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Serum IgA (Immunoglobulin A) 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."]

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

Key facts at a glance

LOINC
71704-1
Short code
RV IgA Ser IA-aCnc
Synonyms
RV 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 Is Immunoglobulin A (IgA)?

IgA is a key part of your immune system. It appears in many body fluids, including saliva, tears, mucus, and breast milk. In the blood, IgA helps prevent harmful substances from entering your body and fights infections. Different types of IgA (IgA1 and IgA2) have slightly different roles, but both are important for immune protection.

Why Might You Need This Test?

Doctors may order an IgA test to check for immune system issues, such as low IgA levels (hypogammaglobulinemia), which can increase your risk of infections. It may also be used to diagnose or monitor conditions like celiac disease, certain autoimmune diseases, or immune deficiencies.

Common Reasons for Testing

Common reasons include recurrent infections, unexplained immune problems, or if you have symptoms like frequent colds, sinus infections, or skin rashes. It can also help evaluate conditions like IgA nephropathy (a kidney disease linked to IgA deposits).

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 blood. If you’re nervous, let your healthcare provider know so they can help make it more comfortable.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgA Level

Frequently asked questions

How low or high are my IgA levels?
IgA levels vary among individuals. A low IgA level may suggest an immune deficiency or an underlying condition like celiac disease. A very high level might rarely indicate certain immune disorders or infections, but this is less common. Your doctor will interpret results in the context of your health and symptoms.
What does an abnormal IgA level mean?
Low IgA levels can mean your body isn’t producing enough antibodies to fight infections, which may lead to frequent illnesses. High levels are less frequently abnormal but could be linked to certain immune conditions or chronic infections. Your doctor will discuss findings with you based on your medical history.
Can diet affect IgA levels?
Diet may influence immune function indirectly, but IgA levels are primarily determined by your immune system’s response. Certain foods or supplements (like probiotics) might support immune health, but they don’t directly change IgA test results. Always follow your doctor’s advice for dietary changes.
  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