Treatment of acute hepatitis C infection with interferon-alfa 2b monotherapy prevents development of chronic HCV infection

but in females the incidence was twice that of males (12% vs. 6%, p=O.05). Two patients developedliver failure and died, one of whom was HBsAg positive at screening. Conclusion: In this study, a high incidence of severe liver toxicity was observed, especially in women. Clinically these events were attributed to NVP in combination with d4T and blinded treatment medication. Consistentwith recent recommendations,liver enzymesin patients receiving NVP with other antiretrovirals should he monitored closely, particularlyduring the first eight weeks.

2882 Efficacy, Safety, and Tolerebility in Patients Switched to PEG (40 kDa) IFN ~2a (PEGASYS®) After Discontinuation From Interferon Alfa-2b Plus Ribavirin (REBETRON") Combination Therapy for Chronic Hepatitis C. Robert P. Perrillo, Ochsner Clin, New Orleans, I_A; Kenneth D. Rothstein, Albert Einstein Medical Ctr, Philadelphia,PA; Imtiaz Alam, Ctr for Clin Research,Austin, TX; Paul J. Thuluvath, Johns Hopkins Hosp, Baltimore, MD; Melissa Palmer, Paul J. Pockros, The Scripps Clin, La Jolla, CA; Susan Cantwell, Stephen C. Pappas, Roche Lab Inc, Nutley, NJ

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Background: Interferon ~2b/ribavirin (IFN/RBV) combination therapy is more effective than IFN monotherapy for the treatment of chronic hepatitis C (CHC). PEG (40 kDa) IFN ~-2a has also demonstrated increased sustained virological response (SVR) compared with IFN monotherapy (30%-39% vs. 10%-19%) and improved safety and tolerability compared to IFN/RBV. The efficacy, safety and tolerability in patients switched from IFN/RBVto PEG (40 kDa) IFN e-2a has not been established. Objective: To evaluate the efficacy, safety, and tolerability of treatment with PEG (40 kDa) IFN o:-2a after discontinuation of IFN/RBV in patients with CHC. Methods: A 72-week, multicenter, treatment study randomized412 eligible subjects to receive PEG (40 kDa) IFN ~-2a or IFN/RBV. Efficacy, safety, and tolerability were assessed by monitoring of virological/biochemical response and adverse events (AEs), and assessmentof quality of life (QoL). Patientswho were discontinued from assigned IFN/RBV therapy due to therapeutic intolerance were evaluatedfor possible switch to PEG (40 kDa) IFN ~2a therapy; eligible patients were permitted to continue treatment with PEG (40 kDa) IFN ~-2a for a cumulative treatment period of 48 weeks. Results: IFN/RBVwas discontinued due to AEs in 26 of 194 randomizedpatients;18 patients were discontinued due to significant AEs directly related to combination IFN/RBV therapy. AEs prohibiting continued treatment included anemia, nausea,fatigue, and anxiety. These patients were switched to PEG (40 kDa) IFN ~-2a therapy. At the time of switch, 8 (44%) of these patients were demonstrating a virological response; 13 of the 18 patients (72%) have attained or maintained a virological response to therapy through 24 weeks of treatment. Patients switched to PEG (40 kDa) IFN ~2a from IFN/RBValso demonstrated improved safety and tolerability to treatment; further follow-up of these and additional switch patients is in progress. Conclusion: The preliminary results observedsuggestthat patients intolerant to standard IFN/RBVtherapy can be switched to monotherapywith PEG (40 kDa) IFN e-2a and that such a switch is most often associated with improved safety and tolerability, eliminating the necessity of discontinuing antiviral therapy. Furthermore,these patients demonstratecontinued virological responseto treatment.

Chances and Shortcomings of Adenovirus-Mediated ATPTBGene Transfer in Wilson Disease: Proof of Principle Demonstrated in a Pilot Studywith LEC Rats Duc Ha-Hag, Univ Hosp, HeidelbergGermany; Christian Hofmann, HepaVecAG for Genetherapy, Beriin-Buch Germany; Horst Wesh, Josef Doll, German Cancer Research Ctr, Heidelberg Germany; Georg Auburger, Univ Hosp, Frankfurt Germany; Sabine Tuma, Uta Merle, Univ Hosp, HeidelbergGermany; Michael Strauss, HepaVecAG for Genetberapy, Ber~in-~uch Germany;Wo~Igang Stremmel, Univ Hosp, HeidelbergGermany Background& Aims: Wilson disease(WD) is an autosomalrecessivelyinheritedcopper storage disease due to mutations in the ATP7Bgene. It results in impaired biliary copper excretion followed by liver injury leading to cirrhosis. In parallel, copper accumulates in other tissues e.g. basalgangliaof the brain inducing motoric disorders. Phenotypicalcure of this monogenic disease by liver transplantation raised the question whether gene therapy may represent a successful alternativetreatment procedure.To examinethe priciple feasibility of this approach we investigatedthe effects of gene transfer using an adenoviralvector construct expressing the human ATP7BcDNA in an established rodent model for WD, the Long-EvansCinnamon rats (LEC). Methods: RT-PCR,Western-Blot and immunofluorescence analysis were used to assesstransduction efficiency of adenovirus-mediatedgene transfer. The therapeutic effects were analyzedby ferroxidaeeactivity assay and formation of holoeeruloplasminin serum. To determine the change in copper homeostasis we have used positron emission tomography (PET) and analyzed bUiary/intestinal and urinary copper excrecion after injection of ~Cu. Results: Adenovirus-mediatedtransfer of the ATP7Bgene was clearly detectableon RNA and protein level at day 3 and fainted thereafter. Functionalassessmentof the ATP7Bgenetransfer was documented by a significant increse in ceruloplasmin dependentferroxidase activity at day 3, even reaching nearly normal levels at day 10, and declined thereafter to undetectable level at day 14 and 20. In fact, this was paralleledby restoration of serum holoceruloplasmin concentrations until day 10. PET was able to visualize differences in ~Cu distribution between wildtype and LEC rats, indicating its principle usefulness as analyticaltool. In view of the low and transient transduction efficiency in this study, PET-visuabledifferences in ~Cu distribution pattern after ATP7Bgene transfer could not be expected. However, the Ad-ATP7Btreated LEC rat revealed a 2-times higher ~Cu content in stool as a result of improved biliary Cu excretion. Conclusion: The data demonstrate proof of principle of successful gene therapy in an experimental model of WD. Now high efficiency and permanent gene transfer strategies can be employed.

Treatment of Acute Hepatitis C Infection with Interferen-alfa 2b Monotherepy Prevents Development of Chronic HCV Infection Elmar Jaeckel, Markus Cornberg, Medicine Hochschule Hannover,Hannover Germany; Teresa Santantonio, Clin Malattie Infettive, Bari Italy; Julika Mayer, Heiner Wedemeyer, Medicine Hochschulc Hannover, HannoverGermany; Myrga Zankel, Essex Pharma, Munich Germany; Christian Trautwein, Medicine Hochschule Hannover,HannoverGermany; Guiseppc Pastors, Clin Malattie Infettive, Bari Italy; Michael P. Manns, Medicine Hochschule Hannover,Hannover Germany

2881 Thiol Sensitivity of Glutathione (GSH) Transport in Sidedness-Sorted Basolateral Liver Plasma Membrane (bLPM) and in Oatpl Expressing HeLa Cell Membrane. Aravind Mittur, Research Ctr for Liver Diseases, USC Sch of Medicine, Los Angeles, CA; Allan W. Wolkoff, Albert Einstein Coil of Medicine, New York, NY; Nell Kaplowitz, Research Ctr for Liver Diseases, USC Sch of Medicine, Los Angeles, CA

Background: Animal models of infections with non-cytopathic RNA viruses as well as recent success in treating acute HIV-infection support the importance of early control of viral replication for preventing or controlling chronic infection. As the incidence of new HCV infections is decreasing,few patients are seen at one institution thereby preventing larger clinical trials. Aim / methods:Thereforein 1998 we initiateda nationalprospectivetreatment trial in Germany. Over 7000 information brochures were distributed to hospitals and private practices. From March 1998 until October 2000, 43 patients with acute HCV infections were included into the study by 24 different centers. All patients were treated within 4 month after infection with 5 Mio. IU interferon-alfa-2b (IFN) s.c. daily for 4 weeks, followed by 5 Mio. U IFN tiw for 20 further weeks (group A). Therapy was initiated medium time of 89 days after acute infection and 34 patients have completed the follow-up of 6 month after end of therapy. 40 patients with acute HCV-infection seen at the University of Bad between 1995 and 2000, who did not receive therapy, were taken as control (group B). Results: Mean age of the patients was 36 / 40 (group A / B) years and 58 / 42% were female. 16 / 60% were infected by medical procedures, 33 / 8% by needle-stick injury, 19 / 18% by intravenous drug abuse which was not ongoing at the time of therapy, 23 / 8% had sexual contact with HCV-infected partners and in 9 / 8% the mode of infection remained unclear. 53 / 63% of patients were infected with HCV-genotype I, 7 / 28% with genotype II, 19 / 8% with genotype and 0 / 5% with genotype IV. Mean ALT was 891 / 1563 U/I. HCV-RNAwas undetectahle in 97% of patients in group A vs. 30% in group B after 24 weeks (p>O.O00001). One patient in group A subsequentlyclearedthe virus after an hepatitisflare. 74% of patients in group A were already HCV-RNA negative at week 2. At the end of follow-up no patient in group A had signs of chronic HCV-infection while 70% of patients in group B developed chronic HCV-infection (p
INTRODUCTION:Sinusoidal efflux of hepatic GSH is a key step in interorgan GSH/cysteine homeostasis and extracellular detoxification. Recently, Oatpl was shown to transport GSH. However, several previously describedfeatures of GSH uptake in bLPM, such as electrogenic property and asymmetric effects of uncharged thiols (increased efflux, decreased uptake), either cannot be accountedfor by Oatpl or have not been studied. The asymmetric effect of thiols has only beenstudied in intact cells and not directly in membranevesicles.To accomplish the latter, mixed orientated vesicles need to be sorted into inside-out (10) and rightside-out (RO) vesicles. AIM: To directly assessthiol sensitivity of GSH transport in side-sorted bLPM and effect of thiols on GSH transport in HeLa cells expressing Oatpl. METHODS: bLPM vesicles isolated from SD rats were separatedinto I0 and RO fractions by lectin-affinity. GSH uptakewas studied in membranevesicles preparedfrom HeLacells in which Oatpl expression was under the control of a Zn-inducihle promoter. Effect of thiols was studied in vesicles treated with Dl-f (5 mM) under voltage clamp. Effect of nigericin-induced H+ gradient and valinomycin-inducedK+ diffusion potential were studied in vesiclesfrom control (un-induced) and Oatpl-expressing (Zn-induced) cells. Kinetics of uptake was estimated by initial uptake (10 sec) at various levels of [3sS]GSH.RESULTS:GSH uptakewas 2-3 fold higher in I0 than RO bLPM (p
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