Heart Transplant Rejection

Demonstrate the relationship between DD-cfDNA levels and HLA antibodies in blood transplant recipient and the Molecular Microscope® (MMDx) Diagnostic System results in indication and protocol biopsies from heart transplants.

The SweD-HTx-study is an observational, multicenter cohort study including adult HTx recipients from Skåne University Hospital (Lund), Sahlgrenska University Hospital (Gothenburg), and Karolinska University Hospital (Stockholm). The aim of the study is to establish a robust, nationwide protocol for dd-cfDNA-based rejection monitoring in Swedish HTx recipients and to enhance our understanding of rejection mechanisms and immune activation. All participants undergo endomyocardial biopsies as part of routine post-transplant surveillance. Heart transplantations are performed at Skåne University Hospital or Sahlgrenska University Hospital, with post-transplant follow-up conducted at the outpatient transplant clinics at the participating centers. Eligible participants are adults (≥18 years) who undergo orthotopic HTx. Exclusion criteria include pregnancy, multi-organ transplantation, or a history of other solid organ or hematopoietic stem cell transplantation. Peripheral blood samples are collected according to standardized operating procedures and transported at ambient temperature to the immunology laboratory for processing. A subset of samples is immediately cryopreserved upon collection. Clinical and demographic data are extracted from the electronic medical record (EMR) using standardized data collection forms. The main outcome is the correlation between analyzed dd-cfDNA fraction levels and biopsy-proven rejection, defined by International Society of Heart and Lung Transplantation (ISHLT)'s histopathological criteria. The longitudinal changes in dd-cfDNA fraction and DSA will be analyzed as well as the association between DSA and dd-cfDNA fraction.

We will conduct a two-group randomized controlled trial to examine the eMocha DOT intervention with pediatric HT recipients.In this population, medication nonadherence remains a primary cause of late acute rejection (LAR) episodes, increased number of hospitalizations, graft failure, and patient mortality. Herein, we propose an innovative approach to promote medication adherence and improve patient and graft outcomes.

Acute allograft rejection (AAR) is an important cause of morbi-mortality in heart transplant (HT) patients, particularly during the first year. Endomyocardial biopsy (EMB) is the "gold standard" to guide post- heart transplantation treatment. However, it is associated with complications that can be potentially serious. The index of microvascular resistance (IMR) is a specific physiological parameter used to assess microvascular function. Invasive coronary assessment has been shown to be both feasible and safe. Detection of coronary microvascular dysfunction (MCD) by IMR may help to identify high risk HT patients. In fact, an increased IMR measured early after HT has been associated with AAR, higher all-cause mortality and adverse cardiac events. A high IMR value early after HT may identify patients at higher risk who require increased surveillance or adjustments in immunosuppressive therapy. Conversely, a low IMR value may support reducing the number of EMBs. Our aim is to evaluate IMR in heart transplant patients within the first year. Changes in management after knowing IMR values and prognostic implications of IMR in a long term follow up will also be assessed.

Patient who received a heart transplant may develop organ rejection. Currently, an invasive biopsy of the heart needs to be performed to diagnose rejection. The purpose of this research study is to identify novel metabolic biomarkers that can be developed into a blood test that can identify signs of rejection without doing a heart biopsy.