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Histone H2A (H2AB) Antibody, Serum/Plasma

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

This test measures antibodies against histone H2A, a protein found in cell nuclei. These antibodies may be linked to certain autoimmune conditions.

Quick summary

["This test helps evaluate possible autoimmune responses involving nuclear proteins."]

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

Key facts at a glance

LOINC
18231-1
Short code
Histone H2a+H2b Ab Ser Ql IF
Synonyms
Histone H2a+H2b Ab Ser Ql IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
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

What Is This Test Measuring?

Histone H2A is a core protein in chromatin, the complex of DNA and proteins that makes up chromosomes. Antibodies against histone proteins can be detected in the blood when the immune system mistakenly targets these molecules, often in autoimmune diseases like systemic lupus erythematosus (SLE) or other connective tissue disorders.

Why Might You Need This Test?

Your healthcare provider may order this test if you have symptoms suggestive of an autoimmune condition, such as joint pain, fatigue, rash, or unexplained inflammation. It can also be part of a broader evaluation for conditions where nuclear protein antibodies are involved.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The sample is then processed into serum or plasma for testing. This test is typically performed on fresh or stored blood samples sent to a laboratory.

What Does a Positive Result Mean?

A positive result indicates the presence of histone H2A antibodies in your blood. While this finding can be associated with autoimmune diseases, it does not definitively diagnose a condition. Further clinical correlation and additional testing may be needed to determine the cause and guide treatment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Histone Antibody Test

Frequently asked questions

What are the normal ranges for this test?
There are no universally standardized reference ranges for histone antibody tests because they vary by assay and laboratory. Results are typically reported as positive or negative based on threshold values set by the testing laboratory.
How often should I get this test?
The frequency of testing depends on your clinical situation. Your healthcare provider will determine if repeat testing is necessary based on changes in your symptoms, disease activity, or response to treatment.
Can this test be done at home?
No, this test requires a blood sample collected by a healthcare professional. It is performed in a clinical laboratory and cannot be done at home.
  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