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Anti-IgA Antibody (Serum) - Immunoassay (IgA Immunoglobulin Blocking Test)

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

This test measures antibodies that may block the body’s ability to produce IgA, a type of antibody important for immune defense in certain areas like the respiratory and digestive tracts.

Quick summary

["Helps diagnose conditions where IgA antibodies could interfere with immune function in specific body systems."]

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

Key facts at a glance

LOINC
48064-0
Short code
G lamblia+C parvum Ag Stl Ql
Synonyms
G lamblia+C parvum Ag Stl Ql
Category
coagulation
Sample
stool
Container
Clean container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your healthcare provider may recommend this test if you have symptoms like recurrent infections in the sinuses, lungs, or gastrointestinal tract, or if you have conditions like IgA nephropathy (a kidney disease) or certain autoimmune disorders. It may also be used to assess immune function in people with genetic or acquired immune deficiencies.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from your arm. The test checks for antibodies that could interfere with IgA production, which may affect how your immune system responds to infections or other immune challenges.

What the Results Mean

Results are qualitative (yes/no) and indicate whether blocking antibodies are present. A positive result suggests these antibodies may be affecting your immune response, which could influence treatment decisions for conditions like recurrent infections or autoimmune diseases.

Common Conditions Linked to This Test

This test is often used in cases of recurrent sinusitis, bronchitis, or gastrointestinal infections that don’t respond to standard treatments. It may also be part of evaluating immune-related conditions like IgA deficiency or certain inflammatory disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgA blocking test

Frequently asked questions

What does a positive result mean?
A positive result means your blood contains antibodies that may block the production of IgA, an important antibody for immune defense. This could affect how your body fights infections in certain areas like the lungs or digestive tract.
How is this test different from a regular IgA blood test?
This test specifically checks for antibodies that *block* IgA production, not the IgA levels themselves. It’s used to assess whether these blocking antibodies are interfering with your immune system’s ability to produce IgA normally.
Can this test be done at home?
No, this test requires a blood sample collected by a healthcare professional in a clinical setting. Results are typically reported within a few days.
  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