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Giardia lamblia IgA Immunoglobulin G (Serum) - Immunoassay

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

This test measures the presence of IgA antibodies against Giardia lamblia, a microscopic parasite that can cause intestinal infections. IgA antibodies help the immune system fight off infections caused by this parasite.

Quick summary

["IgA antibodies may indicate past or current infection by Giardia, a common cause of diarrhea."]

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

Key facts at a glance

LOINC
21301-7
Short code
G lamblia IgM Titr Ser IF
Synonyms
G lamblia IgM Titr Ser IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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 This Test Measures

IgA antibodies are a type of immune protein produced by your body in response to Giardia lamblia. If you have been exposed to this parasite, your immune system may produce these antibodies. This test detects these antibodies in your serum to help diagnose an infection.

Why It’s Done

Doctors may order this test if you have symptoms like persistent diarrhea, stomach cramps, bloating, or gas. It can also be used to confirm a suspected Giardia infection in people with no obvious symptoms or when other tests are inconclusive.

What to Expect Before the Test

No special preparation is usually needed for this blood test. You may be asked to fast for 8–12 hours before the draw, but this depends on your doctor’s instructions. Bring a list of medications you’re taking, as some may affect test results.

What the Test Results Mean

Positive results suggest you may have been infected by Giardia lamblia, though IgA antibodies can sometimes linger even after the infection has cleared. A negative result means no detectable IgA antibodies were found, but this does not definitively rule out infection. Your doctor will interpret results in the context of your symptoms and other tests.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Giardia IgA Antibody (Serum)

Frequently asked questions

How long will it take to get my results?
Results are typically available within 2–5 business days, depending on your lab. Your healthcare provider will contact you with the final report once it’s ready.
Can I have my test repeated if I’m still experiencing symptoms?
Yes, if you continue to have symptoms like diarrhea or abdominal pain, your doctor may recommend repeating the test or ordering additional tests (such as a stool sample for parasite detection) to better diagnose the cause of your illness.
Does this test detect active infection or just past exposure?
This test detects IgA antibodies, which can indicate past exposure or a current infection. However, antibodies may take time to develop after exposure, and they may not always reflect an active infection. Your doctor may combine this test with other diagnostic methods for a full assessment.
  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