[Alveolar macrophage subpopulations and circulating monocytes. Immunophenotypic study in healthy non-smokers]

Peripheral blood monocytes of 10 non-smoker normal subjects and the macrophages of their bronchoalveolar lavage fluid (BAL) were investigated with two commercially available monoclonal antibodies (MAC 387, CD14). Surface membrane monocyte cells show simultaneously both markers. Instead alveolar macrophage (MA) can be divided in three different phenotype groups by the expression of the two markers (MAC 387+/CD14-, MAC 387+/CD14+, MAC 387-/CD14+). Particularly, MA with MAC 387+/CD14+ phenotype are adherent cells and morphologically lack anthracosis. Their alveolar presence in non-smokers can be due to normal turnover of monocytes from blood into alveoli. By contrast MA with MAC 387+/CD14- phenotype are non-adherent cells without anthracosis. At last MA with MAC 387-/CD14+ phenotype are non-adherent cells but different amounts of anthracosis in their cytoplasm can be observed.