4259 – Anti-PR3 hs

The Anti-PR3 hs is a quantitative immunoassay for the determination of IgG antibodies against proteinase 3 (PR3) in human serum. The Anti-PR3 hs is intended as an aid in the diagnosis of systemic vasculitides (SV) in conjunction with other clinical and laboratory findings.

Systemic vasculitis (SV) pathogenesis is majorly identified by the inflammation of different blood vessel walls, and the resulting morphological changes. Arteries and veins can both be affected simultaneously. The clinical manifestation is mainly indicated by general symptoms like exhaustion, fever and weight loss. Depending on which kind of vessels are affected, future disease course varies.

Anti-neutrophil cytoplasmic antibodies (ANCA) play an important role in the serological diagnosis of SV. These antibodies are usually determined by indirect immunofluorescence (IIF) of ethanol-fixed human neutrophils, in which the pattern of the IIF distinguishes cytoplasmic ANCA (cANCA) and perinuclear ANCA (pANCA). In IIF, the pattern of pANCA is mainly caused by the reactivity of MPO, a cationic protein found in azurophilic granules. MPO autoantibodies occur in a variety of vasculitides such as microscopic polyangiitis, Churg-Strauss syndrome and Polyarteritis nodosa. Autoantibodies to PR3 are a specific serological marker for Wegener’s granulomatosis (WG), especially the strong association of the titres with disease activity and the inhibition of the proteolytic activity of PR3.

The ELISA (Enzyme Linked Immunosorbent Assay) is an immunoassay for the determination of specific antibodies. The strips of the microtiter plate are coated with test-specific antigens. If antibodies are present in the patient´s sample, they bind to the antigens. A secondary antibody conjugated with the enzyme peroxidase detects the generated immune complex. A colorless substrate is converted into the colored product. The signal intensity of the reaction product is proportional to the antibody activity in the sample. After stopping the signal intensity of the reaction product is measured photometrically.

The immunoassay is designed for manual professional in vitro diagnostic use.