Table 2 Clinical characteristics of rheumatoid arthritis (RA) patients with or without interstitial lung disease (ILD)
|  | RA-ILD (n = 58) | RA-non-ILD (n = 29) | P value |
|---|---|---|---|
Age (years, mean ± SD) | 65.7 ± 9.4 | 61.8 ± 9.2 | 0.096 |
Female, (n,%) | 36 (62.1) | 25 (86.2) | 0.02* |
Disease duration (months), median, IQR | 60 (19.5,120) | 72 (5.5,46.5) | 0.772 |
Smoker, (n, %) | 15(25.9) | 1(3.4) | 0.011* |
Serum immunology | |||
 Anti-CCP positive, n, %) | 54 (93.1) | 21 (75.0) | 0.008* |
 Anti-CCP titer(RU/ml), mean ± SD | 696.9 ± 531.4 | 429.3 ± 555.8 | 0.004* |
 RF positive, (n, %) | 51(87.9) | 22(75.9) | 0.148 |
 RF titer (IU/ml), mean ± SD | 615.8 ± 1186.5 | 213.8 ± 194.9 | 0.289 |
 ANA positive, (n, %) | 29 (50.0) | 14 (48.3) | 0.879 |
 Anti-ds-DNA, (n, %) | 0 (0.0) | 1 (3.4) | 0.155 |
 Anti-SSA, (n, %) | 7 (12.1) | 1 (3.4) | 0.197 |
 Anti-Ro52, (n, %) | 9 (15.5) | 4 (13.8) | 0.832 |
 Anti-PM-Scl, (n, %) | 0 (0.0) | 1(3.4) | 0.155 |
 Anti-RNP, (n, %) | 1 (1.7) | 0(3.4) | 0.481 |
 Anti-centromere, (n, %) | 2 (3.4) | 0 (0.0) | 0.312 |
 Anti-phospholipid, (n, %) | 4 (6.9) | 2 (6.9) | > 0.99 |
 ANCA, (n, %) | 4 (6.9) | 5 (17.2) | 0.135 |
Disease activity and treatment | |||
 CRP (mg/dl), mean ± SD | 32.8 ± 44.3 | 39.2 ± 35.5 | 0.109 |
 ESR (mm/h), mean ± SD | 54.2 ± 34.3 | 47.1 ± 30.6 | 0.716 |
 IgG (g/L), mean ± SD | 13.67 ± 4.42 | 13.31 ± 3.06 | 0.642 |
 Ferritin (ng/L), mean ± SD | 213.4 ± 128.7 | 188.2 ± 180.5 | 0.341 |
 DAS28-ESR, mean ± SD | 4.8 ± 1.5 | 4.7 ± 1.2 | 0.739 |
 Sharp score, mean ± SD | 18.4 ± 22.2 | 29.8 ± 24.7 | 0.099 |
 Use of biologics, (n, %) | 11 (18.9) | 0 (0) | 0.012* |
 Use of MTX, (n, %) | 10 (17.2) | 18 (62.1) | < 0.0001* |
 Use of GCs, (n, %) | 45 (77.6) | 16 (55.2) | 0.03* |
 Dose of GCs (mg/day), mean ± SD | 13.9 ± 12.8 | 7.6 ± 7.6 | 0.024* |