Olfactory decline in patients with chronic rhinosinusitis (CRS) after endoscopic sinus surgery is linked to superior turbinate eosinophilia, according to recent research released as an abstract from the American Academy of Allergy, Asthma, and Immunology annual meeting. The AAAAI canceled the meeting and provided abstracts and access to presenters for press coverage.
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“,” Dawei Wu, MD, of Beijing Anzhen Hospital, Capital Medical University in Beijing, China, said in an interview.
There has been some research in the literature pointing to the link between CRS-associated olfactory dysfunction and superior turbinate eosinophilia. In a 2017 study, Lavin et al. found eosinophil markers in the superior turbinate tissue were elevated in patients with CRS with nasal polyps. One of the gene expressions of the eosinophil marker Charcot Leyden crystal protein (CLC) was inversely associated with olfactory threshold, which led the researchers to believe there was a link between olfactory decline and superior turbinate eosinophilia in these patients (Laryngoscope. 2017 Oct;127[10]:2210-2218).
Olfactory decline associated with CRS is the most common reason for loss of smell in ear, nose, and throat clinics, Dr. Wu said, but predicting this olfactory decline after endoscopic sinus surgery can be clinically challenging.
“The distinct feature of this smell disorder is the fluctuation in olfactory dysfunction which is mainly due to the recurrence of inflammation within the olfactory cleft. Notably, the level of eosinophils within the olfactory cleft significantly and positively correlated with the degree of olfactory dysfunction in patients with CRS both pre- and postoperatively,” he said.
Dr. Wu and colleagues conducted a prospective study to determine whether there was a link in CRS patients between preoperative superior turbinate eosinophilia and olfactory dysfunction after endoscopic sinus surgery. “We aimed to explore potential predictors of postoperative olfactory decline,” Dr. Wu said.
Overall, the investigators enrolled 78 patients with CRS in the study, where they received an olfactory assessment prior to and 3 months after endoscopic sinus surgery. The investigators used Sniffin’ Sticks (Burghardt; Wedel, Germany), a 12-item psychophysical smell test that uses everyday odors to conduct the olfactory assessment. If patients had a decrease in their threshold-discrimination-identification (TDI) score after surgery, they were determined to have olfactory deterioration. Prior to surgery, investigators measured olfactory cleft opacification using CT, with the olfactory cleft endoscopy scale used after surgery. The investigators also sampled patients’ superior turbinates at the time of surgery.
The results showed 23 of 78 patients (29.49%) had olfactory decline at 3 months after endoscopic sinus surgery. Those patients with olfactory decline had significantly higher tissue, blood eosinophil levels, and TDI scores before surgery, compared with patients with CRS who did not have any loss of smell. Patients with olfactory decline also had olfactory cleft opacification and olfactory cleft endoscopy scale scores, compared with patients who had no loss of smell after surgery.
One factor that predicted olfactory decline in these patients was an absolute count of 23.5 eosinophils per high-power field in the superior turbinate, researchers said (area under the ROC curve, 0.901). “Continuous elimination of the eosinophilic inflammation within the olfactory cleft in CRS patients with olfactory dysfunction may prevent the olfactory fluctuation after endoscopic sinus surgery,” Dr. Wu said.
Dr. Wu reports no relevant conflicts of interest.
SOURCE: Wu D et al. AAAAI. Abstract L7.