Lab Test

Proteinase 3 Autoantibodies

PR3, Serine Protease 3 Antibody

Test Codes

EPIC: LAB1231338, Beaker: XPR3, Warde: PR3AB

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One Lavender EDTA.

Send specimen for processing immediately after collection. 

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Rejection Criteria

  • Grossly hemolyzed specimens.
  • Lipemic specimens.
  • Heparinized plasma
  • Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and freeze (-20°C/-4°F or below).

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 8 hours
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): Undetermined

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Warde Medical Laboratory, Ann Arbor, MI.

Performed

Monday – Friday.
Results available in 1-3 days.

Reference Range

See report.

Test Methodology

Enzyme Linked Fluorescent Immunoassay

Interpretation

A positive test for Anti-PR3 has a high positive value for Wegener's granulomatosis (WG); fewer than 2% of positive results occur in patients who do not have WG. The presence of Anti-PR3 is a specific diagnostic indicator of WG and is found in more than 80% of patients with active WG.

A negative result for Anti-PR3 diminishes the likelihood that a patient has active WG; but approximately 20% of patients with WG may test negative for Anti-PR3.

Clinical Utility

Useful for evaluating patients suspected of having Wegener's granulomatosis (WG).

CPT Codes

83516
LOINC:  46267-1

Contacts

Last Updated

11/15/2024

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