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Sjögren's syndrome or Sjögren syndrome (pronounced or in English, the latter to approximate the Swedish pronunciation (:ˈɧøːˈɡren)) is a chronic autoimmune disease in which the body's white blood cells destroy the exocrine glands, specifically the salivary and lacrimal glands, that produce saliva and tears, respectively.〔Borchers, A. T., Naguwa, S. M., Keen, C. L. & Gershwin, M. E. Immunopathogenesis of Sjögren's syndrome. Clin. Rev. Allergy Immunol. 25, 89-104 (2003)〕 The immune-mediated attack on the salivary and lacrimal glands leads to the development of xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes), which takes place in association with lymphocytic infiltration of the glands.〔Nocturne, G. & Mariette, X. Advances in understanding the pathogenesis of primary Sjogren's syndrome. Nature Reviews Rheumatology 9, 544-556 (2013)〕 That inflammatory process eventually severely damages or destroys the glands. Sjögren’s syndrome is usually classified as either 'primary' or 'secondary'. Primary Sjögren’s syndrome occurs by itself and secondary Sjögren’s syndrome occurs when another connective tissue disease is present. However, this classification does not always correlate with the severity of symptoms or complications. Primary and secondary Sjögren’s syndrome patients can all experience the same level of discomfort, complications, and seriousness of their disease. == Signs and symptoms == The hallmark symptom of Sjögren's syndrome is a generalized dryness, typically including xerostomia and keratoconjunctivitis sicca, part of what are known as sicca symptoms. Sicca syndrome also incorporates vaginal dryness and chronic bronchitis. Sjögren's syndrome may cause skin, nose, and vaginal dryness, and may affect other organs of the body, including the kidneys, blood vessels, lungs, liver, biliary system, pancreas, peripheral nervous system (distal axonal sensorimotor neuropathy) and brain. Skin dryness in some Sjögren's patients may be the result from lymphocytic infiltration into skin glands. The symptoms may develop insidiously, with the diagnosis often not considered for several years, because the complaints of sicca may be otherwise attributed to medications, a dry environment, aging, or may be regarded as not of severity warranting the level of investigation necessary to establish the presence of the specific underlying autoimmune disorder condition.〔Fox, R. I., Stern, M. & Michelson, P. Update in Sjögren syndrome. Curr. Opin. Rheumatol. 12, 391-398 (2000). 〕 Sjögren's syndrome is associated with increased levels in cerebrospinal fluid (CSF) of IL-1RA, an interleukin 1 antagonist. This suggests that the disease begins with increased activity in the interleukin 1 system, followed by an autoregulatory up-regulation of IL-1RA to reduce the successful binding of interleukin 1 to its receptors. Interleukin 1 likely is the marker for fatigue, but increased IL-1RA is observed in the CSF and is associated with increased fatigue through cytokine-induced sickness behavior. Sjögren's syndrome, though, is characterized by decreased levels of IL-1ra in saliva, which could be responsible for mouth inflammation and dryness. Patients with secondary Sjögren's syndrome also often exhibit signs and symptoms of their primary rheumatic disorders, such as systemic lupus erythematosus, rheumatoid arthritis, or systemic sclerosis. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Sjögren's syndrome」の詳細全文を読む スポンサード リンク
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