Hepatitis C viral dynamics during ribavirin priming differ according to prior treatment response and HCV type.

The mode of action of ribavirin is not completely understood. Ribavirin monotherapy has a measurable antiviral effect, which shows great variability. It might lead to an earlier steady state of plasma concentration and therefore enhance the effect of following combination treatment. The aim of this study was to evaluate the antiviral effect of ribavirin priming and its influence on sustained virologic response after combination treatment in a group of patients with different hepatitis C virus (HCV) types with or without prior treatment experience. Retrospective analysis of 75 patients (37 treatment naïve, 20 prior relapse, 16 prior nonresponse, genotype 1 present in 60 patients) from five centres who received ribavirin priming as part of an individual strategy in order to improve treatment outcome. All patients received ribavirin monotherapy with a mean dose of 14.5 mg kg-1 body weight for a mean of 28 days. After ribavirin priming, dual combination treatment with pegylated interferon alfa and ribavirin was started. The mean HCV RNA decline after ribavirin priming was 0.6 log10  IU mL-1 (P<.001). The initial viral decline depended on HCV type and previous treatment status being highest among prior relapsers (0.8 log10  IU mL-1 ; P=.002) and HCV type 2/3 (1.2 log10  IU mL-1 ; P=.05) and lowest among those with prior nonresponse (0.3 log10  IU mL-1 , P=.01). IFNL4 (formerly IL28B) genotype for rs12979860 and IFNL3 genotype rs8099917 did not influence the initial viral decline. The study demonstrates a significant variability in the viral dynamics and antiviral efficacy of ribavirin monotherapy, which is mainly influenced by prior treatment status. The fact that the lowest response pattern was observed in prior nonresponder patients to pegylated interferon alfa plus ribavirin combination therapy can be taken as a hint that not only the individual interferon, but also the ribavirin sensitivity contributes significantly to the nonresponsive state.

High-dose silibinin rescue treatment for HCV-infected patients showing suboptimal virologic response to standard combination therapy.

Incomplete suppression of hepatitis C virus (HCV) replication with persistence of minimal viremia (partial virologic response) leading to treatment failure can be observed in a significant proportion of HCV type 1-infected patients during antiviral therapy. Recently, high-dose intravenous silibinin has demonstrated strong antiviral activity against HCV. We were therefore interested in whether patients with partial virologic response can be rescued by the on-treatment addition of a short-term course of high-dose intravenous silibinin infusions. Twenty patients who failed to achieve a complete virologic response to different interferon-based regimens qualified for the rescue strategy and received 1400 mg/day silibinin infusions on two consecutive days. Complete viral suppression (below the limit of detection <6 IU/mL, TMA assay) could be induced in 13 of 20 patients within the first week after the short-term silibinin infusion, and all but one of them also remained HCV RNA negative during the subsequent follow-up period on continued peginterferon plus ribavirin treatment. In the remaining seven patients, no complete suppression could be achieved although four showed a significant HCV RNA reduction in response to silibinin. Silibinin infusions were generally well tolerated, and activation of abdominal peristalsis with nausea, diarrhoea and vomiting were the most prominent side effects. Of the twelve patients who exhibited a durable response to peginterferon and ribavirin treatment, three achieved an SVR, two achieved a week 12 SVR and four suffered a viral relapse. Three patients could not complete the assigned antiviral treatment with peginterferon alpha and ribavirin for nonvirological reasons. Short-term administration of high-dose intravenous silibinin might be an interesting approach to rescue patients with ongoing minimal residual viremia while on interferon-based therapy. These preliminary findings may stimulate further studies to evaluate more refined therapeutic strategies.

Transluminal endoscopic necrosectomy after acute pancreatitis: a multicentre study with long-term follow-up (the GEPARD Study).

BACKGROUND: As with endoscopic transmural drainage of peripancreatic fluid collections, the same transluminal access can be expanded to introduce an endoscope through the gastrointestinal wall into the retroperitoneum and remove infected pancreatic necroses under direct visual control. This study reports the first large series with long-term follow-up. METHODS: Data for all patients undergoing transluminal endoscopic removal of (peri)pancreatic necroses between 1999 and 2005 in six different centres were collected retrospectively, and the patients were followed up prospectively until 2008. The initial patient and treatment outcome data were recorded, as were long-term results. RESULTS: Ninety-three patients (63 men, 30 women; mean age 57 years) underwent a mean of six interventions starting at a mean of 43 days after an attack of severe acute pancreatitis. After establishment of transluminal access to the necrotic cavity and subsequent endoscopic necrosectomy, initial clinical success was obtained in 80% of the patients, with a 26% complication and a 7.5% mortality rate at 30 days. After a mean follow-up period of 43 months, 84% of the initially successfully treated patients had sustained clinical improvement, with 10% receiving further endoscopic and 4% receiving surgical treatment for recurrent cavities; 16% suffered recurrent pancreatitis. CONCLUSIONS: Direct transluminal endoscopic removal of pancreatic necroses is associated with good long-term maintenance of the high initial efficacy; complications can occur, with an associated mortality of around 7.5%. Further studies are necessary in order to optimise endotherapy and define its role in relation to surgery in the clinical management of such patients.

Late endocytic compartments are major sites of annexin VI localization in NRK fibroblasts and polarized WIF-B hepatoma cells.

Annexin VI is an abundant calcium- and phospholipid-binding protein whose intracellular distribution and function are still controversial. Using a highly specific antibody, we have studied the distribution of annexin VI in NRK fibroblasts and the polarized hepatic cell line WIF-B by confocal microscopy. In NRK cells, annexin VI was almost exclusively found associated with endocytic compartments, which were defined by their ability to receive fluid-phase marker internalized from the cell surface. However, extensive colocalization of annexin VI and the endocytic marker was only observed after about 45 min, indicating that annexin VI was primarily in late endocytic compartments or (pre)lysosomes. Consistent with this, annexin VI was predominantly seen on structures that contained the lysosomal protein lgp120, although not on dense core lysosomes by electron microscopy. Two major populations of annexin VI-containing structures were present in polarized WIF-B hepatocytes. One correlated to lgp120-positive (pre)lysosomes and was still observed after treatment with brefeldin A (BFA), while the other appeared to be partially associated with Golgi membranes and was BFA-sensitive. The striking association with prelysosomal compartments in NRK and WIF-B cells suggests that annexin VI could play a role in fusion events in the late endocytic pathway, possibly by acting as a tether between membranes.

Annexin VI defines an apical endocytic compartment in rat liver hepatocytes.

Annexin VI has been demonstrated previously to be a marker for hepatic endosomes. By western blotting with an affinity purified anti-annexin VI antibody it was shown that annexin VI was present in the three morphologically and functionally different endosomal fractions from rat liver. We have quantified the gold-labeled endosomes by immunoelectron microscopy in ultrathin Lowicryl sections of rat liver and now demonstrate that 80% of the total labeling with anti-annexin VI was associated with endocytic structures surrounding the bile canaliculus, the apical domain of hepatocytes, whereas only 20% was found in the subsinusoidal endosomes. In double immuno-gold labeling experiments 80% of the Rab5 positive apical endosomes were also labeled with anti-annexin VI antibodies. However, there was no significant colocalization with antibodies to the polymeric immunoglobulin receptor. Finally, we demonstrate that 50% of endosomes containing internalized gold-labeled transferrin were double labeled with anti-annexin VI antibodies. Thus, annexin VI becomes the first known structural protein at the apical 'early' endocytic compartment of the hepatocyte that may be involved in the receptor recycling and transport to late endocytic/lysosomal compartment pathways.

[Immunohistochemical localization of annexin VI in the endocytic compartment of rat liver hepatocytes]. / Localización inmunocitoquímica de la anexina VI en el compartimiento endocítico de hepatocitos de hígado de rata.

Annexin VI has been isolated from rat liver endosomes and affinity purified antibodies have been produced. By Western blotting, in rat liver subcellular fractions, anti-annexin VI was demonstrated to recognise a 68 kDa band in the three endosomal fractions. In the present study, immunogold labeling of ultrathin Lowicryl sections of rat liver has been used to get insights into the ultrastructural hepatocyte localization. Although at the immunofluorescence level the staining seemed located at the apical, canalicular plasma membrane, domain of the hepatocytes, the electron microscopy revealed that 80% of the labeling, with the anti-annexin VI antibody was specifically localized not at the plasma membrane but in the close subapical endocytic compartment surrounding the bile canalicular plasma membrane of the hepatocyte. Double immunogold labeling with an anti peptide antibody to Rab5 and anti-annexin VI showed that 80% of the Rab5 positive apical endosomes were also labeled with anti-annexin VI antibodies. However, there was no significant colocalization of annexin VI and structures labeled with antibodies to the polymeric immunoglobulin receptor. The results suggest that annexin VI could be involved in regulating the functioning of this apical compartment in the hepatocyte.