Abstract
Interstitial lung disease (ILD) is a major cause of death in patients with dermatomyositis (DM). This study was aimed to examine the utility of the erythrocyte sedimentation rate (ESR) as a predictor of ILD and prognostic marker of mortality in patients with DM. One hundred-and-fourteen patients with DM were examined, including 28 with clinically amyopathic DM (CADM). A diagnosis of ILD was made based on high resolution computed tomography (HRCT) scans. The association between elevated ESR and pulmonary impairment and mortality was then examined. ILD was diagnosed in 53 (46.5%) of 114 DM patients. Cancer was diagnosed in 2 (3.8%) of 53 DM patients with ILD and in 24 (92.3%) of those without ILD (P < 0.001). The median ESR (50.0 mm/hour) in patients with ILD was significantly higher than that in patients without ILD (29.0 mm/hour; P < 0.001). ESR was inversely correlated with forced vital capacity (Spearman ρ = - 0.303; P = 0.007) and carbon monoxide diffusing capacity (ρ = - 0.319; P = 0.006). DM patients with baseline ESR ≥ 30 mm/hour had significantly higher mortality than those with ESR < 30 mm/hour (P = 0.002, log-rank test). Patients with a persistently high ESR despite immunosuppressive therapy was associated with higher mortality than those with a normalized ESR (P = 0.039, log-rank test). Elevated ESR is associated with increased mortality in patients with DM due to respiratory failure. Thus, monitoring ESR should be an integral part of the clinical care of DM patients.