TTV Viral Load in Heart Transplant Recipients

TTV (Torque Teno Virus) is a ubiquitous virus that is not associated with any disease. A correlation exists between the level of TTV replication and the subject's immunocompetence: weak or non-existent in immunocompetents, very high in immunocompromised patients. In heart transplant patients, pharmacological dosing of immunosuppressants prevents their toxic manifestations but is not correlated with individual immune competence. Only clinical manifestations of overdose (infections) or under dosage (rejections) currently allow optimization of immunosuppressants. A predictive biomarker of these clinical manifestations upstream of their appearance would revolutionize the management of these patients. The TTV fulfills the conditions to be an ideal biomarker: classic blood sampling, possible follow-up in all patients, low cost, carrying out the analysis on already existing molecular biology platforms, reproducibility of inter- and intra-laboratory results, defined thresholds for the reliable interpretation of the results. We believe that this marker will provide the clinician with a useful tool for the management of immunosuppressants and the patient with personalized medicine which will allow their management to be individualized. If this study confirms the expected results, then it will allow, secondly, the setting up of interventional studies to validate the TTV viral load as a biomarker, and a tool for piloting immunosuppressive treatment. The TTV viral load of heart transplant patients will be follow during the first year after transplantation. A tube of blood will be taken during the transplant and then once or twice a month. Samples will be taken at the same time as those taken as part of standard care. The TTV viral load will be measured at the end of the study. The occurrence of events of interest (infections and rejections) will be collected at each corresponding visit.