Test ID: PR3
Proteinase 3 Antibodies, IgG, Serum
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Evaluating patients suspected of having Wegener granulomatosis (WG)
Distinguishing between WG and other forms of vasculitis, in conjunction with MPO/Myeloperoxidase Antibodies, IgG, Serum and ANCA Cytoplasmic Neutrophil Antibodies, Serum (may be obtained as VASC Antineutrophil Cytoplasmic Antibodies Vasculitis Panel, Serum)
May be useful to follow treatment response or to monitor disease activity in patients with myeloperoxidase antibodies
Method Name A short description of the method used to perform the test
Multiplex Flow Immunoassay
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
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 needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 0.5 mL
Forms: If not ordering electronically, submit a General Request Form (Supply T239) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | Mild OK; Gross reject |
| Lipemia | Mild OK; Gross reject |
| Icterus | Mild OK; Gross OK |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 21 days |
| Frozen | 21 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Proteinase 3 (PR3) antigen is a 29kD serine protease that exists as a protein triplet in human neutrophils.
Wegener granulomatosis (WG) is an autoimmune vasculitis that affects the kidneys and lungs, as well as other organs. Patients with WG develop autoantibodies to the PR3 antigen of myeloid lysosomes (PR3 antineutrophil cytoplasmic antibodies [PR3 ANCA]).(1)
Since it is often impossible to distinguish between WG and other forms of vasculitis on the basis of clinical signs and symptoms, tests for PR3 ANCA should be employed with other serologic tests in the initial diagnostic evaluation of patients with clinical features of vasculitis (eg, VASC/83012 Antineutrophil Cytoplasmic Antibodies Vasculitis Panel, Serum).
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
Proteinase 3 antineutrophil cytoplasmic antibodies (PR3 ANCA) are detectable in nearly all patients with severe active Wegener granulomatosis (WG).(2) The presence of PR3 ANCA is a specific diagnostic indicator of WG; <2% of positive results occur in patients who do not have the disease.(3,4)
A negative result for PR3 ANCA diminishes the likelihood that a patient has active WG; but, approximately 20% of patients with limited WG may test negative for PR3 ANCA.(3)
The levels of PR3 ANCA often decline following successful treatment of patients with WG. Nevertheless, follow-up testing for PR3 ANCA to evaluate clinical status in treated patients should be used with caution as the levels of antibodies may correlate poorly with clinical status in some patients.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
While the presence of proteinase 3 antineutrophil cytoplasmic antibodies (PR3 ANCA) is highly specific for Wegener granulomatosis (WG), it is recommended that positive test results obtained by immunoassay be confirmed by another testing method.(4) This is best accomplished by testing for cytoplasmic ANCA (cANCA) and perinuclear ANCA (pANCA) by indirect immunofluorescence microscopy (ANCA/9441 Cytoplasmic Neutrophil Antibodies, Serum). Alternately, VASC/83012 Antineutrophil Cytoplasmic Antibodies Vasculitis Panel, Serum includes tests for PR3 ANCA, myeloperoxidase antibodies, and, if indicated, cANCA and pANCA. This panel is recommended for the initial diagnostic evaluation of patients clinically suspected of having systemic vasculitis. Simultaneous presence of PR3 ANCA and cANCA has a specificity >99% for WG.(3)
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. van der Woude FJ, Rasmussen N, Lobatto S, et al: Autoantibodies against neutrophils and monocytes: tool for diagnosis and marker of disease activity in Wegener granulomatosis. Lancet 1985;1:425-429
2. Finkleman JD, Lee AS, Hummel AM, et al: ANCA are detectable in nearly all patients with active severe Wegener's granulomatosis. Am J Med 2007;120:643
3. Russel KA, Wiegert E, Schroeder DR, et al: Detection of anti-neutrophil cytoplasmic antibodies under actual clinical testing conditions. Clin Immunol 2002;103:196-203
4. Savige J, Gillis D, Benson E, et al: International consensus statement on testing and reporting of antineutrophil cytoplasmic antibodies (ANCA). Am J Clin Pathol 1999;111:507-513
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 IgG anti-PR3 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, Hercules, CA)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; 4 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
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 The location of the laboratory that performs the test
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's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
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 Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
83516
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| PR3 | Proteinase 3 Ab (PR3), S | 6968-2 |
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