Indirect Fluorescent Antibody (IFA), human neutrophil substrate
Multiplex Flow Immunoassay
Neutrophil cytoplasmic antibody testing is useful in the evaluation of patients with vasculitis. GPA is a disease which results in a necrotizing granulomatous vasculitis in the upper and lower respiratory tract as well as in the kidney. Autoantibodies against neutrophil cytoplasmic antigens have been found in these patients. These antibodies have also been observed in microscopic polyarteritis, and other types of vasculitis.
Negative. Pathologists interpretation of results provided. This panel includes neutrophil cytoplasmic antibody testing by indirect immunofluorescence (IFA), anti-proteinase 3 and anti-myeloperoxidase. Two common patterns have been recognized. One pattern is a finely granular staining of cytoplasmic granules; C-Neutrophil Cytoplasmic autoantibodies (C-NCA). The most common antibody that accounts for this pattern is anti-proteinase 3. C-NCA has been described in patients with Granulomatosis with Polyangiitis (GPA), polyarteritis nodosa and some types of crescentic glomerulonephritis. The second pattern shows a strong perinuclear fluorescence but little or no staining in the cytoplasm. This pattern has been attributed to anti-myeloperoxidase. The perinuclear NCA pattern (P-NCA) is associated with vasculitis, but is not as specific for GPA as the cytoplasmic (C-NCA) pattern.
Collect specimen in SST tube. Centrifuge, aliquot serum into a plastic vial and freeze.
If the IFA screen is positive, a titer will be performed at an additional charge. By ordering this test the clinician acknowledges that additional reflex testing will be performed and billed at a separate additional charge if indicated. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.