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.
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.
Other: Nasal swab
Nasal swab
Other: Taste and olfactory function evaluation
Taste and olfactory function evaluation
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
Hôpital Lariboisière, Policlinique
Paris, France
Hôpital Lariboisière, Service ORL
Paris, France
Françoise LAZARINI, PhD, Study Director
Institut Pasteur