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Human Leukocyte Antigen (HLA) Antibody Screening (Serum)

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

This test checks for antibodies in your blood that may react against certain proteins found on white blood cells, often used to assess compatibility for organ transplants or pregnancy-related risks.

Quick summary

["Helps determine if you have antibodies that could affect transplant success or pregnancy outcomes."]

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

Key facts at a glance

LOINC
41618-0
Short code
HLA Ab Ser Ql FC
Synonyms
HLA Ab Ser Ql FC
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
flow-cytometry
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 Matters

HLA antibodies can sometimes develop after exposure to certain infections, blood transfusions, or prior pregnancies. They may also be present in people with autoimmune conditions. This screening helps healthcare providers identify potential risks before organ transplants or during pregnancy to guide treatment decisions.

What to Expect Before the Test

No special preparation is needed. You’ll have a simple blood draw, usually taken from your arm. The blood sample will be sent to a lab for testing.

How the Test Works

The test uses a method called solid-phase immunoassay to detect antibodies against specific HLA proteins. If antibodies are found, they are identified and reported.

Possible Results and Next Steps

A positive result means antibodies were detected. This may require further testing (confirmation) or additional evaluation to understand their significance, especially if you’re considering organ donation or pregnancy.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HLA Antibody Screen

Frequently asked questions

What does a positive result mean?
A positive result indicates the presence of antibodies against certain HLA proteins. This may raise concerns for organ transplant compatibility or pregnancy-related risks, but it doesn’t always mean a problem exists. Your healthcare provider will discuss next steps based on your full medical history and situation.
Can I have this test if I’m not planning a transplant or pregnancy?
Sometimes, this test is performed for other reasons, such as autoimmune conditions or unexplained symptoms. If you’re unsure why it was ordered, ask your doctor for clarification. It’s also sometimes done as part of routine screening in certain high-risk groups.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on lab processing times. Your doctor will contact you once they’re ready to discuss the findings.
  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