Previous studies suggested that chronic hepatitis C may relapse in simple chronic hepatitis C patients who initially obtained sustained virologic responses at 6 months after end of the treatment [Chemello et al, 1996; Marcellin et al, 1997]. Although the HCV SVR could be maintained in around 90%, the remaining 10% of these patients may develop hepatitis C relapse during follow-up. Chemello et al followed up 107 patients with chronic hepatitis C who maintained normal aminotransferase levels as long as 12 months after interferon-alpha therapy [Chemello et al, 1996]. Hepatitis C virus RNA was detected in 27 (25%) patients with sustained biochemical response; 80 (75%) patients were negative for HCV RNA. Patients positive for HCV RNA were older (P < 0.001), had received a smaller interferon-alpha dose (P = 0.02), and were more frequently infected with HCV genotype 2 (P < 0.01). Liver histologic findings were active in 57% of patients positive for HCV RNA, despite normal alanine aminotransferase levels, compared with only 12% of patients who were negative for HCV RNA (P = 0.01). The estimated probability of hepatitis relapse by 4 years after therapy was 53% in viremic patients and 0% in patients negative for HCV RNA (P < 0.001). Marcellin et al followed up 80 patients who had chronic hepatitis C and received interferon-alpha therapy [Marcellin et al, 1997]. The 80 patients had follow-up 1 to 7.6 years (mean +/- SD, 4.0 +/- 2.0 years) after interferon-alpha treatment. The follow-up period was 1, 2, 3, 4, 5, 6, and more than 6 years in 11, 13, 14, 18, 10, 12, and 2 patients, respectively, after the end of therapy. During the entire follow-up period, 93% (95% CI, 84% to 97%) of patients had persistently normal serum ALT levels. Serum HCV RNA remained undetectable in 96% (CI, 89% to 99%) of patients. A comparison of liver histologic findings before and 1 to 6.2 years after interferon-alpha treatment showed a clear improvement in 94% (CI, 83% to 99%) of patients. In 62% of patients, the last biopsy done showed normal or nearly normal histologic findings. Liver HCV RNA was detectable before treatment in all 13 patients tested and was undetectable 1 to 5 years after treatment in all 27 patients tested. They thus concluded that in patients with chronic hepatitis C who have persistently normal serum ALT levels and no detectable serum HCV RNA 6 months after interferon-alpha therapy, long-term sustained biochemical and virologic response is generally seen. Similar finding was noted in one reported case with dual chronic hepatitis B and C [Yalcin et al, 2003]. To be noted, this dually infected patient had reactivation of hepatitis B accompanied by severe flare of hepatitis activity during treatment and had relapse of hepatitis C after end of the treatment. Therefore, it is important to follow up the long-term of these patients with dual chronic hepatitis B and C.