Kidney Biopsies May Help Predict Renal Function After Liver Transplantation.

Background: Renal biopsy has been proposed to determine the cause or reversibility of renal failure for patients with end-stage liver disease and may be useful in the kidney allocation. Nevertheless, little data exist to validate the usefulness of kidney biopsies in this patient population.
Methods: We evaluated the utility of renal biopsies in a cohort of 59 consecutive liver transplant candidates with renal impairment of unclear etiology referred to determine the need for simultaneous liver kidney transplantation (SLK) versus liver alone transplantation (LAT). Pathological diagnoses, patient outcomes and the usefulness of biopsy results in predicting renal recovery were analyzed.
Results: Our biopsy complication rate was relatively low with only 2.9% and 4.2% serious complications occurring with transjugular and percutaneous renal biopsies, respectively. The most common pathological diagnoses on renal biopsies were membranoproliferative glomerulonephritis (23%) followed by IgA nephropathy (19%) and acute tubular injury (19%). Simultaneous liver kidney transplantation was recommended for patients with greater than 40% global glomerular sclerosis, or with interstitial fibrosis greater than 30% or for patients on hemodialysis for 2 months or longer. The best histological predictor for posttransplant glomerular filtration rate in the LAT group was the extent of global glomerulosclerosis (P = 0.0001). Based on biopsy criteria, we were able to avoid kidney allocation to 70% of our patients with renal dysfunction. Over the first year posttransplant, SLK and LAT patients had comparable estimated glomerular filtration rates. Kaplan-Meier survival analysis did not demonstrate a difference in patient survival between patients who underwent LAT versus SLK.
Conclusions: Renal biopsy can be relatively safe in this population, may help elucidate the etiology of renal failure, may predict post-LAT kidney function, and may be helpful in kidney allocation for liver transplant candidates.