Newswise — Dermatomyositis patients who test positive for an autoantibody against the melanoma differentiation-associated gene 5 (MDA5) protein frequently experience a specific set of symptoms. Their muscle pain is often mild or even non-existent, but they have aggressive skin disease, often including ulcers, and rapidly progressive interstitial lung disease. They also have a poor prognosis.

Two years ago, The Myositis Association funded a research fellowship for Xavier Suárez-Calvet, PhD to conduct a project that would identify new therapeutic targets in DM. Working with myositis expert Isabel Illa, MD, PhD at the Autonomous University of Barcelona, Suárez-Calvet recently completed this project, demonstrating a number of important results.

Among these findings is the demonstration that immune response as well as the structure of diseased muscle fibers and blood vessels in MDA5-positive patients are strikingly different than those found in DM patients who do not have MDA5 autoantibodies. This likely accounts for differences in symptoms and response to treatment.

Subsequent research demonstrated that MDA5 autoantibodies induce vascular damage in vitro. In vivo experiments indicated that these circulating molecules may cause the lung damage of interstitial lung disease.

Suárez-Calvet’s work provides new targets for clinical research looking for treatments for this form of DM. These results were published in the American Journal of Pathology and were reported at the recent Global Conference on Myositis 2017

that was held in Potomac, Maryland on May 5-8.

Myositis is a rare autoimmune disease of the muscles. It includes several forms, including dermatomyositis, polymyositis, inclusion-body myositis, necrotizing myopathy, and juvenile forms of the disease. Patients experience severe muscle pain and weakness, difficulty moving and standing, chronic disability, debilitating skin rashes, and other symptoms. Myositis is challenging to diagnose and difficult or impossible to treat, taking on average more than three-and-a-half years and five doctors to correctly diagnose.

The Myositis Association is an international nonprofit organization committed to support and education for myositis patients and caregivers, increasing awareness of myositis throughout the community, and funding for myositis-related research.

Journalists are invited to seek additional information about myositis at For photos, or to set up an interview with a local patient, myositis medical experts, or TMA’s Executive Director, please call 800-821-7356 or email [email protected].




Journal Link: American Journal of Pathology, March 2016 Journal Link: Neuromuscular Disorders, October 2016