Background Interstitial lung disease (ILD) is a common cause of death in patients with dermatomyositis (DM). Especially, patients with clinically amyopathic DM (CADM) have a worse outcome due to ILD which is often refractory to corticosteroids. Lung involvement as an additional target of inflammation increases the total inflammatory burden in patients with DM.
Objectives To investigate whether erythrocyte sedimentation rate (ESR) elevation is associated with ILD and a worse prognosis in patients with DM.
Methods All patients with DM including CADM receiving clinical care in our institution from January 2004 through June 2013 were enrolled. Patients who had shortness of breath or abnormal finding on chest radiograph underwent a high resolution computed tomography (HRCT) and pulmonary function test (PFT). ILD was diagnosed when HRCT showed typical findings compatible with ILD.
Results A total of 114 DM patients were enrolled in this study. The mean age of patients at diagnosis was 49.4±12.3 years. 69.3% were female. The mean follow-up duration was 32.3±29.3 months. ILD was present in 53 (46.5%) patients. Among 28 patients with CADM, 14 (50%) had ILD. The levels of ESR were significantly higher in patients with ILD than those without ILD (49.9±23.3 vs. 34.4±24.1 mm/hr, p=0.001). The difference was more profound between the CADM patients with ILD and those without ILD (56.3±23.8 vs. 25.4±22.9 mm/hr, p=0.002). The ESR levels were inversely correlated with the forced vital capacity (r=−0.238, p=0.036) and diffusing capacity of carbon monoxide (r=−0.334, p=0.004). Further, the patents with baseline ESR ≥30mm/hr had a worse survival as compared to those with ESR <30mm/hr (p=0.002, by log rank test).
Conclusions The ESR elevation at the time of DM diagnosis is associated with pulmonary impairment and a poor outcome in patients with DM.
Disclosure of Interest None declared