Regional and systemic CD4 and CD8 subsets in bronchogenic carcinoma

We studied lung and blood lymphocytes from 12 asymptomatic patients with peripheral bronchogenic carcinoma. Bronchoalveolar lavage was performed in the lung segment with tumor and a contralateral uninvolved lung segment and analyzed separately. After partial removal of macrophages by plastic adherence, cells were labeled with markers for CD4 and CD8 and analyzed by flow cytometric analysis. We found no significant difference in the percentages of mononuclear cells in either immune subset when comparing the lung containing tumor with the uninvolved lung. We did find, however, a depressed CD4/CD8 ratio in the peripheral blood. We conclude that a lung carcinoma does not change the local immunologic milieu of the lung parenchyma containing the carcinoma. It is not clear if the immunologic findings in the lungs and blood are due to the bronchogenic carcinoma, smoking, or the underlying chronic obstructive pulmonary disease.