II. Background
- Protein (120 Amino Acid) found in all human cells with a nucleus, as well as nearly all body fluids and tissues
- Contrast with Creatinine, of which most originates in Muscle
III. Indications
- Alternative to Serum Creatinine as a measure of GFR
- Consider when estimated GFR is decreased, with suspected False Positive test
- Abnormal GFR measurement with no known structural Kidney disease, CKD risk factors or albuminuria
IV. Contraindications: Relative (inaccurate Serum Cystatin-C, use with Serum Creatinine)
- Acute Kidney Injury
- Inflammatory states
- Thyroid dysfunction
- Congestive Heart Failure
- Cirrhosis
- Cancer
- Obesity (Body Mass Index >40 kg/m2)
- High dose Corticosteroid use
- High catabolic states (Tuberculosis, AIDS)
V. Disadvantages
- May not be available at all facilities
VI. Resources
- National Kidney Foundation GFR Calculator
- Wikipedia