Table 1 Comparisons of the demographic, clinical, and laboratory features between the RA-ILD and the RA-non-ILD group
|  | RA-ILD (n = 75) | RA-non-ILD (n = 78) | P |
|---|---|---|---|
Demographic parameters | |||
 Age (years) | 62.84 ± 8.71 | 45.15 ± 13.31 |  < 0.001 |
 Female/male, n | 45/30 | 58/20 | 0.058 |
 Smoker, n (%) | 16 (21.33) | 9 (11.54) | 0.101 |
Clinical parameters | |||
 TJC | 8.00 (2.00, 23.00) | 5.00 (2.00, 14.25) | 0.177 |
 SJC | 2.00 (0.00, 8.00) | 2.00 (0.00, 8.00) | 0.338 |
 DAS28 (ESR) | 5.59 (4.01, 6.56) | 5.01 (3.50, 6.25) | 0.162 |
 Disease duration (years) | 5 (0.75, 16.00) | 3.00 (1.00, 10.00) | 0.280 |
Laboratory parameters | |||
 WBC (*109/L) | 7.36 (6.11, 8.47) | 6.16 (5.26, 7.75) | 0.003 |
 RBC (*1012/L) | 4.25 ± 0.47 | 4.25 ± 0.47 | 0.970 |
 Hb (g/L) | 123.39 ± 16.18 | 121.00 ± 16.88 | 0.373 |
 PLT (*109/L) | 248.00 (195.00, 330.00) | 294.00 (221.5, 347.25) | 0.154 |
 LYMPH (*109/L) | 1.68 (1.32, 2.38) | 1.57 (1.28, 1.85) | 0.117 |
 NEUT (*109/L) | 4.77 (3.76, 6.17) | 3.88 (3.29, 5.40) | 0.017 |
 ALT (U/L) | 14.60 (11.13, 18.23) | 13.90 (9.75, 21.45) | 0.677 |
 AST (U/L) | 17.35 (14.50, 21.80) | 16.80 (13.40, 20.00) | 0.125 |
 TP (g/L) | 67.78 ± 7.41 | 68.55 ± 6.00 | 0.485 |
 ALB (g/L) | 35.61 ± 4.80 | 38.11 ± 4.88 | 0.002 |
 GLO (g/L) | 32.17 ± 7.01 | 30.51 ± 5.57 | 0.111 |
 ESR (mm/h) | 57.00 (30.00, 95.00) | 36.00 (18.00, 67.00) | 0.003 |
 CRP (mg/L) | 26.00 (9.04, 69.13) | 11.70 (3.08, 38.00) | 0.003 |
 IgG (g/L) | 12.75 (10.10, 15.93) | 12.30 (11.03, 15.40) | 0.852 |
 IgA (g/L) | 3.34 ± 1.22 | 3.12 ± 1.20 | 0.307 |
 IgM (g/L) | 1.42 (0.98, 1.82) | 1.33 (0.99, 2.03) | 0.574 |
 RF ( +), n (%) | 63 (84.00) | 56 (71.79) | 0.069 |
 Anti-CCP ( +), n (%) | 59 (78.67) | 53 (67.95) | 0.135 |