Nasal and blood transcriptomic pathways underpinning the clinical response to grass pollen immunotherapy (PBMC)

The Gauging Response in Allergic Rhinitis to Sublingual and Subcutaneous Immunotherapy (GRASS) study was a randomized, double-blind, placebo-controlled trial of individuals with timothy grass allergy who received 2 years of placebo, subcutaneous (SCIT), or sublingual immunotherapy (SLIT) and were followed for a total of 3 years. Here we utilized longitudinal transcriptomic profiling of nasal brush and peripheral blood mononuclear cell (PBMC) samples after allergen provocation collected in the GRASS study to uncover airway and systemic expression pathways mediating responsiveness to immunotherapy. Peripheral blood mononuclear cell samples were collected immediately before and 6-7 hours after nasal allergen challengen with timothy grass pollen allergen in grass allergic subjects and non-allergic controls. In grass allergic subjects samples were collected at 4 timepoints, prior to initation of grass immunotherapy (visit -2), 1 year after starting immunotherapy (visit 107), 2 years after starting immunotherapy (visit 207), and 1 year after stopping immunotherapy (visit 307; 3 years after visit -2).