Torque Teno Virus DNA Load after Heart Transplantation and Its Association with the Strength of Immunosuppression: Preliminary Data of a Prospective Single Center Study

Purpose Long-term survival after heart transplant is still limited due to immunological and drug related adverse events. Immunosuppressive therapy is solely managed via pharmacokinetic analysis and clinical events. TTV (Torque Teno Virus) is a small single-stranded DNA virus associated with increasing viral load under immune compromising conditions. Studies in both kidney and lung transplantation have already shown that the level of plasma TTV - DNA load is associated with the magnitude of immunosuppression. The aim of this prospective observational study was to analyze TTV viral load in patients after heart transplantation (HTX). Methods We prospectively determined the TTV load in 50 heart transplant patients. Samples were collected at pre-transplant and each HTX visit in the out-patient clinic. Viral load analysis was performed by PCR from plasma or serum on the Department of Virology. TTV viral load was compared between pre-transplant and peak levels post transplant. Pre-TX TTV load was compared between different patient groups and between different immunosuppressive protocols after transplantation. Results Patients were transplanted between 1/2016-6/2018. Median age at transplant was 60 (42-67) years and 38% were female. 50%(n=25) of patients were transplanted due to ischemic disease, 44% (n=22) due to dilative Cardiomyopathy and 6% (n=3) due to other disease. 16% of patients were bridged with a mechanical assist device (n=8). Pretransplant TTV levels were 4.4E+00±2.03E+00 cps/ml and significantly increased to 9.39E+00 ±0.75E+00 (p Conclusion TTV viral load increases significantly after heart transplantation and reaches its peak after 90-120 days. VAD pretransplant has an influence of TTV viral load and the choice of calcineurin inhibitor drug seems to be associated with differences in TTV viral load. TTV viral load might be useful as a biomarker for the state of immunosuppression.