Inclusion-body myositis

Marinos C Dalakas MD (Dr. Dalakas of the National and Kapodistrian University of Athens Medical School and Thomas Jefferson University received honorariums from Baxter, Hoffmann LaRoche, Novartis, and Therapath for consulting, serving on advisory committees, and speaking engagements.)
Salvatore DiMauro MD, editor. (Dr. DiMauro, Director Emeritus of H Houston Merritt Clinical Center for the Study of Muscular Dystrophy and Related Diseases at Columbia University, has no relevant financial relationships to disclose.)
Originally released March 23, 1994; last updated January 11, 2017; expires January 11, 2020


Inclusion-body myositis is the most frequent and disabling myopathy seen in patients over 50 years of age. The distinct clinical features that lead to correct diagnosis and inclusion-body myositis mimics are highlighted. Inclusion-body myositis has a complex pathogenesis in which autoimmune and inflammatory features coexist with elements of degeneration and abundant accumulations of various stressor proteins. In this article, the author discusses the pitfalls in diagnosis, the diagnostic markers, and the role of inflammation and degeneration in the pathogenesis of the disease, including the interaction between these processes. The latest trends in therapeutic strategies are also presented.

Historical note and terminology

Inclusion-body myositis (IBM) was first recognized as a distinct entity between 1967 and 1971. Three groups identified distinct microtubular filamentous inclusions by electron microscopy in the muscle biopsies of some patients with presumed polymyositis (Chou 1986; Carpenter et al 1970; Yunis and Samaha 1971). The term "inclusion-body myositis" was coined to stress the uniqueness of the disease and separate it from polymyositis (Yunis and Samaha 1971). Carpenter and colleagues' seminal paper emphasizing the clinical entity (Carpenter et al 1978) brought the disease to the surface and stimulated the interest of a number of investigators, including the author of this article.

The content you are trying to view is available only to logged in, current MedLink Neurology subscribers.

If you are a subscriber, please log in.

If you are a former subscriber or have registered before, please log in first and then click select a Service Plan or contact Subscriber Services. Site license users, click the Site License Acces link on the Homepage at an authorized computer.

If you have never registered before, click Learn More about MedLink Neurology  or view available Service Plans.