This is a prospective, tissue-based, low-risk, non-pharmacological study that will include adult patients undergoing solid organ transplantation (heart, liver, lung, kidney) followed at the following Units of the IRCCS Azienda Ospedaliero-Universitaria di Bologna (IRCCS AOUBO):

• Heart Failure and Transplants (heart-lung)
• Internal Medicine for the Treatment of Severe Organ Failures (liver)
• Nephrology, Dialysis, and Transplantation (kidney).

The aim of this study is to perform objective biological measurements of inflammation and cellular senescence (i.e., plasma profiles of cytokines, inflammatory miRNAs, circulating free DNA, extracellular vesicles), immunosenescence (i.e., circulating and tissue-based leukocyte profiles of aging), and systemic and tissue aging (i.e., epigenetic clocks) in the collected cohort. These measures may help to stratify patients at higher risk of transplant failure (graft damage) or those at higher risk of cardiovascular, renal, metabolic, neoplastic complications, or increased mortality. Additionally, the study aims to implement therapeutic or prophylactic measures based on biological stratification to prevent the progression of biological damage.

It is also important to highlight that the identification of markers of cellular senescence, immunosenescence, and epigenetic aging in the recipient could define patterns that guide more appropriate and personalized immunosuppressive treatments.

Inclusion Criteria:

• Adult patients (≥ 18 years old at the time of enrollment) who have undergone at least one of the following: Liver transplant, Kidney transplant, Heart transplant, Lung transplant during the study period.
• Informed consent acquisition.

Exclusion Criteria:

• none

Consecutive adult patients listed for solid organ transplantation (liver, kidney, heart, lung) at the IRCCS Azienda Ospedaliero-Universitaria di Bologna will be enrolled during the study period.