Pretransplant renal function according to CKD-EPI cystatin C equation is a prognostic factor of death after liver transplantation.

BACKGROUND & AIMS: In patients with cirrhosis, cystatin C (CystC) based equations may be more accurate indicators of glomerular filtration rate (GFR) than creatinine (Pcr) based equations. Renal function before liver transplantation (LT) is thought to impact survival after LT. We aimed at assessing pretransplant creatinine and CystC based equations with respect to their predictive value on long-term survival after LT.

METHODS: From 2001 to 2011, CystC was determined at pre-LT evaluation in 682 patients together with GFR assessed using MDRD-4, MDRD-6, CKD-EPI-cystatin C, CKD-EPI-creatinine and CKD-EPI-creatinine-cystatin C equations. Patients were classified according to the Kidney Disease Outcomes Quality Initiative classification (KDOQI).

RESULTS: Median age at LT was 55 [49-60] years with a median MELD score of 13.5 [8.3-19.2] and a median post-transplant follow-up of 60 [26-89] months. Using CKD-EPI Cystatin C and the KDOQI classification, 21.1% of patients were stage 1, 43.1% stage 2, 29.1% stage 3 and 6.5% stage 4. Kaplan-Meier survival estimates were significantly different between KDOQI stages when determined using the CKD-EPI-CystatinC equation. This was not the case when using the other equations. At multivariate analysis, GFR and KDOQI estimated using the CKD-EPI-CystatinC equation were significantly associated with death (HR: 0.992; CI95%: 0.986-0.999 and 1.24; CI95%: 1.02-1.50 respectively). When assessed using the MDRD-4, MDRD-6, CKD-EPI-Creatinine-CystatinC and CKD-EPI-Creatinine equations GFR was not significantly associated with death.

CONCLUSIONS: Estimated pre-LT renal function is predictive of post-LT survival only when assessed using the CKD-EPI cystatin C equation. This supports the use of Cystatine C and of its related equation for the assessment of renal function before liver transplantation.