PR3-ANCA (capture technique)

Indication

Suspicion of systemic vasculitis and follow-up of patients with vasculitis.

Method

Direct ELISA with granulocyte proteinase 3 (PR3) as antigen.

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Answer

The result is given as international units (IU/ml).

Interpretation

Capture ELISA is a complementary method in the analysis of PR3-ANCA, where a monoclonal antibody is used to capture proteinase 3 to avoid having it bound directly to the plastic surface and thereby increase its availability. The advantage is that the protein maintains its structure and the patient antibodies can more easily bind to the antigen. The capture method has a higher sensitivity than the direct ELISA and therefore the concentration is higher with this technique in individual patients.

Anti-neutrophil cytoplasmic antibodies (ANCA) are a family of autoantibodies with specificity for different antigens in the neutrophil granulocytes’ granules.

PR3-ANCA is a marker for granulomatosis with polyangiitis (GPA) that previously was named Wegener granulomatosis. In the active phase of the disease about 90% of the patients are positive for PR3-ANCA. Studies have shown that the antibody level decreases and often becomes negative when the disease is in remission. A rising level may indicate a relapse.

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Packages and other tests

View other packages ANCA for Systemic Vasculitis/anti-GBM Goodpastures syndrome (501), Glomerulonephritis (500), Sudden deafness (530), Systemic vasculitis – acute screening (009), Systemic vasculitis – follow-up (504,505)

Acute test