Table 2.
Comparison of clinical characteristics, and outcomes of patients between MPA with or without ILD.
| Characteristics | MPA without ILD (n = 33) | MPA with ILD (n = 47) | P value |
|---|---|---|---|
| Age, years | 71 (67–78) | 76 (70–80) | 0.036* |
| Female, n (%) | 18 (55) | 24 (51) | 0.822 |
| Smoking history, n (%) | 17 (51.5) | 27 (57.5) | 0.652 |
| Laboratory findings | |||
| WBC, /mm3 | 12,500 (8135–14,625) | 10,860 (7310–14,190) | 0.458 |
| Hb, g/dL | 9.4 (8.0–11.4) | 10.3 (8.6–12.3) | 0.132 |
| Alb, g/dL | 2.3 (2–3.1) | 2.7 (2.2–3.3) | 0.08 |
| LD, IU/L | 197 (168–228) | 194 (165–253) | 0.458 |
| Cr, mg/dL | 1.7 (1.1–4.6) | 0.9 (0.7–1.5) | 0.0016** |
| CRP, mg/mL | 11.6 (3.1–14.7) | 8.4 (3.0–12.2) | 0.14 |
| Positive anti-MPO-ANCA, n (%) | 32 (97) | 47 (100) | 0.413 |
| Positive anti-PR3-ANCA, n (%) | 1 (3.0) | 2 (4.3) | 1.00 |
| MPO-ANCA titer, U/mL | 144 (52–289) | 94.1 (49.5–235.1) | 0.15 |
| KL-6, U/mL | 174 (120–242) | 383 (245–668) | < 0.0001*** |
| BVAS at onset | 21 (13.5–25) | 14 (8–21) | 0.006** |
| Five factor score 2009 | |||
| ≦ 1 | 8 (24.2) | 11 (23.4) | 1.000 |
| 2 | 16 (48.5) | 29 (61.7) | 0.262 |
| ≧ 3 | 9 (27.3) | 7 (14.9) | 0.256 |
| EUVAS-defined disease severity | |||
| Localized | 1 (3.03) | 2 (4.26) | 1.000 |
| Early systemic | 4 (12.1) | 8 (17.0) | 0.75 |
| Systemic | 20 (60.6) | 27 (57.5) | 0.821 |
| Severe | 8 (24.2) | 10 (21.3) | 0.791 |
| Outcome | |||
| Respiratory related death, n (%) | 2 (6.1) | 12 (25.5) | 0.035* |
| Others, n (%) | 8 (24.2) | 2 (4.3) | |
| Cause of respiratory-related death | |||
| Infectious pneumonia | 1 (3.0) | 9 (19.2) | 0.041* |
| Diffuse alveolar hemorrhage | 1 (3.0) | 2 (4.3) | 1.000 |
| Exacerbation of ILD | 0 (0) | 1 (2.1) | 1.000 |
The laboratory markers are presented as the median (interquartile range). The P-values were estimated using Fisher’s exact test or Wilcoxon rank sum test.
MPA microscopic polyangiitis, ILD interstitial lung disease, WBC white blood cell, Hb hemoglobin, Alb albumin, LD lactate dehydrogenase, Cr creatinine, CRP C-reactive protein, MPO-ANCA myeloperoxidase-anti-neutrophil cytoplasmic autoantibody, PR3-ANCA proteinase 3-anti-neutrophil cytoplasmic antibody, KL-6 Krebs von den Lungen-6, BVAS Birmingham Vasculitis Activity Score, EUVAS European Vasculitis Study Group.
*P < 0.05, **P < 0.01, ***P < 0.001.