[The prevalence of TTV infection in non-A to G chronic liver disease, especially non-A to G hepatocellular carcinoma, and the clinical significance of TTV infection].

We examined the prevalence of TT virus (TTV) infection in non-B, non-C, non-G chronic liver disease, in particular, in hepatocellular carcinoma (HCC), and the clinical significance of TTV infection. Among 829 cases with chronic liver disease, 30 cases (4%) had non-B, non-C, non-G chronic liver disease. The percentage of TTV-DNA positive cases among these 30 cases with non-B, non-C, non-G chronic liver disease was 57% (17/30), significantly higher than the percentage TTV-DNA positivity (14%; 5/107) among blood donors (P < 0.01). All the TTV-DNA positive cases were still positive for TTV-DNA throughout the follow-up period (4 +/- 2 years; 1-7 years), thus demonstrating that TTV infection is persistent. These findings suggest that TTV may be one of the causes of non-B, non-C, non-G chronic liver disease. When the 30 cases of non-B, non-C, non-G chronic liver disease were divided into a TTV-DNA positive group and TTV-DNA negative group and the clinical data between the two groups compared, it was found that the serum ALP and serum gamma-GTP levels in some cases in the TTV-DNA positive group were higher than those in the TTV-DNA negative group. Twelve cases of non-B, non-C, non-G HCC were divided into two groups (TTV-DNA positive and TTV-DNA negative), and the clinical data between the two groups compared. All the four cases of HCC which were not associated with liver cirrhosis were TTV-DNA positive. However, with respect to the age at the time of onset of the HCC, no significant differences were noted between the cases of HCC associated with liver cirrhosis and those not associated with liver cirrhosis. In spite of older patients, many cases of HCC associated with TTV infection are not associated with liver cirrhosis.