Differences in clinical features and prognosis of interstitial lung diseases between polymyositis and dermatomyositis.
OBJECTIVE
To assess the difference in clinical features and prognosis of patients with interstitial lung disease (ILD) comparing polymyositis (PM) and dermatomyositis (DM).


METHODS
Medical records of 28 ILD patients with PM/DM (16 PM-ILD, 12 DM-ILD) were reviewed retrospectively.


RESULTS
Serum CPK concentrations were significantly higher in PM-ILD than in DM-ILD. Bronchoalveolar lavage analysis showed that the percentages of lymphocytes and eosinophils were significantly higher in DM-ILD than in PM-ILD. Ten patients (5 PM-ILD, 5 DM-ILD) underwent surgical lung biopsy, and 3 (3 DM-ILD) had an autopsy. Nonspecific interstitial pneumonia (NSIP) was found in 7 (4 PM-ILD, 3 DM-ILD) and usual interstitial pneumonia (UIP) in 3 (1 PM-ILD, 2 DM-ILD). Interestingly, diffuse alveolar damage (DAD) was found in 3 patients with DM-ILD, who all died of deterioration of ILD; but no one with PM-ILD had DAD. Corticosteroid treatment alone achieved a favorable response in 6 patients (37.5%) with PM-ILD, but in only one (8.3%) with DM-ILD. Administration of cyclosporine in the early phase of onset benefited 4 corticosteroid-resistant patients with DM-ILD. Conclusively, survival in DM-ILD was significantly worse than that in PM-ILD.


CONCLUSIONS
DM-ILD is more refractory to corticosteroid therapy, resulting in poorer prognosis compared with PM-ILD. These data indicate that intensive therapy, including cyclosporine, should be considered for DM-ILD.
Fujisawa
Tomoyuki
T
Second Division, Department of Internal Medicine, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Suda
Takafumi
T
Nakamura
Yutaro
Y
Enomoto
Noriyuki
N
Ide
Kyotaro
K
Toyoshima
Mikio
M
Uchiyama
Hiroshi
H
Tamura
Ryoji
R
Ida
Masaaki
M
Yagi
Takeshi
T
Yasuda
Kazumasa
K
Genma
Hitoshi
H
Hayakawa
Hiroshi
H
Chida
Kingo
K
Nakamura
Hirotoshi
H
D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002452:Cell Count; D003882:Dermatomyositis / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D004359:Drug Therapy, Combination; D004804:Eosinophils / Q000473:pathology; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D008214:Lymphocytes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017285:Polymyositis / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate
D005938:Glucocorticoids; D007166:Immunosuppressive Agents