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Serum Area Under the Curve (AUC) for a Renal Substance (e.g., Cystatin C)

Published: August 9, 2026Updated: August 16, 2026

This test measures how your kidneys process a specific protein over time, helping assess kidney function and filtration efficiency.

Quick summary

["Helps evaluate kidney health by tracking protein clearance in serum samples."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
98668-7
Short code
SNAP area AUC R sural n
Synonyms
SNAP area AUC R sural n
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
nerve-conduction
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

The AUC test evaluates the body’s ability to clear a protein marker from your bloodstream over a defined period. This marker is often used to indirectly assess kidney function, as it reflects how well your kidneys filter waste products from your blood.

Why It Matters in Medicine

Kidney function is critical for removing waste and balancing fluids in your body. This test provides a detailed view of how efficiently your kidneys process certain substances, which can help identify early signs of kidney disease or other related conditions.

Common Uses and Indications

Doctors may order this test if you have symptoms of kidney problems (such as fatigue, swelling, or frequent urination), if you have a history of kidney disease, or if you’re undergoing treatment that could affect kidney function.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm. The sample is then processed to measure the protein’s concentration over time. No special preparation is needed, but fasting may be recommended depending on the clinical context.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

AUC Renal Function (Serum)

Frequently asked questions

How does this test differ from a standard kidney function test like creatinine clearance?
Unlike standard tests that measure a single point in time, this AUC test provides a broader picture of how your kidneys handle protein removal. It can be particularly useful for detecting subtle changes in kidney function that might not be apparent in simpler tests.
What might cause abnormal results on this test?
Abnormal results could indicate kidney disease, dehydration, or conditions that affect fluid balance. Your doctor will consider your medical history, symptoms, and other test results to interpret the findings accurately.
Can this test be used to monitor kidney disease progression?
Yes, this test can help track kidney function over time, especially in cases where kidney disease is suspected or being monitored. Regular follow-ups with your healthcare provider will determine if additional tests or adjustments to treatment are needed.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy