臨牀透析 Vol.13 No.13(2-3)


特集名 透析と呼吸器
題名 肺の防御と免疫
発刊年月 1997年 12月
著者 松元 幸一郎 九州大学医学部附属胸部疾患研究施設
著者 相沢 久道 九州大学医学部附属胸部疾患研究施設
【 要旨 】 肺には呼吸運動により粉塵や病原性物質が吸入される.このような物質による障害を防ぐために,肺は免疫学的および非免疫学的機序により,気道・肺胞系より障害性の物質を排除したり不活化する.鼻咽喉や気管・下気道では,吸入された物質を粘液とともに排出する.ガス交換領域にはさらに他の防御機構が存在する.これらには免疫グロブリンや,マクロファージ・リンパ球・好中球などの細胞が関与し炎症を引き起こす反応がある.これらの防御機構の障害,たとえばIgGサブクラスの欠損やIgAの不活化,細胞性免疫の障害などにより,呼吸器感染が生ずる.
Theme Dialysis Therapy and Respiratory Systems
Title Defense mechanisms and immunology of the lung
Author Koichiro Matsumoto Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University
Author Hisamichi Aizawa Research Institute for Diseases of the Chest, Faculty of Medicine, Kyushu University
[ Summary ] During respiration, airborne dust and pathogens are inhaled into the lung. To prevent the injury induced by these organisms, respiratory host defences effectively remove or inactivate microorganisms in the conducting airways and alveoli, by immunologic and nonimmunologic mechanisms. These mechanisms operating in the naso-oro-pharynx and along the trachea and conducting airways clear the respiratory mucosa of excessive microorganisms that can be inhaled with ambient air or aspirated with oropharyngeal secretions. The air-exchange surface has had to develop additional mechanisms for auto-cleansing. These include immunoglobulins and cells, especially macrophages, Iymphocytes, and polymorphonuclear cells, which generate inflammatory reactions. Respiratory infections may occur when certain components of the defense system are absent, and examplified by IgG subclass deficiency, IgA inactivation, and impaired cell-mediated immunity.
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