Background: Kidney biopsy has been recommended to guide kidney allocation in selected liver transplant (LT) candidates with renal dysfunction. However, post-LT-alone renal outcomes in recipients who showed evidence of reversible renal injury and limited chronicity on pre-LT kidney biopsy are unclear.
Methods: Renal outcomes of 41 LT recipients who had pre-LT kidney biopsy for unexplained renal dysfunction, proteinuria, and hematuria were retrospectively reviewed. All biopsies showed less than 30% interstitial fibrosis and less than 30% to 40% glomerulosclerosis. Study endpoints were renal replacement therapy (RRT) at 1 month and the need for kidney transplantation at 1 year from LT.
Results: Six patients were on RRT at time of biopsy. Median (range) iothalamate glomerular filtration rate and 24-hr urinary protein excretion for the remaining 35 patients were 29 (6-88) mL/min per 1.73 m(2) and 65 (0-4,338) mg/day, respectively. Glomerulonephritis and acute tubular necrosis were present in 28 (68%) and 16 (39%) of the cases. Six patients (15%) did not recover kidney function at 1 month and RRT at time of LT was the only factor associated with this endpoint (P=0.04). Seven of the 31 (22%) patients with 1-year data met criteria for kidney transplantation within the first post-LT year. Surgical re-exploration was the only factor associated with the need for kidney transplantation at 1 year (P=0.05).
Conclusions: The most LT recipients with minimal chronic changes on pre-LT kidney biopsy recovered kidney function within 1 month from LT. A small but significant percentage met criteria for kidney transplantation at 1 year because of the development of unforeseen post-LT complications.