Results of all ANCA tests performed at Brigham and Women’s Hospital between January 2011 and May 2013. The number of samples with each result is shown. The number of independent patients with each result is shown in parentheses.
| IF Pattern | Antibody Test Result | Total | |||
|---|---|---|---|---|---|
| Negative | PR3 | MPO | MPO + PR3 | ||
| Negative | 1949 (1866) | 29 (20) | 20 (18) | 0 | 1998 (1904) |
| Atypical | 131 (119) | 0 | 16 (11) | 0 | 147 (130) |
| C-ANCA | 37 (33) | 41 (19) | 3 (2) | 1 | 82 (54) |
| P-ANCA | 40 (37) | 3 (2) | 74 (44) | 0 | 117 (83) |
| P-ANCA + C-ANCA | 0 | 0 | 0 | 1 | 1 |
| Total | 2157 (2055) | 73 (41) | 113 (75) | 2 (2) | 2345 |
ANCA: antineutrophil cytoplasmic antibodies; IF: immunofluorescence; PR3: proteinase 3; MPO: myeloperoxidase; C-ANCA: cytoplasmic ANCA; P-ANCA: perinuclear ANCA.