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Urine IgG-to-Creatinine Ratio

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

Measures the amount of IgG relative to creatinine in urine, helping assess urinary IgG loss while accounting for variations in urine concentration.

Quick summary

["This test helps evaluate how much IgG is being lost in urine and may support the evaluation of kidney disease."]

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

Key facts at a glance

LOINC
33948-1
Short code
IgG/Creat Ur
Synonyms
IgG/Creat Ur
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This urine test measures the ratio of immunoglobulin G (IgG) to creatinine. Creatinine is used as an adjustment for urine concentration, so the ratio is more useful than a single IgG measurement for assessing urinary IgG loss.

Why might I need this test?

Your clinician may order this test when evaluating kidney disease, symptoms of kidney inflammation, or unusual findings on urine protein testing. It can help estimate the amount of IgG being lost in the urine.

How is the test performed?

A urine sample is collected and tested in the laboratory to determine the IgG and creatinine amounts. The laboratory then calculates their ratio. Sometimes this result is compared with other urine protein measurements.

How do I prepare for the test?

Follow your clinician's instructions about urine collection, including whether a first-morning or timed sample is needed. Tell the healthcare team if you have a known kidney condition, take medicines that affect kidney function, or are pregnant.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine IgG/Creatinine Ratio

Frequently asked questions

What does IgG stand for?
IgG is immunoglobulin G, an antibody that helps the immune system fight infections. Some IgG normally enters urine, but certain kidney conditions can increase urinary IgG loss.
Why is creatinine included in the result?
Urine concentration can vary from day to day. Comparing IgG with creatinine helps account for how concentrated or dilute the urine sample is.
Does an abnormal result diagnose a kidney disease?
No. An abnormal ratio may suggest a problem but does not identify a specific condition by itself. Your clinician will interpret it alongside other laboratory results and your medical history.
  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