Dr Monica Suet Ying Ng1,2,3,4, Andrew T Jones5, Andrew J Mallett2,6,7
1Kidney Health Service, Royal Brisbane and Women’s Hospital, Brisbane, Australia, 2Institute of Molecular Biosciences and Faculty of Medicine, University of Queensland, Brisbane, Australia, 3Conjoint Internal Medicine Laboratory, Chemical Pathology, Pathology Queensland, Brisbane, Australia, 4Nephrology Department, Princess Alexandra Hospital, Brisbane, Australia, 5Queensland Cyber Infrastructure Foundation, Brisbane, Australia, 6Department of Renal Medicine, Townsville University Hospital, Townsville, Australia, 7College of Medicine and Dentistry, James Cook University, Townsville, Australia
Aim
To determine the feasibility of assessing the effect of different immunosuppression regimens on kidney graft failure secondary to glomerular disease (GD) recurrence using registry data.
Background
Current registry studies investigating the effect of immunosuppression regimens on graft outcomes have primarily used discharge medications to categorise treatment groups which does not account for medication changes.
Methods
All patients who received a kidney transplant for glomerular disease between 1985-2020 were extracted from the Australian and New Zealand Dialysis and Transplant (ANZDATA) registry. Immunosuppression regimens were assessed at discharge, 1 year and 5 years post-transplant. Power calculations were completed using the sample size and outcome rates in the dataset to determine relative risk between the groups at a significance level of 0.05.
Results
3615 kidney transplants were performed for GD. 1 year, 2 year and 5 year graft failure rates were 6.1%, 8.2% and 13.5% respectively. In total, 1075 (29.7%) grafts failed (death-censored) with 122 (3.4%) due to disease recurrence, 579 (16.0%) due to chronic rejection, 724 (20.0%) due to death with functioning graft, 95 (2.6%) due to acute rejection, and 10 (0.3%) due to BK virus nephropathy. Immunosuppression medications changed significantly at 1 year and 5 years compared to discharge. Assuming a combined sample size of 3200, an observed rate of graft failure due to disease recurrence of 3.4%, and a significance cut off of 0.05; a log-rank test would be able to detect a relative risk between the groups of 0.50 with a power 0.90.
Conclusions
Even with conservative estimates for sample size, it is feasible to assess the effect of different immunosuppression regimens on graft failure due to disease recurrence in people with GD.
Biography:
Monica Ng is a renal registrar at Princess Alexandra Hospital and, post-doctoral researcher at Conjoint Internal Medicine Laboratory, Royal Brisbane and Women’s Hospital and Institute of Molecular Biosciences. Her research interests include registry data analysis and developing molecular workflows for kidney disease biomarker discovery. Currently, this involves optimising spatial transcriptomics and flow cytometry protocols for biosample analysis.