Table 3.
Characteristics at the onset of acute exacerbation
| Characteristics | Triggered AE | Idiopathic AE | p value |
| Subjects | 10 | 29 | NS |
| Male, sex | 9 | 23 | NS |
| Age (yrs) | 70.8±5.7 | 69.2±7.7 | NS |
| Period from IPF diagnosis (yrs) | 3.3±3.5 | 1.7±1.4 | NS |
| PSL before AE | 1 | 11 | NS |
| Immunosuppressants before AE | 0 | 7 | NS |
| Anti-fibrotic agents before AE | 6 | 16 | NS |
| No previous treatment before AE | 4 | 10 | NS |
| History of AE | 1 | 7 | NS |
| Blood tests | |||
| KL-6 (U/mL) | 1175±778 | 1763±828 | NS |
| SP-D (ng/mL) | 251±212 | 253±123 | NS |
| LDH (U/L) | 343±164 | 361±125 | NS |
| Albumin (g/mL) | 3.1±0.6 | 3.3±0.5 | NS |
| CRP (mg/dL) | 17.7±10.2 | 6.8±7.2 | 0.007 |
| P/F ratio | 242±196 | 230±89 | NS |
Data are presented as n or mean±standard deviation. Date from the most recent acute exacerbation were used. Mann-Whitney U test was used. Definition of abbreviations: IPF: idiopathic pulmonary fibrosis, PSL: prednisolone, AE: acute exacerbation, KL-6: Krebs von den Lungen-6, SP-D: surfactant protein-D, LDH: lactate dehydrogenase, CRP: C-reactive protein, P/F ratio: PaO2/FiO2 ratio, NS: not significant.