Comparison of two murine models of acute and chronic hypersensitivity pneumonitis due to pigeon serum exposure

Abstract

Introduction: The aim of the study was to compare two murine models of hypersensitivity pneumonitis (HP), one acute and one chronic, with a view to their future use for studying the pathogenesis of this disease. Materials and methods: C57BL/6 mice were used. Two intraperitoneal injections of 100 µL of commercial pigeon serum (200 µg protein/ml) or saline were administered with an interval of 48 h in between. Subsequently, intranasal instillations of 40 µL of pigeon serum (200 µg protein/ml) or saline were performed three days a week, for three weeks in the acute model and for 12 weeks in the chronic model. Lung inflammation in bronchoalveolar lavage (BAL), lung function and values of specific IgG in serum were evaluated 24 hours, 7 days and 14 days after the last exposure. Results: The number of total cells in BAL was significantly higher after 24 hours post-inhalation in the chronic model (mean ± SD (cells x10 5 ) = 5.21 ± 2.84) compared to the acute model (mean ± SD (cells x10 5 ) = 2.73 ± 1.51), p = 0.006. As regards lung function, a decrease in TLC was observed in both models: it returned to normal levels in the acute model at 14 days but remained unchanged in the chronic model over time (p Conclusions: The chronic model of HP described here presents a higher inflammation and involvement of lung function than the acute HP model. These models may serve as a tool for future studies of the pathogenesis of HP. Study funded by FUCAP and SEPAR.