TT virus infection in Thailand: Prevalence in blood donors and patients with aplastic anemia

Aplastic anemia has been reported to occur after viral hepatitis of unknown etiology. Recently, TT virus (TTV), a novel DNA virus, was identified in a Japanese patient with posttransfusion non-A-E hepatitis. The prevalence of TTV infection was investigated among blood donors and patients with aplast ic anemia in Thailand. Of 99 blood samples from blood donors, 37 tested pos itive for TTV DNA via semi-nested polymerase chain reaction (PCR) using TTV -specific primers. Seventeen percent of samples from blood donors younger t han 20 were positive for TTV DNA, whereas 48% from donors older than 20 wer e positive. The high prevalence of TTV infection in Thailand is comparable to that reported in China (28%), Mongolia (43%), and Egypt (29%). Forty-two percent of newly diagnosed aplastic anemia patients tested also had TTV DN A in blood. The detection rate of TTV DNA in aplastic anemia patients does not differ significantly from rates in normal blood donors. Our present dat a thus argue against the role of this novel hepatitis-associated virus in t he pathogenesis of aplastic anemia in Thailand. However, larger epidemiolog ical studies may be needed to further evaluate their association. Int J Hem atol. 2000;72:325-328. (C) 2000 The Japanese Society of Hematology.