The use of grass pollen in nasal allergen challenges proved effective in the treatment of allergic rhinitis symptoms and improved patients’ peak nasal flow, according to study results.
“These results provide insight into the mechanisms of specific allergen immunotherapy and suggest a possible role for [nasal allergen challenge (NAC)] as a surrogate clinical outcome in future immunotherapy trials,” G.W. Scadding, PhD, of Imperial College London, and colleagues wrote. “This study demonstrates that grass pollen immunotherapy improves symptoms and peak nasal flow after allergen challenge, associated with reductions in early- and late-phase local inflammatory mediators.”
The researchers recruited volunteers from the allergy clinic at Royal Brompton Hospital, and at NAC initiation, participants recorded their symptoms using a total nasal symptom score (TNSS). The researchers analyzed nasal and cutaneous responses in 14 participants with seasonal grass-pollen allergic rhinitis (AR) who did not receive immunotherapy. They compared those results with 14 AR participants receiving 200 µL spray Timothy grass pollen immunotherapy and 14 nonatopic controls.
Participants receiving immunotherapy had reduced TNSS vs. untreated participants with AR (P = .039). Participants receiving therapy also had reduced peak nasal inspiratory flow when compared with untreated participants (P = .016).
Eight hours after the NAC was conducted, nasal fluid interleukin-4 (P = .027) and interleukin-9 (P = .049) were reduced in participants receiving immunotherapy compared with those who did not receive treatment.
Although study results were encouraging, the researchers said additional research is necessary.
“We have identified several potential local biomarkers of response to allergen immunotherapy — their utility needs to be borne out in larger, prospective studies,” the researchers wrote. – by Ryan McDonald
Disclosure: Scadding reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.