Pilot Study Seeks to Understand Biomarkers in Cat Allergy Response

January 24, 2013 -- 

The Immune Tolerance Network (ITN) and Imperial College London are collaborating on a new pilot study examining immunological responses to cat allergen. Allergy to cat dander is one of the most common forms of allergic disease in the US and Europe, and can reduce the quality of life for allergy sufferers. The only form of disease-modifying therapy that does not just treat symptoms is immunotherapy, in which cat allergens are administered over a period of time to desensitize a patient. The goal of this pilot study is to measure time-dependent cellular patterns and immunological changes in response to cat allergen, and understand how these immunological markers correspond with clinical symptoms.

This pilot study is being led by Stephen Durham, MD (Imperial College London) and conducted at the Royal Brompton Hospital in London. The study has enrolled 12 cat-allergic subjects who are non-cat owners. Participants will receive increasing doses of cat hair allergen extract and investigators will assess clinical symptom scores and collect nasal secretions at multiple  time-points up to 8 hours following administration. Nasal secretions will be collected via sponges using a new technique pioneered by the investigators at the Imperial College London. Specimens will be analyzed for local cytokine and mediator responses, along with peripheral blood circulating basophil and dendritic cell activation, antibody, and other biomarker responses.  

Understanding the timeline of biomarker changes in the immunological response will provide valuable information for the design of larger cat allergy immunotherapy studies in the future. Data from this pilot study is intended to help understand allergic disease and associated biomarkers in response to allergen.  Knowing these time-dependent changes will provide valuable information designing specimen collection schedules for larger cat allergy immunotherapy studies in the future. The ITN and Imperial College London conducted three similar pilot studies to validate local and systemic immunological responses following nasal allergen provocation in grass allergy in 2011. The data informed the design of nasal secretion and peripheral blood/serum collections in the larger ITN GRASS study.  Robust biomarkers identified from such studies can serve as tools to measure the efficacy ofimmunotherapy interventions. Ultimately, the identification of allergen-specific immune  mechanisms will help design more effective treatment strategies targeting allergic pathways.

The clinical portion of this pilot is sponsored by Imperial College London, and the mechanistic analyses will be supported by the ITN.