P2.42: Vascularized composite allografts as immunological monitors

Abstract

Introduction: Abdominal wall transplantation (AWTx) offered a potential solution to the often-challenging closure of the abdominal wall at the time of intestinal transplantation (ITx). However, besides facilitating closure, the AWTx has been proven a promising asset for early, patient led rejection monitoring. We have therefore also used sentinel skin grafts for solely graft monitoring purposes when there was no clinical need for AWTx. Methods: We performed a retrospective analysis of all patients undergoing intestinal and vascularized composite allograft (VCA) transplantation. Clinical presentation of rejection was correlated with histology, stoma output, citrulline levels and endoscopy findings. Results: From October 2008 to October 2018, 45 patients underwent ITx. Ten underwent a modified multivisceral transplant and 35 an isolated small bowel transplant. Mean age was 42.6 years (range 23- 73). M/F: 27:18. Median follow up was 1031 days (range 14- 3651). All patients had Campath induction (30 mg iv) followed initially by Tacrolimus based maintenance (trough level of 8–12 ng/ml). Thirty one patients received a VCA in addition to ITx. Twenty two of these were AWTx. There were 5 intestinal biopsy proven rejections in the IT alone group (36%) and a further 5 patients in the same group were falsely treated for rejection, as this was later labelled as infection. There were 10 patients with rejection in the VCA part of the IT+ VCA group (11/31, 35%). These patients presented with a rash limited to the VCA. Of those 11 patients, there were 5 with concurrent intestinal rejection (5/31, 15%) with a lead-time of 5- 7 days between VCA and ITx. Conclusion: We report on a series of combined VCA and ITx. The skin component has been utilized as a dynamic canvas for remote immune monitoring of visceral grafts. It has so far been useful for patient led monitoring of the ITx graft since it is visible and presents the earliest and only sign of rejection.