Next Generation Sequencing to Detect Acute Rejection in Lung Transplant Patients.

Lung transplantation is a consolidated treatment in selected patients with end-stage respiratory diseases; however, acute rejection remains an important cause of lung allograft loss and a risk factor for chronic allograft dysfunction. Histopathological examination of lung tissue is the gold standard for the diagnosis of acute rejection, therefore recipients undergo surveillance transbronchial biopsy and bronchoalveolar lavage after transplantation. However, the obtained tissue is sometimes inadequate for histopathology, and the endoscopic procedure can lead to complications (bleeding, pneumothorax). The quantification of donor-derived cell-free DNA (ddcfDNA) in the recipient plasma has shown to be increased in case of acute rejection, and could represent an early and non-invasive diagnostic marker to detect acute rejection. We planned to enroll all patients aged 18 to 65 years old enlisted for lung transplantation at our centre. Patients undergoing retransplantation and patients with a history of prior solid organ transplantation were excluded. The quantification of donor-derived cell-free DNA was performed 15 days and 3, 6, and 12 months after transplantation, concurrently with the routine surveillance bronchoscopies as per our protocol; the same analysis was also conducted in case of suspected clinical rejection.