Role of innate immunity in the pathogenesis of allergic rhinitis

Purpose of review: The immunologic causes of allergic rhinitis underscore the important roles of both adaptive and innate immune systems. In recent years, appreciation of the role of nasal innate immunity has grown and evidence suggests that the pathogenesis of allergic rhinitis is partially mediated by the innate immune system. This review focuses on our current knowledge and recent discoveries in nasal innate immunity as they pertain to the cause and management of allergic rhinitis. Recent findings: Previously thought to be nonspecific, innate immunity also possesses specific mechanisms as demonstrated by toll-like receptors. The interplay between the external environment and nasal mucosa contributes to innate-immune-mediated development of allergic rhinitis. Certain innate immune cells such as plasmacytoid dendritic cells and natural killer T cells may be important in the induction of Th2 cytokine production characterized in allergic airway disease. Summary: The increasing knowledge of nasal innate immunity gained from recent research not only expands our understanding of the causes of allergic rhinitis, it also leads to new therapeutic approaches. Although current management of allergic rhinitis includes one or a combination of pharmacotherapy, immunotherapy, and/or surgery, novel treatments such as toll-like receptor agonists used as targets or adjuvants for immunotherapy are being tested and may hold promising roles in future allergic rhinitis treatment.