Unraveling Dynamics and Clinical Impact of Tregs in Allogeneic HSCT With PTCy

This prospective and retrospective, observational, monocentric study aims to investigate the longitudinal dynamics, phenotype, and functional properties of regulatory T cells (Tregs) in patients affected by hematological malignancies undergoing allogeneic hematopoietic stem cell transplantation (HSCT) with post-transplant cyclophosphamide (PTCy)-based GvHD prophylaxis. Peripheral blood and bone marrow samples will be collected according to clinical practice at predefined timepoints and correlated with major transplant outcomes, including graft-versus-host disease (GvHD), relapse and graft-versus-tumor (GvT), infections, and inflammatory complications. The study hypothesis is that quantitative and functional alterations of Tregs after HSCT influence immune tolerance, GvHD occurrence, and graft-versus-tumor activity, and that the characterization of Treg dysfunction may support the development of innovative CAR-Treg-based immunotherapeutic strategies to control GvHD and preserve GvT. This is a prospective and retrospective, observational, biological, monocenter study. The retrospective component will consist of a cohort of patients with previously biobanked biological samples, collected between 2013 and September 2026, which will serve as a control group for the laboratory analyses.