Determination of T lymphocyte subpopulations in patients with lung cancer. A comparison between lung lavage and peripheral blood by monoclonal antibodies and flow cytometry.

In order to determine whether the alterations of immunoregulatory T cells described both in smokers and in patients with lung cancer occur in the deep lung as well as in peripheral blood, we analyzed T lymphocyte subpopulations in bronchoalveolar lavage (BAL) and in the blood of 12 patients with untreated lung cancer and of 8 controls. The immunocompetent cellular population of BAL fluid analyzed by differential cell count of alveolar macrophages, lymphocytes and neutrophils did not show considerable differences in the two groups studied. By contrast, the analysis of BAL T lymphocytes and their subsets showed significant alterations in patients compared with controls: a percentage increase of OKT3+ and OKT8+ lymphocytes and a decrease of the OKT4+/OKT8+ ratio was found in both the involved and uninvolved lung of patients. The immunologic pattern of T lymphocytes in blood did not show significant differences between patients and controls. Our data indicate that alterations in immunoregulatory T cells in lung cancer are more pronounced in BAL fluid obtained from both lungs than in peripheral blood.