Muscle Disease Unit

National Institute Of Arthritis And Musculoskeletal And Skin Diseases

Investigators

Linked publications & trials

Abstract

During the last year, we completed numerous clinical projects involving myositis patients. A selection of published findings included the following: (a) We used Phage ImmunoPrecipitation Sequencing (PhIP-seq) to discover novel autoantibodies recognizing transcription factor Sp4. Anti-Sp4 autoantibodies are only found in dermatomyositis (DM) patients with co-existing anti-TIF1g autoantibodies. While DM patients with only anti-TIF1g autoantibodies have an increased risk of cancer, those with both anti-TIF1g and anti-Sp4 autoantibodies do not. (b) Defined the prevalence and phenotype of pediatric myositis patients with autoantibodies recognizing four-and-a-half LIM domains 1 (FHL1). We found that anti-FHL1 autoantibodies are present in 11% of juvenile myositis patients and commonly co-occur with myositis-associated autoantibodies, including anti-Ro52 autoantibodies. In contrast to adults, anti-FHL1 autoantibodies in juvenile myositis are associated with rash but not with other distinctive clinical features or worse outcomes. (c) Demonstrated that American Indians are at increased risk of statin-associated autoimmune myopathy compared to white or Black patients treated with statins. Whereas 1 in 50,000 white of Black subjects develop myositis when exposed to statins, approximately 1 in 300 American Indians will develop myositis following statin exposure. (d) We described the clinical and histopathologic features of myositis in patients with systemic lupus erythematosus (SLE). In brief, we found that patients with SLE myopathy have a higher prevalence of SLE disease manifestations and that necrotizing myopathy and dermatomyositis are the most prevalent histopathological features in SLE myoapthy.