Renal Histopathology and Outcomes After Orthotopic Liver Transplantation

Background: Chronic kidney disease (CKD) commonly occurs after orthotopic liver transplant (OLT) and was classically attributed to calcineurin inhibitor (CNI) toxicity. Kidney biopsy findings with renal outcomes after OLT are not well characterized in the present literature. Methods: Patients were identified using ICD-10 and CPT codes. Renal parenchymal disease was identified by a pathologist. Weighted averages were used to determine mean and standard deviation. Results: 918 patients underwent OLT between January 1, 2000 and December 31, 2023 at our institution. 15 kidney biopsies were performed in 14 patients, 1 patient had 2 biopsies. All patients received OLT for cirrhosis. 5 had metabolic dysfunction-associated steatohepatitis (MASH) (36%), 5 had hepatitis C (36%) (3 with active viremia), 2 had combined MASH and hepatitis C (14%) and 2 had alcohol related cirrhosis (14%). Kidney biopsy was performed for declining renal function (53%), proteinuria (40%) or both (7%). 36% of patients had focal and segmental sclerosis (FSGS), 21% had diabetic nephropathy, 14% had IgA nephropathy, 14% had acute tubular injury, 7% had acute interstitial nephritis, and 7% had membranoproliferative glomerulonephritis (MPGN). 7 had 30% or more glomerulosclerosis, 11 had interstitial expansion within 1-2 years of liver transplant. 1 had features of hepatic glomerulopathy along with mild IgA nephropathy. Conclusion: Renal dysfunction after OLT was historically attributed to CNI toxicity. In our cohort, renal pathologies were instead due to a variety of patient-specific and immunologic phenomenon. A better understanding of underlying renal pathologies may improve renal outcomes after OLT.