TT virus infection does not affect the clinical profiles of patients with hepatitis B and C in Yanbian City, China.

China is an area of high endemicity for viral hepatitis, and the molecular epidemiological investigation of TT virus (TTV) infection is of interest. In the present study, we investigated the epidemiology, clinical significance and molecular characteristics of TTV infection in patients with chronic hepatitis B and C in Yanbian City, China. Serum samples obtained from 74 patients with hepatitis B and hepatitis C who visited Yanbian Hospital, located in northeast China, were analyzed in this study. The study group included 22 cases of chronic hepatitis B (B-CH), 17 cases of liver cirrhosis B (B-LC), 7 cases of hepatocellular carcinoma (B-HCC), 16 cases of chronic hepatitis C (C-CH), 11 cases of liver cirrhosis C (C-LC) and 1 case of hepatocellular carcinoma (C-HCC). Detection of TTV DNA was performed as described by Nishizawa et al. The second-round PCR products from 7 subjects were sequenced, followed by investigation of nucleotide homology and phylogenetic analysis. TTV DNA was present in 18.2, 5.9, 28.6, 6.3, 9.1 and 0% of the patients with B-CH, B-LC, B-HCC, C-CH, C-LC and C-HCC, respectively. The highest prevalence of TTV infection was seen in the groups aged 40-50 and over 60 years. There was no significant correlation between the presence of TTV DNA and the clinical parameters in patients with hepatitis B and C. The various isolates showed 97.9-100% with isolates reported previously from Japan and 98.4-100% with isolates reported previously from China. Nucleotide sequence analysis revealed that the Yanbian isolates could be classified in the same group as the Japan and China isolates. We concluded that chronic coinfection with TTV did not affect the serological features of chronic hepatitis B and C in China, as found in Tokyo, Japan.