[A focal usual interstitial pneumonia lesion: an important risk factor in diffuse alveolar damage--acute exacerbation of a focal usual interstitial pneumonia patient].

: The aim of this study was to clarify whether the presence of a focal usual interstitial pneumonia lesion (F-UIP) is a risk factor for diffuse alveolar damage (DAD). Our subjects were 977 patients (681 males, 296 females, mean age, 64 years). The incidence of F-UIP increased significantly with age (between 50 and 60 years, 3% and 8%, p < 0.05; between 60 and 70 years, 8% and 14.1%, p < 0.05; and between 70 and 80 years, 14.1% and 27.9%, p < 0.01). The mean age of the non-UIP group was 64 years, and of the F-UIP group was 75 years, showing significance (p < 0.001). The incidence of DAD was higher in the F-UIP group (100 patients, 30%, p < 0.01) and the diffuse UIP group (60 patients, 30%, p < 0.01) than in the non-UIP group (817 patients, 5.3%). Although the causes of DAD were various, the presence of F-UIP was a important risk factor of DAD.