Anti-Neutrophil Cytoplasmic (ANCA) Screen
Label Mnemonic: ANCAS
Epic Lab Code: LAB1327
Downtime Form: A-1a Immunopathology Requisition
Immunopathology
5238 RCP
356-2688
Specimen(s):
Serum
Collection Medium:
or
Red top tube 5 mL (Clot Activator) BD Gold SST 5 mL Vacutainer
Minimum:
Adult - 5 mL; red top tube
Pediatric - 2 mL; red top tube
Testing Schedule:
Daily - Batch analysis performed daily excluding weekends and university holidays.
Turn Around Time:
3 days
Reference Range:
ANCA screen and titer: <1:40 Titer, includes interpretative report.
Comments:
Please include relevant clinical information on test order form.

Test includes both C-ANCA and P-ANCA screening and titering. MPO and PR3 confirmatory tests are performed if screen is positive or inconclusive. Anti-neutrophil cytoplasmic antibodies are associated primarily with two groups of diseases: systemic necrotizing vasculitis/glomerulonephritis and inflammatory bowel and liver disease.

Because the laboratory testing strategies are different for these two groups of disease, different tests must be ordered for each of these workups. "ANCA" is the test to be ordered when vasculitis/ glomerulonephritis is in the differential diagnosis. "UC-ANCA" is the test to order to evaluate patients with suspected inflammatory bowel or liver disease (see UC-ANCA listing for more testing information).

The "ANCA" test starts with immunofluorescence screening for both C-ANCA (primarily associated with Wegner's granulomatosis) and p-ANCA (primarily associated with microscopic polyarteritis and pauci-immune GN). If the ANCA screen is positive, titration to end-point is performed. It is strongly recommended that confirmatory testing for anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) be performed at the time of initial identification of ANCA. P-ANCA can be confused with "UC-ANCA" or ANA on IFA screening. Approximately 5% of patients with either "C-ANCA" or "P-ANCA" will have a specificity different from that usually associated with the ANCA IFA pattern (eg: P-ANCA may have PR3 specificity and the C-ANCA may have MPO specificity).
Methodology:
ANCA screen and titer: Indirect Immunofluorescence
MPO and PR3: Multiplex flow immunoassay
CPT Code:
86255 ANCA screen, 86255-26 ANCA screen interpretation, 86256 ANCA titer, 86256-26 ANCA titer interpretation, 83520 PR3, 83520 MPO