In patients with chronic rhinosinusitis (CRS), a strong association exists between olfactory cleft mucus galectin-10 and olfactory dysfunction, according to study findings published recently in the Annals of Allergy, Asthma & Immunology.
Eosinophils may be involved in olfactory fluctuation occurring in CRS, and galectin-10 protein — which is often linked with type-2 inflammation — may be an indicator of intense eosinophil activation. Notably, more than 80% of patients with CRS present with olfactory dysfunction (OD). Investigators in China hypothesized that analysis of the olfactory cleft mucus galectin-10 levels could help to identify patients at risk of adverse olfactory events and possibly lead to future treatment therapies targeting galectin-10. They therefore chose to investigate olfactory mucosa galectin-10 and olfactory cleft mucus levels and their association with OD in CRS.
The researchers conducted a prospective study of 65 adult patients who were hospitalized from January 2021 through October 2021. The patient cohort included 50 patients with CRS hospitalized for endoscopic sinus surgery and 15 control patients without CRS hospitalized for deviated septum surgery. Superior turbinate biopsies and olfactory cleft mucus were collected from all patients and all patients underwent nasal endoscopy and computerized tomography (CT) within the week before study enrollment. Multivariable logistic regression analysis was used to analyze the predictability of galectin-10 levels in patients with OD.
Olfactory mucosa galectin-10 and olfactory cleft mucus levels in patients with CRS with OD (n=36) were significantly higher than in patients with CRS without OD (n=14) (all P <.0001). The researchers found mucus galectin-10 levels were positively correlated with tissue eosinophils (r=0.541), olfactory cleft CT scores (r=0.432), and olfactory cleft endoscopy scale (r=0.498) in patients with CRS. Mucus galectin-10 levels were negatively correlated with threshold, discrimination, and identification (TDI; r = -0.589), olfactory threshold (r = -0.522), olfactory discrimination (r = -0.488), and olfactory identification (r = -0.466) scores.
The researchers noted that mucus gaclectin-10 levels were associated with OD in patients with CRS (odds ratio=1.299; P =.008) after adjusting for comorbidities and demographics, and that levels greater than 8.975 ng/ml were the best indicator of OD in CRS.
The investigators concluded that “Olfactory cleft mucus galectin-10 is highly associated with OD in CRS.” They added that, “future studies are needed to verify that olfactory cleft mucus galectin-10 levels might be a valuable biomarker for determining biologic treatment to obtain a long-term and sustained olfactory improvement.”
Study limitations include the underpowered sample size, possible selection bias, the inability to determine how galectin-10 adds to olfactory deficits, and the inability to confirm biomarkers as prognosis predictors because galectin-10 levels were not measured after treatment.
Liu Z, Hong J, Huang X, Wu D. Olfactory cleft mucus galectin-10 predicts olfactory loss in chronic rhinosinusitis. Ann Allergy Asthma Immunol. Published online July 21, 2022. doi:10.1016/j.anai.2022.07.014