Predictive factors and unfavourable prognostic factors of interstitial lung disease in patients with polymyositis or dermatomyositis: a retrospective study.
BACKGROUND
Interstitial lung disease (ILD) is a serious lung complication in polymyositis (PM) and dermatomyositis (DM) which affects prognosis and requires a more aggressive approach in therapy. This study investigated the prevalence, characteristics, predictive factors and unfavourable prognostic factors of ILD in newly diagnosed PM, DM and amyopathic DM (ADM).


METHODS
From January 2000 to December 2008, the medical records of 197 consecutive PM and DM patients at the Second Affiliated Hospital of Sun Yat-Sen University were reviewed excluding overlapping, juvenile, and malignancy-associated cases. The patients were assigned to an ILD (69 patients) and a non-ILD group (128 patients). The clinical features, laboratory findings, and prognosis were compared.


RESULTS
The multivariate analysis indicated that older age at onset (OR 1.033, 95%CI 1.009 - 1.058, P = 0.007), fever (OR 4.109, 95%CI 1.926 - 8.767, P < 0.001) and arthritis/arthralgia (OR 2.274, 95%CI 1.101 - 4.695, P = 0.026) were the independent predictive factors for developing ILD in PM/DM after excluding anti-Jo-1. Regarding anti-Jo-1, fever (OR 4.912, 95%CI 2.121 - 11.376, P < 0.001) was associated with ILD. Poor survival in ILD patients was associated with ILD clinical subset (RR 0.122, 95%CI 0.049 - 0.399, P < 0.001), ADM/DM/PM-ILD (RR 0.140, 95%CI 0.031 - 0.476, P = 0.002), cardiac involvement (RR 4.654, 95%CI 1.391 - 15.577, P = 0.013) and serum albumin level (RR 0.910, 95%CI 0.831 - 0.997, P = 0.042).


CONCLUSIONS
Patients who presented with fever tended to have a higher frequency of PM/DM-associated ILD. A Hamman-Rich-like presentation, ADM-ILD, cardiac involvement and hypoalbuminemia were poor prognostic factors in ILD-PM/DM.
Ji
Su-yun
SY
Department of Dermatology, Second Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510120, China.
Zeng
Fan-qin
FQ
Guo
Qing
Q
Tan
Guo-zhen
GZ
Tang
Hong-feng
HF
Luo
Yi-jin
YJ
Tang
Zeng-qi
ZQ
Han
Yan-fang
YF
D000328:Adult; D000368:Aged; D003882:Dermatomyositis / Q000150:complications*; D005260:Female; D006801:Humans; D016015:Logistic Models; D017563:Lung Diseases, Interstitial / Q000209:etiology* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D017285:Polymyositis / Q000150:complications*; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies