Myofascia-dominant involvement on whole-body MRI as a risk factor for rapidly progressive interstitial lung disease in dermatomyositis

Abstract

Objective Rapidly progressive interstitial lung disease (RPILD) is a major cause of death in patients with DM. Although clinically amyopathic DM (CADM) represents risk for RPILD, the incidence rate of RPILD in patients with CADM varies widely. Whole-body (WB) MRI can reveal involvement of systemic muscle and myofascia. The objective of this study was to explore the risk factors for RPILD in patients with DM using WB-MRI. Methods This retrospective study comprised 41 patients with DM who underwent WB-MRI before the initiation of treatment in our hospital. Muscular and myofascial signals were scored on 42 muscular groups. The myofascia/muscle ratio was calculated and used to define the relevance of myofascia-dominant involvement. RPILD was defined as worsening of dyspnoea, hypoxaemia and radiographic ILD/fibrosis within 3 months from the onset of respiratory symptoms. Results Among the 41 patients, 17 had CADM and 30 had ILD, including 10 patients with RPILD. All patients including those with CADM showed abnormal signal intensity in both muscle and myofascia (median score: 15 and 23, respectively). Muscle signal scores positively correlated with the serum creatine kinase level (r = 0.714; P< 0.001). Patients with RPILD showed a significantly higher myofascia/muscle ratio than those without RPILD (1.929 vs 1.200; P= 0.027). Logistic regression analysis identified higher myofascia/muscle ratio as independent risk factors for developing RPILD. Conclusion Myofascia-dominant involvement was defined and appreciated in patients with DM using WB-MRI. This may be one of the risk factors for RPILD.

Efficacy and Tolerability of Nintedanib in Idiopathic-Inflammatory-Myopathy-Related Interstitial Lung Disease: A Pilot Study

“…In this study, all IIM-ILD patients received potent immunosuppressive therapy. However, the incidence of RP-ILD still amounted to 23.5% in the control group, which is similar to the incidence of rapid progression/acute exacerbation in previous reports of IIM-ILD (24-38%) and IPF (8.6-23.9%), but higher than the incidence in Ssc-ILD (9.4%) (10)(11)(12)(13). Efficacy and tolerability of nintedanib in IIM-ILD patients were hereby a worthy subject.…”

“…Idiopathicinflammatory-myopathy-related ILD (IIM-ILD) is frequently aggressive and refractory to conventional therapies including glucocorticoids and immunosuppressive drugs (7)(8)(9). In different studies, the incidences of rapidly progressive interstitial lung disease (RP-ILD) in IIM patients were relatively high (24-8%) compared to those in idiopathic pulmonary fibrosis (IPF, 8.6-23.9%) and systemic-sclerosis-related ILD (Ssc-ILD, 9.4%) (10)(11)(12)(13). RP-ILD has been taken as a major cause of mortality in IIM patients (14,15).…”

MRI and muscle imaging for idiopathic inflammatory myopathies

“…It was shown that among DM, including amyopathic patients, a predominant fascia involvement was an independent risk factor for rapidly progressive interstitial lung disease (54). Some authors (27) argued that WB MRI could assess the whole body musculature and detect neoplasia at the same time.…”

“…It was shown that among DM, including amyopathic patients, a predominant fascia involvement was an independent risk factor for rapidly progressive interstitial lung disease (54).…”

Subclinical involvement of the trunk muscles in idiopathic inflammatory myopathies

“…7 Whole-body MRI (WB-MRI) was recently reported to be useful in revealing the disease-specific distribution of affected muscles and clinically asymptomatic muscle involvements in some subtypes of IIMs. 8 , 9 To clarify the involvement of the thoracoabdominal trunk muscles in IIMs, we evaluated systemic skeletal muscles, focusing not only on the limbs but also on the trunk, by applying WB-MRI STIR images in 10 Japanese patients with IIMs.…”