Vascularised Sentinel Skin Flaps for Immune Monitoring in Solid Organ Transplantation

HL Stark, CS Honeyman, J Hester, F Issa, H Giele Background  The long-term outcomes of lung, intestine and pancreas transplants are severely limited by high rates of rejection that predispose to later transplant dysfunction or failure.  Despite this, there are no specific tests currently available that diagnose rejection accurately without the need for a biopsy. Due to the invasive nature of this, monitoring is intermittent and infrequent, only performed when there is a clinical suspicion of rejection. Vascularised sentinel skin flaps (SSFs) may provide a method for non-invasive transplant monitoring. Aim  To develop continuous, patient-driven monitoring for acute rejection in solid organ transplants with the use of SSFs. To use this model to analyse very early rejection samples in order to identify immunological pathways, biomarkers and potential therapeutic targets that may predict, diagnose and prevent rejection. Methods  I have access to an already collected biobank of blood and tissue samples from patients who have had a pancreas or intestine transplant and sentinel skin flap in Oxford. I will use these samples as my initial discovery set, with the aim of identifying a profile (SSF and immunological changes) of acute rejection that correlates to solid organ rejection. I will then test this profile in patients undergoing lung transplantation with SSF. Conclusion SSFs are an attractive method for transplant rejection monitoring. In this presentation I will discuss the rationale for SSF-based immune monitoring in transplantation and how I am planning on identifying a biomarker profile of acute rejection.