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Total IgA (Immunoglobulin A) Serum Concentration

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

This test measures the amount of Immunoglobulin A (IgA), a type of antibody in your blood. IgA helps protect your body from infections by fighting bacteria and viruses.

Quick summary

["IgA helps defend against common infections and supports immune function; low levels may indicate immune disorders or digestive issues."]

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

Key facts at a glance

LOINC
46128-5
Short code
tTG IgA Ser IA-aCnc
Synonyms
tTG IgA Ser IA-aCnc
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 IgA Does in Your Body

IgA is part of your immune system’s first line of defense. It appears in saliva, tears, mucus, and breast milk, where it helps prevent infections from entering your body. IgA also plays a role in managing immune responses to allergens and chronic inflammation.

Why It’s Tested

Doctors may order this test if you have symptoms like frequent infections, digestive problems (such as celiac disease), or if you’re at higher risk for immune-related conditions. It can also help diagnose or monitor certain autoimmune diseases.

Common Reasons for Testing

Common reasons include diagnosing conditions like IgA deficiency, evaluating symptoms of recurrent infections, or assessing immune function in patients with chronic illnesses.

Sample Collection

A small blood sample is taken from a vein in your arm. The blood is processed to separate serum (the liquid part without clots) for testing.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

IgA Blood Test

Frequently asked questions

What might low or high IgA levels suggest?
Low IgA levels may indicate a weakened immune response, potentially linked to conditions like IgA deficiency, celiac disease, or other autoimmune disorders. Very high levels could rarely suggest immune system overactivity or certain inflammatory conditions.
How is IgA tested?
IgA levels are measured using an immunoassay method, which detects the presence and concentration of IgA antibodies in your serum. This test is typically done in a laboratory using automated equipment.
What do my results mean?
Your doctor will compare your IgA levels to reference ranges appropriate for your age and health. If results are outside normal limits, further testing or evaluation may be needed to understand the cause.
  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