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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 the surface of donor cells, often used before organ transplants to ensure compatibility.

Quick summary

["Helps prevent transplant rejection by identifying potential immune responses to donor tissues."]

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

Key facts at a glance

LOINC
50968-7
Short code
HLA Ab Ser
Synonyms
HLA Ab Ser
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 Is Done

Doctors order an HLA antibody screen before organ transplants to assess whether your immune system might reject a donated organ. It helps match donors and recipients based on compatibility.

How the Test Works

A small blood sample is taken from you. The serum (liquid part of blood) is tested for antibodies that could attack donor cells, using a method called immunoassay to detect these antibodies.

What to Expect Before the Test

You may need to fast for a few hours before the test, but this depends on your doctor’s instructions. Wear comfortable clothing and plan to stay near the testing site for a short time.

What to Expect During the Test

A healthcare provider will insert a needle into your arm to draw blood. You may feel a brief pinch, but it usually doesn’t cause significant discomfort. The test itself takes only a few minutes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Positive results indicate the presence of antibodies that could increase the risk of transplant rejection. This information is critical for selecting a compatible donor and planning post-transplant immune monitoring.

Short name

HLA Antibody Screen

Frequently asked questions

What does a positive result mean?
A positive result means your immune system may recognize certain donor cells as foreign, which could lead to rejection. Your doctor will work with you to find a compatible donor and monitor your immune response closely.
Can lifestyle changes affect this test?
Generally, lifestyle factors like diet or exercise don’t directly affect HLA antibody screening results. However, if you’re undergoing treatment for an autoimmune condition, your doctor may advise adjustments to avoid false positives or complications.
How often will I need this test?
The frequency depends on your transplant plan and ongoing health. Your doctor may schedule follow-up tests before and after transplantation to monitor antibody levels and ensure compatibility.
  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