Quantification of Torque Teno Virus and Epstein-Barr Virus Is of Limited Value for Predicting the Net State of Immunosuppression After Lung Transplantation

Nordén, Rickard; Magnusson, Jesper; Lundin, Anna; Tang, Ka-Wei; Nilsson, Staffan; Lindh, Magnus; Andersson, Lars-Magnus; Riise, Gerdt C; Westin, Johan

It is possible that the observed higher mean TTV-DNA levels in other studies could be explained by differences in induction therapy and distribution of respective immunosuppressive regimen. For example, in the study by Görzer et al. [16] , the type of induction therapy was not defined and only 26% of the patients were treated with Cyclosporine. There is some evidence that TTV replication is dependent on the type of induction therapy that appears to reflect changes in lymphocyte concentration; however, the duration is brief, after which the levels of TTV recover [30] . In the present study, TTV viral load was determined in serum samples, whereas plasma was used in previous studies [16, 31] . However, to our knowledge, there are no apparent reasons for variations in TTV-DNA load, depending on whether plasma or serum is being used for analysis.