Upper Airway Inflammation and Olfaction: Mechanisms of Loss and Recovery

Cliniques universitaires Saint-Luc- Université Catholique de Louvain140 enrolled

Overview

The goal of this clinical trial is to understand the mechanisms leading to olfactory dysfunction (OD) in chronic rhinosinusitis (CRS). The main questions it aims to answer are: * Is the type 2 inflammation impacting the olfactory epithelium regeneration, leading to OD? * Does a treatment interfering with one of the major T2 inflammatory cytokines, have an impact on the mechanisms of OD in CRS? Participants will undergo olfactory testing and nasal brushing before and after 3 months of treatment.

Study Type

INTERVENTIONAL

Allocation

Purpose

BASIC_SCIENCE

Masking

NONE

Enrollment

140

Conditions

Chronic Rhinosinusitis With Nasal Polyps (CRSwNP)

Interventions

Nasal brushing of the olfactory cleft

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * At least two of the following symptoms: nasal obstruction, rhinorrhoea, smell loss, facial pain for 12 weeks. * Endoscopic visualisation of bilateral sinonasal polyps * SSI (TDI) \< 30.75 and decreased sense of smell subjectively * Eosinophilia \> 300/μl of blood Ku/l * On a stable nasal steroid treatment for at least 4 weeks Exclusion Criteria: * Active smoking * Primary and secondary immune deficiencies * Ciliary diseases (cystic fibrosis, primary ciliary diskinesia) * History of or current nasal malignancies * \< 18 years and \> 70 years * Patients unable to express consent * Use of systemic corticosteroids for \< 4 weeks before visit 1 • Use of systemic or local antibiotics for \< 4 weeks before visit 1

Outcomes

Primary Outcomes

Genetic profile comparison after single-cell RNA sequencing

The primary objective of this study is to compare the genetic profile of the olfactory epithelium from T2 CRSwNP patients harvested with a nasal brush, to the olfactory epithelium from healthy controls (HC) by means of RNA sequencing.

Time frame: Through study completion, an average of 2 years

Secondary Outcomes

Functional characterization of olfactory epithelium

The secondary objectives are to characterize the OE of T2 CRSwNP patients in a functional way by means of immunocytochemistry (ICC), calcium imaging, and proliferation assays, and to compare the results with healthy controls, patients with non-inflammatory OD and non-T2 CRSsNP.