. Author manuscript; available in PMC: 2015 May 6.

Published in final edited form as: Am J Kidney Dis. 2011 Aug 19;58(4):682–684. doi: 10.1053/j.ajkd.2011.05.019

Table 2.

Values for Cystatin C and Estimated GFR before and after standardization of the Cystatin C assay and re-expression of the GFR estimating equation

Cystatin Values Mg/L			Estimated GFR using equation 5 ml/min per 1.73m²			Estimated GFR using equation 8 ml/min per 1.73m²
Scys-CCRL'03	Scys-UMN'09^*	Standardized Scys^**	Scys-CCRL'03	Scys-UMN'09	Standardized Scys	Standardized Scys
0.5	0.48	0.53	175	185	162	175
0.9	0.79	0.89	87	101	88	87
1.0	0.87	0.98	77	90	79	77
1.1	0.95	1.07	68	81	71	69
1.3	1.11	1.24	56	68	59	56
1.5	1.27	1.42	47	58	51	47
2.0	1.66	1.86	34	42	37	34
2.5	2.06	2.30	26	33	28	26

Converted from Scys-CCRL'03 using equation 1

^**

Converted from Scys-UMN '09 using equation 2. Cystatin C traceable to the reference materials produced and characterized from the International Federation for Clinical Chemists (IFCC) Working Group for the standardization of Scys and the Institute for Reference Materials and Measurements (IRMM)