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.

Effect of Angiostrongylus costaricensis extract on eosinophilic pulmonary response in BALB/c mice.

Epidemiological and experimental studies have demonstrated an association between parasitic infections and the allergic diseases. A protective effect in asthma was shown in animals infected with helminths. The aim of this study was to determine the effect of Angiostrongylus costaricensis extract on inflammatory lung response to ovalbumin (OVA) in mice. Four BALB/c mice received A. costaricensis extract by intraperitoneal (i.p.) injection on the first day. Mice were immunised against OVA by i.p. injection on day (D) 5 and D12 and received a daily intranasal OVA challenge (40 microl) between the D19 and D21. On D23, we performed a bronchoalveolar lavage (BAL) on the mice. Four BALB/c mice (control group) were immunised against OVA using the same protocol, but did not receive parasite extract. Total cell counts (TCC) and differential cell counts were performed in BAL fluid samples. Eosinophil cell counts in BAL fluid were lower in the group that received A. costaricensis extract when compared with the control group (0.04 x 10(6) cells/ml and 0.01 x 10(6) cells/ml, respectively; p=0.04). TCC were not different between the groups studied. A. costaricensis extract in mice decreases eosinophilic response to OVA in BAL fluid.