P HOWSON1, A IRISH2, G PERRY3, A SHARMA4, G WONG4, WH LIM1
1Department of Renal Medicine, Sir Charles Gairdner Hospital, Perth; 2Department of Renal Medicine, Fiona Stanley Hospital, Perth; 3Department of Nephrology and Transplantation, Royal Perth Hospital, Perth; 4Centre for Kidney Research & Department of Renal Medicine, Westmead Hospital, Sydney.
Aim: We aimed to examine the incidence, risk factors and patterns of acute rejection in indigenous kidney transplant recipients in Western Australia (WA).
Background: Indigenous kidney transplant recipients have a greater risk of premature allograft loss and mortality after kidney transplantation compared to indigenous recipients, but the incidence and patterns of acute rejection are not well described.
Methods: Indigenous end-stage kidney disease patients who have received a kidney transplant between 2000-2010 in WA were included. Patient-level data were extracted from local databases to determine the incidence and patterns of acute rejection. Predictors of rejection were examined using a logistic regression model.
Results: Of 642 patients who have received a kidney transplant in WA, 60 (9%) were indigenous patients. During the study period, 23% were highly-sensitised (panel reactive antibody >50%) and 68% had received kidneys with 4-6 HLA-mismatches (vs. 12% and 35% for non-indigenous patients during the same time-period, p<0.001). In the indigenous cohort during a median (IQR) patient follow-up time of 7.9 (5.7) years, 43 (72%) experienced rejection, with 21 (35%) experiencing multiple rejections. Of those who had experienced rejections, 43 (100%), 13 (30%) and 24 (56%) were cellular, vascular and antibody-mediated rejections (AMR), respectively. HLA-mismatches were associated with AMR with adjusted odds ratio (OR) of 1.68 (95%CI 1.11-2.54, p=0.01) for every HLA-mismatch. There was no association with vascular rejection (adjusted OR 1.28, 95%CI 0.82-2.02).
Conclusions: Almost three-quarters of indigenous kidney transplant recipients experienced acute rejection after transplantation, with over 50% of rejections attributed to AMR. HLA-mismatches is a risk factor for developing AMR and allocation policies aim to reduce the number of HLA-mismatches could potentially improve transplant outcome.