A recent study published in Signal Transduction and Targeted Therapy suggests that clearing symptom-driving nasal viruses could reduce allergic inflammation and offer a new treatment path for individuals with allergic rhinitis, according to findings released on June 28.
Researchers explored how viruses residing in the nasal cavities contribute to the development of allergic rhinitis. The study found that removing commensal viruses from the nose using intranasal ribavirin drops improved symptoms in mice, while a ribavirin spray showed improvement in patients during a small phase 2 trial. This points to a potential role for these viruses in allergic rhinitis development.
The research indicated that certain nasal cavity viruses activate innate immunity sensors, leading to an accumulation of type I interferon-associated neutrophils. These immune cells form neutrophil extracellular traps, which appeared to promote the onset of allergic rhinitis. In murine models, daily administration of intranasal ribavirin drops over seven days reduced viral abundance and alleviated symptoms such as sneezing and scratching. Reduced eosinophil counts and lower production of type I interferon and interleukins were also observed following treatment.
In the clinical portion of the study, known as the Ribavirin-Spray Therapy for Allergic Rhinitis (R-STAR) trial, 42 randomized patients received either ribavirin or placebo for four weeks. Ribavirin-treated participants demonstrated significantly fewer viral commensals in their noses along with improved total nasal symptom scores, rhinitis control assessment test scores, and visual analog scale values after therapy. Cytokine levels associated with inflammation were also reduced among treated participants.
The therapeutic effects were more pronounced among those with severe symptoms or high initial viral abundance, with some benefits persisting at one-year follow-up after only four weeks of treatment. No serious adverse events or significant drug reactions were reported during the trial period.
Researchers caution that larger multicenter phase 3 trials are needed before drawing definitive conclusions about efficacy and safety. They note that nasal viruses may reappear after treatment withdrawal, and further causal validation is required regarding candidate viruses linked to human allergic rhinitis.
