Lymphocyte subsets in pulmonary venous and arterial blood of lung cancer patients.

Lymphocyte subsets in pulmonary venous blood (PVB) smears from 42 patients with lung cancer were immunocytochemically determined. In four patients, pulmonary arterial blood (PAB) smears were also studied for comparison with PVB. Seven healthy donor peripheral blood (PB) smears were used as controls. The percentage of T cells, helper/inducer T (Th) cells and B cells were significantly lower (P less than 0.01) than in normal controls but those of suppressor/cytotoxic T (Ts) cells, natural killer (NK) cells (P less than 0.01) and S100+ small lymphoid cells (P less than 0.05) were higher. This resulted in a decrease in the Th:Ts value in cancer patients (1.46 vs. 2.28 for normal controls; P less than 0.01). The Th and Ts value of PVB from patients in pathological Stages III and IV was lower than from those in Stages I and II because of the increase in Ts cells in the former (P less than 0.05). S100+ small lymphoid cells were increased in cancer patients, especially in those with adenocarcinoma. The present study demonstrates immunoregulation abnormalities in cancer bearing hosts, the results correlating well with the stage of the cancer. Determining lymphocyte subset alterations in PVB did not, however, enable us to detect the changes associated with local immune responses against cancer.