When used in conjunction with other autoantibody tests (ANCA, MPO), may assist in differentiating suspected Wegener granulomatosis (WG) from other vasculitides. May be useful when monitoring patients with PR3 antibodies.
Panel tests are available. For the workup of suspected vasculitis, refer to ANCA-Associated Vasculitis Profile (ANCA/MPO/PR3) Reflex to ANCA Titer (2006480). For patients with a history of vasculitis, refer to the ANCA Reflex to Titer and MPO/PR3 Antibodies (2002068).
Semi-Quantitative Multiplex Bead Assay
Serum separator tube.
Separate serum from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.2 mL)
Plasma, urine, or other body fluids. Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
|Negative||19 AU/mL or less|
|Positive||26 AU/mL or greater|
Approximately 85% of patients with a C-ANCA pattern by IFA have antibodies specific for PR3.
|Component Test Code*||Component Chart Name||LOINC|
|0050527||Serine Proteinase 3, IgG||6968-2|
- PR3 Ab
- PR3 IgG Antibodies