ARUP's Laboratory Test Directory

0050811: Anti-Neutrophil Cytoplasmic Antibody, IgG

Test Mnemonic: ANCA IFA
Methodology: Indirect Fluorescent Antibody

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: 0.15 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:
< 1:20: Not significant

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.


                                                             


 
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
Systematic lupus erythematosus (SLE) <10 0 >90
Rheumatoid Arthritis <5 0 >90
Sjögren syndrome 25 0 >90
*No quantitation in the literature.


Note:
Samples are screened on ethanol-fixed slides which allow differentiation of C and P patterns.  Negatives are reported.  Positives 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-ANCAs by removing ANA receptor sites and maintaining cytoplasmic localization of myeloperoxidase or other antigens.

IFA is considered the screening procedure of choice for ANCAs.  However, if confirmation of Anti-PR3 or confirmation of Anti-MPO in samples positive for ANCA is desired, please contact Client Services at ARUP to order specific ELISA testing offered by ARUP.  We retain samples in the laboratory for four weeks and the ELISA tests can usually be performed on the same sample if sufficient sample was received and the appropriate test request is added. Refer also to Neutrophil Cytoplasmic Antibody with Reflex to Titer & MPO/PR3 Antibodies (0050523).

CPT Code(s):
86255 ANCA; if positive, add 86256 ANCA titer

 

 

 
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