Blood, Vol. 93 No. 8 (April 15), 1999:
pp. 2485-2490
TT Virus in Bone Marrow Transplant Recipients
Yoshinobu Kanda,
Yuji Tanaka,
Masahiro Kami,
Toshiki Saito,
Takashi Asai,
Koji Izutsu,
Koichiro Yuji,
Seishi Ogawa,
Hiroaki Honda,
Kinuko Mitani,
Shigeru Chiba,
Yoshio Yazaki, and
Hisamaru Hirai
From the Department of Cell Therapy and Transplantation Medicine and
the Third Department of Internal Medicine, Faculty of Medicine,
University of Tokyo, Tokyo, Japan.
TT virus (TTV) is a newly discovered transfusion-transmissible
DNA virus, which may cause posttransfusion hepatitis. The virus was
detected in 12% of Japanese blood donors. The aim of the study is to
investigate the prevalence and clinical influence of TTV in bone marrow
transplant (BMT) recipients. Sera from 25 BMT recipients obtained 6 to
12 weeks after the transplant were examined for TTV-DNA by the
seminested polymerase chain reaction. Serial samples were additionally
analyzed in patients with TTV-DNA. Fifteen of 25 recipients (60%) were
positive for TTV-DNA after transplant, whereas it was detected in only
two of 20 BMT donors (10%). In patients positive for TTV-DNA before
BMT, the amount of TTV-DNA decreased to an undetectable level during
the myelosuppressed period after BMT. We also found that there was a
novel group of TTV, G3, classified by the nucleotide sequences. The
median peak alanine aminotransferase (ALT) levels were 135.0 IU/L and
116.5 IU/L (normal range, 4 to 36 IU/L) in TTV-positive and
TTV-negative recipients, respectively. In one of the seven TTV-positive
patients who developed hepatic injury (ALT > 150 IU/L), a serial
change in the serum TTV titer showed a good correlation with the ALT level. We concluded that (1) the prevalence of TTV is high in BMT
recipients, (2) TTV might be replicated mainly in hematopoietic cells,
(3) transfusion-transmitted TTV may cause persistent infection, (4) a
novel genetic group of TTV, G3, was discovered, and (5) TTV does not
seem to frequently cause hepatic injury, although one patient was
strongly suggested to have TTV-induced hepatitis.
