Biliary excretion of TT virus (TTV)

A novel DNA virus (TT virus; TTV) was isolated from a patient with post-tra nsfusion hepatitis of unknown etiology. If TTV replicates in the liver, TTV may appear in the bile. In the present study, to clarify whether fecal-ora l infection occur via biliary excretion, the presence of TN DNA was assesse d in paired serum and bile samples collected from 28 patients with obstruct ive jaundice without parenchymal liver disease. TTV DNA was detected by pol ymerase chain reaction (PCR) using semi-nested primers, and quantified by R eal Time Detection PCR (RTD-PCR). The nucleotide sequence of isolates TTV D NAs was also determined and the sequences were compared between serum and b ile samples. Among 28 patients, 7 were positive for TN DNA in both samples, and 3 and 2 were positive in serum and bile respectively. Of 7 patients po sitive for TTV DNA in both samples, the TTV DNA titer was higher in serum o f 4 patients and in bile of 1 patient. Among 7 patients positive for TTV DN A in serum and bile, 6 had the same sequence in both samples. Multiple dist inct types of TTV DNA clones were isolated from serum in 2 patients and fro m bile in 4 patients. in conclusion, TTV DNA is detected frequently in bile from patients with obstructive jaundice, suggesting a fecal-oral route of infection and high prevalence of asymptomatic mi carriers. TTV DNA was dete cted only in serum from some patients, suggesting that replication of TTV m ay occur in other organs as well as in the liver. J. Med. Virol. 61:462-467 , 2000. (C) 2000 Wiley-Liss, Inc.