Impairment of Renal Function at One Year After Liver Transplantation Is a Prognostic Factor for Mortality.

Abstract

Renal dysfunction/failure are risk factors for poor outcome after liver transplantation (LTX). Our aim is to determine if renal dysfunction has impact on the long term outcome after LTX. We used multiple cutoffs for GFR at 1 year post LTX to look for association with later mortality. 985 primary LTX transplant recipients from a single institution were studied. All included survived >1 year after LTX and underwent iothalamate glomerular filtration rate (GFR) testing. Patients were stratified by GFR at 1 year post LTX [GFR≤40 (n=140), 41-60 (n=290), >60 ml/min (n=555)]. 37 patients had GFR≤30, of which 13 had GFR≤20. The GFR≤40 group had significantly more patients >60 years old, female gender, cyclosporine maintenance, anemia, but did not differ by HTN, DM, liver disease etiology. The 5-year Kaplan Meier survival (6 years post LTX) was 81.6%, 89.1%, and 91.6% for 1-year GFR of ≤40, 41-60,>60 respectively (p=0.01), and dropped to 75.6% if GFR ≤30, compared to 90.1% for GFR>30 (p<0.001), and further to 53.8% if GFR≤20 compared to 84.5-91.6% for GFR>20 (p<0.001). Recurrence of liver disease did not correlate with GFR. Multivariate Cox regression analysis showed statistically significant increased risk of mortality for African American recipients [risk ratio (RR) 2.35,p=0.0002), GFR≤40 (RR 1.95, p=0.0009). Analysis for GFR≤30 showed a RR for mortality of 2.91 (p=0.009). Kaplan Meier 5-year graft survival was 81% for GFR≤40, compared to 88.7% with GFR>40 (p=0.024), and 72.7% if GFR≤30 (p=0.005). In conclusion, a GFR of 40 ml/min or lower at 1 year post LTX is associated with higher mortality and graft loss and therefore requires more agressive follow-up and intervention and thus has therapeutic implications. This GFR threshold is higher than previously anticipated. An accurate GFR measurement is essential for intermediate and long-term prognosis after LTX.