ANCA--Detection methods: For indirect immunofluorescence, isolated PMNs are placed on glass slides, fixed in absolute ethanol, incubated with the patient's serum, and then incubated with fluorescein isothiocyanate-labeled, anti-human immunoglobulin. The ethanol fixation causes the myeloperoxidase to move from the primary granules (where PR3 remains) to a perinuclear position. The slides are observed with a fluorescence microscope for a perinuclear or cytoplasmic pattern of signal .
Enzyme-linked immunosorbent assays for ANCA are performed as diagramed below. Several different types of ANCA antigens--whole cell extract, granule extract, affinity purified antigen, or characterized protein--may be used in the assay .
1. Antigen-coated medium. 2. Serum is added, and the presence of the antibody is detected with anti-human immunoglobulin (Ig) labeled with an enzymatic or radioactive tag.
1. Wieslander J. How are antineutrophil cytoplasmic autoantibodies detected? Am J Kid Dis 1991; 18:154-158.
Clinical summary Discussion
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