Inclusion Body Myositis October 14, 2024

Inclusion Body Myositis

BY Usman November 4, 2022

What is inclusion-body myositis (IBM)?

One of the most prevalent and incapacitating inflammatory myopathies in people over 50 is inclusion body myositis (IBM). According to two modest studies from the 1980s and 1990s, 1 to nearly 8 cases of IBM is predicted to occur annually in every 1 million Americans.

Myositis is another term for inflammatory myopathy. Myositis is an inflammatory muscle condition because the roots “myo” and “itis” both refer to muscles and inflammation, respectively.

As one of the idiopathic inflammatory myopathies, IBM is grouped with polymyositis, dermatomyositis, and autoimmune necrotizing myopathy (a group of disorders characterized by inflammation of the skeletal muscle). Invading the muscular tissue, inflammatory cells gather in the spaces between the muscle fibers. An IBM patient’s biopsy reveals many inclusion bodies that contain the cellular makeup of dead tissue. The “bodies”—clumps of wasted cellular material—that gather in the muscle tissues are how IBM got its name. Surrounding these bodies are concentrated immune cells.

There are also hereditary types of IBM in which inflammation does not often play a significant role. Because of this, these variants are frequently referred to as inclusion-body myopathy (muscle disorder), omitting the word “itis” to highlight the disease’s generally low inflammatory level.

What causes IBM?

Inflammatory myopathies like IBM are unknown causes. An autoimmune reaction occurs when the immune system of the body attacks its own muscles, causing muscle tissue damage. Additionally, it is unknown what causes the muscular deterioration that happens in IBM.

IBM genetic variants can be dominant or recessive.

What is the progression of IBM?

Although the illness can affect women, inclusion-body myositis (IBM) primarily affects men. Patients with IBM typically develop a disability over a number of years. The loss of strength and mobility occurs more quickly the older the age starts. By the age of 15, the majority of patients need assistance with basic daily tasks, and some end up in a wheelchair or are completely bedridden. Despite the lack of evidence from natural history research, the majority of clinicians concur that IBM can be an indirect cause of death, particularly in patients who have trouble swallowing since it can lead to aspiration pneumonia (dysphagia). Rarely, respiratory failure brought on by weakened respiratory muscles may happen.