Testing and reporting antineutrophil cytoplasmic antibodies (ANCA) in treated vasculitis and non-vasculitic disease

Abstract

Testing for antineutrophil cytoplasmic antibodies (ANCA) is performed to diagnose or exclude small vessel vasculitis, and, in treated patients, to monitor disease activity. However testing is also undertaken to assist with the diagnosis of other autoimmune diseases and some infections. Most laboratories use the same assays for all sera regardless of the testing indications. The International Consensus Statement on ANCA Testing and Reporting recommended screening for ANCA by indirect immunofluorescence (IIF) and confirming IIF-positive sera in antigen-specific ELISAs for both proteinase 3 (PR3) and myeloperoxidase (MPO). These guidelines have been reviewed after many refinements of the assays..