Progression of Kidney Disease in Kidney Transplant Recipients With a Failing Graft: A Matched Cohort Study.

Abstract

Few studies have assessed outcomes in transplant recipients with failing grafts as most studies have focused on outcomes after graft loss. To determine whether renal function declines faster in kidney transplant recipients with a failing graft than in people with chronic kidney disease of their native kidneys. Retrospective cohort study. Alberta, Canada (2002-2019). We identified kidney transplant recipients with a failing graft (2 estimated glomerular filtration rate [eGFR] measurements 15-30 mL/min/1.73 m2 ≥90 days apart). We compared the change in eGFR over time (eGFR with 95% confidence limits, LCLeGFRUCL) and the competing risks of kidney failure and death (cause-specific hazard ratios [HRs], LCLHRUCL). Recipients (n = 575) were compared with propensity-score-matched, nontransplant controls (n = 575) with a similar degree of kidney dysfunction. The median potential follow-up time was 7.8 years (interquartile range, 3.6-12.1). The hazards for kidney failure (HR1.101.331.60) and death (HR1.211.592.07) were significantly higher for recipients, while the eGFR decline over time was similar (recipients vs controls: -2.60-2.27-1.94 vs -2.52-2.21-1.90 mL/min/1.73 m2 per year). The rate of eGFR decline was associated with kidney failure but not death. This was a retrospective, observational study, and there is a risk of bias due to residual confounding. Although eGFR declines at a similar rate in transplant recipients as in nontransplant controls, recipients have a higher risk of kidney failure and death. Studies are needed to identify preventive measures to improve outcomes in transplant recipients with a failing graft.