The effect of primary renal disease upon outcomes after renal transplant

Abstract Background This study investigated whether nature of primary renal disease affects clinical outcomes after renal transplantation at a single center in the United Kingdom. Methods This was a retrospective cohort study of 961 renal transplant recipients followed up at a large renal center from 2000 to 2020. Separation of diseases responsible for end‐stage kidney disease included glomerulonephritis, diabetic kidney disease, hypertensive nephropathy, autosomal dominant polycystic kidney disease, unknown cause, other causes and chronic pyelonephritis. Outcome data included graft loss, cardiovascular events, malignancy, post‐transplant diabetes mellitus and death, analyzed according to primary disease type. Results The mean age at transplantation was 47.3 years. During a mean follow‐up of 7.6 years, 18% of the overall cohort died corresponding to an annualised mortality rate of 2.3%. Death with a functioning graft occurred at a rate of 2.1% per annum, with the highest incidence observed in in patients with diabetic kidney disease (4.1%/year). Post‐transplant cardiovascular events occurred in 21% of recipients (2.8% per year), again highest in recipients with diabetic kidney disease (5.1%/year) and hypertensive nephropathy (4.5%/year). Post‐transplant diabetes mellitus manifested in 19% of the cohort at an annualized rate of2.1% while cancer incidence stood at 9% with an annualized rate of 1.1% . Graft loss occurred in 6.8% of recipients at the rate of1.2% per year with chronic allograft injury, acute rejection and recurrent glomerulonephritis being the predominant causative factors. Median + IQR dialysis‐free survival of the whole cohort was 16.2 (9.9 ‐ > 20) years, being shortest for diabetic kidney disease (11.0 years) and greatest for autosomal dominant polycystic kidney disease (18.2 years) .The collective mean decline in eGFR over time was ‐1.14ml/min/year. Recipients with Pre‐transplant diabetic kidney disease exhibited the fastest rate of decline(‐2.1ml/min/year) a statistically significant difference in comparison to the other native kidney diseases with Autosomal dominant polycystic kidney disease exhibiting the lowest rate of decline(‐0.05ml/min/year) Conclusion Primary renal disease can influence the outcome after renal transplantation, with patients with prior diabetic kidney disease having the poorest outcome in terms of dialysis‐free survival and loss of transplant function. Autosomal polycystic kidney disease, other cause and unknown cause had the best outcomes compared to other primary renal disease groups.