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Human Leukocyte Antigen (HLA) Typing (Serum Antibody Screening)

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

This test checks for antibodies against specific proteins found on white blood cells (human leukocyte antigens, or HLA). These antibodies may be present if your body has reacted to a previous transplant, pregnancy, or blood transfusion.

Quick summary

["Helps identify potential risks of transplant rejection or compatibility issues in medical procedures."]

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

Key facts at a glance

LOINC
13298-5
Short code
HLAA
Synonyms
—
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 Might Be Ordered

Your healthcare provider may recommend this test if you’re preparing for a kidney, heart, or other organ transplant, or if you’ve had a recent blood transfusion or pregnancy. It can also be used to assess compatibility for stem cell transplants or certain autoimmune conditions.

What to Expect Before the Test

No special preparation is needed. A blood sample will be drawn from a vein in your arm. You may feel slight discomfort, but it usually lasts only a few minutes. If you’re pregnant or have a history of bleeding disorders, let your provider know before the test.

How the Test Works

The test involves analyzing your serum (liquid part of blood) for antibodies against common HLA proteins. This is done using immunoassay methods to detect the presence of these antibodies, which can be confirmed with further testing if needed.

What the Results Mean

Results are qualitative (present or absent) and indicate whether antibodies are detected against specific HLA types. A positive result means antibodies are present, which may affect transplant compatibility or other clinical decisions.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HLA Antibody Screen

Frequently asked questions

Why might my doctor be concerned about these results?
If you’re a transplant candidate, positive HLA antibodies may increase the risk of organ rejection or reduce the number of compatible donor organs available. In some cases, they may also suggest an autoimmune condition or a past exposure to foreign tissues.
How long will it take to get my results?
Results are typically available within 1–3 business days, depending on lab processing times. Your healthcare provider will discuss the findings with you during your follow-up visit.
Can I eat or drink before this test?
No special diet is required. You can eat and drink normally before the blood draw, but avoid alcohol for 24 hours if possible, as it may affect blood components.
  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