Abstract

Clinical signs in severe asthma vary widely. We hypothesize that the severity correlates with abundance of inflammatory cells in defined compartments of the lung. In this study we examined the bronchiolar wall lamina propria compartment to assess EOs from 14 cases of fatal asthmatics and 6 control subjects. Formalin-fixed, paraffin-processed tissues were immunohistochemically stained, with the DAKOcytomation Auto-stainers. IHC localized EOs with (MPO) antibodies for major basic protein (MBP), tagged with peroxidase and visualized with DAB. With the Aperio ImageScope program, the number of EOs in the bronchiolar wall were counted and related to 1mm² of lamina propria. Average EOs count in bronchioles of asthmatics with a diameter >1mm (#br 10) was 449.63 EOs/mm² and with a diameter < 1mm (#br 43) was 223.54 EOs/mm². In the control bronchioles < 1mm (#br 27) the cell count was 82.73 EOs/mm² vs. 292.4 EOs/mm² in bronchioles >1mm (#br 6). Statistical analysis of EOs counts/mm² between asthmatics and controls of bronchioles < 1mm showed statistically significant differences (p < 0.01). For bronchioles >1mm, there was no statistical significance (p ≈ 0.1). EOs were more abundant in larger bronchioles of asthmatic, compared to the smaller bronchioles. Further morphometric assessment is required to determine the correlation between other inflammatory cell distribution in the bronchioles and the clinical signs. Funded by: NSU FRG, NIEHS 00628.