Optimal Pediatric Heart Transplant Immunosuppression With MicroRNAs

This study aims to discover circulating microRNAs (associated with drug doses and levels) that can be used to characterize the overall immune state in pediatric heart transplant patients and predict patients that will go on to develop infection and rejection. MicroRNAs (miRs) are small, non-coding RNA molecules that regulate gene expression and serve as molecular biomarkers found in the circulation.

Inclusion Criteria: * Age ≤ 18 years at time of transplant listing * Subject is within 10-50 days post-orthotopic heart transplant at time of enrollment. * Planned follow-up at the transplant center for a minimum of one-year. * Caregiver able and willing to comply with the study visit schedule, study procedures, and study requirements. Exclusion Criteria: * Recipient of a multi-organ transplant * History of prior solid organ transplant before the index heart transplant * Ongoing mechanical circulatory support or hemodynamic instability after transplant * Active infection requiring either a) hospitalization or b) treatment with antimicrobial drugs (does not include prophylaxis for infection or suppressive antibiotics given after transplant) * History of treated rejection prior to study enrollment * Inability to collect specified blood volume after enrollment and prior to 50 days post-transplant