Kidney histology and function in liver transplant patients.

BACKGROUND Chronic kidney disease is a common complication after liver transplantation. However, few reports regarding kidney histology exist for this setting. METHODS Inulin clearance was measured and a kidney biopsy was performed in 99 patients at 60 ± 48 months after liver transplantation. Kidney biopsies were scored according to the Banff classification, and interstitial fibrosis was measured by a computerized quantitative method. RESULTS There was a steep decrease in kidney function within the first 6 months following transplantation, but this lessened thereafter. At kidney biopsy, inulin clearance and estimated glomerular filtration rate (eGFR) (using the abbreviated Modification of Diet in Renal Disease equation) were highly correlated (r(2) = 0.47, P < 0.0001). A decrease in eGFR at 6 months post-transplant was the sole predictive factor for inulin clearance of < 60 mL/min/1.73 m(2) at 5 years post-transplant. Few patients had a specific pattern of kidney histopathology and all patients had complex primary lesions. Lowered eGFR at 6 months post-transplant was a predictive factor for > 50% sclerotic glomeruli on the kidney biopsy. The duration of tacrolimus therapy, as compared to cyclosporine A, was a protective factor for < 20% interstitial fibrosis on the kidney biopsy. CONCLUSION In the setting of liver transplantation, this is the largest kidney-histology study to confirm that histological kidney lesions are complex, multiple and interrelated. Kidney function at 6 months post-transplant can predict long-term kidney function and histology.