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Test Code PR3 Proteinase 3 Antibodies, IgG, Serum

Additional Codes

CNE Order Code: Proteinase3

Reporting Name

Proteinase 3 Ab (PR3), S

Useful For

Evaluating patients with clinical features of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, specifically granulomatosis with polyangiitis (GPA), microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis

 

Distinguishing between GPA and other forms of ANCA-associated vasculitis, in conjunction with myeloperoxidase antibody and cytoplasmic neutrophil antibody testing

 

Following treatment response or monitoring disease activity in patients with proteinase 3 antibodies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Additional Testing Requirements


To distinguish between granulomatosis with polyangiitis and other forms of anti-neutrophil cytoplasmic antibody-associated vasculitis, also order MPO / Myeloperoxidase Antibodies, IgG, Serum and ANCA / Cytoplasmic Neutrophil Antibodies, Serum; alternatively, VASC / Antineutrophil Cytoplasmic Antibodies Vasculitis Panel, Serum may be ordered instead, which initially tests for MPO and proteinase 3 antibodies, with reflex to ANCA when appropriate.



Specimen Required


Supplies: Sarstedt Aliquot Tube 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

0.35 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 21 days
  Frozen  21 days

Reference Values

<0.4 U (negative)

0.4-0.9 U (equivocal)

≥1.0 U (positive)

Reference values apply to all ages.

Day(s) Performed

Monday through Saturday

CPT Code Information

83516

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PR3 Proteinase 3 Ab (PR3), S 74106-6

 

Result ID Test Result Name Result LOINC Value
PR3 Proteinase 3 Ab (PR3), S 74106-6

Interpretation

Positive results for proteinase 3 (PR3) anti-neutrophil cytoplasmic antibodies (ANCA) by antigen-specific immunoassay and cytoplasmic ANCA by indirect immunofluorescence are consistent with the diagnosis of granulomatosis with polyangiitis (GPA), in patients with the appropriate clinical presentation.

 

The reactivity of PR3-ANCA may decline with treatment of patients with GPA.

Report Available

2 to 3 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus OK

Method Name

Multiplex Flow Immunoassay

Forms

If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.