Predictive score for acute kidney injury in DCD vs. DBD liver transplantation. UK single centre study

Background: Acute kidney injury (AKI) is a major cause of mortality after liver transplantation (LT). Furthermore, liver transplant recipients with post- operative AKI are more likely to develop chronic kidney disease, compared to the transplant recipients without AKI. Liver transplantation from Donation after Circulatory Death (DCD) is a model with increased occurrence of AKI compared to Donation after Brain Death (DBD). This is likely to be related to a more severe ischaemic reperfusion injury sustained by the graft. Aim of the study is to identify a predictive score for AKI in DCD and DBD liver transplant. Methods: Retrospective single-centre study of 1150 patients undergone LT at Queen Elizabeth Hospital Birmingham from 2007 to 2014. Exclusion criteria: urgent transplantation (=66), combined with other organs (=16), living donor liver transplants (=7) and previous renal (=1) grafting. We considered: renal function pre-transplant and daily within one week post-transplant, characteristics of recipient and donor, graft variables and indicators of initial graft function. AKI was defined and classified on the basis of KDIGO Guidelines (2012). Results: 1060 LT patients (247 DCD and 813 DBD) were included in the analysis. Predictive variables of AKI development in DCD patients were donor height, warm ischaemia time, plasma transfusions during transplant, recipient BMI and diabetes. We performed internal validation of the equation using bootstrapping methods: this model correctly classified the 67.4–81.7% of patients with sensitivity of 77.9–91.6% and specificity of 27.6–73.5%. Variables in the DBD equation included MELD, plasma transfusions during transplant, donor age and recipient BMI. This model correctly classified the 61.1%-69.4% of patients with sensitivity of 69.7–86.6% and specificity of 30.9–58.9%. Conclusion: We produced risk prediction equations that may be used to improve our understanding of the risk of AKI after DCD and DBD liver transplantation.