The Role of Immune Checkpoints in Lung Transplant: the Pathways of Rejection and the Immunomodulatory Therapeutic Perspectives

Lung transplantation is the less common solid organ transplant performed; it is the treatment of choice for end stage lung disease. Lung transplantation is "problematic" for a number of reasons: low graft availability, high waitlist mortality and unsatisfactory survival. Acute rejection, occurring days to months after surgery, has been identified as one of the main risk factors for the development of chronic rejection: in the first five years after lung transplantation, chronic rejection is the major cause of graft failure, morbidity and mortality. A deep knowledge of the immunological scenarios associated with lung graft tolerance could allow selectively switch-off T-cells involved in the rejection process. The researches, preliminary demonstrated the central role of immunological checkpoints in the development of acute rejection and its evolution towards chronic rejection. The aim of this study is the identification of markers that could be associated with the establishment of lung graft tolerance.

The project is articulated into two parts: a retrospective and a prospective section. The retrospective section is constituted by a cross-sectional study of immune checkpoints on lungs explanted during lung re-transplantation for chronic rejection (cohort 1). In addition, the retrospective section includes a retrospective cohort study of immune checkpoints on specimens from transbronchial lung biopsies of participants who received lung transplantation and have 3 years of follow-up (cohort 2). The prospective section is a cohort study of immune checkpoints on specimens from transbronchial lung biopsies and gene expression analysis on immune cells purified from bronchoalveolar lavage; participants will be subjects receiving the lung transplantation during the first year of recruitment and followed for one year (cohort 3).