Wulf O. Böcher

Long‐term efficacy of tenofovir monotherapy for hepatitis B virus‐monoinfected patients after failure of nucleoside/nucleotide analogues

Tenofovir disoproxil fumarate (TDF) has demonstrated high antiviral efficacy in treatment‐naive patients with chronic hepatitis B virus (HBV) infection but experience in nucleoside/nucleotide analogue (NA)‐experienced patients is limited. In this retrospective multicenter study we therefore assessed the long‐term efficacy of TDF monotherapy in patients with prior failure or resistance to different NA treatments. Criteria for inclusion were HBV DNA levels >4.0 log10 copies/mL at the start and a minimum period of TDF therapy for at least 6 months. In all, 131 patients (mean age 42 ± 12 years, 95 male, 65% hepatitis B e antigen [HBeAg]‐positive) were eligible. Pretreatment consisted of either monotherapy with lamivudine (LAM; n = 18), adefovir (ADV; n = 8), and sequential LAM‐ADV therapy (n = 73), or add‐on combination therapy with both drugs (n = 29). Three patients had failed entecavir therapy. Resistance analysis in 113 of the 131 patients revealed genotypic LAM and ADV resistance in 62% and 19% of patients, respectively. The mean HBV DNA level at TDF baseline was 7.6 ± 1.5 log10 copies/mL. The overall cumulative proportion of patients achieving HBV DNA levels <400 copies/mL was 79% after a mean treatment duration of 23 months (range, 6–60). Although LAM resistance did not influence the antiviral efficacy of TDF, the presence of ADV resistance impaired TDF efficacy (100% versus 52% probability of HBV DNA <400 copies/mL, respectively). However, virologic breakthrough was not observed in any of the patients during the entire observation period. Loss of HBeAg occurred in 24% of patients and HBsAg loss occurred in 3%. No significant adverse events were noticed during TDF monotherapy. Conclusion: TDF monotherapy induced a potent and long‐lasting antiviral response in NA‐experienced patients with previous treatment failure. Our data may have implications for current add‐on strategies. (HEPATOLOGY 2009.)

Reduced virus specific T helper cell induction by autologous dendritic cells in patients with chronic hepatitis B – restoration by exogenous interleukin‐12

Insufficient stimulatory capacities of autologous dendritic cells (DC) may contribute in part to impaired T cell stimulation and therefore viral persistence in patients with chronic hepatitis B virus (HBV) infection. In order to characterize the antigen presenting functions of DC from chronic HBV carriers and controls antigen specific T cell responses were analysed. CD34+ peripheral blood progenitor cells were differentiated to immature DC in the presence of GM‐CSF, IL‐6/IL‐6R fusion protein and stem cell factor. Proliferative CD4+ T cell responses and specific cytokine release were analysed in co‐cultures of DC pulsed with HBV surface and core antigens or tetanus toxoid and autologous CD4+ T cells. Cultured under identical conditions DC from chronic HBV carriers, individuals with acute resolved hepatitis B and healthy controls expressed similar phenotypical markers but chronic HBV carriers showed less frequent and weaker HBV antigen specific proliferative T helper cell responses and secreted less interferon‐γ while responses to the tetanus toxoid control antigen was not affected. Preincubation with recombinant IL‐12 enhanced the HBV specific immune reactivities in chronic HBV patients and controls. In conclusion, the weak antiviral immune responses observed in chronic hepatitis B may result in part from insufficient T cell stimulating capacities of DC. Immunostimulation by IL‐12 restored the HBV antigen specific T cell responses and could have some therapeutical benefit to overcome viral persistence.

Regulation of the neutralizing anti-hepatitis B surface (HBs) antibody response in vitro in HBs vaccine recipients and patients with acute or chronic hepatitis B virus (HBV) infection

Antibodies directed to the HBs antigen indicate viral clearance and the development of life‐long immunity in patients that recovered from HBV infection. In HBs antigen vaccine recipients anti‐HBs antibodies provide protective immunity. However, little is known about the regulation of this HBs‐specific antibody response. The existence of anti‐HBs‐secreting B cells was demonstrated using the highly sensitive ELISPOT technique compared with conventional ELISA in serum and cell culture supernatants. In the peripheral blood of patients with acute self‐limited hepatitis B, HBs‐specific B cells were demonstrated with a high frequency despite undetectable anti‐HBs serum antibodies. HBV‐immunized patients that had recovered from infection and vaccine recipients had significantly lower frequencies, whereas chronic HBV carriers and negative controls showed no anti‐HBs‐secreting B cells. Coculture experiments of isolated B and T cells revealed that the anti‐HBs antibody response was restricted to the presence of T helper cells, but not to identical HLA class II molecules. Allogeneic T cells derived from vaccine recipients or chronic HBV carriers stimulated the HBs‐specific B cell response in HBs vaccine recipients. Otherwise, isolated T helper cells could never provide sufficient help to induce the HBs‐specific B cell response in chronic HBV carriers. Furthermore, peripheral blood mononuclear cells (PBMC) of six out of 10 vaccine recipients, one out of five HBV‐immunized patients, but of no chronic HBV carrier showed a proliferative response to different HBs antigen preparations. This study demonstrated a high frequency of circulating anti‐HBs‐producing B cells in the early phase of acute HBV infection, but a lower frequency of HBs‐specific B cells years after resolution of HBV infection. In chronic HBV carriers, however, deficient HBs‐specific T and B cell responses were observed.

Efficacy of an escalating dose regimen of pegylated interferon α-2a plus ribavirin in the early phase of HCV reinfection after liver transplantation

We evaluated the safety and efficacy of an escalating dose regimen of pegylated interferon α‐2a (PEG‐IFNα‐2a) and ribavirin in the early phase of recurrent hepatitis C after orthotopic liver transplantation (OLT). In this prospective study, 26 patients transplanted for hepatitis C virus cirrhosis with recurrent hepatitis C were treated 3.4u2003±u20033.6u2003months after OLT and compared with an untreated historical control. PEG‐IFNα‐2a was initiated as monotherapy, following stepwise dose escalation up to 180u2003μg/week and the addition of ribavirin up to 1200u2003mg/day or maximally tolerated doses for 48u2003weeks. In the intent‐to‐treat analysis, 38% showed an early virological response (EVR), 35% an end of treatment response (ETR) and 19% a sustained virological response (SVR). SVR was associated with EVR (Pu2003=u20030.0001) and cumulative PEG‐IFNα‐2a dose (Pu2003=u20030.04). There was no significant histological improvement compared with untreated patients. There were no treatment‐related serious adverse events. Adverse events included leucopenia (77%) and thrombocytopenia (46%). Three patients discontinued therapy due to side effects, fourteen were nonresponders and four relapsers. Treatment with PEG‐IFNα‐2a and ribavirin in the acute phase of post‐transplant recurrent hepatitis C yielded an EVR of 38% and an SVR of 19%. The combination was safe and well tolerated.

Peripheral blood dendritic cells are phenotypically and functionally intact in chronic hepatitis B virus (HBV) infection

Persistence of hepatitis B virus (HBV) infection is associated with reduced anti‐viral T cell responses. Impaired dendritic cell (DC) function was suggested as the cause of reduced T cell stimulation in chronic HBV carriers. Thus, we compared myeloid (mDC) and plasmacytoid DC (pDC) from chronic HBV carriers and controls. Frequency and phenotype of isolated DC were analysed by fluorescence activated cell sorter staining, DC function by mixed lymphocyte reaction, cytokine bead array, intracellular cytokine staining, enzyme‐linked immunosorbent assay and enzyme‐linked immunospot. Expression of HBV DNA and mRNA was studied by polymerase chain reaction (PCR). Circulating total DC, mDC or pDC were not reduced in chronic HBV carriers. Isolated mDC and pDC from chronic HBV carriers exhibited similar expression of co‐stimulatory molecules and alloreactive T helper cell stimulation as control DC, whether tested directly ex vivo or after in vitro maturation. Secretion of pro‐ and anti‐inflammatory cytokines by CD40 or Toll‐like receptor ligand‐stimulated patient DC was intact, as was human leucocyte antigen A2‐restricted HBV‐specific cytotoxic lymphocyte stimulation. Although both DC populations contained viral DNA, viral mRNA was undetectable by reverse transcription–PCR, arguing against viral replication in DC. We found no quantitative, phenotypic or functional impairment of mDC or pDC in chronic hepatitis B, whether studied ex vivo or after in vitro maturation.

Consensus interferon and ribavirin for patients with chronic hepatitis C and failure of previous interferon-alpha therapy.

Abstract: Background: The efficacy of consensus interferon (CIFN), a synthetic IFN with optimised in vitro activity, was assessed in chronic hepatitis C virus (HCV) patients who had failed the pretreatment with interferon‐α (IFNα) and ribavirin.

All‐trans retinoic acid for treatment of chronic hepatitis C

Background/Aims: In vitro studies in the subgenomic hepatitis C virus (HCV) replicon system have identified all‐trans retinoic acid (ATRA) as a potential therapeutic against hepatitis C. Thus, the antiviral potential of this drug should be assessed in vivo.

Hepatitis B surface antigen presentation and HLA-DRB1*- lessons from twins and peptide binding studies.

The aim of this study was to investigate the underlying mechanisms of the genetic association between certain HLA‐DRB1* alleles and the immune response to HBsAg vaccination. Therefore, HBsAg peptide binding to HLA‐DR molecules was measured in vitro by peptide binding ELISAs. Additionally, HBsAg‐specific T cell reaction and cytokine profile of immune response were analysed ex vivo in ELISPOT assays and DR‐restriction of T‐cell proliferative responses was investigated with HBsAg specific T cell clones. In addition, we compared HBsAg specific T cell responses of 24 monozygotic and 3 dizygotic twin pairs after HBsAg vaccination. Our results showed that the peptide binding assays did not reflect antigen presentation in vivo. DR alleles associated with vaccination failure like DRB1*0301 and 0701 efficiently presented HBsAg peptides. In 11 of 24 investigated monozygotic twin pairs we observed pronounced differences in the recognition of HBsAg peptides. This study indicates that HLA–DR associations with HBsAg vaccination response are not caused by differences in peptide binding or by a shift in the Th1/Th2 profile. Our findings strongly argue for differences in the T cell recognition of peptide/MHC complexes as the critical event in T cell responsiveness to HBsAg.

Detection of hepatitis C virus replication in ovarian metastases of a patient with hepatocellular carcinoma.

Hepatocellular carcinoma is one of the most common human cancers with an annual incidence of about 1,000,000 cases worldwide. Although hepatocellular carcinoma is predominant in hepatitis B virus endemic areas, it has also become a major problem in Europe, Japan and North America in close association with the increasing incidence of hepatitis C virus infection. The pathogenetic role of hepatitis C virus infection in the development of HBsAg-negative hepatocellular carcinoma needs to be clarified. In this paper the case of a 66-year-old HBsAg-negative and anti-HCV positive female who developed hepatocellular carcinoma in a cirrhotic liver is reported. After 1 year of follow up, urgent laparotomy had to be performed due to highly differentiated ovarian metastases of the hepatocellular carcinoma. Plus- and minus-stranded HCV-RNA was detected by reverse transcription and nested polymerase chain reaction in both the patients serum and in the metastatic ovarian tissue.