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Human Leukocyte Antigen (HLA) Antibody Screening (Serum)

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

This test checks for antibodies against specific proteins found on white blood cells (HLA antigens). These antibodies can sometimes develop in response to pregnancy, blood transfusions, or certain medical conditions.

Quick summary

["Helps identify potential risks of transplant rejection or complications in pregnancy or blood transfusions."]

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

Key facts at a glance

LOINC
46993-2
Short code
HLA Ab Pnl Ser
Synonyms
HLA Ab Pnl 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 may order this test if you’re preparing for a pregnancy, considering a blood transfusion, or planning a kidney, liver, or other organ transplant. It helps ensure compatibility between your blood or body fluids and those of the donor or fetus.

How the Test Works

A small blood sample is drawn from your arm. The serum (liquid part of blood) is tested for antibodies against common HLA antigens using a method called immunoassay, which detects the presence of these antibodies.

What to Expect Before the Test

No special preparation is needed. Wear comfortable clothing and fast if instructed by your healthcare provider, as fasting may not apply to this test.

What to Expect During the Test

You’ll sit comfortably while a healthcare professional inserts a needle into your vein. The blood sample is collected into a tube. The process usually takes a few minutes.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: This test is critical for preventing complications such as transplant rejection, fetal-maternal hemorrhage risks, or adverse reactions to blood transfusions. Positive results may guide further testing or treatment plans.

Short name

HLA Antibody Screen

Frequently asked questions

What does a positive result mean?
A positive result means your blood contains antibodies against certain HLA antigens. This may increase the risk of complications in pregnancy, organ transplants, or blood transfusions, prompting additional evaluation.
Will I need to repeat this test?
Yes, if your initial result is positive, your doctor may order confirmatory testing or additional HLA antibody panels to identify specific antibodies and tailor your care.
Does this test affect my insurance coverage?
This test is typically covered by insurance if medically necessary for pregnancy, transplants, or blood transfusions. Always confirm with your insurance provider for specifics.
  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