with hemophagocytic syndrome (HPS) and extra-nodal natural killer (NK)/T-cell lymphoma (ENKL) is a rare life-threatening disorder. This disease is easily misdiagnosed because of its varied presentations.

PATIENT CONCERNS

An 18-year-old girl was admitted to our hospital with a history of edema in the lower limbs and intermittent fever lasting for more than 1 month. At admission, she had severe liver injury of unknown etiology. Laboratory test results revealed pancytopenia, hyperferritinemia, hypertriglyceridemia, and hypofibrinogenemia. Results of serologic tests for EBV were positive. Results of a skin biopsy indicated EBV-positive NK/T-cell lymphoma, and bone marrow aspiration revealed focal hemophagocytosis and atypical lymphoid cells.

DIAGNOSIS

On the basis of these findings, we diagnosed the case as extra-nodal NK/T-cell lymphoma-associated HPS (natural killer/T-cell lymphoma-associated hemophagocytic syndrome), which is commonly induced by CAEBV.

INTERVENTIONS

Treatment consisted of general management of hepatitis, supplemented with albumin and empirical antibiotic therapy.

OUTCOMES

The patient died from massive gastrointestinal hemorrhage a week after she was discharged from the hospital.

LESSONS

ENKL and HPS present with varied features and are generally fatal; therefore, clinicians should proceed with caution in suspected cases. HPS should be considered when the patient presents with fever, hepatosplenomegaly, pancytopenia, and liver failure. When HPS is suspected, clinicians should determine the underlying cause, such as severe infection, including infection with viruses such as EBV; genetic predisposition; or underlying malignancies, especially lymphoma because of its strong association with HPS.

Epstein-Barr Virus-Associated Acute Liver Failure Present in a 67-Year-Old Immunocompetent Female

Acute liver failure (ALF) is a rare illness with a high mortality rate. The only favorable management is emergent liver transplantation. About 13% of ALF cases have no clear etiology. Epstein-Barr virus (EBV)-associated ALF accounts for less than 1% of all ALF cases, and is seen mostly in adults younger than 40 years. There are only a few cases of EBV-associated ALF in elderly immunocompromised adults. We report a case of ALF in an immunocompetent 67-year-old woman caused by EBV infection that was treated by orthotopic liver transplantation (OLT). The diagnosis of EBV-associated ALF was established by EBV-DNA polymerase chain reaction (PCR) and EBV-encoded RNA (EBER-RNA) in situ hybridization (EBER-RISH). The patient is currently doing well 6 months after transplantation without any evidence of clinical EBV infection. This case illustrates the importance of early recognition and diagnosis of EBV-associated ALF by detection of EBV from liver biopsy, especially when patients are immunocompetent and other causes are excluded. To the best of our knowledge, this is the first case of EBV-associated ALF present in an immunocompetent elderly female.

[A Case of Severe Chronic Active Epstein-Barr Virus Infection with Aplastic Anemia and Hepatitis]

Epstein-Barr virus (EBV) causes various acute and chronic diseases. Chronic active EBV infection (CAEBV) is characterized by infectious mononucleosis-like symptoms that persist for more than 6 months with high viral loads in peripheral blood and/or an unusual pattern of anti-EBV antibodies. Severe CAEBV is associated with poor prognosis with severe symptoms, an extremely high EBV-related antibody titer, and hematologic complications that often include hemophagocytic lymphohistiocytosis. However, CAEBV which led to the development of aplastic anemia (AA) has not been reported yet. A 73-year-old woman was admitted to our hospital with intermittent fever, general weakness and elevated liver enzymes. In the serologic test, EBV-related antibody titer was elevated, and real-time quantitative-PCR in peripheral blood showed viral loads exceeding 10(4) copies/μg DNA. Liver biopsy showed characteristic histopathological changes of EBV hepatitis and in situ hybridization with EBV-encoded RNA-1 was positive for EBV. Pancytopenia was detected in peripheral blood, and the bone marrow aspiration biopsy showed hypocellularity with replacement by adipocytes. AA progressed and the patient was treated with prednisolone but deceased 8 months after the diagnosis due to multiple organ failure and opportunistic infection. Herein, we report a rare case of severe CAEBV in an adult patient accompanied by AA and persistent hepatitis.

Cholestatic Hepatitis Induced by Epstein-Barr Virus in a Pediatric Population

OBJECTIVE

We present 5 cases of Epstein-Barr virus (EBV)-induced cholestatic hepatitis (CH) and review all additional pediatric cases from the literature.

DESIGN

The medical records of 5 patients with EBV-induced CH were reviewed. A comprehensive review of the literature was performed.

RESULTS

Including our patients, a total of 17 patients with EBV-induced CH were reviewed. The average age was 11 years (range 1-18 years); male to female ratio was 0.9:1. The most common presenting symptoms included fever, jaundice, and cervical lymphadenopathy. However, a significant number of patients presented with jaundice alone, without other suggestive signs of an EBV infection. Hepatocellular enzyme levels were significantly higher than in classical infectious mononucleosis. In many cases, serum alkaline phosphatase was also elevated, accompanied by direct hyperbilirubinemia.

CONCLUSION

EBV infection should be included in the differential diagnosis of CH in all age groups. In the vast majority, full recovery is expected.

Epstein-Barr virus--associated posttransplantation lymphoproliferative disorder with tacrolimus metabolism deterioration in infants after living-donor liver transplantation

BACKGROUND

Posttransplantation lymphoproliferative disorder (PTLD) in infants after liver transplantation is strongly associated with tacrolimus (Tac) administration and primary Epstein-Barr virus (EBV) transmission.

METHODS

From 1991 to 2012, 32 survivors younger than 2 years who had undergone living-donor liver transplantation using Tac for primary immunosuppression were retrospectively investigated for changes in Tac trough levels before and at the onset of posttransplantation viral infection episodes.

RESULTS

Twenty-one recipients experienced 33 viral infection episodes associated with EBV-related PTLD (n = 5), symptomatic EBV infection without development of PTLD (n = 8), and other viral infections (n = 20). Although the average Tac trough levels during the 2 months before the onset of viral infection episodes were similar among the 33 episodes (9.0 ± 2.8 ng/mL), the Tac trough levels at the onset were significantly higher in the episodes with PTLD than in those with EBV infection without the development of PTLD and with other viral infections (19.2 ± 9.0 ng/mL vs. 9.3 ± 5.2 ng/mL and 10.6 ± 5.1 ng/mL, respectively) (P<0.05). Tacrolimus trough levels at the onset of PTLD were significantly higher during the 2 months before the onset (median, 1.83 times higher than average) compared with EBV infection (1.14 times higher) and other viral infections (1.06 times higher) (P<0.05). The Tac blood concentration-to-dose ratio at the onset of PTLD was more than twice as high as the average value during the 2 months before the onset.

CONCLUSION

Deteriorated Tac metabolism accompanied by a positive change in the blood EBV DNA load may enable us to predict the development of PTLD in liver-transplanted infants with viral infection.

Liver involvement in systemic infection

The liver is often involved in systemic infections, resulting in various types of abnormal liver function test results. In particular, hyperbilirubinemia in the range of 2-10 mg/dL is often seen in patients with sepsis, and several mechanisms for this phenomenon have been proposed. In this review, we summarize how the liver is involved in various systemic infections that are not considered to be primarily hepatotropic. In most patients with systemic infections, treatment for the invading microbes is enough to normalize the liver function tests. However, some patients may show severe liver injury or fulminant hepatic failure, requiring intensive treatment of the liver.

Epstein-Barr virus (EBV) related acute liver failure: a case series from the US Acute Liver Failure Study Group

PURPOSE

Acute liver failure (ALF) is a rare clinical syndrome associated with a high case fatality rate. Asymptomatic primary infection with Epstein-Barr virus (EBV) is common in the general population while acute hepatitis and jaundice are much less common and ALF has been rarely reported. We reviewed the presenting features as well as clinical outcomes amongst consecutive adults with EBV-related ALF.

METHODS

Amongst the 1,887 adult ALF patients enrolled into the US ALF Study Group from January 1998 to February 2012, there were four patients (0.21 %) with EBV-related ALF. Diagnostic criteria for acute EBV infection included compatible serologies and/or the detection of EBV-encoded RNA (EBER) in liver tissue.

RESULTS

Median patient age was 30 years (range 18-44); 75 % were male, and only 25 % were immunosuppressed. The median presenting ALT was 504 IU/mL (range 156-4,920), median Alk P was 431 (range 136-1,009), and median bilirubin was 17 mg/dL (range 13-22.1). Liver biopsy findings ranged from cholestasis to submassive necrosis with EBER + staining in two of the three samples tested. Although all of the patients were treated with an antiviral agent, two died of ALF, one underwent liver transplantation (LT) and one survived with supportive care and is well at 5 years. A review of the literature identified four additional LT recipients with favorable long-term outcomes.

CONCLUSION

Primary EBV infection accounts for <1 % of consecutive adult ALF cases but is associated with a high case fatality rate. LT is associated with favorable short- and long-term outcomes.

Viral Diseases of the Liver

Viruses other than the classic hepatotropic viruses, hepatitis A through E, may cause hepatic injury [1]. Among these are Epstein–Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus (HSV), varicella zoster virus (VZV), human herpes viruses (HHV) 6, 7, and 8, human parvovirus B19, and adenoviruses (Table 11.1). The clinical presentation of infections with these viruses may be indistinguishable from that associated with infection with classic hepatotropic viruses. The presentation ranges from mild and transient elevation of aminotransferases to acute hepatitis and can also lead to acute liver failure [1]. These viruses should be considered as possible etiologic agents in patients who have acute liver injury and whose serologic markers for the classic hepatotropic viruses are not indicative of an active infection [1]. In the present chapter, we review the clinical manifestations and the potential for immune-mediated liver injury associated with several of these viruses (see summary Table 11.2).

The levels of liver enzymes and atypical lymphocytes are higher in youth patients with infectious mononucleosis than in preschool children

BACKGROUND/AIMS

Infectious mononucleosis (IM) is the clinical presentation of primary infection with Epstein-Barr virus. Although the literature contains a massive amount of information on IM, most of this is related specifically to only children or adults separately. In order to distinguish any differences between preschool children and youth patients, we retrospectively analyzed their demographic and clinical features.

METHODS

Records of patients hospitalized from December 2001 to September 2011 with a diagnosis of IM were retrieved from Peking University First Hospital, which is a tertiary teaching hospital in Beijing. The demographic data and clinical characteristics were collected.

RESULTS

IM was diagnosed in 287 patients during this 10-year period, with incidence peaks among preschool children (≤7 years old, 130/287, 45.3%) and youth patients (>15 and <24 years old, 101/287, 35.2%). Although the complaints at admission did not differ between these two patient groups, the incidence of clinical signs (tonsillopharyngitis, lymphadenopathy, hepatomegaly, and edema of the eyelids) was much higher in preschool children. The incidence of liver lesion and percentage of atypical lymphocytes were significantly higher in the youth group (P<0.001), and the average hospital stay was longer in this group. Pneumonia was the most common complication, and there was no case of mortality.

CONCLUSIONS

The incidence of IM peaks among preschool children and youth patients in Beijing, China. The levels of liver enzymes and atypical lymphocytes increase with age.

Clinicopathologic features of chronic active Epstein-Barr virus hepatitis

AIM: To investigate the clinicopathologic features of chronic active Epstein-Barr virus hepatitis (CAEBVH) as well as its diagnosis, differential diagnosis, treatment and prognosis.

METHODS: We presented the clinical manifestations, histopathological characteristics, diagnosis, treatment and prognosis of two cases of CAEBVH. A literature review was also performed to summarize the characteristics of this clinical entity.

RESULTS: Of two young male patients, one presented with intermittent fever, jaundice, hepatosplenomegaly and abnormal liver function, the other had abnormal liver biochemical tests and symptoms including edema of lower limbs, yellowish urine, fatigue, splenomegaly, and central nervous system symptoms. Histopathologic examination of liver biopsies revealed varying degrees of macrovesicular steatosis and fibrosis, scattered lobular necrosis, beaded sinusoidal lymphocytic infiltration, portal inflammation and interface activity. Electron microscopic investigation showed chronic hepatitis along with steatosis of liver cells and fibrosis. No mylinoid body, special lysosome, glycogen storage or hepatitis B surface antigens were found. In situ hybridization (ISH) for EBV early RNA (EBER) showed EBER-positive nuclei of lymphocytes. Both patients ended in death. The course was 2 years and 4 mo for case 1 and 13 years and 5 mo for case 2.

CONCLUSION: CAEBVH has no specific clinical features, which makes it easy to reach a misdiagnosis. Pathologic features include macrovesicular steatosis, fibrosis, beaded sinusoidal lymphocytes infiltration, scattered lobular necrosis, interface activity and portal inflammation. EBER-positive nuclei of lymphocytes can be detected by ISH. This disease has a poor prognosis and early diagnosis is pivotal for appropriate clinical management.

Sudden unexpected death due to hemophagocytic lymphohistiocytosis syndrome

The hemophagocytic lymphohistiocytosis (HLH) syndrome is a hyperimmune disorder characterized by lymphohistiocytic infiltrations, elevated cytokine levels in the blood, macrophage activation, and hemophagocytosis, frequently presenting with a febrile septic picture. This unusual disease is more common in infancy and childhood than adulthood. It is classified as primary or familial when a genetic defect is identified and secondary or acquired when triggered by certain infections, autoimmune disorders, or malignancies. If or when such patients expire, they typically do so within a hospital or under a physician's care and so such cases rarely come to the attention of forensic pathologists. We report on the unexpected deaths of two hospitalized adult cases of HLH brought to autopsy without a premortem diagnosis. Postmortem examination demonstrated marked hepatosplenomegaly and lymphadenopathy in association with hemophagocytosis. Although very uncommon HLH must be considered in infants, children, or adults who die unexpectedly with an undiagnosed septic presentation.

Characteristics of Epstein-Barr virus hepatitis among patients with jaundice or acute hepatitis

BACKGROUND

Abnormal liver blood tests are common in Epstein-Barr virus (EBV) infection, but symptomatic hepatitis is rare. The demographics, clinical features and outcome of EBV hepatitis are incompletely understood, particularly in the elderly people.

AIM

To identify the demographics, presenting features and natural history of EBV hepatitis.

METHODS

Retrospective review of 1995 consecutive patients attending the jaundice hotline clinic over a 13-year period. Data collected included demographic information, presenting features, clinical and laboratory parameters, radiology imaging and clinical outcome.

RESULTS

Seventeen of 1995 (0.85%) had EBV hepatitis. The median age was 40 years (range 18-68 years). Ten of 17 (59%) patients were aged >30 years, and seven of 17 (41%) patients were aged ≥60 years. Fifteen of 17 (88%) patients presented with clinical/biochemical evidence of jaundice. Seventeen of 17 (100%) patients had a serum lymphocytosis at presentation. 2/17 (12%) patients with EBV hepatitis presented with the classical features of infectious mononucleosis (fever, sore throat and lymphadenopathy). Splenomegaly was present in 15/17 (88%) of patients. Symptoms lasted for a median 8 weeks (range 1-12 weeks). Three of 17 (18%) patients required a brief hospital admission.

CONCLUSIONS

In patients presenting with jaundice/hepatitis, EBV hepatitis is an uncommon diagnosis and causes a self-limiting hepatitis. The diagnosis is suggested by the presence of a lymphocytosis and/or splenomegaly. The majority of patients do not have infectious mononucleosis. Compared with infectious mononucleosis, EBV hepatitis affects an older age group, with nearly half of patients being aged more than 60 years. The diagnosis should be considered in all patients with unexplained hepatitis irrespective of their age.

Murine gamma herpes virus 68 infection promotes fatty liver formation and hepatic insulin resistance in C57BL/6J mice

PURPOSE

Murine gamma herpes virus 68 (MHV68) is a naturally occurring mouse pathogen that is homologous to Epstein-Barr virus. This study was designed to determine the correlation between MHV68 infection and lipid accumulation and insulin resistance in livers of C57BL/6J mice, and to explore the underlying mechanisms.

METHODS

C57BL/6J mice fed a high fat diet were randomly assigned to receive either MHV68 or phosphate buffered saline treatment. Insulin sensitivities were evaluated by glucose tolerance tests. Serum was analyzed for lipids and cytokines. Liver was taken for histology and lipid analysis. Quantitative RT-PCR and western blotting were used to measure expression of hepatic mammalian target of rapamycin (mTOR), ribosomal S6 kinase 1 (S6K1), insulin receptor substrate-1 (IRS-1), sterol regulatory element binding protein-1 (SREBP1), fatty acid synthase (FAS), and acetyl CoA carboxylase (ACC).

RESULTS

MHV68 infection promoted fatty liver, hypertriglyceridemia, insulin resistance, and hyperinsulinemia in association with elevated inflammatory cytokines. In the livers of MHV68-infected C57BL/6J mice, SREBP1, FAS, ACC levels were increased. MHV68 infection also inhibited total IRS-1 expression and increased serine phosphorylation levels of IRS-1, which is parallel to the over activation of mTOR signaling pathway. Sirolimus, a specific inhibitor of mTOR pathway, inhibited MHV68-induced hepatic expression of serine p-IRS-1, increased total IRS-1 levels and improved MHV68-induced hepatic insulin resistance.

CONCLUSION

In C57BL/6J mice, MHV68 infection promotes fatty liver formation and hepatic insulin resistance, which can be ameliorated by sirolimus.

Epstein Barr virus hepatitis

OBJECTIVES

Epstein-Barr Virus (EBV) infection has the potential to establish life-long, benign infections in their hosts. Although biochemical evidence of hepatocellular damage is common, jaundice is uncommon and complete recovery is the rule. The present study describes clinical characteristics and changes of liver function tests during the course of infectious mononucleosis.

PATIENTS AND METHODS

All immunocompetent patients with hepatic dysfunction associated with acute EBV infection, cared for at the University Hospital of Heraklion, over a 6-year period, were identified and retrospectively studied.

RESULTS

The study included 41 patients with a median age of 18.5 (15-51) years. Aspartate-aminotransferase (AST) and alanine-aminotransferase (ALT) were increased in an average maximum of 5-fold. Both transaminase levels started to rise 2 days after the clinical onset of the disease, and returned to normal after a period of 20 days. Alkaline-phosphatase (ALP), γ-glutamyltransferase (γ-GT) and bilirubin levels also increased above the normal values during the course of the disease and returned to normal after a period of 20, 30 and 22 days respectively. The changes of mean AST and ALT levels over time were statistically significant, while those of mean ALP, γ-GT and bilirubin levels over time were not. Anicteric cholestatic liver disease was observed in 24 patients (59%), while icteric only in 2 (6%).

CONCLUSION

Liver involvement in acute EBV infection represents mild and self-limited hepatitis with predominantly cholestatic features.

Epstein-Barr virus: Silent companion or causative agent of chronic liver disease?

The Epstein-Barr virus (EBV) has an important and multifaceted role in liver pathology. As a member of the herpes virus family, EBV establishes a persistent infection in more than 90% of adults. Besides acute hepatitis during primary infection, many clinical syndromes of interest for the hepatologist are associated with EBV infection. The role of EBV in the evolution of chronic hepatitis from hepatotropic viruses is considered. Chronic EBV-associated hepatitis is suspected in immunocompetent adults with compatible serology, suggestive histology and detection of the viral genome in the liver and/or increase of specific circulating cytotoxic T-lymphocytes. EBV is the main cause of post-transplant lymphoproliferative disorders which occur in up to 30% of cases. EBV-driven lymphoproliferative diseases are also recognized in non-immunocompromised patients and liver is involved in up to a third of the cases. Directly implicated in the pathogenesis of different tumors, EBV has a disputable role in hepatocellular carcinoma carcinogenesis. Further research is required in order to establish or reject the role of EBV in human liver cancer. This paper attempts to discuss the range of EBV-associated chronic liver diseases in immunocompetent patients, from mild, self-limiting mononuclear hepatitis to liver cancer.

EBV Chronic Infections

The infection from Epstein-Barr virus (EBV) or virus of infectious mononucleosis, together with other herpes viruses' infections, represents a prototype of persistent viral infections characterized by the property of the latency. Although the reactivations of the latent infection are associated with the resumption of the viral replication and eventually with the "shedding", it is still not clear if this virus can determine chronic infectious diseases, more or less evolutive. These diseases could include some pathological conditions actually defined as "idiopathic"and characterized by the "viral persistence" as the more credible pathogenetic factor. Among the so-called idiopathic syndromes, the "chronic fatigue syndrome" (CFS) aroused a great interest around the eighties of the last century when, just for its relationship with EBV, it was called "chronic mononucleosis" or "chronic EBV infection".Today CFS, as defined in 1994 by the CDC of Atlanta (USA), really represents a multifactorial syndrome characterized by a chronic course, where reactivation and remission phases alternate, and by a good prognosis. The etiopathogenetic role of EBV is demonstrated only in a well-examined subgroup of patients, while in most of the remaining cases this role should be played by other infectious agents - able to remain in a latent or persistent way in the host - or even by not infectious agents (toxic, neuroendocrine, methabolic, etc.). However, the pathogenetic substrate of the different etiologic forms seems to be the same, much probably represented by the oxidative damage due to the release of pro-inflammatory cytokines as a response to the triggering event (infectious or not infectious).Anyway, recently the scientists turned their's attention to the genetic predisposition of the subjects affected by the syndrome, so that in the last years the genetic studies, together with those of molecular biology, received a great impulse. Thanks to both these studies it was possibile to confirm the etiologic links between the syndrome and EBV or other herpesviruses or other persistent infectious agents.The mechanisms of EBV latency have been carefully examined both because they represent the virus strategy to elude the response of the immune system of the host, and because they are correlated with those oncologic conditions associated to the viral persistence, particularly lymphomas and lymphoproliferative disorders. Just these malignancies, for which a pathogenetic role of EBV is clearly documented, should represent the main clinical expression of a first group of chronic EBV infections characterized by a natural history where the neoplastic event aroused from the viral persistence in the resting B cells for all the life, from the genetic predisposition of the host and from the oncogenic potentialities of the virus that chronically persists and incurs reactivations.Really, these oncological diseases should be considered more complications than chronic forms of the illness, as well as other malignancies for which a viral - or even infectious - etiology is well recognized. The chronic diseases, in fact, should be linked in a pathogenetic and temporal way to the acute infection, from whom start the natural history of the following disease. So, as for the chronic liver diseases from HBV and HCV, it was conied the acronym of CAEBV (Chronic Active EBV infection), distinguishing within these pathologies the more severe forms (SCAEBV) mostly reported in Far East and among children or adolescents. Probably only these forms have to be considered expressions of a chronic EBV infection "sensu scrictu", together with those forms of CFS where the etiopathogenetic and temporal link with the acute EBV infection is well documented. As for CFS, also for CAEBV the criteria for a case definition were defined, even on the basis of serological and virological findings. However, the lymphoproliferative disorders are excluded from these forms and mantain their nosographic (e.g. T or B cell or NK type lymphomas) and pathogenetic collocation, even when they occur within chronic forms of EBV infection. In the pathogenesis, near to the programs of latency of the virus, the genetic and environmental factors, independent from the real natural history of EBV infection, play a crucial role.Finally, it was realized a review of cases - not much numerous in literature - of chronic EBV infection associated to chronic liver and neurological diseases, where the modern techniques of molecular biology should be useful to obtain a more exact etiologic definition, not always possibile to reach in the past.The wide variety of clinical forms associated to the EBV chronic infection makes difficult the finding of a univocal pathogenetic link. There is no doubt, however, that a careful examination of the different clinical forms described in this review should be useful to open new horizons to the study of the persistent viral infections and the still not well cleared pathologies that they can induce in the human host.

Concurrent reactivation of latent EBV with hepatitis A can affect clinical feature of childhood hepatitis

AIMS

Some children with acute hepatitis A virus (HAV) infection have concurrent Epstein-Barr virus (EBV) reactivation serologically. We studied the frequency of EBV reactivation during HAV infection and determined whether simultaneous occurrence of EBV reactivation and HAV infection affected the clinical features of HAV infection.

METHODS

The medical records of patients under 19 years of age diagnosed with acute hepatitis A between January 1996 and June 2009 were reviewed.

RESULTS

Among 72 patients with acute hepatitis A, 22 patients (30.6%) had EBV reactivation. A markedly prolonged duration of full recovery from hepatitis was observed in reactivated group. The peak levels of AST and ALT in reactivated group were higher than non-reactivated group (p = 0.012 and p < 0.001, respectively). Higher peak levels of AST and ALT in reactivated subgroups over 10 years old were observed compared to non-reactivated subgroup (p = 0.027 and p = 0.001, respectively). Duration of recovery showed significant differences between two subgroups.

CONCLUSIONS

Concurrent reactivation of latent EBV and HAV infections is common. EBV reactivation with HAV infection adversely affects the clinical feature of hepatitis. Therefore, we should keep in mind that the concurrence especially in older children may cause worse injury to the liver.

Hepatocellular apoptosis associated with cytotoxic T/natural killer-cell infiltration in chronic active EBV infection

The aim of the present study was to identify the mechanism of hepatocellular apoptosis induced by EBV-infected cytotoxic T/natural killer (NK) cells in chronic active EBV infection (CAEBV). Eight patients with CAEBV were studied, and infected T-cell expansion and NK-cell expansion were detected in four patients each. Biopsy or necropsy was performed on lymph node, liver, or spleen, and each specimen was subjected to immunohistochemical double staining of CD3 plus caspase-3 with the addition of cytotoxic markers of T-cell restricted intracellular antigen-1 (TIA-1), perforin, and granzyme B, as well as EBV in situ hybridization (EBV-ISH). In the liver, some of the infiltrating CD3-positive lymphocytes stained positively for EBV-ISH and cytotoxic markers. Double staining of CD3 plus caspase-3 indicated caspase-3 positive hepatocytes with apoptotic features, accompanied by extensive infiltration of CD3-positive cells, which were directly attached to the apoptotic caspase-3 positive hepatocytes. In contrast, far fewer cells stained positive for caspase-3 in lymph node and spleen than in liver. The present findings suggest that in patients with CAEBV, cytotoxic T/NK cells may directly induce hepatocytes to undergo apoptosis more frequently than they do cells in other organs of the reticulo-endothelial system.