Figure 1. Positivity of antineutrophil cytoplasmic antibodies (ANCA) tests performed at diagnosis. This analysis includes all study participants that had ANCA tests performed at diagnosis. The positivity rate was 32.0% (10/31) for indirect immunofluorescence (IIF)-ANCA tests performed at the Immuno-Rheumatology laboratory (A), 75.0% (9/12) for IIF-ANCA tests performed by other laboratories (B), and 72.8% (8/11) for ELISA tests performed at diagnosis by other laboratories (C). Analyses were performed with Fisher's exact test.