Fortilin, also known as histamine-releasing factor [HRF] and translationally controlled tumor protein, has been studied as a HRF and implicated as a mediator in late phase allergic reactions. It has a proinflammatory role in murine asthma and skin immediate hypersensitivity. However, the ability of allergen challenge to modulate the levels of fortilin in the nasal secretion of subjects with allergic rhinitis has not been reported.
Nine adult subjects with allergic rhinitis and positive skin prick testing to ragweed pollen extract (RWPE) were recruited for this study. The mean age of the subjects was 41.6 years. Intranasal challenge with saline and provoking doses of RWPE solution were performed on two different days. During nasal challenge, symptom scores were recorded at baseline, 30 min, and hourly for a total of 6 hours. Nasal lavage was performed at baseline, 30 min and 5 hours post-challenge, and the collected nasal fluid was analyzed for fortilin levels by ELISA.
Compared to saline challenge, RWPE challenge rapidly increased congestion, drainage, sneezing, and total symptom scores at 30 min post-challenge (p<0.05). These scores decreased 2 hours post-challenge. Compared to saline challenge, ragweed extract increased the level of fortilin 5 hours after challenge (p<0.05), but not at 30 min post challenge.
Exposure to ragweed pollen induces a delayed secretion of fortilin in the nasal airway of ragweed-IgE skin test positive subjects with allergic rhinitis. Fortilin may play a role in the pathophysiology of allergic rhinitis.