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Immunoglobulin A (IgA) in Serum or Plasma

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.

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

Key facts at a glance

LOINC
10488-5
Short code
IgA Ag Tiss Ql ImStn
Synonyms
IgA Ag Tiss Ql ImStn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-stain
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

Why This Test Might Be Ordered

Your healthcare provider may order this test to check for low or high levels of IgA, which can occur in conditions like immune deficiencies, certain autoimmune diseases, or after certain treatments. It may also be used to monitor immune responses or diagnose conditions like IgA nephropathy (a kidney disease).

What to Expect During the Test

A blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The sample is then sent to a lab for analysis.

Understanding Your Results

Results are typically reported as a concentration of IgA in the blood. While specific reference ranges can vary by lab, low IgA levels may suggest immune system issues, while very high levels might be associated with certain autoimmune conditions or overproduction of antibodies.

Common Conditions Linked to IgA Levels

Low IgA levels can be linked to conditions like Common Variable Immune Deficiency (CVID), which makes it harder to fight infections. High IgA levels may be seen in some autoimmune diseases or after certain medical treatments.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: IgA plays a critical role in mucosal immunity, helping protect surfaces like the respiratory and digestive tracts. Abnormal levels can indicate underlying immune dysfunction or specific diseases, guiding treatment decisions.

Short name

IgA Level

Frequently asked questions

What causes IgA levels to be low?
Low IgA levels can result from genetic immune deficiencies, certain infections, or treatments that weaken the immune system, such as chemotherapy. It may also be part of an inherited condition like CVID.
What does it mean if my IgA level is high?
High IgA levels can occur in autoimmune diseases, chronic infections, or as a side effect of certain medications. In some cases, it may be a normal variation, but your provider will discuss findings with you based on your overall health.
Can diet affect IgA levels?
Diet generally does not directly affect IgA levels, but maintaining a balanced diet supports overall immune function. If you suspect diet may influence your test results, discuss it with your healthcare provider.
  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