Assessment of a Novel Automatic Real-Time PCR Assay on the Cobas 4800 Analyzer as a Screening Platform for Hepatitis C Virus Genotyping in Clinical Practice: Comparison with Massive Sequencing.

The unequivocal identification of hepatitis C virus (HCV) subtypes 1a/1b and genotypes 2 to 6 is required for optimizing the effectiveness of interferon-free, direct-acting antiviral therapies. We compared the performance of a new real-time HCV genotyping assay used on the Cobas 4800 system (C4800) with that of high-resolution HCV subtyping (HRCS). In total, 502 samples were used, including 184 samples from chronic HCV patients (from routine laboratory activity during April 2016), 5 stored samples with double HCV genotype infections for testing the limitations of the method, and 313 samples from a screening protocol implemented in our hospital (from May to August 2016) based on the new method to further determine its genotyping accuracy. A total of 282 samples, including 171 from April 2016 (the 13 remaining had too low of a viral load for HRCS), 5 selected with double infections, and 106 from screening, were analyzed by both methods, and 220 were analyzed only by the C4800. The C4800 correctly subtyped 125 of 126 1a/1b samples, and the 1 remaining sample was reported as genotype 1. The C4800 correctly genotyped 38 of 45 non-1a/1b samples (classified by HRCS), and it reported the remaining 7 samples as indeterminate. One hundred two of 106 non-1a/1b genotype samples that were identified using the C4800 for screening were confirmed by HRCS. In the 4 remaining samples, 3 were correctly reported as genotype 1 (without defining the subtype) and 1 was reported as indeterminate. None of the samples were misgenotyped. Four of 7 samples with double HCV infections were correctly genotyped by the C4800. Excluding the 5 selected double-infected samples, the C4800 showed 95.7% concordant results for genotyping HCVs 2 to 6 and 1a/1b subtyping, and 99.2% concordance for subtyping 1a/1b single infections in clinical samples. To improve laboratory workflow, we propose using the C4800 as a first-line test for HCV genotyping and 1a/1b classification, followed by transferring non-1a/1b samples to a center where HRCS is available, if further characterization is needed.

Twelve-week posttreatment follow-up to predict sustained virologic response for recurrent hepatitis C infection in liver recipients.

BACKGROUND: The current standard for determining sustained virologic response (SVR) in patients treated for hepatitis C virus (HCV) infection is undetectable serum HCV-RNA 24 weeks after treatment. This study evaluates the value of HCV-RNA determination at 12 weeks posttreatment (W+12) to predict SVR in liver transplant (LT) patients treated with pegylated interferon and ribavirin for recurrent HCV infection. METHODS: This study, performed in 2001 to 2010, included HCV-LT patients with an end-of-treatment response (undetectable serum HCV-RNA) and HCV-RNA testing at 12 and 24 weeks posttreatment (W+12/W+24). HCV-RNA was detected with a qualitative polymerase chain reaction assay (detection limit 50 IU/mL) and, when positive, measured by quantitative PCR (detection limit 600 IU/mL) up to 2006. Since 2007, a real-time PCR-based test (detection limit 15 IU/mL) has been used. The positive predictive value (PPV) was defined as the probability that SVR would occur in patients with undetectable HCV-RNA at W+12 and W+24. RESULTS: Of 162 patients treated during the study period, 57 (35%) had end-of-treatment response and were included. Of these, 45 (79%) had SVR and 12 (21%) had virologic relapse. At W+12, HCV-RNA was undetectable in 45 (79%) patients, all of whom had SVR, yielding a PPV for SVR at W+12 of 100% (95% confidence interval, 75.8%-100%). CONCLUSIONS: Undetectable HCV-RNA at W+12 posttreatment has a high PPV for predicting SVR. HCV-RNA testing to assess SVR at this time point seems as valid as W+24 testing and could be considered for predicting SVR in HCV-LT patients receiving treatment with pegylated interferon and ribavirin.

[Adefovir dipivoxil compassionate use program in Spain: efficacy and resistance analysis]. / Programa de uso compasivo con adefovir dipivoxil en España: valoración de su eficacia y estudio de las resistencias.

BACKGROUND AND OBJECTIVE: The extended treatment with lamivudine in patients with chronic hepatitis B is associated with the emergence of resistances. Patients with resistance to lamivudine show a loss of biochemical and virological responses and a higher progression of their liver disease. Adefovir dipivoxil, an analogue of the nucleotides, is effective for the treatment of patients with resistance to lamivudine. The aim of this study was to evaluate the efficacy, safety and resistance of adefovir dipivoxil in patients with chronic hepatitis B refractory to treatment with lamivudine. PATIENTS AND METHOD: One hundred and twenty hepatits B virus patients refractory to lamivudine were treated with adefovir dipivoxil. Seventy-four patients were followed up during two years. In all cases, the hepatitis B virus-DNA was determined by polymerase chain reaction, and in those cases without response to treatment, the presence of resistances to adefovir and lavimudine were studied. RESULTS: At the second year of treatment, we observed a biological response of 54.1%, a biochemical response of 62.2%, while an elimination of hepatitis B e antigen was seen in 21% cases. 20% patients developed resistance to adefovir dipivoxil, and the most frequent detected mutations were: A181V, A181T and N236T. Drug safety was excellent; in fact, only one adverse effect related to the drug was detected. CONCLUSIONS: Treatment with adefovir dipivoxil for 2 years in mono-therapy in patient who are previously non-responders to lavimudine is associated with a high biochemical and virologycal response with an excellent safety. At the second year of treatment, the adefovir dipivoxil resistance rate is 20%.