Quantiferon CMV to Identify Treatment Need for Asymptomatic CMV Infection After Solid Organ Transplant (QUANTIFOT)

Context Cytomegalovirus (CMV) infection is a frequent and potentially severe event in solid organ transplant (SOT) recipients. Most of available treatment display adverse effects that limit their use. Therefore, in case of an infection, it is of primary importance to identify the patients at high risk of severe infection and/or disease, and who ill benefit the most from antiviral therapy. As CMV infection is mainly controlled by cellular immunity, measuring specific anti-CMV T lymphocyte immunity could be an interesting tool for identifying these at-risk individuals. One of these tests is the QuantiFERON-CMV (QF-CMV) assay (QuiagenTM, Courtabœuf, France). Aim of the study The aim of the study is to determine the extent to which the QF-CMV can be use to identify, among SOT recipients with a CMV viremia, those that may not need antiviral therapy. Methods Participation to the study will be proposed to SOT recipients with an asymptomatic CMV infection with a blood viral load between 1,000 and 15,000 IU/mL. The QF-CMV will be performed in included participants, and the result will be given or not to the clinician in charge (according to the attributed group through randomisation). * In the group without result communication, the clinician in charge will determine whether a treatment is needed according to the guidelines and the local practices. * in the group with result communication, the clinician in charge will be advised not to introduce antiviral therapy if the result is positive, and to determine whether a treatment is needed according to the guidelines and the local practices if the result is positive. In the following weeks, the viral load will be monitored, along with creatininemia, cell blood count, and kalemia (to detect antiviral adverse effect). The participants will be sampled: * 5 to 12 days after QF-CMV sampling (V2) ; * 7 to 14 days days after V2 (V3 - between D12 and D26) ; * 7 to 14 days days after V3 (V4 - between D19 and D40) . Endpoints The primary endpoint is the rate of uncontrolled infection 5 to 12 days after QF-CMV sampling, defined as follows: * Blood CMV viral load \>10,000 IU/mL \[4 log\]; * And/or increase in blood viral load ≥0.5 log IU/mL with CV otherwise \>5000 IU/mL; * And/or the onset of CMV disease. The secondary endpoint is the is the occurrence antiviral adverse effects (hematoxicity or nephrotoxicity).