In adults with myositis, autoantibodies recognizing the muscle-specific protein FHL1 are associated with muscle atrophy and poor clinical outcomes. The current study described for the first time the clinical features of children with myositis who have anti-FHL1 autoantibodies. These children were more likely to have a rash on their chest and co-existing anti-Ro52 autoantibodies than those without anti-FHL1 autoantibodies. Moreover, this study showed that children with both anti-Ro52 and anti-FHL1 autoantibodies had a high rate of gastroesophageal reflux disease. However, unlike in adults, children with anti-FHL1 autoantibodies did not have worse muscle disease or clinical outcomes than children with myositis without anti-FHL1 autoantibodies.
What is exciting about this article?
Myositis is a rare life-threatening disease that affects children and causes muscle weakness and skin rashes. The presence of myositis-associated autoantibodies is one of the hallmarks of this autoimmune condition. Unlike in adults, children with myositis who have anti-FHL1 autoantibodies do not have worse muscle disease. This study shows that the presence of certain autoantibodies, including those recognizing FHL1, should be interpreted differently in children than adults with myositis.
How does this fit into the larger NIAMS portfolio?
Dr. Mammen’s research focuses on human muscle disease as well as the basic biology of skeletal muscle regeneration. This study is an example of a productive collaboration between several basic scientists and clinicians. In the future, identifying new biomarkers that may be used to screen juvenile patients with myositis for other associated clinical features may improve the management of this life-threatening autoimmune condition.
Research reported in this publication was supported by the Intramural Research Program of the NIHʼs National Institute of Arthritis and Musculoskeletal and Skin Diseases.