Roles of human alveolar macrophages in the pathogenesis of some diseases of the lung.

We reviewed roles of human alveolar macrophages (AM) in the pathogenesis of some diseases of the lung, based mainly on our own experimental results. Two main subjects were as follows;1) Effects of smoking and pretreatment with lipopolysaccharide on superoxide anion and leukotriene B4 secretion from AM in association with the pathogenesis of emphysema and adult respiratory distress syndrome (ARDS).2) Effects of certain macrophage-active cytokines on Mycobacterium avium complex (MAC) growth in AM in combination with myeloperoxidase in association with the pathogenesis of primary MAC infection in the lung.In conclusion, hyperactivated state of AM might cause some forms of inflammatory lung disease, such as emphysema, pulmonary fibrosis, and ARDS, while some defects of their function might cause some forms of chronic pulmonary infection, such as primary MAC disease. The demonstration of the real role of AM in the disease process are worth pursuing in the future study.