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 and is important for immune function.

Quick summary

["IgA levels help doctors assess immune health and check for conditions affecting antibody production."]

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

Key facts at a glance

LOINC: 44584-1
Short code: IgA Ab SerPl Ql
Synonyms: IgA Ab SerPl Ql
Category: chemistry
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

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like frequent infections, unexplained bleeding, or if they suspect conditions like IgA deficiency, autoimmune diseases, or certain types of kidney disease. It can also be part of a general health check or to monitor treatment for immune-related conditions.

What to Expect Before the Test

No special preparation is needed for this test. You may have a blood sample drawn from a vein in your arm, or if testing urine or saliva, follow any specific instructions your healthcare provider gives you.

What the Test Results Mean

IgA levels can vary based on age, overall health, and certain medical conditions. While reference ranges exist, they can differ slightly between labs. Your doctor will interpret the results in the context of your health history and symptoms.

Low IgA levels may indicate a weakened immune system, such as IgA deficiency, which can increase susceptibility to infections. High levels might be seen in certain autoimmune diseases or during pregnancy. Always discuss any changes in your test results with your healthcare provider.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgA Level

Frequently asked questions

How often do I need this test?

The frequency of this test depends entirely on your healthcare needs. Your doctor will determine how often you need it based on your symptoms, medical history, and treatment plan. Regular monitoring may be recommended for chronic conditions or ongoing health management.

Can I eat or drink before the test?

For blood tests, you can usually eat and drink normally unless instructed otherwise. For urine or saliva tests, follow any specific instructions provided by your healthcare provider to ensure accurate results.

What are typical reference ranges for IgA?

IgA reference ranges can vary between labs and may not be standardized. Your doctor will use the results in relation to your health status and medical history rather than a single numeric range.

Sources

1
MedlinePlus — Laboratory TestsSource
2
Lab Tests OnlineSource
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