呼吸器感染症--急性感染症と慢性感染症の病態

[Respiratory infections--pathogenesis of acute and chronic infections].

• K Matsumoto

抄録

我が国の呼吸器感染症は、化学療法剤の開発や医学の進歩に伴う宿主や高齢者の増加により病態も急速に変化してきている。当科では20年近くの間に様々な呼吸器感染症が蓄積されており、これらの疾患の臨床研究が行われてきた。まず、成人T細胞白血病における肺炎は非常に重症であり、これらの疾患は病原性口腔内細菌の下気道への負荷が原因で発生している。別の臨床研究では、特に慢性呼吸器感染症を伴うBranhamellaや肺炎球菌感染症では、まず病原性口腔粘膜上皮細胞に病原性細菌が付着し、下気道に移動して感染するという病態が明確に示されました。ポビドンヨード液を用いた病原性口腔内細菌の正確な除去は、これらの急性・慢性呼吸器感染症の予防に非常に有用であった。急性気管支炎が流行していますが，二次的な細菌の病原体は世界的に見ても不明な点が多くありました．我々は，日本，タイ，バングラデシュにおいて，急性気管支炎の二次侵入菌としてH. influenzae，S.pneumoniae，B.catarrhalisが共通の主要病原体であることを明らかにした．近年，エリスロマイシン治療の発展に伴い，びまん性汎気管支炎などの重症慢性呼吸器感染症の発症機序が注目されている．本研究では、エリスロマイシンがIL-8産生を抑制するマクロライドの有効性を明らかにした。また、気管支・気管支気道の炎症状況を深く理解するためには、喀痰や気管支分泌物中の炎症細胞の分類が重要であることを述べた。 (ABSTRACT TRUNCATED)

Respiratory infections in Japan have rapidly changed, because pathogenesis has also changed by the increase of compromised hosts and aged people with the development of chemotherapeutic agents and another medical progresses. Various respiratory infections have been accumulated in our clinical department and clinical investigations were done for these diseases during almost 20 years. Firstly, pneumonias in adult T cell leukemia have been very severe and these diseases have occurred with load from pathogenic orophayngeal bacteria to lower respiratory airway. With another clinical studies, these pathogenesis which firstly pathogenic bacteria attach to orophayngeal epithelial cells and would move to lower respiratory airway to infect were given very clear evidences especially for Branhamella and Pneumococcus infections with chronic respiratory infections. The exact clearance of pathogenic orophayngeal bacteria using povidon iode solution was very useful for prevention of these acute or chronic respiratory infections. Although acute bronchitis is very popular, the secondary bacterial pathogens remained to be unknown, in the world. We showed that H. influenzae, S.pneumoniae and B.catarrhalis were common major pathogens as the secondary invading bacteria of acute bronchitis in Japan, Thailand and Bangladesh. Recently, the pathogenesis of severe chronic respiratory infections such as diffuse panbronchiolitis is focused after the development of erythromycin therapy. We gave some evidences of macrolides effectiveness which these drugs inhibited IL-8 production. We described the importance of inflammatory cell classification in sputa or bronchial secretions for deep understanding of inflammatory situation in broncho-bronchiolar airway.(ABSTRACT TRUNCATED)