Transbronchial biopsy is clinically useful in classifying patients with interstitial pneumonia associated with polymyositis and dermatomyositis.
OBJECTIVE
The histological type of intraluminal fibrosis is an important prognostic factor for interstitial pneumonia. We therefore examined whether transbronchial lung biopsy (TBLB) specimens are useful for predicting the clinical course and prognosis of patients with interstitial pneumonia associated with polymyositis and dermatomyositis (PM/DM), with particular attention to the different types of intraluminal fibrosis.


METHODS
Twenty-five cases of interstitial pneumonia associated with PM/DM were classified according to the pattern of intraluminal fibrosis as assessed by TBLB, and the clinical course and response to treatment were compared. Interstitial fibrosis was evaluated by sequential thin-section CT scans.


RESULTS
In 19 of 25 (76%) cases, there was sufficient intraluminal fibrosis to perform an evaluation. Intraluminal fibrosis was classified as bud (polyp) type or mural incorporation type (either alone or mixed with bud type). The bud type was seen in five cases and these improved following treatment with corticosteroids only. The mural incorporation type was seen in 14 cases. In 11 of these 14 cases, progressive long-term fibrosis developed and four cases were fatal, in spite of corticosteroid and immunosuppressive therapy. The response to drugs (P < 0.01) and survival (P < 0.05) were significantly greater in patients with bud-type than mural incorporation-type intraluminal fibrosis.


CONCLUSIONS
Classification of the pattern of intraluminal fibrosis as assessed by TBLB is useful for predicting the response to treatment, clinical course and prognosis of interstitial pneumonia associated with PM/DM.
Mochimaru
Hiroshi
H
Department of Internal Medicine, Division of Pulmonary Medicine, Infectious Disease, and Oncology, Nippon Medical School, Tokyo, Japan. mochi123@dj8.so-net.ne.jp
Kawamoto
Masashi
M
Enomoto
Tatsuji
T
Saitoh
Yoshinobu
Y
Abe
Shinji
S
Nei
Takahito
T
Fukuda
Yuh
Y
Kudoh
Shoji
S
D000328:Adult; D000368:Aged; D003882:Dermatomyositis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000145:classification / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010784:Photomicrography; D017285:Polymyositis / Q000453:epidemiology*; D011379:Prognosis; D014057:Tomography, X-Ray Computed; D055815:Young Adult