Birch pollen allergen immunotherapy normalizes nasal gene-expression and microbial community -- ScienceDailyIn total, 44 nasal brushings were subjected to RNA-sequencing analysis to find gene expression and microbial community changes driven by allergic rhinitis and allergen immunotherapy. According to the results, the group who started allergen immunotherapy showed decreased symptom score and reprogramming of nasal epithelial transcriptome, set of RNA molecules, during the pollen season. "The immunotherapy affected asthma-, chemokine signaling-, and toll like receptor signaling pathways in the spring. No major differential expression was found between the two winters in any group," says researcher Sanna Toppila-Salmi from the University of Helsinki and Helsinki University Hospital. The results also indicated that microbial community diversity of the group that underwent allergen immunotherapy approached that of the healthy controls.