B. Bremer

Hepatitis E virus infection as a cause of graft hepatitis in liver transplant recipients

Hepatitis E virus (HEV) infection induces self‐limiting liver disease in immunocompetent individuals. Cases of chronic hepatitis E have recently been identified in organ transplant recipients. We questioned if chronic hepatitis E plays a role in graft hepatitis after liver transplantation in a low endemic area. Two hundred twenty‐six liver transplant recipients, 129 nontransplanted patients with chronic liver disease, and 108 healthy controls were tested for HEV antibodies. HEV RNA was investigated in all sera from transplanted patients. HEV antibodies were detected in 1 healthy control (1%), 4 patients with chronic liver disease (3%), and 10 liver transplant recipients (4%). Three liver transplant patients also tested positive for HEV RNA. Two of them developed persistent viremia with HEV genotype 3. The patients were anti‐HEV immunoglobulin G–negative and HEV RNA–negative before transplantation and had an episode of acute hepatitis 5 or 7 months after transplantation, which led to advanced liver fibrosis after 22 months in 1 patient. Seroconversion to anti‐HEV occurred not before 4 months after the first detection of HEV RNA. The possibility of reverse zoonotic transmission was experimentally confirmed by the infection of 5 pigs with a patients serum. The pigs showed histological inflammation in the liver, and HEV RNA was detectable in different organs, including muscle. In conclusion, the prevalence of HEV infection in Central European liver transplant recipients is low; however, chronic hepatitis E may occur and needs to be considered in the differential diagnosis of graft hepatitis. The diagnosis of HEV infection should be based on HEV RNA determination in immunosuppressed patients. We suggest that immunocompromised individuals should avoid eating uncooked meat and contact with possibly HEV‐infected animals. Liver Transpl 16:74–82, 2010.

Chronic Hepatitis E in Heart Transplant Recipients

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

Hepatitis E virus (HEV)‐specific T‐cell responses are associated with control of HEV infection

Hepatitis E virus (HEV) infection is usually self‐limited but may lead to acute hepatitis and rarely to fulminant hepatic failure. Persistent HEV infections have recently been described in organ transplant recipients receiving immunosuppressive medications, suggesting that HEV is controlled by adaptive immune responses. However, only few studies have investigated HEV‐specific T‐cell responses and immune correlates for the failure to clear HEV infection have not been established so far. We investigated T‐cell responses against HEV in 38 subjects including anti‐HEV‐positive (exposed, n = 9) and anti‐HEV‐negative (n = 10) healthy controls, 12 anti‐HEV‐positive but HEV RNA‐negative organ transplant recipients, and seven transplant recipients with chronic hepatitis E. Proliferation as well as cytokine production of CD4+ and CD8+ T cells was studied after stimulation with overlapping peptides spanning all proteins encoded by HEV‐open reading frame (ORF)2 and HEV‐ORF3. We show that (1) strong and multispecific HEV‐specific T‐cell responses are present in exposed healthy controls, and to a lesser extent also in recovered patients after transplantation; (2) that these responses are absent in patients with chronic hepatitis E but become detectable after viral clearance; and (3) that HEV‐specific T‐cell responses can be restored in vitro by blocking the PD‐1 or CTLA‐4 pathways. However, a combination of PD‐1 and CTLA‐4 blockade had no synergistic effects. We conclude that chronic hepatitis E is associated with impaired HEV‐specific T‐cell responses and suggest that enhancing adaptive cellular immunity against HEV might prevent persistent HEV infections. (HEPATOLOGY 2012)

Late HDV RNA relapse after peginterferon alpha-based therapy of chronic hepatitis delta

Interferon alpha is the only treatment option for hepatitis delta virus (HDV). Trials investigating the efficacy of pegylated interferon alpha (PEG‐IFNa) showed HDV RNA negativity rates of 25‐30% 24 weeks after therapy. However, the clinical and virological long‐term outcome of HDV‐infected patients treated with PEG‐IFNa is unknown. We performed a retrospective‐prospective follow‐up of 77 patients treated for 48 weeks with either PEG‐alfa‐2a and adefovir (ADV) or either drug alone in the Hep‐Net‐International‐Delta‐Hepatitis‐Intervention‐Study 1 (HIDIT‐1) trial. Long‐term follow‐up data were available for 58 out of 77 patients (75%) with a median time of follow‐up of 4.5 (0.5‐5.5) years and a median 3 visits per patient. Patients treated with ADV alone received retreatment with PEG‐IFNa (48% versus 19%; P = 0.02) more often. Hepatitis B virus surface antigen (HBsAg) became negative in six PEG‐IFNa‐treated patients until the end of long‐term follow‐up (10%). Sixteen patients tested HDV RNA‐negative 6 months after PEG‐IFNa treatment who were entered in the long‐term follow‐up study. Out of these, nine individuals tested HDV RNA‐positive at least once during further long‐term follow‐up, with seven patients being HDV RNA‐positive at the most recent visit. Clinical endpoints (liver‐related death, liver transplantation, hepatic decompensation, hepatocellular carcinoma) were observed in three PEG‐IFNa‐treated (8%) and three ADV‐treated (14%) patients during posttreatment long‐term follow‐up with an overall annual event rate of 2.5% (4.9% in cirrhosis). Sequencing confirmed the reappearance of pretreatment virus strains in all cases. Conclusion: Late HDV RNA relapses may occur after PEG‐IFNa therapy of hepatitis delta and thus the term sustained virological response should be avoided in HDV infection. The annual posttreatment rate of clinical events in hepatitis delta patients eligible for PEG‐IFNa therapy is about 2.5% and 4.9% in patients with cirrhosis. (Hepatology 2014;60:87‐97)

Establishment of a Novel Quantitative Hepatitis D Virus (HDV) RNA Assay Using the Cobas TaqMan Platform To Study HDV RNA Kinetics

ABSTRACT Determination of hepatitis D virus (HDV) viremia represents the “gold standard” for the diagnosis of HDV infection. Hepatitis B virus (HBV)-HDV coinfection frequently leads to end-stage liver disease and hepatocellular carcinoma. No commercial assay for HDV RNA quantification that includes automated nucleic acid extraction is available, and in-house PCR tests are not well standardized. However, knowledge of HDV RNA levels may give important information for patient management and could be a useful tool for monitoring the response to antiviral therapies. One platform that is widely used for HBV DNA or HCV RNA quantification is the Cobas Ampliprep/TaqMan system. Using the utility channel of this platform, we established a novel protocol for TaqMan-based HDV RNA quantification after automatic extraction of RNA by the Ampliprep system. The assay was specific and showed linearity over a wide range from 3 × 102 to 107 copies/ml. Reproducibility was demonstrated by determination of the interrun and intrarun variabilities, which were similar to those achieved with the commercially available Cobas TaqMan assays for HCV RNA and HBV DNA. HDV RNA levels were stable in whole blood (n = 4), plasma (n = 3), and serum (n = 3) samples at room temperature for up to 6 days. Importantly, HDV RNA viremia showed only minor fluctuations, with the log10 coefficient of variation being between 1.3 and 11.2% for hepatitis delta patients studied every 2 weeks for up to 3 months (n = 6), while a rapid viral decline was observed early during treatment with pegylated alfa-2a interferon (n = 6). In conclusion, this novel automated HDV RNA assay is a useful tool for monitoring HDV-infected patients both before and during antiviral therapy.

Compromised Function of Natural Killer Cells in Acute and Chronic Viral Hepatitis

BACKGROUND  Natural killer (NK) cells are an integral part of the innate immune system. They have been suggested to play an important role in both defense against viral hepatitis and the pathogenesis of other liver diseases. METHODS  NK cells from 134 individuals including patients with acute hepatitis B and C as well as chronic hepatitis B, C, and delta (D) patients were studied. RESULTS  Infection with viral hepatitis was associated with increased frequencies of NK cells in the peripheral blood; that NK cells showed a less activated phenotype and were compromised in cytolotytic function and cytokine production in all viral hepatitis infections: Hepatitis virus infections did not alter NK cell differentiation, and the activity and severity of liver disease were reflected by alterations of NK cell surface receptors as demonstrated by principal component analysis. CONCLUSION  NK cell phenotypic and functional alterations can equally be observed in HBV, HCV, and HDV infections. Instead, patterns of NK cell alterations differ in acute and chronic infections. Thus, our data suggest a common mechanism in the alteration of NK cell phenotype and function with unique variations that depend on disease activity rather than virus-specific factors.

Hepatitis B core-related antigen (HBcrAg) levels in the natural history of hepatitis B virus infection in a large European cohort predominantly infected with genotypes A and D

Hepatitis B core-related antigen (HBcrAg) has been suggested as an additional marker of hepatitis B virus (HBV) infection. HBcrAg combines the antigenic reactivity resulting from denatured hepatitis B e antigen (HBeAg), HBV core antigen and an artificial core-related protein (p22cr). In Asian patients, high levels of HBcrAg have been suggested to be an independent risk factor for hepatocellular carcinoma, while low levels could guide safe cessation of treatment with nucleos(t)ide analogues. We here studied HBcrAg levels in different phases of HBV infection in a large European cohort predominantly infected with genotypes A and D: HBeAg-positive immune tolerance (n = 30), HBeAg-positive immune clearance (IC) (n = 60), HBeAg-negative hepatitis (ENH) (n = 50), HBeAg-negative inactive/quiescent carrier phase (c) (n = 109) and acute hepatitis B (n = 8). Median HBcrAg levels were high in the immune tolerance and immune clearance phases (8.41 and 8.11 log U/mL, respectively), lower in ENH subjects (4.82 log U/mL) but only 2.00 log U/mL in ENQ subjects. Correlation between HBcrAg and HBV DNA varied among the different phases of HBV infection, while HBcrAg moderately correlated with hepatitis B surface antigen in all phases. ENQ patients had HBcrAg levels <3 log U/mL in 79%, in contrast to only 12% in the ENH group. HBcrAg levels vary significantly during the different phases of HBV infection. HBcrAg may serve as valuable marker for virus replication and reflect the transcriptional activity of intrahepatic cccDNA. In HBeAg-negative patients, HBcrAg may help to distinguish between inactive carriers (ENQ) and those with active disease (ENH).

Clinical value of on-treatment HCV RNA levels during different sofosbuvir-based antiviral regimens.

BACKGROUND & AIMS The European Association for the Study of the Liver (EASL) guidelines recommend HCV RNA measurements at specific time points during sofosbuvir(SOF)-therapy. However, it remains unclear, how these results should be interpreted. We aimed to analyze whether on-treatment HCV RNA levels predict relapse comparing the CobasAmpliPrep/CobasTaqMan v2.0 (CAP/CTM) and Abbott RealTime HCV (ART) assays. METHODS Samples were collected from 298 patients (HCV genotypes; GT1-5) at weeks (w) 0, 1, 2, 4, 8, 12, 16, 20 and 24 during SOF-based therapy at two university clinics and tested for HCV RNA level by CAP/CTM and ART. Patients were treated with SOF/ribavirin (RBV) 12/24 w (n=99), pegylated-interferon-alfa (PegIFN)/SOF/RBV 12 w (n=51), SOF/simeprevir (SMV)±RBV 12 w (n=69) or SOF/daclatasvir±RBV 12/24 w (n=79). RESULTS HCV RNA levels during the first 4weeks of SOF/RBV therapy were significantly lower in GT3 patients who achieved SVR compared with those who relapsed. All GT3 patients with a week 2 result <45IU/ml by CAP/CTM achieved SVR but only 33% of those with ⩾45IU/ml (p=0.0003). Similar results were documented with ART and 60IU/ml as cut-off (SVR: 100% vs. 29%; p=0.0002). In contrast, HCV RNA levels during early treatment phases were not significantly related to relapse in patients treated with other SOF-based regimens. Residual HCV RNA was frequently detected by ART at later stages of therapy. However, SVR rates remained high in these patients. At the end of SOF/SMV±RBV therapy HCV RNA was detectable with ART in 20% of patients, of whom 92% achieved SVR. CONCLUSIONS HCV RNA levels assessed at week 2 of SOF/RBV therapy can predict relapse in GT3-patients. Detectable HCV RNA results at later stages during SOF-based therapy may occur frequently with the more sensitive ART. However, this should not lead to treatment extension. LAY SUMMARY We analyzed the predictive value of hepatitis C virus (HCV) RNA levels measured at different time points for treatment efficacy. We found that the level of HCV RNA measured at week 2 of antiviral therapy can be used to predict treatment success in patients with HCV genotype 3 infection treated with sofosbuvir and ribavirin but not in patients treated with other sofosbuvir-based regimens. Low level HCV RNA is frequently detected by the RealTime HCV assay during later stages of antiviral therapy. However, this is not associated with reoccurrence of HCV RNA after the end of treatment.

In vivo evidence for ribavirin-induced mutagenesis of the hepatitis E virus genome

Objective Hepatitis E virus (HEV) infection can take chronic courses in immunocompromised patients potentially leading to liver cirrhosis and liver failure. Ribavirin (RBV) is currently the only treatment option for many patients, but treatment failure can occur which has been associated with the appearance of a distinct HEV polymerase mutant (G1634R). Here, we performed a detailed analysis of HEV viral intrahost evolution during chronic hepatitis E infections. Design Illumina deep sequencing was performed for the detection of intrahost variation in the HEV genome of chronically infected patients. Novel polymerase mutants were investigated in vitro using state-of-the-art HEV cell culture models. Results Together, these data revealed that (1) viral diversity differed markedly between patients but did not show major intraindividual short-term variations in untreated patients with chronic hepatitis E, (2) RBV therapy was associated with an increase in viral heterogeneity which was reversible when treatment was stopped, (3) the G1634R mutant was detectable as a minor population prior to therapy in patients who subsequently failed to achieve a sustained virological response to RBV therapy and (4) in addition to G1634R further dominant variants in the polymerase region emerged, impacting HEV replication efficiency in vitro. Conclusions In summary, this first investigation of intrahost HEV population evolution indicates that RBV causes HEV mutagenesis in treated patients and that an emergence of distinct mutants within the viral population occurs during RBV therapy. We also suggest that next-generation sequencing could be useful to guide personalised antiviral strategies.

Increased HEV Seroprevalence in Patients with Autoimmune Hepatitis

Background Hepatitis E virus (HEV) infection takes a clinically silent, self-limited course in the far majority of cases. Chronic hepatitis E has been reported in some cohorts of immunocompromised individuals. The role of HEV infections in patients with autoimmune hepatitis (AIH) is unknown. Methods 969 individuals were tested for anti-HEV antibodies (MP-diagnostics) including 208 patients with AIH, 537 healthy controls, 114 patients with another autoimmune disease, rheumatoid arthritis (RA), and 109 patients with chronic HCV- or HBV-infection (HBV/HCV). Patients with AIH, RA and HBV/HCV were tested for HEV RNA. HEV-specific proliferative T cell responses were investigated using CFSE staining and in vitro stimulation of PBMC with overlapping HEV peptides. Results HEV-antibodies tested more frequently positive in patients with AIH (n = 16; 7.7%) than in healthy controls (n = 11; 2.0%; p = 0.0002), patients with RA (n = 4; 3.5%; p = 0.13) or patients with HBV/HCV infection (n = 2; 2.8%; p = 0.03). HEV-specific T cell responses could be detected in all anti-HEV-positive AIH patients. One AIH patient receiving immunosuppression with cyclosporin and prednisolone and elevated ALT levels had acute hepatitis E but HEV viremia resolved after reducing immunosuppressive medication. None of the RA or HBV/HCV patients tested HEV RNA positive. Conclusions Patients with autoimmune hepatitis but not RA or HBV/HCV patients are more likely to test anti-HEV positive. HEV infection should been ruled out before the diagnosis of AIH is made. Testing for HEV RNA is also recommended in AIH patients not responding to immunosuppressive therapy.