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Serum IgA (Immunoglobulin A) by Immunoassay

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

This test measures the amount of Immunoglobulin A (IgA) in your blood serum. IgA is a type of antibody that helps protect your body from infections.

Quick summary

["IgA helps fight germs and keeps your immune system strong."]

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

Key facts at a glance

LOINC
13922-0
Short code
T spiralis IgA Ser Ql IA
Synonyms
T spiralis IgA Ser Ql IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
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 Does IgA Serve in Your Body?

IgA is part of your immune system’s first line of defense. It’s found in many body fluids, including saliva, tears, mucus, and breast milk. In blood serum, IgA helps neutralize bacteria and viruses before they enter your body. Low levels may indicate immune system issues or certain infections.

Why Might Your Doctor Order This Test?

Your doctor may check IgA levels if you have symptoms like frequent infections, digestive problems, or if they suspect conditions like immunodeficiency, celiac disease, or certain autoimmune disorders. It can also help monitor treatment responses in some cases.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into your arm to draw a blood sample. If you’re on blood thinners, let your doctor know before the test.

What Happens During the Test?

A healthcare professional will take a small blood sample from your arm. The blood is then sent to a lab where it’s analyzed using an immunoassay method to measure IgA levels.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgA Level

Frequently asked questions

IgA levels can be low in people with weakened immune systems, chronic infections, or certain genetic disorders. High levels may sometimes indicate autoimmune conditions or overactive immune responses, though this is less common. Always discuss results with your doctor for proper interpretation.
IgA levels are typically measured in milligrams per deciliter (mg/dL). Normal ranges can vary slightly by lab, so your doctor will compare your results to their specific reference values.
How long does it take to get results?
Results are usually available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will contact you once they have the results.
Can I eat or drink before this test?
You can eat and drink normally before this test, as no special diet or fasting is required.
  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