BACKGROUND: As survival with an orthotopic liver transplant (OLT) improves, the incidence of chronic kidney disease in OLT recipients increases. Measurement of kidney function using creatinine-based estimates is often inaccurate, while cystatin C may overcome the biases that effect creatinine. The aim of this study was to assess the accuracy of creatinine- and cystatin C-based equations to estimate kidney function in long-term OLT recipients. METHODS: This was a cross-sectional study performed on OLT recipients within a single liver transplant centre where creatinine (n = 41) and cystatin C (n = 30) were measured and glomerular filtration rate (GFR) estimated using the Modification of Diet and Renal Disease (MDRD), Cockcroft-Gault (CG), Hoek, Larsson, Filler and Le Bricon equations. Comparison was made with the nuclear GFR (nGFR) (n = 41) measured through 51-Cr EDTA clearance. RESULTS: The mean age of recipients was 56 +/- 13 years, and they were 6.5 +/- 4.7 years post-OLT. Fifty-six percent of recipients had a nGFR < or =60 mL/min/1.73 m(2). nGFR correlated significantly with all predictive equations (P < 0.001). The MDRD, CG and Le Bricon equations had the smallest degree of bias (-7.6, -7.3 and 3.4 mL/min/1.73 m(2), respectively), with 22%, 22% and 27% of estimates, respectively, being within 10% of nGFR measurements. In OLT recipients with nGFR < or =60 mL/min/1.73 m(2), the degree of bias of both the creatinine-base MDRD and cystatin-based Hoek equations was within 2 mL/min/1.73 m(2) difference between the measured and estimated GFR, but 41% and 36% of estimates were within 10% of the nGFR measurement. CONCLUSIONS: Therefore, the degree of inaccuracy in cystatin C- and creatinine-based predictive equations brings into question their clinical utility in OLT recipients. We have no evidence that cystatin C is superior to creatinine in this population.
BACKGROUND: As survival with an orthotopic liver transplant (OLT) improves, the incidence of chronic kidney disease in OLT recipients increases. Measurement of kidney function using creatinine-based estimates is often inaccurate, while cystatin C may overcome the biases that effect creatinine. The aim of this study was to assess the accuracy of creatinine- and cystatin C-based equations to estimate kidney function in long-term OLT recipients. METHODS: This was a cross-sectional study performed on OLT recipients within a single liver transplant centre where creatinine (n = 41) and cystatin C (n = 30) were measured and glomerular filtration rate (GFR) estimated using the Modification of Diet and Renal Disease (MDRD), Cockcroft-Gault (CG), Hoek, Larsson, Filler and Le Bricon equations. Comparison was made with the nuclear GFR (nGFR) (n = 41) measured through 51-Cr EDTA clearance. RESULTS: The mean age of recipients was 56 +/- 13 years, and they were 6.5 +/- 4.7 years post-OLT. Fifty-six percent of recipients had a nGFR < or =60 mL/min/1.73 m(2). nGFR correlated significantly with all predictive equations (P < 0.001). The MDRD, CG and Le Bricon equations had the smallest degree of bias (-7.6, -7.3 and 3.4 mL/min/1.73 m(2), respectively), with 22%, 22% and 27% of estimates, respectively, being within 10% of nGFR measurements. In OLT recipients with nGFR < or =60 mL/min/1.73 m(2), the degree of bias of both the creatinine-base MDRD and cystatin-based Hoek equations was within 2 mL/min/1.73 m(2) difference between the measured and estimated GFR, but 41% and 36% of estimates were within 10% of the nGFR measurement. CONCLUSIONS: Therefore, the degree of inaccuracy in cystatin C- and creatinine-based predictive equations brings into question their clinical utility in OLT recipients. We have no evidence that cystatin C is superior to creatinine in this population.
Authors: J Levitsky; D R Salomon; M Abecassis; P Langfelder; S Horvath; J Friedewald; E Wang; S M Kurian; T Mondala; S Gil; R McDade; K Ballard; L Gallon Journal: Am J Transplant Date: 2011-07-27 Impact factor: 8.086
Authors: Mitra K Nadim; John A Kellum; Andrew Davenport; Florence Wong; Connie Davis; Neesh Pannu; Ashita Tolwani; Rinaldo Bellomo; Yuri S Genyk Journal: Crit Care Date: 2012-02-09 Impact factor: 9.097
Authors: Jeffrey C Sirota; Angela Walcher; Sarah Faubel; Alkesh Jani; Kim McFann; Prasad Devarajan; Connie L Davis; Charles L Edelstein Journal: BMC Nephrol Date: 2013-01-17 Impact factor: 2.388