The variable pathology of kidney disease after liver transplantation

Background. Chronic kidney disease is a frequent complication in orthotopic liver transplant (OLT) recipients, observed in 10% to 60% after 5 years. Patients and methods. We analyzed clinical and pathological data from 81 OLT recipients who developed impaired kidney function with a serum creatinine greater than or equal to 1.5 mg/dL or new proteinuria on dipstick urinalysis. All patients underwent percutaneous kidney biopsy. The most common reason for liver transplantation was hepatitis C virus infection. The mean time until biopsy was 4.89 years. At the time of biopsy, the mean serum creatinine was 2.0 mg/dL, Modified Diet of Renal Disease glomerular filtration rate was 38.7 mL/min, and 24-hr urine protein was 1.37 g. Results. All biopsies demonstrated glomerular abnormalities, 42% showed primary glomerular diseases, and only 16% had evidence of calcineurin inhibitor toxicity. Electron microscopy was performed on 74 biopsies and podocyte effacement was detected in 88%. Mean postbiopsy follow-up was 20 months; eight patients progressed to end-stage renal disease. Conclusion. This study demonstrates universal glomerular abnormalities in kidney biopsies after OLT. The pathology is suggestive of diabetic nephropathy and hypertensive change, but there are also specific glomerular disease processes present. There is little calcineurin inhibitor toxicity in this group. These findings underscore the importance of understanding the causes of kidney disease in the constantly changing liver transplant population, and the need to change current management of these patients.