Background:Tobacco smokers are at a higher risk of lung cancer than nonsmokers. This may be a result of changes in immunological status. The aim of this study was to evaluate lymphocyte phenotypes in the peripheral airways of patients with lung cancer and healthy subjects in relation to smoking history.Material/Methods:BALF cells from patients with primary lung cancer and from healthy smokers and nonsmokers were analyzed by a flow cytometry method using monoclonal antibodies directed to subpopulations of lymphocytes.Results:The total cell count was elevated in the BALF from smokers. We found a low proportion of T helper (Th) and high proportion of T suppressor/cytotoxic (T s/c) cells in the BALF from smokers with lung cancer. The ratios of Th to T cells and Th to Ts/c cells were significantly lower, and the ratio of Ts/c to T cells was significantly higher in the BALF from the lung cancer patients than from healthy controls. The ratios of Th to Ts/c and Th to T cells were significantly lower in the BALF of the smoking controls when compared to nonsmoking controls. The proportion of T activated cells was lower in the group of smokers with lung cancer when compared with healthy smokers.Conclusions:We found significant differences in lymphocyte subpopulations in BALF between lung cancer patients and healthy persons and between smokers and nonsmokers. Smoking history should be taken into consideration in the analysis of BALF cells.

Keywords: Aged, 80 and over, Bronchoalveolar Lavage Fluid - cytology, Lung Neoplasms - immunology, Lung Neoplasms - pathology, Lymphocyte Subsets, Smoking