Cytoplasmic Neutrophil Antibodies, Serum

Casandra

Casandra Test Code MC14579Version 1 (DRAFT)

Performing Lab

Lab Mayo Clinic LabLab Test ID ANCACPT Codes 86036, 86037

Cytoplasmic Neutrophil Antibodies, Serum

Clinical Use

Use

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are characterized by a pauci-immune inflammation within the walls of small blood vessels. There are 3 specific diseases identified as ANCA-associated vasculitides: microscopic polyangiitis (MPA), granulomatosus with polyangiitis (GPA), and eosinophilic granulomatosus with polyangiitis (EGPA). The serological hallmark of these disorders is the presence of ANCA, which are antibodies that bind to cytoplasmic antigens found in the granules of neutrophils. Patients with GPA frequently have antibodies specific for proteinase 3 (PR3), while individuals with MPA or EGPA are more likely to have antibodies that bind to myeloperoxidase (MPO).

Special Instructions

If not ordering electronically, complete and send one of the following forms with the specimen: General Request, Renal Diagnostics Test Request, or Kidney Transplant Test Request. It is recommended that specific tests for proteinase 3 antibodies and myeloperoxidase antibodies be performed first, with additional testing for anti-neutrophil cytoplasmic antibodies only needed in certain circumstances.

Limitations

A positive result for proteinase 3 (PR3)-ANCA, myeloperoxidase (MPO)-ANCA, or ANCA by IIF is not diagnostic for any ANCA-associated vasculitis and must be interpreted in the clinical context of the patient. Negative results for PR3-ANCA, MPO-ANCA, and ANCA by indirect immunofluorescence (IIF) do not exclude the possibility of ANCA-associated vasculitis. Antibodies specific for antigens other than PR3 and MPO may lead to nuclear, perinuclear or cytoplasmic staining on ethanol-fixed neutrophils.

Test Details

New York Approved