Equations of Grubb et al for Estimating Glomerular Filtration Rate (GFR) from Serum Cystatin C

 

Patient selection: any age (from 0 to over 9 years)

 

Cystatin C analysis was performed on a Hitachi Modular P analysis using Dako reagents. Reference ranges were 0.55 to 1.15 mg/L for ages 1 to 50 years and 0.63 to 1.44 mg/L for ages > 50 years.

 

Parameters:

(1) serum cystatin C concentration

(2) age

(3) gender

 

With Age Only

Parameter	Finding	Points
age	< 14 years	1.384
	>= 14 years	1

 

GFR in mL per minute per 1.73 square meter BSA =

= 84.69 * ((serum cystatin C in mg/L) ^ (-1.680)) * (points for age)

 

With Age and Gender

 

Parameter	Finding	Points
age	< 14 years	1.376
	>= 14 years	1
gender	male	1
	female	0.94

 

GFR in mL per minute per 1.73 square meter BSA =

= 87.62 * ((serum cystatin C in mg/L) ^ (-1.693)) * (points for age) * (points for gender)