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Human Leukocyte Antigen (HLA) Class I Grouping by Immunoassay (Serum/Plasma)

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

This test identifies specific human leukocyte antigen (HLA) Class I molecules present on your white blood cells and some tissues. HLA molecules help your immune system recognize your own cells and distinguish them from foreign invaders.

Quick summary

["HLA Class I testing helps match donors and recipients for organ transplants and blood transfusions, as well as guide immune-related treatments."]

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

Key facts at a glance

LOINC
94441-3
Short code
HLA-A+B+C (class I) IgG SerPl FC
Synonyms
HLA-A+B+C (class I) IgG SerPl 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
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

Why This Test Is Done

Doctors may order HLA Class I testing to help ensure a compatible match for organ transplants, such as kidneys, liver, or heart. It may also be used in blood donation screening or for diagnosing certain autoimmune conditions where immune response patterns are being evaluated.

What to Expect Before the Test

No special preparation is needed. You’ll provide a blood sample, usually drawn from a vein in your arm. The sample is collected in a tube containing an anticoagulant to prevent clotting.

How the Test Works

The blood sample is tested using an immunoassay method to detect and quantify specific HLA Class I antigens. These antigens are proteins found on the surface of cells that play a key role in immune recognition.

What the Results Mean

Results identify which HLA Class I alleles (versions) are present in your blood. These results are used by healthcare providers to assess compatibility for transplants or other immune-related evaluations. Exact interpretations depend on clinical context and specific testing protocols.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

HLA Class I Typing

Frequently asked questions

What does an HLA Class I test measure?
This test measures the presence and type of specific human leukocyte antigen (HLA) Class I molecules on your blood cells. These molecules are essential for immune function and compatibility assessments.
How long does it take to get results from this test?
Results typically take several days to a few weeks, depending on the laboratory’s processing schedule and clinical urgency. Follow-up with your healthcare provider for interpretation.
Can I eat or drink before this test?
No special dietary restrictions apply. You can eat and drink normally before the blood draw, as this test only requires a small blood sample.
  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