Experimental common cold increases mucosal output of eotaxin in atopic individuals

Background: In view of recent observations demonstrating that rhinovirus in fections are associated with increased local activity of eosinophils, we hy pothesized that eotaxin, a selective eosinophil chemoattractant, may be inv olved in eosinophil recruitment/activation in common cold infections. Methods: Twenty-three patients with seasonal allergic rhinitis were inocula ted with human rhinovirus 16 (HRV 16) outside the pollen season. Sequential diluent and allergen (10(3) SQ-U) challenges, each followed by nasal lavag e, were carried out about 3 months before and 4 days after virus inoculatio n. Results: Seventeen patients developed common cold and were further analyzed . Lavage fluid levels of eotaxin were increased at the height of active com mon cold (day 4 after inoculation) both at baseline (after diluent challeng e) (P<0.01) and acutely after allergen challenge (P<0.05). Conclusions: Common cold symptoms after nasal HRV 16 inoculation are associ ated with increased nasal mucosal output of eotaxin, suggesting that this c hemokine is partly responsible for recruitment/activation of airway mucosal eosinophils in common cold infections.