Autoantibodies Prognostic of Dysphagia in Dermatomyositis

Researchers have found that in patients with dermatomyositis (DM), dysphagia develops more frequently in those with positive anti-TIF-1y antibody titers, internal malignancy, or severe weakness of the sternocleidomastoid muscle (SCM).

“Dysphagia has been reported to develop in 10 to 73% of patients with inflammatory myopathy during the clinical course, especially in inclusion body myositis … Recognition of dysphagia is important, since dysphagia is associated with various clinical features such as nasal speech, hoarseness, regurgitation, nutritious deficits, aspiration pneumonia, impaired quality of life, and poor prognosis,” wrote Minoru Hasegawa, MD, from the Department of Dermatology at the University of Fukui, Yoshida-gun, in Fukui, Japan and colleagues. 

They sought to determine the clinical and laboratory features that can serve to identify patients with DM who were at higher risk of developing dysphagia. 

The researchers recruited 92 Japanese patients with DM (72 women and 20 men; mean age 54.9 ± 16.2 years) who visited Kanazawa University Hospital between January 2004 and December 2015. The mean disease duration was 9.7 ± 14.9 months, and at the time of evaluation, no patients were receiving oral prednisolone therapy and other immunosuppressive drugs. Eighty patients fulfilled Bohan and Peter’s criteria, and the remaining 12 fulfilled Sontheimer’s criteria due to the absence of clinical muscle symptoms and the presence of subsistent skin eruptions.

The participants were evaluated for pharyngeal pooling, nasal regurgitation, and nasal speech by otorhinolaryngologists and speech therapists. Interstitial lung disease (ILD) was diagnosed according to the results of chest radiography, chest computed tomography, and pulmonary function testing. Presence of internal malignancy was examined using computed tomography, gastrointestinal fiberscope, gallium scintigraphy and other procedures as needed. 

Dysphagia was confirmed using videofluoroscopy swallow study, and disease activity based on individual organ systems was assessed with the Myositis Disease Activity Assessment Visual Analogue Scales. The global VAS score was used to rate overall disease activity.

The researchers found that 13 of the participants had clinical dysphagia (14.1%). By univariate analysis, the average age and the male to female ratio, internal malignancy, and anti-TIF-1γ antibody were significantly higher, and the frequency of interstitial lung diseases and manual muscle testing (MMT) scores of SCM and deltoid muscles were significantly lower, in patients with dysphagia compared with patients without dysphagia.

Summary and Clinical Applicability

Dysphagia development in DM was most closely associated with anti-TIF-1γ positivity, internal malignancy, and disease involving the SCM. 

Dysphagia was markedly improved in all 13 participants after DM treatment.

Limitations and Disclosures

The number of participants in this study, and especially the number of participants with dysphagia, was small. Further longitudinal studies with  a larger population are needed to clarify factors associated with the development of dysphagia in patients with DM. 

Reference

Mugii N, Hasegawa M, Matsushita T, et al. Oropharyngeal Dysphagia in Derematomyositis: Associations with Clinical and Laboratory Features Including Autoantibodies. PloS One. 2016; doi:10.1371/journal.pone.0154746.