Performance of Three Common Hepatitis C Virus (HCV) Genotyping Assays for Identification of HCV Genotype 2/1 Chimeras.

Besides seven major hepatitis C virus (HCV) genotypes (GT), a number of intergenotypic recombinant strains have been described. These so-called chimeras combine genetic characteristics of different HCV genotypes. However, correct genotype classification is important, as choice and duration of direct-acting antiviral (DAA) treatment is mainly based on the viral genotype. Therefore, misclassification of chimeras might lead to suboptimal treatment of patients infected with these strains. For example, 2k/1b chimeras are typically described as HCV genotype 2 strains by commercially available hybridization assays, but real-time PCR-based tests recognizing another HCV region might be more suitable for correct chimera detection. In this study, the analytic capacity of the hybridization-assay Versant HCV Genotype 2.0 (LiPA 2.0) and the real-time PCR-based-assays cobas HCV GT and Abbott RealTime HCV Genotype II were tested in a selected cohort of 230 patients infected with HCV genotype 1 (n = 53) and 2 (n = 177) and 48 patients infected with HCV 2/1 chimeric strains. While the Versant HCV Genotype 2.0 (LiPA 2.0) assay failed to identify chimeras in all of the patients (48/48, 100%), cobas HCV GT and Abbott HCV Genotype II assays identified chimeras correctly in 90% (43/48) and 65% (31/48) of the cases, respectively. In conclusion, while the hybridization-based Versant HCV Genotype 2.0 (LiPA 2.0) assay seems to be unsuitable for detection of HCV 2/1 chimeras, use of the real-time PCR-based assays cobas HCV GT and Abbott RealTime HCV Genotype II led to a higher rate of chimera detection.

Multiple plastic stents versus covered metal stent for treatment of anastomotic biliary strictures after liver transplantation: a prospective, randomized, multicenter trial.

BACKGROUND AND AIMS: Treatment of anastomotic biliary strictures (ABSs) after orthotopic liver transplantation by endoscopic insertion of multiple plastic stents (MPSs) is well established. The use of covered self-expandable metal stents (cSEMSs) for this indication is less investigated. METHODS: In an open-label, multicenter, randomized trial, patients with confirmed ABSs were randomly assigned 1:1 to receive either an MPS or a cSEMS. The primary endpoint was the number of endoscopic interventions until ABS resolution. Secondary endpoints were frequency of adverse events, treatment success rates, and time to treatment success and recurrence of ABS during follow-up of at least 1 year. RESULTS: Fifty-eight patients were included between 2012 and 2015, and 48 patients completed follow-up. Patients receiving MPS (n = 24) underwent a median of 4 (range, 3-12) endoscopic retrograde cholangiography examinations, whereas those in the cSEMS group (n = 24) underwent a median of 2 (range, 2-12) sessions until ABS resolution (P < .001). A median of 8 (range, 2-32) stents was used until ABS resolution within the MPS group and 1 (range, 1-24) in the cSEMS group (P < .0001). cSEMS migration occurred in 8 (33.3%) patients. Treatment duration did not differ significantly. Initial treatment success rates were high with 23 (95.8%) in the MPS group and 24 (100%) for cSEMSs (P = 1). Five (20.8%) patients in both groups showed stricture recurrence after a median follow-up of 500 days (range, 48-1317 days). CONCLUSIONS: cSEMSs for treatment of ABSs needed less endoscopic interventions to achieve similar efficacy as MPS and might become a new treatment standard. However, the optimal duration of cSEMS therapy and cost-efficacy have to be evaluated. (Clinical trial registration number: NCT01393067.).

The capsule endoscopy "suspected blood indicator" (SBI) for detection of active small bowel bleeding: no active bleeding in case of negative SBI.

OBJECTIVE: Capsule endoscopy (CE) is the gold standard to diagnose small bowel bleeding. The "suspected blood indicator" (SBI) offers an automated detection of active small bowel bleeding but validity of this technique is unknown. The objective was to analyze specificity and sensitivity of the SBI using the second small bowel capsule generation for the detection of active bleeding. METHODS: This is a retrospective analysis of all patients (199) who attended our clinic for CE from June 2008 through March 2013. The second-generation PillCam SB 2 capsule was used for detection of (1) luminal blood content and (2) potentially responsible small bowel lesions. The findings of an independent investigator were correlated to SBI findings and a number of SBI markings were analyzed by a receiver operating characteristic (ROC). RESULTS: In 157/199 cases, no sign of active bleeding or altered blood was detected. One hundred and thirty-seven of these 157 cases provided at least one SBI marking and a mean of 18.4 positive SBI markings per record were found. In 20 cases, neither SBI nor the human investigator detected abnormalities. Thirteen patients showed investigator-detected minor bleeding with mean SBI findings of 36 positive screenshots per record. When major bleeding was diagnosed by the investigator (n = 29), SBI detected a mean of 46.6 SBI-positive markings. SBI turned positive in 179 patients, whereas the investigator detected active bleeding in 42 cases. All patients with active bleeding were detected by SBI (sensitivity 100%, specificity 13%). ROC analysis revealed 51.0 SBI markings being the optimal cutoff for active versus no bleeding (sensitivity 79.1%, specificity 90.4%, misclassification of 15.3%). CONCLUSION: The new SBI software is a reliable tool to exclude active bleeding and/or major lesions but analysis of the CE video by a trained investigator is still important for the detection of lesions responsible for past bleeding.

Intraductal endoscopic radiofrequency ablation for the treatment of hilar non-resectable malignant bile duct obstruction.

AIM: To evaluate the safety and technical success of endoscopic radiofrequency ablation (RFA) for palliative treatment of malignant hilar bile duct obstruction. METHODS: In this study, a recently CE and FDA-approved endoscopic RFA catheter was first tested in an ex vivo pig liver model to study the effect of electrosurgical variables on the extent of the area of induced necrosis. Subsequently, a retrospective analysis was conducted of all patients treated with endoscopic RFA for malignant biliary obstruction at our center between February 2012 and April 2013. All patients received an additional plastic stent implantation into the biliary tree following RFA. RESULTS: In the pig model, ablation time of 60-90 seconds using the bipolar soft coagulation mode at 8-10 watts with an effect of 8 was found to be the most feasible setting. Twelve patients (5 females, 7 males; mean age, 70 years) underwent 19 endoscopic RFA (range, 1-5) sessions. Deployment of RFA was successful in all patients. Systemic chemotherapy was administered in four patients. We observed biliary bleeding 4-6 wk after the intervention in three cases and two of these patients died: in one patient, spontaneous hemobilia occurred, whereas bleeding started during stent extraction in the other. In the third patient, bleeding was stopped by insertion of a non-covered self-expanding metal stent. Another three patients developed cholangitis during follow-up. Seven patients died during follow-up and median survival was 6.4 mo (95%CI: 0.05-12.7) from the time of the first RFA. CONCLUSION: Endoscopic RFA is an easy to perform and technically highly successful procedure. However, hemobilia possibly associated with RFA occurred in three of our patients. Therefore, larger prospective studies are needed to further evaluate the safety and efficacy of this promising new method.