Serum cystatin C, serum creatinine and the MDRD as predictors for renal function defined by the inulin clearance after orthotopic liver transplantation*

BACKGROUND: With improved survival post liver transplantation (LT) a highly sensitive and effective monitoring of post-transplant renal function (RF) is mandatory. The aim of this study was to evaluate the prognostic value of cystatin C on RF measured by the inulin clearance 24 months after LT. METHODS: 98 patients were enrolled, serum creatinine and cystatin C were collected prior to transplantation as well as 1, 6, 9, 12 and 24 months thereafter. The inulin clearance was used as reference standard for renal function with a cut off of 100 mL/min to define renal impairment 24 months after LT. All parameters were compared with respect to the defined cutoff. RESULTS: Univariate analysis showed a prognostic impact of antihypertensive medication prior to transplantation (p = 0.0008) and serum cystatin C one month after liver transplantation (p < 0.0001) on renal failure after transplantation. Auroc analysis yielded cystatin C as a superior prognostic parameter compared to creatinine based GFR in predicting renal failure as well as serum creatinine at all time points (AUROC 0.96-0.98). CONCLUSIONS: Our results revealed a high impact of serum cystatin C as an early prognostic biomarker for monitoring renal dysfunction following liver transplantation.