Chronic lung allograft dysfunction (CLAD) is the leading cause of long-term mortality after lung transplantation. Several risk factors for CLAD have been identified, but the exact pathophysiology and triggering molecular factors remain largely unknown. Moreover, in clinical practice, no integration of the different risk factors is achieved. CLAD is therefore diagnosed most often late with the persistent decline in respiratory function, revealing a profound and irreversible alteration of the pulmonary graft. Several blood biomarkers that can predict the occurrence of CLAD more than 6 months before clinical diagnosis have been identified and validated. From these preliminary results, a composite score is being developed from independent samples from the COLT (COhort in Lung Transplantation) cohort. The main objective of this project is to validate this robust and predictive composite score (biological and clinical) of CLAD.

Inclusion Criteria:

• Patients to receive lung transplants awaiting registration on the transplant waiting list
• Patients affiliated to a social security system
• Patients who have given their informed consent
• Patients weighing more than 26 kg
• Patients over 16 years of age

Exclusion Criteria:

• Pregnant or breastfeeding women
• Patients unable to follow the protocol
• Patients with concomitant inflammatory diseases, regardless of acute, chronic or infectious rejection.
• Patients with a history of cancer in remission for less than 5 years, with the exception of localized skin cancers, excluding melanoma.

Patients newly enrolled on the waiting list in transplant centres will be included in the PRELUD study.

Based on the number of annual transplants in France (300/year), we plan to include 240 patients at the time of their registration on the transplant waiting list. Of these 240 patients, we estimate that 190 patients will be transplanted.

It will be possible to include patients in emergencies. In this case, the consent of a trusted person or relative will be obtained and then the patient will give his or her consent as soon as his or her condition permits.