Incidence and clinical presentation of posttransfusion TT virus infection in prospectively followed transfusion recipients: emphasis on its relevanceto hepatitis

BACKGROUND: A novel transfusion-transmissible human DNA virus, TT virus (TT V), has been discovered recently. An attempt was made to determine the inci dence and clinical outcome of TTV infection in recipients of blood transfus ion. STUDY DESIGN AND METHODS: Serial serum samples collected as part of a prosp ective study of posttransfusion hepatitis were examined for TTV DNA by a ne sted PCR assay. RESULTS: Among 150 adults undergoing cardiac surgery, posttransfusion speci mens from 59 individuals were positive for rn! DNA. Pretransfusion sera wer e found to be positive in 13 of these individuals. Therefore, 46 (33.6%) of the 137 previously uninfected patients developed new TTV viremia after tra nsfusion. Among the 46 patients, 3 were coinfected with HCV, 5 were coinfec ted with HGV, and 38 were infected with TTV alone. No apparent symptoms or signs were noted in the 38 patients infected by TTV alone or the 5 infected with HGV plus TTV. The average peak serum ALT activity was 31 IU per L, wi th persistently normal levels in 34 of the 38 patients with TTV infection a lone. In 8 other patients who subsequently developed well-documented non-A- G hepatitis, 3 were positive for TTV (3/8 vs. 46/137, p = 0.8). In 12 patie nts followed for more than 1 year, TTV viremia persisted in every case. CONCLUSION: In this population, TTV is transmitted by transfusion to approx imately 30 percent of patients who undergo cardiac surgery. Most of the inf ections appear to become persistent. Despite the high prevalence rate, TTV does not appear to cause hepatitis on its own.