Antigen-specific ANCA ELISAs have different sensitivities for active and treated vasculitis and for nonvasculitic disease.

This study evaluated the performance of 12 assays for antineutrophil cytoplasmic antibodies (ANCA) directed against proteinase 3 (PR3) and myeloperoxidase (MPO) in 55 active and 68 treated cases of vasculitis and in nonvasculitic disease. It examined within- and between-assay precision; binding curves, binding levels, and interassay consistency; and sensitivity, specificity, and receiver operating characteristic analysis. All assays were highly sensitive for active vasculitis (median, 94%; range, 91%-96%), but sensitivities were more varied in treated disease (median, 69%; range, 57%-82%).

Antineutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis after immunisation with bacterial proteins.

Objective: There is circumstantial evidence for a role for infections in the development of the small vessel vasculitides associated with antineutrophil cytoplasmic antibodies (ANCA). The aim of this study was to determine whether the immunisation of rats with bacterial proteins could result in circulating ANCA, T cells with specificity for ANCA antigens, and a systemic vasculitis.

Methods: Adult male Wistar rats were immunised with pasteurised sonicated S.

Indirect immunofluorescence (IIF) of normal washed peripheral blood cells to demonstrate antineutrophil cytoplasmic antibodies (ANCA).

Background: The "International consensus document on testing and reporting of antineutrophil cytoplasmic antibodies (ANCA)" requires all sera to be examined by indirect immunofluorescence (IIF). However, commercial neutrophil slides are expensive, fluorescence patterns can be difficult to interpret, and coincidental antinuclear antibodies (ANA) cannot be demonstrated; in addition, in house cytospin neutrophil preparations are time consuming to prepare and deteriorate with time.

Aims: To compare the IIF demonstration of ANCA, using washed peripheral blood cell smears, with commercial neutrophil preparations and with ANCA positivity as demonstrated by enzyme linked immunosorbent assay (ELISA).

Clinical associations and characterisation of antineutrophil cytoplasmic antibodies directed against bactericidal/permeability-increasing protein and azurocidin.

Bactericidal/permeability-increasing protein (BPI) and azurocidin (AZ) are recently described target antigens of antineutrophil cytoplasmic antibodies (ANCA). In this study, BPI-ANCA were demonstrated most often in patients with ulcerative colitis (36/92, 39%), Crohn's disease (17/66, 26%) and cystic fibrosis (11/14, 79%), but also in patients with rheumatoid arthritis (8/40, 20%), systemic lupus erythematosus (SLE) (111/65, 17%) and mixed connective tissue disease (4/18, 22%). BPI-ANCA were also common in sera containing antinuclear (ANA) (9/43, 21%) or antidouble-stranded (ds) DNA (7/28, 25%) antibodies.