Flow Cytometric Analysis of Lymphocyte Subsets in the Bronchoalveolar Lavage Fluid and Peripheral Blood of Healthy Volunteers

The lymphocyte subsets in the bronchoalveolar lavage fluid (BALF) and the peripheral blood of 25 healthy volunteers were examined by analysis with a fluorescence-activated cell sorter. Comparison of the lymphocyte subsets in the BALF with those of the peripheral blood revealed much higher values for the ratios of each Leu 3a+ (CD4), Leu 3+8-, and Leu 2+15- cells, while the ratios of Leu 1+ (CD5), Leu 2a+ (CD8), Leu 7+, Leu 8+, Leu 10+, Leu 11a+ (CD16), Leu 12+, and Leu 2+15+ cells were low in the BALF. The above results indicate that the lymphocyte subsets in the BALF from healthy individuals are mainly composed of cells with surface phenotypes of helper T cells and cytotoxic T cells with virtual absence of cells carrying suppressor T and NK cell phenotypes, and with low B cell ratio. Therefore, it is assumed that the local immune mechanism of the lung is different from that of the peripheral blood.