Torque Teno Virus as a Novel Biomarker Targeting the Efficacy of Immunosuppression After Lung Transplantation.

Torque teno viruses (TTV) are small DNA-viruses, of the genus Alphatorquevirus, whose replication is linked to immune status. TTV load may be an indicator for efficacy of IS in lung transplant recipients (LTRs). In a prospective single-center-study 143 LTRs were followed up and tested by quantitative TTV-DNA PCR. Using multivariate Cox-regression contribution of TTV-load to the occurrence of severe infections, chronic lung allograft dysfunction (CLAD), acute cellular rejection (ACR), and death was assessed. During follow-up 28 (20%) patients developed infections with a rate of 7.7 per 100 patient-years (PY). The hazard-ratio (HR) associated with a one-log10 increase of TTV-load before the event was 5.05. CLAD occurred with a rate of 6.0%-PY. HR for a 1 log10 increase of the lowest TTV level before the event was 0.71 (CI: 0.54-0.93). TTV-load predicts clinical events and may be useful to optimize IS during the first years of follow-up of LTRs.