ARUP's Laboratory Test Directory

0050523: Anti-Neutrophil Cytoplasmic Antibody with Reflex to Titer & MPO/PR3 Antibodies

Test Mnemonic: ANCA-PAN
Methodology: Indirect Fluorescent Antibody/Multi-Analyte Fluorescent Detection

Performed: Mon-Sat

Reported: 2-5 days

Specimen Required:  
Collect: One 4 mL SST.

Transport: 1 mL serum at 2-8°C. (Min: 0.5 mL) Submit specimen in an ARUP Standard Transport Tube.

Pediatric Collection/Transport: 0.25 mL serum at 2-8°C.

Remarks: Separate serum from cells ASAP.

Unacceptable Conditions: Plasma, CSF, urine, or other body fluids.  Severely lipemic, contaminated, or hemolyzed specimens.

Stability: After separation from cells: Ambient: 2 days; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval:
 
Test Number Components Reference Interval
0050811Anti-Neutrophil Cytoplasmic Antibody, IgG < 1:20: Not significant
0050526Myeloperoxidase Antibody Negative: 19 AU/mL or less
Equivocal: 20-25 AU/mL
Positive: 26 AU/mL or greater
0050527Serine Protease 3 Antibody Negative: 19 AU/mL or less
Equivocal: 20-25 AU/mL
Positive: 26 AU/mL or greater

Interpretive Data:
Neutrophil Cytoplasmic Antibodies (C-ANCA = granular cytoplasmic staining, P-ANCA = perinuclear staining) are found in the serum of over 90% of patients with certain necrotizing systemic vasculitides, and usually in less than 5% of patients with collagen vascular disease or arthritis. Approximately 90% of patients with a P-ANCA pattern by IFA have antibodies specific for MPO.  Approximately 85% of patients with a C-ANCA pattern by IFA have antibodies specific for PR3.

 
ANCAs in Vasculitic Syndromes
Approximate % pos ANCA Approximate % of patients demonstrating
 Combined patterns C Pattern P Pattern
Wegener granulomatosis:    
-Active generalized 85-92 85-90 2-5
-Limited forms 60-67 85-90 2-5
-Inactive 30-35 85-90 2-5
Idiopathic Crescentic Glomerulonephritis 80 some* majority*
Polyarteritis Nodosa 50 86 14
Churg-Strauss 50 80 20
Systemic lupus erythematosus (SLE) <10 0 >90
Rheumatoid arthritis <5 0 >90
Sjögren syndrome 25 0 >90
* No quantitation in the literature


Note:
Specimens are screened by IFA on ethanol-fixed slides which allow differentiation of C and P patterns. If screen result is 1:20, titer and MPO/PR-3 Antibodies will be added.

Specimens are serially diluted and tested on ethanol fixed slides to establish titer and confirm pattern. All P-ANCA patterns are also tested on formalin-fixed slides to confirm P-ANCA by removing ANA receptor sites and maintaining cytoplasmic localization of myeloperoxidase.

CPT Code(s):
86255 ANCA; if reflexed, add 86256 ANCA titer and 83516 x2 MPO/PR3

 

 

 
All ARUP Sites:        www.aruplab.com     ·     www.arupconsult.com     ·     www.arup.utah.edu     ·     www.childx.org     ·     www.utahblood.org