[Causes of idiopathic interstitial pneumonia (IIP): inhaled dust as environmental problem].
We have reported that patients with IIP can be roentgenologically grouped into two subtypes, typical (type-A) and atypical (type-B). The characteristic feature of X-ray findings in type-A is marked restriction of the lung, especially of the lower lobes, and in type-B is emphysematous changes in addition to the findings of type-A. In this study, to clarify the pathological findings of these two subtypes, 60 IIP patients in whom open lung biopsy and/or autopsy were performed were studied both clinically and pathologically. The following results were obtained. 1) Pathological features of type-A were alveolitis, marked restriction of the lung secondary to atelectasis and fibrosis of lung parenchyma, and honeycombing as a result of remodeling. 2) The features of type-B were intra-alveolar organization and secondary emphysema after intra-alveolar inflammation (pneumonia) overlapped the pathological changes of type-A. 3) Patients with a history of dust inhalation were much more frequently observed in type-B than in type-A (p < 0.01). These results suggest that inhaled dust may be a causative factor of IIP, especially of type-B.
Homma
Y
Y
Department of Medicine, Hokkaido University, Sapporo, Japan.
Saeki
S
S
Doi
O
O
Yoneda
R
R
Mikami
R
R
Tamura
M
M
Ohtsuka
Y
Y
Munakata
M
M
D004391:Dust; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000209:etiology* / Q000473:pathology; D011650:Pulmonary Alveoli / Q000473:pathology; D011656:Pulmonary Emphysema / Q000473:pathology
D004391:Dust