Test Id : PR3
Proteinase 3 Antibodies, IgG, Serum
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Method Name
A short description of the method used to perform the test
Multiplex Flow Immunoassay
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
ACPA (Antineutrophil Cytoplasmic Antibodies)
ANCA (Antineutrophil Cytoplasmic Antibodies)
Anticytoplasmic Autoantibodies
Antineutrophil Cytoplasmic Antibodies (ACPA)
Autoantibodies to Proteinase 3
c-ANCA (Antineutrophil Cytoplasmic Antibodies)
cANCA (Antineutrophil Cytoplasmic Antibodies)
Cytoplasmic Neutrophil Antibodies
Neutrophil Cytoplasmic Antibodies
pANCA (Perinuclear Antineutrophil Cytoplasmic Antibodies)
Perinuclear Antineutrophil Cytoplasmic Antibodies (pANCA)
PR3 (Proteinase 3 Ab), S
PR3 (Proteinase 3) Antineutrophil Cytoplasmic Antibodies
PR3 ANCA
Proteinase 3 (PR3) Antineutrophil Cytoplasmic Antibodies
Wegener's Granulomatosis
Specimen Type
Describes the specimen type validated for testing
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
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
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.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
0.35 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | OK |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 21 days | |
| Frozen | 21 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are characterized by a pauci-immune inflammation within the walls of small blood vessels.(1) There are 3 specific diseases which are identified as ANCA-associated vasculitides: microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA). The serological hallmark of these disorders is the presence of ANCA, which are antibodies that bind to cytoplasmic antigens found in the granules of neutrophils.(2) Patients with GPA frequently have antibodies specific for proteinase 3 (PR3), while individuals with MPA or EGPA are more likely to have antibodies that bind to myeloperoxidase (MPO). The presence of PR3-ANCA and MPO-ANCA can be detected using antigen-specific immunoassays or indirect immunofluorescence (IIF). IIF is typically performed using ethanol-fixed neutrophils. Using this substrate, anti-PR3 antibodies produce a granular cytoplasmic staining pattern, which is referred to as cANCA. In comparison, due to an artefact that is a result of the fixation process, anti-MPO antibodies display a perinuclear pattern (pANCA).
Patients with suspected ANCA-associated vasculitis should be evaluated for the presence of PR3-ANCA, MPO-ANCA and ANCA by IIF. A consensus guideline published in 2017 recommends that patients with possible GPA or MPA be tested for PR3-ANCA and MPO-ANCA using antigen-specific immunoassays.(3) ANCA by IIF should then be used in cases where there is a high degree of suspicion for GPA or MPA, but the PR3-ANCA and MPO-ANCA testing is negative. To improve specificity of the testing, this guideline also suggests that ANCA be used in situations where a low-positive PR3-ANCA or MPO-ANCA level is detected. The classification criteria for MPA, GPA, and EGPA published by the American College of Rheumatology and the European Alliance of Associations for Rheumatology include PR3-ANCA and MPO-ANCA detected by either antigen-specific immunoassay or IIF.(4-6) These classification criteria incorporate serological ANCA testing along with clinical symptoms, imaging, and biopsy results to determine a score that allows for the classification of the various ANCA-associated vasculitides.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
<0.4 U (negative)
0.4-0.9 U (equivocal)
> or =1.0 U (positive)
Reference values apply to all ages.
Interpretation
Provides information to assist in interpretation of the test results
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.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A positive result for proteinase 3 (PR3)-anti-neutrophil cytoplasmic antibodies (ANCA), myeloperoxidase (MPO)-ANCA, or ANCA by indirect immunofluorescence is not diagnostic for any ANCA-associated vasculitis and must be interpreted in the clinical context of the patient.
Negative results for PR3-ANCA, MPO ANCA, and ANCA by IIF do not exclude the possibility of ANCA-associated vasculitis.
Monitoring reactivity of PR3-ANCA or MPO-ANCA should not be relied upon exclusively to evaluate response to treatment or to assess for risk of disease flare.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Kitching AR, Anders HJ, Basu N, et al. ANCA-associated vasculitis. Nat Rev Dis Primers. 2020;6(1):71
2. Ramponi G, Folci M, De Santis M, et al. The biology, pathogenetic role, clinical implications, and open issues of serum anti-neutrophil cytoplasmic antibodies. Autoimmun Rev. 2021;20(3):102759
3. Bossuyt X, Cohen Tervaert JW, Arimura Y, et al. Position paper: Revised 2017 international consensus on testing of ANCAs in granulomatosis with polyangiitis and microscopic polyangiitis. Nat Rev Rheumatol. 2017;13(11):683-692
4. Suppiah R, Robson JC, Grayson PC, et al. 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for microscopic polyangiitis. Ann Rheum Dis. 2022;81(3):321-326. doi:10.1136/annrheumdis-2021-221796
5. Robson JC, Grayson PC, Ponte C, et al. 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for granulomatosis with polyangiitis. Ann Rheum Dis. 2022;81(3):315-320. doi:10.1136/annrheumdis-2021-221795
6. Grayson PC, Ponte C, Suppiah R, et al. 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology classification criteria for eosinophilic granulomatosis with polyangiitis. Ann Rheum Dis. 2022;81(3):309-314. doi:10.1136/annrheumdis-2021-221794
Method Description
Describes how the test is performed and provides a method-specific reference
Proteinase 3 (PR3) antigen is covalently coupled to polystyrene microspheres that are impregnated with fluorescent dyes to create a unique fluorescent signature. PR3 antibodies, if present in diluted serum, bind to the PR3 antigen on the microspheres. The microspheres are washed to remove extraneous serum proteins. Phycoerythrin (PE)-conjugated antihuman IgG antibody is then added to detect anti-PR3 IgG bound to the microspheres. The microspheres are washed to remove unbound conjugate, and bound conjugate is detected by laser photometry. A primary laser reveals the fluorescent signature of each microsphere to distinguish it from microspheres that are labeled with other antigens. A secondary laser reveals the level of PE fluorescence associated with each microsphere. Results are calculated by comparing the median fluorescence response for PR3 microspheres to a 4-point calibration curve.(Package insert: Bio-Plex 2200 Vasculitis. Bio-Rad Laboratories; 12/2018)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Saturday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
83516
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| PR3 | Proteinase 3 Ab (PR3), S | 74106-6 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| PR3 | Proteinase 3 Ab (PR3), S | 74106-6 |