BRIEF ORAL BOS01 – PROGNOSTIC ASPECTS IN KIDNEY DONATION AND TRANSPLANTATION BOS001 RENAL TRANSPLANTS USING KIDNEYS WITH BIOPTIC SCORE ≥ 5 (KARPINSKI) AS SINGLE GRAFTS HAVE ACCEPTABLE LONG-TERM FUNCTION Andrea Collini, Stefania Angela Piccioni, Dario Cassetti, Giuliana Ruggieri, Mario Carmellini Azienda Ospedaliero-Universitaria Senese Background: The Karpinski scoring system used to allocate kidneys as single (? 4) or double transplants (5 or 6) has been considered overprotective, excluding potentially suitable organs. It has been proven that double kidney transplants who lost 1 of the 2 grafts maintained acceptable renal function as long as 10 years in 70% of cases. This observation suggested extending the histological allocation criteria for single grafts. Methods/Materials: Among 235 patients who received a single graft from either Standard Criteria Donors (SCD) or Expanded Criteria Donors (ECD) in our renal transplantation program from 2004 and 2014, we analyzed the graft survival, delayed graft function (DGF) and acute rejection rate between a group (48 patients) with histologic Karpinski score? 5 (score 6 in 3 cases) and a control group (187 patients) with score < 5. Results: The mean age of donors were comparable in both groups (67.3 vs 65.2 years) as well as the patient’s age at transplant (58.3 vs 56 years). We recorded a delayed graft function in 27 cases (56.2%) in the high score rate group vs 102 (54.5%) in the control. The actuarial death censored graft survival rate (Kaplan-Meyer) at 5 years was 72.8% in the study group vs 73.5% in the control, while at 10 years was 55.2% vs 56.5%. No differences were recorded in terms of acute rejections 18 patients (37.5%) in the study group vs 75 (40.1%), either clinical or biopsy proven. Conclusion: We found no differences in death censored graft survival rate, suggesting the utilization of score 5 kidneys as single grafts (instead of double transplants) can safely lead to an acceptable long-term renal function, expanding accordingly the donor pool. BOS002 MACROSCOPIC ASSESSMENT OF THE QUALITY OF PERFUSION OF KIDNEYS DURING DECEASED-DONOR KIDNEY TRANSPLANTATION: A UK POPULATION COHORT STUDY Dilan Dabare, James Hodson, Adnan Sharif, Neena Kalia, Nicholas Inston University Hospital Birmingham Background: Macroscopic assessment of the quality of perfusion remains a fundamental, yet poorly evaluated, aspect of donor kidney appraisal. We aimed to evaluate its association with organ utilization and graft outcomes and the consistency of grading at two different time points in the pre-transplant period. Methods: A retrospective analysis of all deceased-donor kidney transplants from 2000–2016 was performed using the UK Transplant Registry database. The quality of perfusion of each retrieved kidney is routinely graded by the retrieval and implanting surgeon: 1 = good, 2 = fair, 3 = poor, 4 = patchy. Multivariable analyses were performed to determine whether grade of perfusion is an independent predictor for several outcomes including discard rates, primary non-function (PNF) rates and long-term graft survival. Results: Analysis included 31,167 kidneys from 15,750 donors, of which 2,556 (8.2%) were discarded. Grade of perfusion at retrieval was independently associated with discard rates (p < 0.001), which increased from 6.5% at grade 1, to 41.8% at grade 3 [OR: 7.52 (95% CI: 6.16–9.19)], before falling to 27.1% at grade 4. It was also associated with PNF rates (6.6% vs. 2.8% for grade 3 vs. 1), but not graft survival (p = 0.454). However, grade at implanting was significantly associated with both outcomes. PNF rates increased progressively with the perfusion grade at implanting (p < 0.001). Graft survival declined significantly only between grades 1 and 3 (p = 0.002), with grade 1 and 4 organs having similar outcomes (HR: 1.03, p = 0.764). In transplanted organs (n = 28,611), consistency of grading at retrieval vs. implanting centre was poor (Kappa = 0.179), with only 17.2% of grade 4 organs retaining the same grade. Conclusions: This study represents the largest review of this aspect of viability assessment. Despite discrepancy between the two gradings, perfusion grade has affected organ utilisation and is associated with outcomes, suggesting the need for further evaluation. BOS003 UTILITY OF NEWCASTLE SCORE IN DETERMINING PROLONG LENGTH OF STAY IMMEDIATELY FOLLOWING KIDNEY TRANSPLANTATION Duha Ilyas, Christopher Pearce, Richard Baker, Matthew Welberry-Smith, Adam Barlow, Sonsoles Martinez-Lopez, Jessica Weemes, Sunil Daga, David Keane St James University Hospital Leeds Background: The optimum length of stay following kidney transplantation is 5–7 days. Recent recommendations by the GIRFT (Getting It Right First Time) programme advises discharge within 7 days. In the work up to transplantation, scoring systems can be used to identify suitable candidates for kidney transplantation. In this work, we looked at the association between the Newcastle Score and the length of stay in patients immediately after transplantation. Methods: We looked at data from 01/09/16 to 01/09/18 for all transplant recipients. Out of 367 patients, a Newcastle score was available for 197 recipients in our database. We extracted data on recipient & donor demo- graphics, focusing on length of hospital stay. Logistic regression was used to investigate which variables were associated with prolonged stay. We used two models, one using variables at baseline (at the time of transplantation) and one using variables post-transplantation (using MATLAB statistical software). We categorised the Newcastle score into two categories based on a cut off of 9. Results: Our results are demonstrated in Table 1.Using univariate analysis, a Newcastle score greater than 9 was significant when considering length of stay. On multivariate analysis (for both baseline and post-transplant models), Newcastle score did not demonstrate a statistically significant correlation. Conclusion: Our findings suggest a Newcastle score greater than 9 had a trend towards significance; statistically this was not significant when consid- ering length of stay post kidney transplantation. The total number of patients in our analysis is small and it is possible that a correlation would be seen in a larger cohort of patients. Therefore, further investigation is required to clarify the role of Newcastle score and recovery following kidney transplantation. BOS004 ª 2019 The Authors Transplant International ª 2019 European Society for Organ Transplantation Vol. 32 (Suppl. 2), 159–261 159