NCT06482138

Brief Summary

Investigation of the mechanisms of persistent SARS-CoV-2 associated olfactory dysfunction (OD) in patients with well-documented olfactory function. The investigators plan to collect olfactory cleft biopsies and cytobrushes in COVID-19 patients and controls.

Trial Health

80
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
240

participants targeted

Target at P50-P75 for not_applicable covid19

Timeline
8mo left

Started Jan 2024

Longer than P75 for not_applicable covid19

Geographic Reach
3 countries

7 active sites

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress78%
Jan 2024Dec 2026

Study Start

First participant enrolled

January 24, 2024

Completed
26 days until next milestone

First Submitted

Initial submission to the registry

February 19, 2024

Completed
4 months until next milestone

First Posted

Study publicly available on registry

July 1, 2024

Completed
2.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2026

Expected
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2026

Last Updated

May 6, 2026

Status Verified

April 1, 2026

Enrollment Period

2.9 years

First QC Date

February 19, 2024

Last Update Submit

April 30, 2026

Conditions

Covid19Olfactory Dysfunction

Keywords

Olfactory DysfunctionCOVID-19SARS-CoV-2AnosmiaHyposmia

Outcome Measures

Primary Outcomes (2)

  • Analysis of olfactory cleft biopsies

    Morphological and histomolecular differences between OD and control patients * Evaluating tissue pathology: * Metaplasia * hypertrophy * aberrant scar formation * apoptosis * presence of inflammatory cells \[H\&E, CD68 and CD3 stainings, RNAscope\] * Presence of SARS-CoV-2 RNA * Percentage of OSNs versus sustentacular cells; maturation of OSNs

    From enrollment of 1 patient until analyzed, 1 month

  • Analysis of olfactory cytobrushes

    Morphological and histomolecular differences between OD and control patients * Evaluating tissue pathology: * Metaplasia * hypertrophy * aberrant scar formation * apoptosis * presence of inflammatory cells \[H\&E, CD68 and CD3 stainings, RNAscope\] * Presence of SARS-CoV-2 RNA * In the olfactory epithelium: percentage of OSNs versus sustentacular cells; maturation of OSNs

    From enrollment of 1 patient until analyzed, 1 month

Study Arms (2)

Control

OTHER

Biopsy and cytobrush during a scheduled structural intervention in general anesthesia

Procedure: Biopsy and Cytobrush

Olfactory Dysfunction

OTHER

Biopsy and cytobrush during consultation in local anesthesia

Procedure: Biopsy and Cytobrush

Interventions

Biopsy and CytobrushPROCEDURE

Collection of olfactory cleft biopsies and cytobrushes

ControlOlfactory Dysfunction

Eligibility Criteria

Age18 Years - 70 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Olfactory Dysfunction group: Presence of evident OD (Parosmia, Threshold-Discrimination-Identification (TDI)-score ≤24, Subjective abnormal quantitative olfactory function; measured by a visual analogue score (VAS) of smell impairment ≥5/10
  • Control group: No OD (TDI-score \>30.5.)

You may not qualify if:

  • Presence of concomitant nasal mucosal pathology that might affect olfactory function or bias the study investigations
  • Use of anticoagulation therapy
  • Allergy to local anesthetics

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (7)

Cliniques Universitaires Saint-Luc

Brussels, Brussels Capital, 1000, Belgium

RECRUITING

UZ/KU Leuven

Leuven, Vlaams-Brabant, 3000, Belgium

RECRUITING

AZ Sint-Jan Brugge

Bruges, West-Vlaanderen, 8000, Belgium

RECRUITING

University Hospital Carl Gustav Carus

Dresden, Dresden, 01307, Germany

RECRUITING

Max Planck Research Unit for Neurogenetics

Frankfurt am Main, Frankfurt, 60438, Germany

ACTIVE NOT RECRUITING

Hôpitaux Universitaires de Genève

Geneva, Canton of Geneva, 1211, Switzerland

RECRUITING

University of Zurich and University Hospital Zurich

Zurich, Canton of Zurich, 8091, Switzerland

RECRUITING

MeSH Terms

Conditions

COVID-19Anosmia

Interventions

Biopsy

Condition Hierarchy (Ancestors)

Pneumonia, ViralPneumoniaRespiratory Tract InfectionsInfectionsVirus DiseasesCoronavirus InfectionsCoronaviridae InfectionsNidovirales InfectionsRNA Virus InfectionsLung DiseasesRespiratory Tract DiseasesOlfaction DisordersSensation DisordersNeurologic ManifestationsNervous System DiseasesSigns and SymptomsPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

CytodiagnosisCytological TechniquesClinical Laboratory TechniquesDiagnostic Techniques and ProceduresDiagnosisSpecimen HandlingDiagnostic Techniques, SurgicalSurgical Procedures, OperativeInvestigative Techniques

Study Officials

  • Laura van Gerven

    UZ/KU Leuven

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Laura van Gerven

CONTACT

+3216336342laura.vangerven@uzleuven.be

Sabrina Bischoff

CONTACT

+41763655671sabrina.bischoff@uzleuven.be

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 19, 2024

First Posted

July 1, 2024

Study Start

January 24, 2024

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2026

Last Updated

May 6, 2026

Record last verified: 2026-04

Locations

DE(2)BE(3)CH(2)