Baseline characteristics of the study patients with IPF according to ANCA positivity at diagnosis
| ANCA | |||||
|---|---|---|---|---|---|
| Positive | Negative | ||||
| Characteristic | Total | MPO-ANCA | PR3-ANCA | p Value* | |
| Number of patients | 504 | 20 | 16 | 468 | |
| Male | 376 (74.6%) | 11 (55.0%) | 11 (68.8%) | 354 (75.6%) | 0.072 |
| Age, years | 69.5±8.1 | 71.4±7.6 | 73.1±6.1 | 69.3±8.2 | 0.041 |
| Smoker | 383 (76.0%) | 11 (55%) | 13 (81.3%) | 359 (76.7%) | 0.414 |
| Emphysema | 131 (26.0%) | 5 (25.0%) | 4 (25.0%) | 122 (26.1%) | 1 |
| %FVC predicted | 74.7±19.7 | 68.9±23.9 | 61.6±20.1 | 75.3±19.3 | 0.011 |
| FEV1/FVC, % | 81.1±10.7 | 81.1±14.8 | 86.7±8.9 | 80.9±10.6 | 0.716 |
| DLCO, % predicted | 77.0±23.4 | 74.0±11.5 | 62.5±20.4 | 77.5±23.6 | 0.124 |
| WCC, /μL | 7292±2213 | 8440±3614 | 7731±1729 | 7227±2139 | 0.078 |
| ESR, mm/h | 37.8±27.9 | 74.1±41.5 | 51.9±22.5 | 35.8±26.1 | <0.001 |
| Creatinine, mg/dL | 0.80±0.48 | 0.73±0.15 | 0.76±0.18 | 0.81±0.50 | 0.078 |
| CRP, mg/d† | 0.20 (0.10–0.63) | 1.17 (0.50–5.30) | 0.45 (0.16–1.63) | 0.20 (0.10–0.60) | <0.001 |
| KL-6, IU/L† | 778 (512–1263) | 646 (389–878) | 1296 (495–2118) | 784 (519–1247) | 0.589 |
| RF positive | 84 (16.7%) | 14 (70.0%) | 2 (12.5%) | 68 (14.5%) | <0.001 |
| ANA positive | 284 (56.3%) | 17 (85.0%) | 12 (75.0%) | 255 (54.5%) | 0.016 |
| Urinary blood positive | 35 (6.9%) | 6 (30.0%) | 1 (6.3%) | 28 (6.0%) | 0.143 |
| Urinary protein positive | 30 (6.0%) | 3 (15.0%) | 0 (0%) | 27 (5.8%) | 1 |
*p Values were calculated in relation to ANCA positivity.
†Median value with IQR in parentheses.
ANA, antinuclear antibody; ANCA, antineutrophil cytoplasmic antibody; CRP, C reactive protein; DLCO, diffusing capacity for carbon monoxide; ESR, erythrocyte sedimentation rate; FEV1/FVC, forced expiratory volume in 1 s/FVC ratio; FVC, forced vital capacity; IPF, idiopathic pulmonary fibrosis; KL-6, Krebs von den Lungen-6; MPO, myeloperoxidase; PR3, proteinase 3; RF, rheumatoid factor; WCC, white cell count.