Bal T lymphocyte subsets are reduced in primary lung neoplasias

Direct observation with an optic fibre bronchoscope facilitates the diagnosis, staging and treatment of both neoplastic and other lung diseases, and the varying diameters available enable IVth or even Vth-order bronchi to be examined. The technique can be employed for deep lung lavage or bronchoalveolar lavage (BAL) and for transbronchial biopsy. The BAL fluid, too, can be used to study lung cells and soluble components. In this study, 21 patients aged 32-79 (mean 55.5), namely 16 with lung cancer and with non-neoplastic lung diseases, were subjected to BAL to allow a study to be made of the BAL fluid cell composition. In the neoplastic group, CD3 lymphocytes were 41.3% compared with 63.2% in the peripheral blood. CD4 (24.6% vs 40.6%) and CD8 (16.6% vs 28.7%) displayed the same pattern. The CD4/CD8 ratio, on the other hand, was much the same in both groups: 1.7 vs 1.5. CD19 were higher in the BAL fluid (20.1%) than in the peripheral blood (4.8%). In the non-neoplastic group the differences between the BAL fluid and the peripheral blood are of the same sign, but less marked. In conclusion, the BAL fluid subset composition in primary lung neoplasia differs from that in the peripheral blood through a reduction of CD3, CD4 and CD8 and an increase in CD19 compared with the peripheral blood. These modifications are less evident in patients with non-neoplastic lung diseases.