Atsushi Tanaka 1 , Naoko Hanawa 1 , Mitsuhiko Aiso 1 , Yoriyuki Takamori 1 , Hajime Takikawa 1 1 Teikyo University School of Medicine Background and Aim: Pegylated interferon (PEG-IFN) therapy is not indicated for many cases with HCV-related cirrhosis due to various adverse effects. However, patients with HCV cirrhosis are at high risk for development of hepatocellular carcinoma (HCC). Thus we have introduced low-dose PEG-IFN treatment for patients for compensated HCV cirrhosis. Patients and Methods: Selection criteria for low dose PEG-IFN is 1) compensated HCV-related cirrhosis, and 2) either the elderly (>65) or presence of thrombocytopenia (<8.0x10 6 / l). We have treated patients who met these criteria with low-dose PEG-IFN, consisting of either PEG-2a 90 g/1 -2w or PEG-2b 0.5 g/kg/w+ribavirin 200mg/d. [Results] Twenty patients with compensated HCV cirrhosis (all patients genotype 1b) have been treated with low-dose PEG-IFN (PEG-2a:9, PEG -2b+rib:11 . The age, platelet counts (x10 6 / l), and ALT (IU/l) of 20 patients at baseline were 64.1±8.3, 7.8±4.6, and 90.4±68.6 respectively. All patients were well tolerated. Low-dose PEG-IFN has been continued 59.6±43.8 weeks on average. Although viral response was not detected, biological response (BR), defined as maintenance of ALT within normal range, was obtained in 12 patients (12/20=60%). Of note, neither development of HCC nor decompensated cirrhosis was observed in these 12 BR cases. By contrast, HCC and decompensation developed in 5 and 1 patients respectively among 8 patients who failed to achieve BR. Conclusion: Low-dose PEG-IFN treatment was safe and well tolerable, and could potentially prevent HCC or decompensation in patients with liver cirrhosis when BR was obtained. Aims: To study the efficacy of peginterferon and ribavirin in treating chronic hepatitis C (CHC) with genotype 6a in Hong Kong Chinese. Methods: To assess sustained virological response (SVR) (serum HCVRNA< 500IU/mL) at 6-months follow-up. Results: Nine patients with genotype 6a CHC (included from Jan2003 to Dec2007) received peginterferon and ribavirin. Mean age: 50 (range 28-64). Mean ALT before treatment: 96 IU/L (range 29-173 IU/L). Seven patients had liver biopsy performed, only one showed stage 3-4 fibrosis and others showed active hepatitis without advanced fibrosis. Mean serum HCV-RNA: 9.17x10 5 IU/mL(range 9.0x10 3 -3.3x10 6 IU/mL). Six patients had received peginterferon alfa-2b (1.5mcg/kg/week), other 3 received peginterferon alfa-2a (135mcg/week). Ribavirin dosage ranged from 600mg-1000mg/day depending on body weight and baseline haemoglobin. Treatment durations were 48-52 weeks in 7 patients, 24-26 weeks in 2 patients as one showed rapid virologic response at week 4 and the other was intolerant to side effect of peginterferon. Eight patients had early virologic response at week 12 and one had >2log drop of HCVRNA. Eight patients had end-of-treatment response. Eight patients (88.9%) achieved SVR at end of follow-up. Two patients who received only 24-26 weeks of combination therapy also achieved SVR. The one who failed to achieve SVR was at older age of 60 and had advanced fibrosis. Conclusions: The efficacy of pegylated interferon and ribavirin in treating Chinese patients with chronic hepatitis C genotype 6a can achieve high sustained virologic response rate of 88.9%.