How do antibodies affect muscles in myositis patients?

This past June, a team of international researchers, led by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), uncovered a novel mechanism by which myositis autoantibodies contribute to disease progression. Myositis refers to a group of rare conditions that cause inflammation and muscle weakness. Through this study, the researchers aimed to determine if autoantibodies can penetrate muscle cells and disrupt the normal functioning of the proteins they target.

The research, published in Annals of the Rheumatic Diseases, involved analyzing muscle biopsy samples from patients with various forms of myositis. Researchers found that myositis autoantibodies were located in the same cellular compartments as their corresponding target proteins. Using RNA sequencing, researchers also found distinct patterns of gene activity associated with different autoantibodies, which were consistent with disruptions in the function of target proteins.

To confirm their findings, the researchers introduced isolated and purified autoantibodies from myositis patients into cultures of lab-grown human muscle cells. The gene expression patterns observed in these cells mirrored those seen in patient biopsies, providing further evidence that autoantibodies play a direct role in myositis pathology by affecting protein function. "This mechanism through which autoantibodies enter the cells may be relevant in other tissues affected by myositis, as well as in other autoimmune diseases such as systemic sclerosis, vasculitis, and lupus," says Dr. Iago Pinal-Fernandez, co-author of the study.

The Autoimmune Registry recently partnered with GettingUp, a 501(c)(3) that works to help educate the public and bring attention to rare adult-onset conditions, specifically inclusion body myositis. Their primary goals are to find treatments and cures through supporting research, identifying needs, advocating, and serving patients where they can.

We're also hosting a webinar tomorrow, September 19th from 12-1 pm ET with Yan Valle, the Executive Director of Vitiligo Research Foundation to discuss using AI in patient education. If you are interested in attending, click here to register. To support the Autoimmune Registry, please share our information with others with autoimmune diseases. Donations are also greatly appreciated!