The role of soluble interleukin-4 receptor and interleukin-5 antibody in preventing late-phase allergy-induced eustachian tube dysfunction.

Abstract

We investigated the role of soluble interleukin (IL)-4 receptors (sIL-4R) and IL-5 antibodies (IL-5Ab) in preventing allergic eustachian tube dysfunction (ETD) and middle ear effusion (MEE). Brown-Norway rats were sensitized to ovalbumin (OVA) and challenged transtympanically. Two groups of rats received either IL-4R or IL-5Ab transtympanically 1 hour before challenge. Three additional groups were used as controls. Following the second transtympanic challenge, the ventilatory and clearance functions of the eustachian tube (ET) were assessed at 0, 2, and 8 hours. Histology was prepared using cut paraffin sections stained with hematoxylin and eosin. sIL-4R-pretreated rats showed no significant changes in ventilatory or clearance functions of the ET or inflammatory changes in ET mucosa, whereas IL-5Ab pretreatment showed significant late ventilatory and clearance dysfunction as well as inflammatory mucosal changes. These data demonstrate that the late-phase allergic inflammatory response that leads to subsequent formation of ETD and MEE is prevented by pretreatment with sIL-4R and, more modestly, with IL-5Ab.