Analysis of pulmonary allergic vasculitis with eosinophil infiltration in asthma model of mice

Here the authors report pulmonary allergic vasculitis with eosinophil infiltration in an asthma model of mice and investigated its pathogenesis. C57BL/6 and BALB/c mice were sensitized with ovalbumin (OVA). After the inhalation of OVA, the authors measured the cell number and cytokine concentration in the blood and bronchoalveolar lavage fluid (BALF). The authors also examined the histological changes of the pulmonary. The number of eosinophils increased in the blood and BALF in both strains; however, the number in C57BL/6 in BALF was significantly higher than that in BALB/c. Histological analysis demonstrated severe vasculitis of the pulmonary arteries with derangement of the muscle layer and smooth muscle cell hyperplasia in C57BL/6. Semiquantitative analysis of the severity of vasculitis in the pulmonary arteries revealed that the internal vascular space was highly reduced by smooth muscle hyperplasia in C57BL/6 compared to BALB/c mice. The concentrations of interleukin (IL)-4, IL-5, and interferon (IFN)-gamma in BALF of C57BL/6 were significantly high compared to those of BALB/c. C57BL/6 mice exhibited severe allergic vasculitis in the pulmonary arteries compared to BALB/c mice. The high concentrations of IL-4, IL-5, and IFN-gamma in the lung may play a critical role in the pathogenesis of allergic vasculitis in C57BL/6 mice.