Table 1. Baseline characteristics of the CADM-RPIL.
| Variables | Pirfenidone add-on (n = 30) | Control (n = 27) | P-value |
|---|---|---|---|
| Age at diagnosis (years) | 46.3 ± 11.3 | 51.8 ± 7.8 | 0.124 |
| Gender (F:M) | 20: 10 | 15: 12 | 0.426 |
| History of smoking, n (%) | 9 (30.0%) | 10 (37.0%) | 0.589 |
| Duration of CADM (months) | 3.2 ± 2.2 | 2.9 ± 1.8 | 0.843 |
| Duration of ILD (months) | 2.3 ± 1.1 | 2.3 ± 1.4 | 0.885 |
| Acute ILD: (<3 months) (n) | 1.7 ± 0.6 (20) | 1.5 ± 0.6 (18) | 0.329 |
| Subacute ILD: (3–6 months) (n) | 3.7 ± 0.7 (10) | 3.9 ± 1.1 (9) | 0.673 |
| ANA antibody (≥1:80), n (%) | 5 (16.7%) | 6 (22.2%) | 0.740 |
| Ferritin >1500 ng/ml, n (%) | 11 (36.7%) | 9 (33.3%) | 1.000 |
| KL-6 (U/ml)§ | 1238.5 ± 782.1 | 892.8 ± 296.0 | 0.627 |
| MDA-5 antibody, n (%)§ | 22 (84.6%) | 4 (57.1%) | 0.145 |
| CK (U/L) | 91.4 ± 83.0 | 124.0 ± 95.6 | 0.244 |
| HRCT score (%) | 152.4 ± 22.4 | 154.2 ± 24.7 | 0.896 |
| High-dose prednisolone | |||
| >5 mg/kg, n (%) | 4 (13.3%) | 4 (14.8%) | 1.000 |
| 1–5 mg/kg, n (%) | 17 (56.7%) | 14 (51.9%) | 0.793 |
| Immunosuppressant | |||
| CsA n (%) | 14 (46.7%) | 17 (63.0%) | 0.289 |
| MMF n (%) | 7 (23.3%) | 5 (18.5%) | 0.754 |
| AZA n (%) | 1 (3.3%) | 1 (3.7%) | 1.000 |
| CTX n (%) | 1 (3.3%) | 0 (0.0%) | 1.000 |
Note: CADM, clinically amyopathic dermatomyositis; ILD, interstitial lung disease; ANA, anti-nuclear antibody; KL-6, krebs von den lungen-6; MDA-5 antibody, anti-melanoma differentiation-associated gene 5 antibody; CK, creatine kinase; HRCT, high-resolution computed tomography; CsA, cyclosporine A; MMF, mycophenolate mofetil; AZA, azathioprine; CTX, cyclophosphamide.
§Number of tested cases: pirfenidone add-on group 26 cases, control group 7 cases.