Transfusion transmission of highly prevalent commensal human viruses.

BACKGROUND: Anellovirus species Torque teno virus (TTV), Torque teno mini virus (TTMV), and Torque teno midi virus (TTMDV) and flavivirus GBV-C are highly prevalent and genetically diverse chronic human viral infections that have not yet been associated with disease. STUDY DESIGN AND METHODS: To determine if these commensal viruses are transmitted by blood transfusions, we genetically analyzed viral species in cryopreserved samples from blood donors and corresponding pre- and posttransfusion samples from recipients enrolled in the Transfusion-Transmitted Viruses Study cohort. RESULTS: All 24 individuals in 12 donor-recipient pairs were infected with TTV, while 16 were infected with TTMV, 15 with TTMDV, and four with GBV-C. None of the 12 informative cases of TTV transfusion or eight cases of TTMV transfusion, where the donor and recipient viruses could be genetically differentiated, resulted in detectable transmissions in which the donor viruses were detected in the recipient by direct sequencing of the polymerase chain reaction products. Of the five informative cases of TTMDV transfusion, including two cases of transfusion into TTMDV-negative recipients, one case of superinfection was seen with both the recipient and the donor viral variants detected in the transfusion recipient for at least 11 days posttransfusion. Three donor-recipient pairs were informative for GBV-C transmission with only one transfusion into a GBV-C-negative recipient resulting in a transiently detected infection. CONCLUSIONS: Transmission of the common commensal anelloviruses and GBV-C during transfusion was detected in 2 of 12 already infected or uninfected recipients. Underestimation of the true rate of viral transmission may be due to limitations in detecting donor viral variants present as minority variants in the already infected transfusion recipients.

Clearance of hepatitis C virus RNA from the peripheral blood mononuclear cells of blood donors who spontaneously or therapeutically control their plasma viremia.

UNLABELLED: We determined whether hepatitis C virus (HCV) RNA could be detected associated with peripheral blood mononuclear cells (PBMC) of seropositive blood donors who had spontaneously or therapeutically cleared their plasma viremia. Blood donor plasma viremia status was first determined with a highly sensitive transcription-mediated amplification (TMA) test performed in duplicate assays. PBMC from 69 aviremic and 56 viremic blood donors were then analyzed for the presence of HCV RNA with TMA adapted to detect viral RNA in PBMC and with a reverse transcription-nested polymerase chain reaction assay. PBMC-associated HCV RNA was detected in none of the 69 aviremic donors, including all 6 subjects with a sustained viral response following antiviral therapy. PBMC-associated HCV RNA was detected in 43 of the 56 viremic donors. The 13 viremic donors with no detectable PBMC-associated HCV RNA all had very low viral loads (6 positive only in 1 of 2 duplicate plasma TMA assays, 6 with viral loads below 100 HCV RNA copies/mL, and 1 with a viremia of 2700 HCV RNA copies/mL). The absence of detectable PBMC HCV RNA detection in all 69 aviremic donors reported here contrasts with prior studies, possibly as a result of the higher sensitivity of the TMA assay used to test for plasma viremia. CONCLUSION: Our results indicate that PBMC are unlikely to serve as a long-lived reservoir of HCV in aviremic subjects.