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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 levels can help diagnose or monitor conditions affecting your immune system."]

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

Key facts at a glance

LOINC
25444-1
Short code
IgA Ur Ql IEP
Synonyms
IgA Ur Ql IEP
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immunoelectrophoresis
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

Why This Test Is Done

Your healthcare provider may order an IgA test to check for immune system issues, such as certain autoimmune diseases, infections, or conditions like IgA deficiency. It can also be used to monitor treatment progress for conditions like lupus or other immune disorders.

What to Expect Before the Test

No special preparation is usually needed. You may have a small needle inserted into a vein in your arm to draw blood. If you’re concerned about needles, let your healthcare provider know.

What the Test Results Mean

IgA levels can vary based on health, age, and other factors. While reference ranges exist, they can differ by lab. Your results will be compared to your own baseline or to a general range provided by your healthcare team.

Common Conditions Monitored

Low IgA levels may indicate immune system problems like IgA deficiency or certain autoimmune diseases. High levels might be seen in some infections or inflammatory conditions, but this isn’t always straightforward.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

IgA plays a key role in protecting mucosal surfaces (like your lungs, digestive tract, and sinuses). Abnormal levels can signal underlying immune dysfunction or disease, guiding treatment decisions.

Short name

IgA Level

Frequently asked questions

What causes IgA levels to be low?
Low IgA levels can be due to genetic conditions like IgA deficiency, certain autoimmune diseases (e.g., lupus), or immune system disorders. Rarely, it may also be linked to infections or medications.
How often should I get this test?
Your healthcare provider will determine how often you need this test based on your medical history, symptoms, and treatment plan. Follow their advice for scheduling.
Does diet affect IgA test results?
Diet generally does not directly affect IgA levels, but certain foods or supplements (like high-protein diets) might influence overall health that indirectly impacts immune function. Avoid special diets unless advised by your 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