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IgG, Serum and Urine — Mass Concentration

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

Measures the amount of immunoglobulin G (IgG) in serum and urine. Results may help evaluate immune protein production and the loss of IgG through the kidneys.

Quick summary

["This test measures IgG levels in blood and urine to help assess immune function and possible urinary protein loss."]

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

Key facts at a glance

LOINC
99461-6
Short code
Rat Epith+Ser+Ur IgG-mCnc
Synonyms
Rat Epith+Ser+Ur IgG-mCnc
Category
urine
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 is this test?

This test measures immunoglobulin G (IgG), a type of antibody, in serum and urine. IgG helps the immune system recognize and fight infections.

Why might I need this test?

A clinician may order this test to evaluate immune function or investigate unusual IgG levels. Comparing IgG in blood with IgG in urine can also help assess whether IgG is being lost through the kidneys.

How is the test performed?

Blood and urine samples are analyzed in a laboratory to determine the concentration of IgG. The laboratory may report the measurements separately for serum and urine.

How do I prepare for the test?

Follow your clinician's instructions about sample timing and collection. For a 24-hour urine collection, collect all urine for the specified period and store the container as directed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low serum IgG may be associated with impaired antibody production or conditions that cause loss of immune proteins. IgG in the urine may reflect normal small amounts, but increased urinary IgG can suggest kidney injury or impaired filtering of proteins. Results should be interpreted with symptoms, medical history, and other kidney or immune tests.

Short name

Serum and Urine IgG

Frequently asked questions

What does IgG measure?
IgG is an antibody that helps protect against infections. The test measures how much IgG is present in blood and urine.
Why are serum and urine tested together?
Serum shows the IgG level in the blood, while urine helps show whether IgG is being lost through the kidneys. The results provide more context than either sample alone.
Does an abnormal result confirm a specific disease?
No. An abnormal result can occur with several immune or kidney conditions and must be interpreted by a clinician alongside the rest of your evaluation.
  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