METHODS: HDM extract from cultured Dermatophagoides pteronissunus that are indigenous to Korea was intranasally administrated for three times a week for 8 consecutive weeks. We then investigated allergic responses by the measurement of the level of total and specific IgE in blood, cell infiltration and airway hyperresponsiveness in lung, and Th2-related cytokines in bronchoalveolar lavage fluid (BALF). Airway remodeling parameters such as collagen expression were also examined.
RESULTS: In the chronic exposure group, we found increased neutrophil recruitment in BALF and cell infiltration around airways, and aggravated airway hyperresponsiveness. On the other hand, the plasma level of total IgE is increasing in early period, but is decreased in late. Th2 and inflammatory cytokines in BALF and airway remodeling parameters showed partial difference but no significantly between chronic exposure and normal control group.
CONCLUSIONS: We conducted only intranasal administration for 8 weeks in our chronic models without systemic sensitization of allergen, which showed significant difference in cell infiltration and airflow obstruction, but not in cytokines and remodeling parameters. Further studies for the cell-mediated stimulatory or suppressive responses are needed to establish the distinct murine model by chronic allergen exposure.