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2622509 
Journal Article 
Abstract 
Dual sensitization to house dust mite and ragweed allergen leads to similar allergic sensitization in beagle dogs regardless of primary exposure route 
Rudolph, K; Royer, C; Kuehl, PJ; Barrett, EG 
2010 
Yes 
American Journal of Respiratory and Critical Care Medicine
ISSN: 1073-449X
EISSN: 1535-4970 
181 
A5767 
English 
WOS:000208771004127 
is part of a larger document 3452678 Proceedings of the American Thoracic Society 2010 International Conference, May 14-19, 2010, New Orleans
Rationale: Dogs sensitized to allergens are an excellent model to study the role of pulmonary immunity in allergic asthma. Allergic responses in dogs can be induced by subcutaneous injection of a single adjuvanted allergen early in life. The purpose of this study was to determine the allergic phenotype that occurs in puppies exposed to two allergens simultaneously by different sensitization routes and schedules.

Methods: A total of 14 puppies used in this study were the offspring of two ragweed (RW) sensitized females and the same RW sensitized male. Offspring were sensitized with different numbers of subcutaneous injections (SC, 50μg RW + 10μg house dust mite (HDM) D. farinae with 1 mg ALUM) and inhalation exposures with RW + HDM (IH, 10 minute nebulization of a mixed solution of 10 mg/ml each of RW and HDM) between 1 and 20 wks of age: (1) 2 SC + 6 IH (n=4), (2) 4 SC + 4 IH (n=3) and (3) 6 SC + 2 IH (n=7). Blood samples to assess total (T) IgE and specific antibody levels (S-AB) were collected at different time points during and after the immunization process. Airway hyperresponsiveness (AHR) to aerosolized methacholine (MCh), RW, and HDM was measured at 24 weeks. At 28 and 35 weeks of age puppies were exposed by inhalation to either RW or HDM (crossover design). Pulmonary inflammation was assessed following exposure (total lung deposition 200 to 250 μg) by bronchoalveolar lavage collected before and on day 1 and 4 after RW or HDM exposure.

Results: TIgE and S-AB to both allergens increased during the sensitization to comparable levels. Changes in pulmonary resistance following a challenge of MCh, RW or HDM tended to be higher in group (1). An inhalation challenge to RW or HDM at week 28 or 35 resulted in a similar increase in pulmonary resistance for treatment group (1), (2) or (3) (RW: 698.6±252.1, 576.0±85.9 and 620.6±138.6, respectively; HDM: 662.5±113.5, 650.8±90.9 and 547.1±72.6, respectively). In addition, RW and HDM induced significant eosinophilia in all three groups on day 1 and 4 post-exposure and neutrophilia on day 1 but no differences between treatment groups were detected.

Conclusion: These results indicate that dual sensitization to allergens produce similar allergic airway responses to both allergens with a tendency to be increased in dogs exposed to a higher number of inhalation challenges versus subcutaneous injections. Research funded by NIH grant 5R01AI061787-03. 
American Thoracic Society 2010 International Conference 
New Orleans, LA 
May 14-19, 2010