Detection of TT virus DNA in patients with liver disease and recipients ofliver transplant

TT virus (TTV) is transfusion-transmissible but its involvement in post-tra nsfusion hepatitis is uncertain. To investigate the potential association o f TTV with liver diseases, the prevalence of TTV DNA was tested by semi-nes ted PCR in 113 carriers of hepatitis C virus (HCV), 10 patients with acute liver failure, 11 patients with cryptogenic cirrhosis and 200 control blood donors. Thirty-seven of these patients underwent liver transplantation and were tested pre- and posttransplantation. TTV DNA was semi-quantified in s erial samples from seven patients with unexplained post-transplant hepatiti s. TTV genotyping was performed on samples from 28 patients by sequence ana lysis. The prevalence of TTV DNA in brood donors was 1.5% and 17% in HCV in fected haemophiliacs. In patients with acute or chronic liver disease or he patitis, 6 to 27% prevalence was observed. After liver transplantation, the prevalence of TTV DNA increased from 16 to 46% (P < 0.01). In patients who developed unexplained hepatitis post-transplantation, TTV viraemia did not parallel ALT levels. TTV DNA either increased in titre or became detectabl e shortly after transplantation, suggesting that either TTV was transfusion -transmitted, or, more likely, that immunosuppression caused a recurrence o f low level or undetectable TTV viraemia. TTV had considerable genomic dive rsity in the N22 region, corresponding to at least 4 genotypes. Genotype 2 was found in 14/28 patients. J. Med. Virol. 61:455-461, 2000. (C) 2000 Wile y-Liss, Inc.