Bronchoalveolar lavage. Influence of cytologic methods on the cellular picture.

Bronchoalveolar lavage (BAL) was applied to 803 subjects who had various lung diseases or were healthy controls. Combined Millipore (MiPo) filtration of alcohol-fixed cells and cytocentrifugation (CCF) of fresh, air-dried cells was used for the cytologic studies. On the MiPo preparations the proportions (mean +/- SD) of lymphocytes (30.6 +/- 23.7), neutrophils (5.4 +/- 11) and respiratory epithelial cells (2.4 +/- 3.8) were significantly (P less than .001) higher when compared with those on the CCF slides (21.0 +/- 2.3, 3.6 +/- 1.0 and 0.4 +/- 1.5, respectively). The proportions of eosinophils and basophils were nearly the same on the CCF (1.9 +/- 5.3) and MiPo slides (1.6 +/- 6.1). In MiPo filtration the loss and degeneration of cells can be avoided if the cell suspension is fixed prior to filtration. In cellular morphology the two methods complemented each other, and the specificity and sensitivity were the same. In nonparenchymal lung diseases false pathologic cell findings due to bronchial content contamination can be more reliably excluded from MiPo specimens than from CCF ones.