Inclusion body myositis

Inclusion body myositis
Other namessIBM
SpecialtyRheumatology, Neurology, Neuromuscular medicine
SymptomsWeakness
Usual onsetTypically after age 45[1]
Differential diagnosisdeconditioning, hereditary muscle diseases[1]
Frequency5-71/100,000,000[1]

Inclusion body myositis (IBM) (/maɪoʊˈsaɪtɪs/) (sometimes called sporadic inclusion body myositis, sIBM) is the most common inflammatory muscle disease in older adults.[2] The disease is characterized by slowly progressive weakness and wasting of both proximal muscles (located on or close to the torso) and distal muscles (close to hands or feet), most apparent in the finger flexors and knee extensors.[3] IBM is often confused with an entirely different class of diseases, called hereditary inclusion body myopathies (hIBM).[4][5] The "M" in hIBM is an abbreviation for "myopathy" while the "M" in IBM is for "myositis".[6] In IBM, two processes appear to occur in the muscles in parallel, one autoimmune and the other degenerative. Inflammation is evident from the invasion of muscle fibers by immune cells. Degeneration is characterized by the appearance of holes, deposits of abnormal proteins, and filamentous inclusions in the muscle fibers.[7] sIBM is a rare disease, with a prevalence ranging from 1 to 71 individuals per million.[8][9]

Weakness comes on slowly (over months to years) in an asymmetric manner and progresses steadily, leading to severe weakness and wasting of arm and leg muscles. IBM is more common in men than women.[10] Patients may become unable to perform activities of daily living and most require assistive devices within 5 to 10 years of symptom onset.[11] sIBM does not significantly affect life expectancy,[1] although death related to malnutrition and respiratory failure can occur.[12] The risk of serious injury due to falls is increased.[1] There is no effective treatment for the disease as of 2019.[1]

  1. ^ a b c d e f Weihl, CC (December 2019). "Sporadic Inclusion Body Myositis and Other Rimmed Vacuolar Myopathies". Continuum (Minneapolis, Minn.). 25 (6): 1586–1598. doi:10.1212/CON.0000000000000790. PMID 31794461. S2CID 208531761.
  2. ^ Ahmed, Mhoriam; Machado, Pedro M; Miller, Adrian; Spicer, Charlotte; Herbelin, Laura; et, al (March 23, 2016). "Targeting protein homeostasis in sporadic inclusion body myositis". Science Translational Medicine. 8 (331): 331ra41. doi:10.1126/scitranslmed.aad4583. PMC 5043094. PMID 27009270.
  3. ^ Jackson, CE; Barohn, RJ; Gronseth, G; Pandya, S; Herbelin, L; and, The Muscle Study Group (April 2008). "Inclusion body myositis functional rating scale: a reliable and valid measure of disease severity". Muscle and Nerve. 37 (4): 473–476. doi:10.1002/mus.20958. PMID 18236463. S2CID 22284747.
  4. ^ IBMmyositis.com
  5. ^ cureibm.org
  6. ^ Greenberg, SA (May 2019). "Inclusion body myositis: clinical features and pathogenesis". Nature Reviews. Rheumatology. 15 (5): 257–272. doi:10.1038/s41584-019-0186-x. PMID 30837708. S2CID 71146208.
  7. ^ Machado, P; Dimachkie, MM; Bahron, RJ (October 2014). "Sporadic Inclusion Body Myositis: new insights and potential therapy". Current Opinion in Neurology. 27 (5): 591–598. doi:10.1097/WCO.0000000000000129. PMC 4248565. PMID 25159931.
  8. ^ Machado, P; Brady, S; Hanna, MG (2013). "Update in inclusion body myosities". Current Opinion in Rheumatology. 25 (763–771): 763–771. doi:10.1097/01.bor.0000434671.77891.9a. PMC 4196838. PMID 24067381.
  9. ^ "Sporadic Inclusion Body Myositis".
  10. ^ "Inclusion Body Myositis. IBM information; Age Related illness". 20 June 2016.
  11. ^ "Understanding IBM".
  12. ^ Cox, FM; Titulaer, MJ; Sont, JK; Wintzen, AR; et, al (November 1, 2011). "A 12-year follow-up in sporadic inclusion body myositis: an end stage with major disabilities". Brain. 134 (11): 3167–3175. doi:10.1093/brain/awr217. PMID 21908393.