Table 2.
Laboratory tests and pulmonary function test findings of patients with ANCA-IIPs versus patients with MPA-ILDs
| Combined (N = 80) | ANCA-IIPs (N = 49) | MPA-ILDs (N = 31) | p value | |
|---|---|---|---|---|
| Laboratory findings | ||||
| WBC, × 10^9/L | 8.54 (6.18, 10.36) | 7.44 (5.95, 9.75) | 9.34 (7.15, 13.56) | 0.061 |
| NEUT, × 10^9/L | 5.65 (3.97, 7.81) | 4.68 (3.76, 6.94) | 6.79 (5.06, 9.00) | 0.011* |
| LY, × 10^9/L | 1.90 (1.42, 2.36) | 2.00 (1.55, 2.33) | 1.47 (1.06, 2.41) | 0.045* |
| HGB, g/L | 132 (116, 147) | 137 (130, 149) | 116 (95, 139) | < 0.001* |
| PLT, × 10^9/L | 246 (186, 290) | 234 (176, 284) | 251 (202, 322) | 0.133 |
| ESR, mm/h | 53 (17, 87) | 28 (13, 62) | 86 (49, 99) | < 0.001* |
| CRP, mg/dL | 15.92 (3.88, 53.70) | 13.87 (2.21, 30.42) | 35.77 (5.67, 71.18) | 0.005* |
| PaO2, mmHg | 75.9 (69.8, 82.2) | 77.4 (72.3, 82.2) | 71.5 (64.5, 83.0) | 0.134 |
| Cr (E), μmol/L | 68 (57, 79) | 67 (57, 74) | 73 (61, 104) | 0.035* |
| MPO-ANCA positive | 45 (56.25%) | 19 (38.78%) | 26 (83.87%) | < 0.001* |
| MPO-ANCA titer, EU | 141 (72, 200) (n = 45) | 104 (53, 165) (n = 19) | 170 (105, 200) (n = 26) | 0.015* |
| PR3-ANCA positive | 2 (2.50%) | 2 (4.08%) | 0 (0.00%) | 0.519 |
| PR3-ANCA titer, EU | 69 (38, 69) (n = 2) | 69 (38, 69) (n = 2) | 0 | - |
| RF, IU/mL | 55.9 (22.7, 211.0) | 26.7 (6.8, 442.9) | 113.1 (53.5, 207.8) | 0.157 |
| ANA positive | 45 (56.25%) | 30 (61.22%) | 15 (48.39%) | 0.355 |
| CCP positive | 8 (10.00%) | 8 (16.33%) | 0 (0.00%) | 0.020* |
| SSA positive | 9 (11.25%) | 6 (12.24%) | 3 (9.68%) | 1.000 |
| SSB positive | 4 (5.00%) | 2 (4.08%) | 2 (6.45%) | 0.639 |
| Jo-1 positive | 1 (1.25%) | 1 (2.04%) | 0 (0.00%) | 1.000 |
| Scl-70 positive | 2 (2.50%) | 1 (2.04%) | 1 (3.23%) | 1.000 |
| Pulmonary function tests | ||||
| FEV1, % predicted (n = 75)# | 82.35 ± 17.32 | 84.03 ± 16.93 | 79.36 ± 17.92 | 0.265 |
| FVC, % predicted (n = 75)# | 81.85 ± 18.42 | 83.84 ± 19.10 | 78.30 ± 16.89 | 0.213 |
| TLC, % predicted (n = 75)# | 77.59 ± 13.43 | 79.53 ± 13.55 | 74.16 ± 12.73 | 0.096 |
| DLCO, % predicted (n = 75)# | 60.12 ± 15.53 | 62.12 ± 14.09 | 56.56 ± 17.52 | 0.138 |
Data are presented as median (IQR) or mean ± SD or No. (%)
*p < 0.05
#Seventy-five patients underwent pulmonary function tests at initial presentation, but the remaining 5 could not complete the tests because of the severity of their disease
ANCA: anti-neutrophil cytoplasmic antibody; IIP: idiopathic interstitial pneumonia; MPA: microscopic polyangiitis; ILD: interstitial lung disease; WBC: white blood cell; NEUT; neutrophil; LY: lymphocyte; HGB: haemoglobin; PLT: platelet; ESR: erythrocyte sedimentation rate; CRP: C reactive protein; PaO2: arterial oxygen tension; Cr: creatinine; MPO: myeloperoxidase; PR3: proteinase 3 antibody; RF: rheumatoid factor; ANA: antinuclear antibody; CCP: anti-cyclic citrullinated peptide antibody; SSA: anti-Ro; SSB: anti-La; Jo-1: anti-Jo-1; Scl-70: anti-Scl-70; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; TLC: total lung capacity; DLCO: diffusing capacity of lung for carbon monoxide