Polymyositis

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Polymyositis
Polymyositis HE.jpg
Micrograph of polymyositis. Muscle biopsy. H&E stain.
Specialty Rheumatology

Polymyositis (PM) is a type of chronic inflammation of the muscles (inflammatory myopathy) related to dermatomyositis and inclusion body myositis. Its name means 'inflammation of many muscles' ( poly- + myos- + -itis ). The inflammation of polymyositis is mainly found in the endomysial layer of skeletal muscle, whereas dermatomyositis is characterized primarily by inflammation of the perimysial layer of skeletal muscles. [1]

Contents

Signs and symptoms

The hallmark of polymyositis is weakness and/or loss of muscle mass in the proximal musculature, as well as flexion of the neck and torso. [1] These symptoms can be associated with marked pain in these areas as well. The hip extensors are often severely affected, leading to particular difficulty in climbing stairs and rising from a seated position. The skin involvement of dermatomyositis is absent in polymyositis. Dysphagia (difficulty swallowing) or other problems with esophageal motility occur in as many as 1/3 of patients. Low grade fever and enlarged lymph nodes may be present. Foot drop in one or both feet can be a symptom of advanced polymyositis and inclusion body myositis. The systemic involvement of polymyositis includes interstitial lung disease (ILD) and heart disease, such as heart failure and conduction abnormalities. [2]

Polymyositis tends to become evident in adulthood, presenting with bilateral proximal muscle weakness often noted in the upper legs due to early fatigue while walking. Sometimes the weakness presents itself as an inability to rise from a seated position without help or an inability to raise one's arms above one's head. The weakness is generally progressive, accompanied by lymphocytic inflammation (mainly cytotoxic T cells).[ citation needed ]

Associated illnesses

Polymyositis and the associated inflammatory myopathies have an associated increased risk of cancer. [3] The features they found associated with an increased risk of cancer were older age, age greater than 45, male sex, difficulty swallowing, death of skin cells, cutaneous vasculitis, rapid onset of myositis (<4 weeks), elevated creatine kinase, higher erythrocyte sedimentation rate and higher C-reactive protein levels. Several factors were associated with lower-than-average risk, including the presence of interstitial lung disease, joint inflammation/joint pain, Raynaud's syndrome, or anti-Jo-1 antibody. [3] The malignancies that are associated are nasopharyngeal cancer, lung cancer, non-Hodgkin's lymphoma and bladder cancer, amongst others. [4]

Cardiac involvement manifests itself typically as heart failure and is present in up to 77% of patients. [2] Interstitial lung disease is found in up to 65% of patients with polymyositis, as defined by HRCT or restrictive ventilatory defects compatible with interstitial lung disease. [5]

Causes

Polymyositis is an inflammatory myopathy mediated by cytotoxic T cells with an as yet unknown autoantigen, while dermatomyositis is a humorally mediated angiopathy resulting in myositis and a typical dermatitis. [6]

The cause of polymyositis is unknown and may involve viruses and autoimmune factors. Cancer may trigger polymyositis and dermatomyositis, possibly through an immune reaction against cancer that also attacks a component of muscles. [7] There is tentative evidence of an association with celiac disease. [8]

Diagnosis

Diagnosis is fourfold: History and physical examination, elevation of creatine kinase, electromyograph (EMG) alteration, and a positive muscle biopsy. [9]

The hallmark clinical feature of polymyositis is proximal muscle weakness, with less important findings being muscle pain and dysphagia. Cardiac and pulmonary findings will be present in approximately 25% of cases of patients with polymyositis.[ citation needed ]

Sporadic inclusion body myositis (sIBM) is often misdiagnosed as polymyositis or dermatomyositis but it can be differentiated as myositis that does not respond to treatment is likely IBM. sIBM comes on over months to years; polymyositis comes on over weeks to months. Polymyositis tends to respond well to treatment, at least initially; IBM does not.[ citation needed ]

Treatment

The first line treatment for polymyositis is corticosteroids. Specialized exercise therapy may supplement treatment to enhance quality of life. [10]

Epidemiology

Polymyositis affects females at greater frequency than males. [11]

Polymyositis as a distinct diagnosis

The discovery of several myositis-specific autoantibodies during the past decades has enabled the description of other discrete subsets of diagnosis, specifically the discovery of Antisynthetase syndrome in reducing the number of diagnoses of polymyositis. [12]

Society and culture

Notable cases

See also

Related Research Articles

Inclusion body myositis (IBM) is the most common inflammatory muscle disease in older adults. The disease is characterized by slowly progressive weakness and wasting of both proximal muscles and distal muscles, most apparent in the finger flexors and knee extensors. IBM is often confused with an entirely different class of diseases, called hereditary inclusion body myopathies (hIBM). The "M" in hIBM is an abbreviation for "myopathy" while the "M" in IBM is for "myositis". 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. sIBM is a rare disease, with a prevalence ranging from 1 to 71 individuals per million.

<span class="mw-page-title-main">Corticosteroid</span> Class of steroid hormones

Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involved in a wide range of physiological processes, including stress response, immune response, and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior.

<span class="mw-page-title-main">Myalgia</span> Location of pain

Myalgia or muscle pain is a painful sensation evolving from muscle tissue. It is a symptom of many diseases. The most common cause of acute myalgia is the overuse of a muscle or group of muscles; another likely cause is viral infection, especially when there has been no injury.

<span class="mw-page-title-main">Juvenile dermatomyositis</span> Medical condition

Juvenile dermatomyositis (JDM) is an idiopathic inflammatory myopathy (IMM) of presumed autoimmune dysfunction resulting in muscle weakness among other complications. It manifests itself in children; it is the pediatric counterpart of dermatomyositis. In JDM, the body's immune system attacks blood vessels throughout the body, causing inflammation called vasculitis. In the United States, the incidence rate of JDMS is approximately 2-3 cases per million children per year. The UK incidence is believed to be between 2-3 per million children per year, with some difference between ethnic groups. The sex ratio is approximately 2:1. Other Idiopathic inflammatory myopathies include; juvenile polymyositis (PM), which is rare and not as common in children as in adults.

<span class="mw-page-title-main">Dermatomyositis</span> Medical condition

Dermatomyositis (DM) is a long-term inflammatory disorder which affects the skin and the muscles. Its symptoms are generally a skin rash and worsening muscle weakness over time. These may occur suddenly or develop over months. Other symptoms may include weight loss, fever, lung inflammation, or light sensitivity. Complications may include calcium deposits in muscles or skin.

In medicine, myopathy is a disease of the muscle in which the muscle fibers do not function properly. Myopathy means muscle disease. This meaning implies that the primary defect is within the muscle, as opposed to the nerves or elsewhere.

Hereditary inclusion body myopathies (HIBM) are a group of rare genetic disorders which have different symptoms. Generally, they are neuromuscular disorders characterized by muscle weakness developing in young adults. Hereditary inclusion body myopathies comprise both autosomal recessive and autosomal dominant muscle disorders that have a variable expression (phenotype) in individuals, but all share similar structural features in the muscles.

<span class="mw-page-title-main">Cryptogenic organizing pneumonia</span> Medical condition

Cryptogenic organizing pneumonia (COP), formerly known as bronchiolitis obliterans organizing pneumonia (BOOP), is an inflammation of the bronchioles (bronchiolitis) and surrounding tissue in the lungs. It is a form of idiopathic interstitial pneumonia.

<span class="mw-page-title-main">Myositis</span> Medical condition

Myositis is a rarely-encountered medical condition characterized by inflammation affecting the muscles. The manifestations of this condition may include skin issues, muscle weakness, and the potential involvement of other organs. Additionally, systemic symptoms like weight loss, fatigue, and low-grade fever can manifest in individuals with myositis.

<span class="mw-page-title-main">Masticatory muscle myositis</span>

Masticatory muscle myositis (MMM) is an inflammatory disease in dogs affecting the muscles of mastication (chewing). It is also known as atrophic myositis or eosinophilic myositis. MMM is the most common inflammatory myopathy in dogs. The disease mainly affects large breed dogs. German Shepherd Dogs and Cavalier King Charles Spaniels may be predisposed. There is a similar disease of the eye muscles found in Golden Retrievers. Symptoms of acute MMM include swelling of the jaw muscles, drooling, and pain on opening the mouth. Ophthalmic signs may include third eyelid protrusion, red eyes, and exophthalmos. In chronic MMM there is atrophy of the jaw muscles, and scarring of the masticatory muscles due to fibrosis may result in inability to open the mouth (trismus). The affected muscles include the temporalis, masseter, and pterygoid muscles. The disease is usually bilateral.

Mixed connective tissue disease, commonly abbreviated as MCTD, is an autoimmune disease characterized by the presence of elevated blood levels of a specific autoantibody, now called anti-U1 ribonucleoprotein (RNP), together with a mix of symptoms of systemic lupus erythematosus (SLE), scleroderma, and polymyositis. The idea behind the "mixed" disease is that this specific autoantibody is also present in other autoimmune diseases such as systemic lupus erythematosus, polymyositis, scleroderma, etc. MCTD was characterized as an individual disease in 1972 by Sharp et al., and the term was introduced by Leroy in 1980.

Scleromyositis, is an autoimmune disease. People with scleromyositis have symptoms of both systemic scleroderma and either polymyositis or dermatomyositis, and is therefore considered an overlap syndrome. Although it is a rare disease, it is one of the more common overlap syndromes seen in scleroderma patients, together with MCTD and Antisynthetase syndrome. Autoantibodies often found in these patients are the anti-PM/Scl (anti-exosome) antibodies.

<span class="mw-page-title-main">Interferon alpha-1</span> Protein-coding gene in the species Homo sapiens

Interferon alpha-1 is a protein that in humans is encoded by the IFNA1 gene.

<span class="mw-page-title-main">Inflammatory myopathy</span> Medical condition

Inflammatory myopathy, also known as idiopathic inflammatory myopathy (IIM), is disease featuring muscle weakness, inflammation of muscles (myositis), and in some types, muscle pain. The cause of much inflammatory myopathy is unknown (idiopathic), and such cases are classified according to their symptoms and signs, electromyography, MRI, and laboratory findings. It can also be associated with underlying cancer. The main classes of idiopathic inflammatory myopathy are polymyositis (PM), dermatomyositis (DM), inclusion-body myositis (IBM), immune-mediated necrotising myopathy (IMNM), and focal autoimmune myositis.

Although they vary in particulars, polymyositis, dermatomyositis and inclusion body myositis are idiopathic inflammatory myopathies (IIM) primarily characterized by chronic inflammation of human skeletal muscle tissue that ultimately causes the necrosis of muscle cells. This degeneration leads to muscle tissue wasting, weakness and fatigue among other serious effects. Until recently, exercise has been avoided as a type of therapy, and even forbidden due to the risk of triggering or amplifying inflammation. However, several studies have been conducted to test this assumption and have shown that aerobic exercise as well as resistance training can maintain and even improve quality of life for IIM-affected individuals without increased inflammatory response.

Undifferentiated connective tissue disease (UCTD) is a disease in which the connective tissues are targeted by the immune system. It is a serological and clinical manifestation of an autoimmune disease. When there is proof of an autoimmune disease, it will be diagnosed as UCTD if the disease doesn't answer to any criterion of specific autoimmune disease. This is also the case of major rheumatic diseases whose early phase was defined by LeRoy et al. in 1980 as undifferentiated connective tissue disease.

<span class="mw-page-title-main">Acquired non-inflammatory myopathy</span> Medical condition

Acquired non-inflammatory myopathy (ANIM) is a neuromuscular disorder primarily affecting skeletal muscle, most commonly in the limbs of humans, resulting in a weakness or dysfunction in the muscle. A myopathy refers to a problem or abnormality with the myofibrils, which compose muscle tissue. In general, non-inflammatory myopathies are a grouping of muscular diseases not induced by an autoimmune-mediated inflammatory pathway. These muscular diseases usually arise from a pathology within the muscle tissue itself rather than the nerves innervating that tissue. ANIM has a wide spectrum of causes which include drugs and toxins, nutritional imbalances, acquired metabolic dysfunctions such as an acquired defect in protein structure, and infections.

<span class="mw-page-title-main">Antisynthetase syndrome</span> Medical condition

Antisynthetase syndrome (ASS) is a multisystematic autoimmune disease associated with inflammatory myositis, interstitial lung disease, and antibodies directed against various synthetases of aminoacyl-transfer RNA. Other common symptoms include mechanic's hands, Raynaud's phenomenon, arthritis, and fever.

Statin-associated autoimmune myopathy (SAAM), also known as anti-HMGCR myopathy, is a very rare form of muscle damage caused by the immune system in people who take statin medications. However, there are cases of SAAM in patients who have not taken statin medication, and this can be explained by the exposure to natural sources of statin such as red yeast rice, which is statin rich. This theory is supported by the higher prevalence of statin-naive SAAM patients in Asian cohorts, who have statin-rich diets.

References

  1. 1 2 Strauss KW, Gonzalez-Buritica H, Khamashta MA, Hughes GR (July 1989). "Polymyositis-dermatomyositis: a clinical review". Postgraduate Medical Journal. 65 (765): 437–43. doi:10.1136/pgmj.65.765.437. PMC   2429417 . PMID   2690042.
  2. 1 2 Zhang L, Wang GC, Ma L, Zu N (November 2012). "Cardiac involvement in adult polymyositis or dermatomyositis: a systematic review". Clinical Cardiology. 35 (11): 686–91. doi:10.1002/clc.22026. PMC   6652370 . PMID   22847365.
  3. 1 2 Xin Lu; Hanbo Yang; Xiaoming Shu; Fang Chen; Yinli Zhang; Sigong Zhang; Qinglin Peng; Xiaolan Tian; Guochun Wang (2014). "Factors Predicting Malignancy in Patients with Polymyositis and Dermatomyositis: A Systematic Review and Meta-Analysis". PLOS ONE. 9 (4): e94128. Bibcode:2014PLoSO...994128L. doi: 10.1371/journal.pone.0094128 . PMC   3979740 . PMID   24713868.
  4. ↑ Hill, C.L.; Zhang, Y.; Sigurgeirsson, B.; Pukkala, E.; Mellemkjaer, L.; Airio, A.; Evans, S.R.; Felson, D.T. (January 2001). "Frequency of specific cancer types in dermatomyositis and polymyositis: a population-based study". Lancet. 357 (9250): 96–100. doi:10.1016/S0140-6736(00)03540-6. PMID   11197446. S2CID   35258253 . Retrieved 20 April 2015.
  5. ↑ Fathi M, Dastmalchi M, Rasmussen E, Lundberg IE, Tornling G (March 2004). "Interstitial lung disease, a common manifestation of newly diagnosed polymyositis and dermatomyositis". Annals of the Rheumatic Diseases. 63 (3): 297–301. doi:10.1136/ard.2003.006122. PMC   1754925 . PMID   14962966.
  6. ↑ Gerald J D Hengstman, Baziel G M van Engelen (2004). "Polymyositis, invasion of non-necrotic muscle fibres, and the art of repetition". British Medical Journal. 329 (7480): 1464–1467. doi:10.1136/bmj.329.7480.1464. PMC   535982 . PMID   15604185.
  7. ↑ Hajj-ali, Rula A. (August 2013). "Polymyositis and Dermatomyositis". Merck Manual Home Edition. Archived from the original on 19 April 2015. Retrieved 20 April 2015.
  8. ↑ Shapiro M, Blanco DA (2017). "Neurological Complications of Gastrointestinal Disease". Semin Pediatr Neurol (Review). 24 (1): 43–53. doi:10.1016/j.spen.2017.02.001. PMID   28779865.
  9. ↑ Scola RH, Werneck LC, Prevedello DM, Toderke EL, Iwamoto FM (September 2000). "Diagnosis of dermatomyositis and polymyositis: a study of 102 cases". Arquivos de Neuro-Psiquiatria. 58 (3B): 789–99. doi: 10.1590/S0004-282X2000000500001 . PMID   11018813.
  10. ↑ "Myositis". medlineplus.gov. Retrieved 2022-11-18.
  11. ↑ "Signs and Symptoms of Polymyositis (PM) - Diseases". Muscular Dystrophy Association. 2015-12-18. Retrieved 2023-05-18.
  12. ↑ Leclair, Valérie; Notarnicola, Antonella; Vencovsky, Jiri; Lundberg, Ingrid E. (November 2021). "Polymyositis: does it really exist as a distinct clinical subset?". Current Opinion in Rheumatology. 33 (6): 537–543. doi:10.1097/BOR.0000000000000837. PMID   34494607. S2CID   237443416.
  13. ↑ "Dan Christensen, 64, Painter of Abstract Art, Dies". The New York Times. 27 January 2007. Archived from the original on 5 June 2015. Retrieved 20 April 2015.
  14. ↑ "Obituary - Robert Erickson". SF Gate. 29 April 1997. Archived from the original on 1 January 2015. Retrieved 20 April 2015.
  15. ↑ Stevens, George Jr. (2006). Conversations with the Great Moviemakers of Hollywood's Golden Age at the American Film Institute. Knopf. p. 427. ISBN   978-1-4000-4054-4.
  16. ↑ Brownlow, Kevin (1996). David Lean: A Biography. Macmillan. pp. 1466–1467. ISBN   978-1-4668-3237-4. Archived from the original on 13 January 2018. Retrieved 20 April 2015.
  17. ↑ "Noted Latter-day Saint playwright and LGBT ally Eric Samuelsen dies". The Salt Lake Tribune. Retrieved 2022-11-18.
  18. ↑ Vecsey, George (1979-08-12). "John Cardinal Wright Dies at 70; Top-Ranking American in Vatican". The New York Times. ISSN   0362-4331 . Retrieved 2022-11-18.
  19. ↑ "Rosita Velázquez".
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