Estimation of glomerular filtration rates after orthotopic liver transplantation: Evaluation of cystatin C–based equations

✍ Scribed by Thomas Gerhardt; Uwe Pöge; Birgit Stoffel-Wagner; Manuela Ahrendt; Martin Wolff; Ulrich Spengler; Holger Palmedo; Tilman Sauerbruch; Rainer P. Woitas

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 142 KB
• Volume: 12
• Category: Article
• ISSN: 1527-6465
• DOI: 10.1002/lt.20881

✦ Synopsis

Early detection of renal dysfunction in patients after orthotopic liver transplantation is important. Creatinine-based equations to estimate glomerular filtration rate (GFR) were found to be less accurate in liver transplant recipients than in their original populations. Since cystatin C (CysC) is independent from muscle mass and hepatic biosynthesis, we evaluated the diagnostic accuracy of 3 CysC-based equations (Larson, Hoek, and Filler formulae) that are based on the same CysC method as that of our center in comparison to the abbreviated creatinine-based modification of diet in renal disease (MDRD) formula in 59 liver transplant recipients. "True GFR" was measured by 99mTc-diethylene triamine pentaacetic acid ( 99m Tc-DTPA) clearance. Neither correlation with the GFR (correlation coefficients: 0.594-0.640) nor precision (root mean square error: 15.7-18.17 mL/min/1.73 m 2 ) differed significantly between the tested formulae. The biases of the Hoek and Larsson formulae were significantly smaller than those of the MDRD and Filler equations (Ϫ0.1 and Ϫ2.3 vs. 10.1 and 7.9 mL/min/1.73 m 2 , respectively; P Յ 0.0023). Mean estimates of MDRD (61.9 Ϯ 21.4 mL/min/1.73 m 2 ) and Filler (61.2 Ϯ 22.1 mL/min/1.73 m 2 ) differed significantly from the measured GFR (52.3 Ϯ 17.5 mL/min/1.73 m 2 ; P Ͻ 0.005), whereas Larsson and Hoek did not (49.5 Ϯ 20.2 and 51.4 Ϯ 17.9 mL/min/1.73 m 2 , respectively). Accuracy within 30% and 50% of the true GFR was best for the Hoek (76.3% and 93.2%) formula, albeit not significantly different from MDRD (64.4% and 83.1%). Taken together, these data show the best overall performance for GFR estimates derived from the Hoek equation with respect to bias, precision, and accuracy.