Semiquantitative cytochemistry in evaluation of apoptotic capacity in bronchoalveolar lavage of smokers and patients with non-small-cell lung cancer.

Apoptotic capacity of pulmonary tissue to produce or remove apoptotic cells by alveolar macrophages (ALMs) was investigated in three groups: healthy volunteers, smokers and patients with non-small-cell lung cancer (NSCLC). Differential cell counting of bronchoalveolar lavage (BAL) specimens revealed significantly higher percentages of neutrophils and eosinophils and decreased percentage of macrophages in BAL of patients with NSCLC in comparison with nonsmokers and smokers. Proportion of lymphocytes was significantly higher in patients with NSCLC than in smokers. These changes in the BAL cell profile may reflect immunology of the lung in pulmonary malignancies. BAL eosinophils were significantly lower and AMs increased in smokers in comparison with nonsmokers. This result might be understood as a consequence of changed tissue architecture of pulmonary tissue in situ, influenced by smoking. Apoptotic detection in cytocentrifuge preparations of BAL cell suspensions was evaluated by TUNEL method. Subsequent steps, adsorption, internalization and digestion of apoptotic cells by alveolar macrophages (AMs) were estimated by semiquantitative cytochemical scoring and indexing method and correlated with percent of free apoptotic cells. Significant increase of apoptotic capacity of pulmonary tissue in control smokers (289.55+/-50.77) in comparison with that of non-smokers (218.29+/-56.24) could be a consequence of stimulated digestion inside the AMs; decreased apoptotic capacity of pulmonary tissue in NSCLC (150.30+/-40.61; p<0.05), in comparison with non-smokers and smokers is in relation to a reduced phagocytosis of the apoptotic remnants, which might be either the cause or the consequence of the oncogenic process.