Description:

The Diagnostic Automation Proteinase-3 (PR-3) Enzyme-Linked Immunosorbent Assay (ELISA) is intended for the detection and semi-quantitative determination of antibodies to PR-3 in human sera. The assay is to be used to detect antibodies in a single serum specimen. The results of the assay are to be used as an aid in the diagnosis of Wegenerâ??s granulomatosis. This test is for in vitro diagnostic use.

Proteinase-3 is a lysosomal enzyme that can be found in human neutrophils. There are two subsets of autoantibody to human neutrophils: c- ANCA and p-ANCA. The first subtype, c-ANCA, shows cytoplasmic staining by IFA and is diagnostic for Wegener\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\'s granulomatosis. The major antigen responsible for the c-ANCA staining is Proteinase-3. The second subtype, p-ANCA, shows perinuclear staining by IFA. The major antigen responsible for the p-ANCA response has been shown to be myeloperoxidase. The ANCA staining patterns are obtained using ethanol-fixed human neutrophils. Anti- PR-3 autoantibody has been associated with Wegener's granulomatosis but less often with microscopic polyangiitis. Other antigen specificity's (CAP 57) can be responsible for the c-ANCA pattern. These antigens are generally not diagnostic for PR-3 associated vaculitus diseases.

The DAI PR-3 test is an Enzyme-Linked Immunosorbent Assay to detect IgG, IgA, and IgM antibodies to PR-3 antigens. Purified PR-3 antigens are attached to a solid phase microassay well. Diluted test sera are added to each well. If the antibodies are present that recognize the antigen, antigen-antibody complexes are formed. After incubation, the wells are washed to remove unbound antibody. An enzyme labeled anti-human IgG, A, M, is added to each well. If antibody is present the conjugate will bind to the antigen-antibody complexes. After incubation, the wells are washed to remove unbound conjugate. A substrate solution is added to each well. If enzyme is present the substrate will undergo a color change. After an incubation period, the reaction is stopped and the color intensity is measured photometrically, producing an indirect measurement of specific antibody in the patient specimen.