Abstract
Introduction: The immunopathological mechanisms of hypersensitivity pneumonitis (HP) are not well known. Animal models with different forms of HP are essential for the study of these mechanisms.
Methods: C57Bl/6 mice were used. Two intraperitoneal injections of 100µL of pigeon serum (200µg protein/ml) or saline solution were administered, separated by an interval of 48h. Subsequently, 40 µL intranasal instillations of pigeon serum (200µg protein/ml) or saline solution were performed three days a week for three weeks. Pulmonary inflammation in bronchoalveolar lavage (BAL) was evaluated and histological studies were performed 24 hours, seven days, and 14 days after the last exposure.
Results: Histological studies showed changes consistent with HP using this model, with pericentrolobular inflammation and mixed infiltrate with polymorphonuclear predominance. In the BAL a significant increase was observed in the number of neutrophils, mean (SD) = 2.11 (3.25) cells (x104), and the number of lymphocytes, mean (SD) = 2.5 (2.02) cells (x104), 24h after inhalation (p = 0.004 and 0.017 respectively). This increase persisted until a week after inhalation. An increase in the number of eosinophils, 28.69 (17.50) cells (x 104) at 24 hours was also observed, with a tendency towards progressive decline a week after exposure. The levels of pigeon serum antigen-specific IgG were higher than in the control group 24 hours after inhalation (p < 0.0001).
Conclusions: Our results provide evidence of lung inflammation and pathology study are consistent with acute HP. The animal model described may serve as a tool for future studies on the pathogenesis of acute HP.
Study funded by Fis PI 001577, FUCAP and SEPAR.
- © 2014 ERS