Coexistence of anti-melanoma differentiation-associated gene 5 and anti-aminoacyl-transfer RNA synthetase antibodies in a patient with dermatomyositis and rapidly progressive and relapsing interstitial lung disease

Abstract

We describe the immunologic findings and the long-term clinical course of 43-year-old woman with classic dermatomyositis and associated rapidly progressive and relapsing course of interstitial lung disease (ILD). Patient’s serum obtained at diagnosis showed coexistence of two myositis-specific autoantibodies, anti-melanoma differentiation-associated gene 5 and anti-threonyl-transfer RNA synthetase (anti-PL-7) antibodies. Initially she had rapidly progressive ILD despite initial combination therapy with high-dose glucocorticoids, a calcineurin inhibitor, and intravenous cyclophosphamide, but were substantially improved by adjunctive high-dose intravenous immunoglobulin. During follow up, relapses of ILD and myositis were observed. Coexistence of anti-melanoma differentiation-associated gene 5 and anti-aminoacyl transfer RNA synthetase antibodies has never been reported before this case. Rapidly progressive and relapsing course of ILD have been reported as the clinical characteristics of ILD in patient populations with anti-melanoma differentiation-associated gene 5 antibodies and anti-aminoacyl-transfer RNA synthetase antibodies, including anti-PL7 antibodies, respectively, which seem to penetrate in this patient who had both autoantibodies. Moreover, chest computed tomographic features associated with each of the autoantibodies were also observed in the early course of the disease. This case reinforces the association between clinical phenotypes, especially of ILD, and myositis-specific autoantibodies in patients with inflammatory myopathy.

Keywords:

• Dermatomyositis
• autoantibodies
• melanoma differentiation-associated gene-5
• amino acyl-transfer RNA synthetases
• interstitial lung disease

Acknowledgements

The authors would like to thank Drs. Shiho Iwagaitsu, Shin-ichiro Ohmura and Jun-ichi Wada, Division of Rheumatology, Department of Internal Medicine. Nagoya City University Hospital, who cared for the patient, and Prof. Akio Niimi, Department of Respiratory Medicine, Allergy and Clinical Immunology, Nagoya City University Graduate School of Medical Sciences, who provided general support as a Department Chair.

Disclosure statement

M. K. holds a patent on the anti-MDA5 antibody measurement system and receives grants and personal fees from Medical and Biological Laboratories and Astellas. T. N., S. T., Y. O. and S. M. have reported that no potential conflicts of interest exist with any companies/organizations whose products or services may be discussed in this article.