Abstract
PURPOSE OF REVIEW: Survival outcomes for heart transplant recipients have improved in recent decades, but infection remains a significant cause of morbidity and mortality. In this review, we discuss several biological markers, or biomarkers, that may be used to monitor immunologic status in this patient population. RECENT FINDINGS: While modest, data on the utility of immune biomarkers in heart transplant recipients suggest correlation between low level of immune response and increased infection risk. More novel assays, such as the detection of circulating levels of pathogen cell-free DNA in plasma and the use of Torque teno virus load as a surrogate for net state of immunosuppression, have potential to be additional important biomarkers. Biomarker approaches to individualize immunosuppression therapy among heart transplant recipients is a promising area of medicine. However, additional studies are needed to inform the optimal protocol in which to incorporate these biomarkers into clinical practice.