Investigating the Metabolomic Profile of Transplanted Heart With and Without Pathological Signs of Rejection

Background:

Cardiac transplantation remains the treatment of choice for end-stage heart failure. Rejection is a major risk factor affecting the outcome and survival in transplant recipients. Endomyocardial biopsy is the gold standard for diagnosis of post-transplantation rejection, but it is an invasive procedure with potential serious complications. Moreover, due to limited catheterization lab time and time required to process biopsied tissue, the transplanted organs could potentially receive irreversible damages upon diagnosis of acute rejection. Current available non-invasive test involving detecting donor DNA in recipient's blood is still costly and has many limitations. Hence, a better non-invasive and timely diagnostic approach with high sensitivity and specificity is needed to help improve the diagnosis of acute post-cardiac transplant rejection.

Methods At the London Health Science Centre, patient who had a cardiac transplant will undergo routine weekly blood sample collection and endomyocardial biopsy for the first 4 weeks to screen for acute rejection. After informed consent was obtained for routine endomyocardial biopsy and research study, endomyocardial tissue samples and blood will be collected from the patient. Two to three biopsy samples and the blood were processed according to the protocols provided by the Metabolomic Innovation Centre (Edmonton, Alberta, Canada). The sample will be analyzed using the high-performance chemical isotope labelling liquid chromatography mass spectrometry metabolomics platform.

Expected Results:

Using the non-targeted metabolomics, the primary objective is to identify promising novel candidate biomarkers from the blood samples that can help us identify patients who are in acute rejection post-cardiac transplant. The blood sample biomarkers can be validated with endomyocardial biopsy metabolomics data. In addition, characterizing the metabolic profile of transplanted heart can provide insights for the myocardial energetics in transplanted heart. These data can potentially help physicians predict the likelihood of patients developing rejection.