Blood-based immunological monitoring after heart transplant. Current status and future prospects

The development of effective immunosuppressive strategies has been a key to successful outcomes in heart transplantation. Immunosuppression however is a double-edged sword with consequences of rejection when underutilized and risk for infection, malignancy, and drug toxicity when used in excess. The search for non-invasive blood-based monitoring not only to assess allograft rejection but also to monitor overall state of immunosuppression remains very attractive, potentially reducing cost and complications and allowing more frequent testing to assess response to anti-rejection therapy. This review outlines the current status of blood-based immunological monitoring after heart transplantation including serological monitoring, biomarkers, and evolution of molecular technologies.