Diagnosis of pulmonary aspiration: A mouse model using a starch granule test in bronchoalveolar lavage

Background and objective: Pulmonary aspiration (PA) is a significant respiratory disease in children. However, the diagnosis of aspiration is often difficult owing to the poor efficacy of currently available diagnostic tests. The aim of this study was to assess in a mouse model the specificity of starch granule detection in BAL as a new method for detecting PA in children. Methods: Twenty BALB/c mice were divided into the following groups according to the solution instilled into the airways: corn flour milk 7.5%-a source of starch (CM), Pseudomonas aeruginosa, normal saline and a control group. BAL was performed 2 days after instillation. Detection of starch granules and lipid-laden macrophages were compared in BAL. Results: Starch granules were detected in BAL fluids from all mice in the CM group (food aspiration model), whereas no starch granules were detected in the other three groups, demonstrating a sensitivity and specificity of 100%. On the other hand, lipid-laden macrophages were found in all mice from all the groups studied. Conclusions: The detection of starch granules in BAL is a simple and highly specific method for the diagnosis of PA in an experimental model. Clinical studies using the starch granule detection method in BAL should be tested in at risk patients to evaluate the utility of this method for investigating PA.