Detection and Clinical Associations of Autoantibodies to Myeloid Granular Proteins

Abstract

At the end of the third International ANCA Workshop in Washington D.C., USA, in 1990 it was concluded, that antineutrophil cytoplasmic autoantibodies (ANCA), that produce a cytoplasmic fluorescence pattern on ethanol fixed granulocytes (c-ANCA) usually react with proteinase 3 (PR 3), whereas ANCA that produce a nuclear to perinuclear fluorescence pattern on ethanol fixed granulocytes (p-ANCA) usually react with myeloperoxidase (MPO) (1). p-ANCA, however, may also -infrequently-react with human leukocyte elastase (HLE), lactoferrin (LF), and/or cathepsin G (CG) (1). Therefore, a positive p-ANCA test should always be followed by antigen-specific assays (2).