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

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)