Jiri Prazma, MD, PhD
Jiri Prazma, MD, PhD, and his colleagues have continued in their study of allergy-induced Eustachian tube dysfunction. The role of allergy in the development of Eustachian tube dysfunction (ETD) and otitis media with effusion (OME) has been investigated in the laboratory for many years. While the etiology of OME most likely involves many factors, allergic inflammation in and around the nasopharyngeal portion of the Eustachian tube (ET) or within the middle ear leads to the breakdown of the protective functions of the ET, thereby resulting in increased risk for the development of otitis media. For this reason, it is theorized that by modulating the pathways that lead to the allergic response, we can limit the inflammation caused by the allergic response resulting in ETD.
We have developed a model of ETD where rats are sensitized to ova-albumin (OVA) and subsequently challenged with this allergen either transtympanically or through the nasopharynx. This challenge causes an allergic-like response leading to inflammation within the middle or around the nasopharyngeal portion of the ET. This inflammation consequently leads to worsening of the ET’s ventilatory function manifested as increased passive opening and closing pressures as well as worsening of active clearance of negative pressure. It also impairs the mucociliary clearance of the ET.
Supported by the Resident Research Grant of the American Academy of Otolaryngic Allergy, Joshua Surowitz, MD (PGY2), Stefan Mlot (MS4), and Carlton J. Zdanski, MD, have investigated new oligodeoxynucleotides with CpG motifs (CpG ODN), which are known mediators of allergic inflammation. This study has demonstrated that TLRA 9 and 7 antagonist increases patency of the Eustachian tube and slows mucociliary transport in the Eustachian tube. This study demonstrates that antagonists were efficacious in the treatment of allergic-like airway inflammation and airway hyperresponsiveness by preventing naive T-lymphocyte differentiation. Antagonist of these receptors may have opposing effects when applied into the middle ear.
Conclusion: CpG ODN given via transtympanic or nasopharyngeal application can treat allergy-induced ETD in rats and may offer substantial promise in the future management of otitis media and otitis media with effusions.