Study of the Pathogenesis of Olfactory Disorders in COVID-19

Completed

• Conditions: Sars-CoV2; Severe Acute Respiratory Syndrome; Coronavirus Infection
• Interventions: Other: Nasal swab; Other: Taste and olfactory function evaluation

• Registration Number: NCT04366934
• Lead Sponsor: Institut Pasteur

Brief Summary

This study is a case-control study to characterize the molecular and cellular anomalies of the olfactory epithelium of COVID-19 patients with isolated anosmia, by comparison with the olfactory epithelium of non-infected subjects.

Detailed Description

Olfactory and taste dysfunctions are common and early onset in COVID-19, especially in pauci symptomatic patients, and may be the main clinical manifestations of the infection. Olfactory dysfunction could result from infection of the olfactory system by SARS-CoV-2 or from inflammation induced by the virus. While the recent development of COVID-19 pulmonary lesion research has revealed a viral, inflammatory and vascular origin, factors that cause olfactory disorders in COVID-19 are just beginning.

Acute anosmia observed in some patients with COVID-19 could result from:

* the direct infection of olfactory sensory neurons or neural stem cells of the olfactory mucosa,

* an underlying inflammation of the olfactory mucosa, leading to possible neurodegeneration of olfactory sensory neurons, and neural stem cells of the olfactory mucosa, by analogy with the respiratory viruses responsible for chronic rhinosinusitis.

It is therefore necessary to conduct a virological, cellular, immunological and inflammatory study of the olfactory epithelium from COVID-19 patients with isolated anosmia to identify the origin of these olfactory disorders.

This study is a case-control study to characterize the molecular and cellular anomalies of the olfactory epithelium of COVID-19 patients with isolated anosmia, by comparison with the olfactory epithelium of non-infected subjects.

Following measures will be performed at inclusion :

* Taste and olfactory function evaluation by a self-questionnaire taste and smell survey (TTS) and a visual analogue scale (VAS)

* Nasal swab sampling for collection of epithelium cells and olfactory mucus.

Study Timeline

• Study First Submitted: 2020-04-22
• Study First Submitted QC: 2020-04-27
• Study First Posted: 2020-04-29
• Study Start: 2020-05-04
• Primary Completion: 2020-10-29
• Study Completion: 2020-10-29
• Status Verified: 2021-01
• Last Update Submitted: 2021-01-28
• Last Update Posted: 2021-01-29

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 26

Inclusion Criteria

COVID-19 patients

• Age > 18 years
• Subject consulting in the context of the COVID-19 screening care for a suspected SARS-CoV-2 infection

Controls

• Age > 18 years
• Subject consulting in the ear, nose and throat department with no biologically confirmed COVID-19 or suspected COVID-19 in the past 8 weeks, and no symptoms suggestive of COVID-19 or another respiratory disease and therefore no recent anosmia or ageusia

Exclusion Criteria (both COVID-19 patients and controls):

• Refusal or contraindication to nasal swab
• Presence of nasal sinus pathology

Exclusion Criteria

Not provided

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
COVID-19 patients	Taste and olfactory function evaluation	Subject consulting in the Lariboisière hospital (Paris) in the context of the COVID-19 screening care for a suspected SARS-CoV-2 infection
Control subjects	Nasal swab	Subject consulting in the ear, nose and throat department at the Lariboisière hospital (Paris) with no biologically confirmed COVID-19 or suspected COVID-19 in the past 8 weeks, and no symptoms suggestive of COVID-19 or another respiratory disease and therefore no recent anosmia or ageusia
COVID-19 patients	Nasal swab	Subject consulting in the Lariboisière hospital (Paris) in the context of the COVID-19 screening care for a suspected SARS-CoV-2 infection
Control subjects	Taste and olfactory function evaluation	Subject consulting in the ear, nose and throat department at the Lariboisière hospital (Paris) with no biologically confirmed COVID-19 or suspected COVID-19 in the past 8 weeks, and no symptoms suggestive of COVID-19 or another respiratory disease and therefore no recent anosmia or ageusia

Primary Outcome Measures

Name	Time	Method
Molecular and cellular defects in olfactory epithelium	30 months	Ratio of olfactory sensory cells in the nasal cytological sample

Secondary Outcome Measures

Name	Time	Method
Biological mechanisms involved in the pathogenesis of the disease	30 months	Multiple measurements will be analyzed to characterize the immune and inflamatory status of the olfactory mucosa (presence of infiltrated immune cells, activation state of the immune cells in the epithelium, cytokine and interleukin level)
Epidemiological characteristics	30 months	Demographic variables (sex, age, blood type), risk factors (tobacco, overweight, diabetes, rhinosinusitis disease, respiratory allergy)
Olfactory and taste dysfunction	30 months	Visual analogue scale (VAS) (units from 0 normal perception to 100 no perception)

Trial Locations

Locations (2)

Hôpital Lariboisière, Service ORL; 🇫🇷 Paris, France

Hôpital Lariboisière, Policlinique; 🇫🇷 Paris, France