Differential cell analysis in bronchoalveolar lavage from various pulmonary diseases.

ABSTRACT

To obtain characteristics of cellular responses of the lung to various disease processes, we analyzed the cells in bronchoalveolar lavage fluid retrieved from various lung lesions. Patients affected with five groups of pulmonary diseases were included in this study. These were pulmonary tuberculosis (21), malignancy (7), interstitial lung disease (11), bacterial pneumonia (10), and invasive fungal infection (7). Diagnoses were made from histopathological or microbiological evidence and were followed by compatible clinical courses. We compared total cell counts, alveolar macrophages, neutrophils, and lymphocytes in both percentages and absolute numbers to the values in the normal population reported in previous studies. Comparisons within each disease were also made. Compared to the normal population reported in previous increased percentages of neutrophils and lymphocytes in nearly all groups. However, if the comparison was made among the five groups, only the bacterial pneumonia had a significantly higher total cell count, absolute count and percentage of neutrophils. A value of more than 50% neutrophils gave sensitivity and specificity as 80% and 89%, respectively, in differentiatind bacterial pneumonia from other diseases. No parameter was demonstrated as useful in distinguishing between nonbacterial conditions. In conclusion, increases in the percentage of neutrophils and lymphocytes were discovered in nearly all pulmonary diseases. The markedly increased percentage of neutrophils in bacterial pneumonia may be useful as adjunctive evidence in the diagnostic process in some special conditions.