P764 ANALYSIS OF THE EFFECT OF CYCLOPHILIN INHIBITOR ALISPORIVIR ON THE INTERFERON RESPONSE IN HCV-INFECTED CELLS AND PATIENTS

POSTERS positive at baseline and those with HCV antibody seroconversion during follow-up were tested for HCV RNA and sequenced (CoreHVR1/NS5B). Year of infection was estimated as one year after selfreported initiation of injecting. Trends in HCV genotype distribution were evaluated. Factors associated with genotype 3a infection were assessed using logistic regression. Results: Among 818 participants, HCV genotype prevalence was: G1a: 52% (n = 422), G1b: 6% (n = 46), G2a: 3% (n = 22), G2b: 6% (n = 53), G3a: 32% (n = 263), G4a: <1% (n = 4), G6a: 1% (n = 7) and G6e: <1% (n = 1). Overall, 37% were female and 21% were HIV+. The prevalence of HCV genotype 3a infection increased from 28% among those infected prior to 1980 to 40% among those infected between 1995 and 2010 (P = 0.009). Factors independently associated with HCV genotype 3a infection included female sex (AOR 1.45; 95% CI 1.03, 2.03), HIV co-infection (AOR 0.65; 95% CI 0.44, 0.95) and more recent year of infection. Conclusions: The prevalence of genotype 3a infection appears to have increased among PWID in this setting. This has implications for HCV treatment as prevention strategies, given reduced efficacy of IFN-free DAA-based therapy in people with genotype 3a. P763 ANALYSIS OF HCV MARKERS AND IMMUNE RESPONSES 5–20 YEARS AFTER SUCCESSFUL HCV THERAPY SUGGESTS THAT MOST PATIENTS ARE CURED 1 E.D. Brenndorfer ¨ , M. Hedenstierna2 , D. Bankwitz3 , P. Behrendt3 , A. Brass1 , I. Uhnoo4 , S. Aleman5 , A. Fryden6 , G. Norkrans7 , A. Eilard7 , H. Glaumann8 , K. Cardell6 , T. Pietschmann3 , O. Weiland2 , 1 1 M. Sallberg ¨ . Division of Clinical Microbiology, Department of Laboratory Medicine, 2 Division of Infectious Diseases, Department of Medicine, Karolinska Institutet, Stockholm, Sweden; 3 Institute of Experimental Virology, Twincore Centre for Experimental and Clinical Infection Research, Hannover, Germany; 4 Department of Infectious Diseases, Akademiska University Hospital, Uppsala, 5 Department of Gastroenterology and Hepatology, Karolinska University Hospital Solna and Huddinge, Stockholm, 6 Department of Infectious Diseases, University Hospital, Link¨ oping, 7 Department of Infectious Diseases, Sahlgrenska University Hospital, Gothenburg, 8 Clinical Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden E-mail: [email protected] Background and Aims: Studies have suggested that HCV can persist at low levels in patients who have achieved SVR after IFN-based therapy. The clinical importance of these findings is unclear. We here evaluated virological and immunological markers 5–20 years after SVR. Methods: We tested for HCV RNA by a highly sensitive method detecting 2 copies/ml in serum, PBMC, and liver of 54 patients. HCVspecific T cell responses were monitored by ELISpot and pentamer staining, humoral responses by measuring a-HCV NS3 antibodies and virus neutralization. A routine clinical workup was performed. Results: In three patients, HCV RNA was detected in PBMCs 5–9 years after SVR but became negative 3–5 years later. These three patients had strong HCV-specific T cell responses and 2/3 high a-HCV NS3 antibody levels but low neutralizing antibody levels. None of these three had clinical or histological signs of liver disease. In all 54 patients, HCV-specific T cell responses, a-HCV antibody levels and signs of liver disease decreased with the duration of SVR. Conclusions: Although we could confirm that low levels of HCV RNA can be detected in a minority of the patients, the preponderance of the data suggests that an SVR corresponds to a cure on long-term. All markers analyzed support a complete disappearance of the virus, such as the decrease in B and T cell activity, and the waning liver disease. Thus, albeit we confirmed previous studies reporting traces of HCV RNA in PBMCs after SVR, the clinical significance of this finding seems to be limited.

P764 ANALYSIS OF THE EFFECT OF CYCLOPHILIN INHIBITOR ALISPORIVIR ON THE INTERFERON RESPONSE IN HCV-INFECTED CELLS AND PATIENTS M. Bobardt1 , J. Baugh1 , P. Gallay1 , S. Ma2 , S. Kaiser3 , N. Hartmann3 , M. Letzkus3 , F. Staedtler3 , A. Riva4 , S. Chokshi4 , N.R. Nirmala2 , K.J. Johnson2 , C.A. Brass5 , N.V. Naoumov6 , B. Li2 . 1 Scripps Research Institute, La Jolla, CA, 2 Novartis Institutes for Biomedical Research, Cambridge, MA, United States; 3 Novartis Institutes for BioMedical Research, Basel, Switzerland; 4 Institute of Hepatology, Foundation of Liver Research, London, United Kingdom; 5 Novartis Pharma Corporation, East Hanover, NJ, United States; 6 Novartis Pharma AG, Basel, Switzerland E-mail: [email protected] Background and Aims: Alisporivir (ALV) has demonstrated potent anti-HCV activity in vitro and in clinical studies. Its main mechanism of action is preventing HCV NS5A protein and host cyclophilin A (CypA) interactions, which are essential for HCV replication. Here, we investigated whether ALV has an additional effect in modulating type-I interferon (IFN) response. Methods: Protein levels of IFNa, IFNb, or IFNl and expression levels of IFN-stimulated genes (ISGs) were evaluated in: i) 26 HCV patients at baseline and week 4 of ALV treatment; ii) peripheral blood mononuclear cells (PBMCs) from 20 HCV-infected patients, and iii) 8 liver-derived replicon cell lines treated with ALV. Results: In patients, plasma IFNa or IFNb levels at baseline (1.1±1.6 and 1.0±0.7 pg/mL, respectively) did not change after 4 weeks of ALV treatment (1.1±1.7 and 1.0±0.5 pg/mL respectively), whereas ISG expression significantly decreased in PBMCs of ALV-treated HCV patients (p < 0.05; baseline to week 4). In vitro, no up-regulation of IFNa or IFNl protein levels was detected either in 7/8 replicon cell lines, or in 18/20 HCV patients-derived PBMC samples during 5 days of ALV treatment. When treated with IFNa, a 15–60-fold increase in ISG expression was observed in all 8/8 replicon cell lines. In contrast, no detectable expression of ISG56 or IFITM1 was seen in any cell line treated with ALV. Conclusions: These results further demonstrate that ALV inhibits HCV replication by blocking NS5A-CypA interactions, and no induction of endogenous type-I IFN or IFN-stimulated genes was observed in vitro or in HCV patients treated with ALV. P765 DRIED BLOOD SPOTS (DBS), A PROMISING TOOL FOR LARGE-SCALE HEPATITIS C SCREENING, DIAGNOSIS AND TREATMENT MONITORING S. Chevaliez, A. Soulier, L. Poiteau, J.-M. Pawlotsky. Department of Virology & INSERM Unit U 955, Creteil, France E-mail: [email protected] Background and Aims: The utility of dried blood spots (DBS) as a template for serological and molecular testing has been demonstrated in the HIV setting. The aim of the study was to assess the performance of DBS for anti-HCV antibodies (Ab) detection, HCV core antigen (AgC) and HCV RNA quantification in a large number of subjects chronically infected with HCV genotypes 1 to 6. Methods: 529 patients, including 183 HCV-seronegative and 346 HCV-seropositive patients were included. Anti-HCV Ab was detected by 3rd -generation EIA. HCV RNA levels were quantified by means of real-time PCR assays. AgC levels were assessed with the Architect HCV Ag assay. Results: Among the 529 DBS specimens, the mean±SD signal/cutoff values for anti-HCV Ab detection were 13.3±7.2 and 0.1±0.2 in HCVseropositive and -seronegative patients, respectively. A cutoff value of 0.2 was associated with a specificity of 98.9% (95% CI: 96.1%99.7%) and a sensitivity of 99.1% (95% CI: 97.4%-99.7%). Only three DBS were falsely negative for anti-HCV Ab detection. A positive significant correlation was found between the HCV RNA levels

Journal of Hepatology 2014 vol. 60 | S215–S359

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