LAUSR

Introduction: Donor specific antibodies (DSA) are implicated in poor renal transplant outcome, however their impact in intestinal transplantation (ITx) is not fully understood. DSA data is collected in all UK centres, but has not yet been combined or collected centrally. Aim: To identify the impact of DSA on episodes of rejection and graft loss post ITx. To begin collaboration in DSA data collection between centres in the UK. Method: A retrospective case note and laboratory data review of all patients transplanted in one paediatric and one adult ITx centre between 2008-2016. Results: 91 transplants were performed in 83 patients (66 adults, 17 children). DSA: 18 (21.6%) patients were DSA positive (16 adults, 2 children (24.2% and 11.7% respectively)). 56% of these had at least one episode of rejection. 5 patients had preformed DSA of which 3 persisted. 60% of patients with preformed DSA had rejection, this represented 12.5% of all patients with rejection. 13 patients developed DSA de novo after ITx. They cleared in 3 patients. 54% of patientswith de novo DSA had rejection, this represented 29.1% of all patientswith rejection. In 71.5% of cases, the de novoDSAwere identified before the onset of rejection. Of those without DSA, 18% had at least one episode of rejection. Mortality in those DSA positive was 22.2%. Mortality in those without DSA was 38.4%. Rejection: 24 (28.9%) patients had at least one episode of acute rejection. Of those with rejection, 10 (42%) had previously identified DSA. 2 further patients developed DSA after the episode of rejection. 7 adult patients had rejection directly following a change in immunosuppression or a period of non-adherence. 2 of these were DSA positive. 6 of the rejection group had severe rejection defined on histology; 4 of these were DSA positive. 6 grafts were lost due to rejection; 2 of these patients had DSA. 3 patients developed chronic rejection; none had DSA. Conclusions: DSA positivity did not increase the risk of chronic rejection, nor did it adversely affect mortality. However, there was a trend to increased likelihood of acute rejection and increased severity of rejection episodes in those with previously identified preformed or de novo DSA. Despite the collaboration between two ITx centres, numbers are small. There is a need to collaborate further to collect prospective data which may inform future DSA management. 325.1