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Anti-Proteinase 3 Antibody (Serum) - Qualitative/Quantitative

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

This test measures the presence and level of antibodies against proteinase 3, a protein found in certain white blood cells. It helps diagnose conditions like certain types of vasculitis, an inflammation of the blood vessels.

Quick summary

["This test may help identify inflammatory diseases affecting blood vessels."]

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

Key facts at a glance

LOINC
6968-2
Short code
Proteinase3 Ab Ser-aCnc
Synonyms
Proteinase3 Ab Ser-aCnc
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 have symptoms of vasculitis, such as unexplained skin rashes, joint pain, kidney problems, or unexplained fevers. It could also be used to monitor treatment progress or rule out other conditions.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein in your arm to draw blood. This is usually done in a clinic or hospital setting.

What the Test Results Mean

Results are qualitative (positive/negative) or quantitative (specific antibody levels). A positive result suggests the presence of these antibodies, which can support a diagnosis of vasculitis or related conditions. Your doctor will interpret results in the context of your symptoms and medical history.

Common Conditions Linked to This Test

Positive results are often associated with **granulomatosis with polyangiitis (GPA)**, a type of vasculitis that affects small and medium-sized blood vessels. It can also be linked to other forms of vasculitis or autoimmune diseases.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Anti-PR3 Antibody (Qualitative/Quantitative)

Frequently asked questions

What does a positive result mean?
A positive result means your blood contains antibodies targeting proteinase 3, which may suggest an underlying inflammatory condition like vasculitis. Your doctor will discuss this with you and may recommend further testing or treatment plans.
How often will I need this test?
The frequency depends on your condition and treatment plan. If you have vasculitis or are being monitored for it, your doctor may order this test periodically to check for changes in your antibody levels or disease activity.
Can lifestyle changes affect this test result?
While lifestyle factors like diet or stress may influence overall health, they typically do not directly affect antibody levels measured in this test. However, managing your condition with prescribed treatments can help control symptoms and reduce disease activity.
  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