Flow cytometry counting of bronchoalveolar lavage leukocytes with a new profile of monoclonal antibodies combination.

Background: Differential cell count in bronchoalveolar lavage (BAL) has an important role in the diagnosis of pulmonary diseases. Optical microscopy method is usually chosen to identify BAL leukocyte populations despite its technical limitations. As there are no guidelines to make this analysis by flow cytometry (FCM), we propose a new monoclonal antibodies combination for this analysis. Methods: Thirty-four BAL samples were stained with the monoclonal antibodies combination CD15/CD16/CD45/HLA-DR and analyzed in a 2-laser cytometer (FACSCalibur). The results were compared with those obtained by optical microscopy. Results: Both methods showed a good correlation, but FCM overestimates lymphocyte population and conversely underestimates alveolar macrophage population. Conclusions: The proposed monoclonal antibodies combination is effective and reliable to identify leukocyte populations in BAL. © 2011 International Clinical Cytometry Society