Dr Paayal Naidu1,2, Ms Narelle Watson3, Professor Kevan Polkinghorne1,2,4, Mr Chris Davies5,6, Dr Georgina Irish5, Dr Henry Guo1,2, Professor John Kanellis1,2, Professor William Mulley1,2
1Department of Nephrology, Monash Health, Clayton , Australia, 2Centre for Inflammatory Diseases, Department of Medicine, Monash University, Clayton, Australia, 3Australian Redcross Lifeblood, , Australia , 4Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia, 5Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia, 6Faculty of Health & Medical Sciences, University of Adelaide, Adelaide, Australia
Biography:
Bio to come
Background:
Preformed DSA may increase the risk of kidney allograft rejection and failure, but Australian data have not been comprehensively evaluated.
Aim:
To determine rejection risk, allograft and patient survival by DSA status and characteristics.
Methods:
Retrospective cohort study using ANZDATA–OrganMatch for all adult kidney transplant recipients in Australia (2014–2023). DSA status was defined by presence of preformed DSA by Luminex single antigen beads, characterised by HLA class, mean fluorescence index, and presence in current versus peak sera. Outcomes were analysed using multivariable Cox proportional hazards models.
Results:
Of 9,583 transplants, 1,862 (19.4%) were DSA-positive. DSA-positive recipients were more often female, repeat transplants, had longer wait-times (3.6 vs 1.9 years), and deceased donor recipients (94.4% vs 72.8%). DSA were against HLA-class-I (42%), HLA-class-II (35%) or both (23%); 87% had weak (500–2000) or moderate (2000–4000) peak immunodominant MFI.
DSA-positive recipients had more: rejection (24.9% vs 20.4%, p<0.001); antibody mediated rejection (AMR) (14.1% vs 8.3%, p=0.006); recurrences (≥2: 18.6% vs 16.1%, p=0.009) and earlier onset (23 vs 37 days, p=0.015). DSA-positivity independently predicted rejection (aHR 1.36; 95% CI 1.22–1.51).
Five-year allograft survival was lower in DSA-positive recipients (79.9% vs 84.9%), particularly those who developed AMR (71%). DSA-positivity independently predicting allograft loss (aHR 1.17; 95% CI 1.04–1.31).
No significant associations were observed between outcomes and DSA characteristics.
DSA positivity was not associated with risk of death (aHR 1.06, 95% CI 0.92–1.22).
Conclusion:
Preformed DSA were independently associated with an increased rejection risk, especially for AMR. The combination of preformed DSA and AMR conferred the highest risk of allograft loss. Lack of association with examined DSA characteristics supports the need for nuanced approaches, including epitope-level assessment.