Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review
Introduction: SARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins secreted by sustentacular cells in order to be processed by olfactory receptor neurons. Olfactory disorder is one of the ma...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-09-01
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| Series: | Brazilian Journal of Otorhinolaryngology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S1808869421000732 |
| _version_ | 1828419163156119552 |
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| author | Mateus Henrique de Las Casas Lima Ana Luiza Brusiquesi Cavalcante Sydney Correia Leão |
| author_facet | Mateus Henrique de Las Casas Lima Ana Luiza Brusiquesi Cavalcante Sydney Correia Leão |
| author_sort | Mateus Henrique de Las Casas Lima |
| collection | DOAJ |
| description | Introduction: SARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins secreted by sustentacular cells in order to be processed by olfactory receptor neurons. Olfactory disorder is one of the main manifestations of COVID-19, however, research is still required to clarify the mechanism involved in SARS-CoV-2 induced anosmia. Objective: This article aims to analyze current scientific evidence intended to elucidate the pathophysiological relationship between COVID-19 and the cause of olfactory disorders. Methods: Pubmed, Embase, Scopus and ScienceDirect were used to compose this article. The research was conducted on November 24th, 2020. Original articles with experimental studies in human, animal and in vitro, short communications, viewpoint, published in the English language and between 2019 and 2020 were included, all related to the pathophysiological relationship between olfactory disorders and COVID-19 infection. Results: Both human cell receptors ACE2 and TMPRSS2 are essential for the SARS-CoV-2 entrance. These receptors are mostly present in the olfactory epithelium cells, therefore, the main hypothesis is that anosmia is caused due to damage to non-neuronal cells which, thereafter, affects the normal olfactory metabolism. Furthermore, magnetic resonance imaging studies exhibit a relationship between a reduction on the neuronal epithelium and the olfactory bulb atrophy. Damage to non-neuronal cells explains the average recovery lasting a few weeks. This injury can be exacerbated by an aggressive immune response, which leads to damage to neuronal cells and stem cells inducing a persistent anosmia. Conductive anosmia is not sufficient to explain most cases of COVID-19 induced anosmia. Conclusion: Olfactory disorders such as anosmia and hyposmia can be caused by COVID-19, the main mechanism is associated with olfactory epithelium damage, targeting predominantly non-neuronal cells. However, neuronal cells can also be affected, worsening the condition of olfactory loss. |
| first_indexed | 2024-12-10T14:49:05Z |
| format | Article |
| id | doaj.art-58f14d0ee13d401b974e5e9f4ec427b9 |
| institution | Directory Open Access Journal |
| issn | 1808-8694 |
| language | English |
| last_indexed | 2024-12-10T14:49:05Z |
| publishDate | 2022-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Brazilian Journal of Otorhinolaryngology |
| spelling | doaj.art-58f14d0ee13d401b974e5e9f4ec427b92022-12-22T01:44:29ZengElsevierBrazilian Journal of Otorhinolaryngology1808-86942022-09-01885794802Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic reviewMateus Henrique de Las Casas Lima0Ana Luiza Brusiquesi Cavalcante1Sydney Correia Leão2Corresponding author.; Universidade Federal do Vale São Francisco (UNIVASF), Paulo Afonso, BA, BrazilUniversidade Federal do Vale São Francisco (UNIVASF), Paulo Afonso, BA, BrazilUniversidade Federal do Vale São Francisco (UNIVASF), Paulo Afonso, BA, BrazilIntroduction: SARS-CoV-2 is the pathogen of COVID-19. The virus is composed of the spike, membrane and envelope. On physiological smell, odoriferous substances bind to proteins secreted by sustentacular cells in order to be processed by olfactory receptor neurons. Olfactory disorder is one of the main manifestations of COVID-19, however, research is still required to clarify the mechanism involved in SARS-CoV-2 induced anosmia. Objective: This article aims to analyze current scientific evidence intended to elucidate the pathophysiological relationship between COVID-19 and the cause of olfactory disorders. Methods: Pubmed, Embase, Scopus and ScienceDirect were used to compose this article. The research was conducted on November 24th, 2020. Original articles with experimental studies in human, animal and in vitro, short communications, viewpoint, published in the English language and between 2019 and 2020 were included, all related to the pathophysiological relationship between olfactory disorders and COVID-19 infection. Results: Both human cell receptors ACE2 and TMPRSS2 are essential for the SARS-CoV-2 entrance. These receptors are mostly present in the olfactory epithelium cells, therefore, the main hypothesis is that anosmia is caused due to damage to non-neuronal cells which, thereafter, affects the normal olfactory metabolism. Furthermore, magnetic resonance imaging studies exhibit a relationship between a reduction on the neuronal epithelium and the olfactory bulb atrophy. Damage to non-neuronal cells explains the average recovery lasting a few weeks. This injury can be exacerbated by an aggressive immune response, which leads to damage to neuronal cells and stem cells inducing a persistent anosmia. Conductive anosmia is not sufficient to explain most cases of COVID-19 induced anosmia. Conclusion: Olfactory disorders such as anosmia and hyposmia can be caused by COVID-19, the main mechanism is associated with olfactory epithelium damage, targeting predominantly non-neuronal cells. However, neuronal cells can also be affected, worsening the condition of olfactory loss.http://www.sciencedirect.com/science/article/pii/S1808869421000732SARS-CoV-2AnosmiaCOVID-19Olfaction disordersSmell |
| spellingShingle | Mateus Henrique de Las Casas Lima Ana Luiza Brusiquesi Cavalcante Sydney Correia Leão Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review Brazilian Journal of Otorhinolaryngology SARS-CoV-2 Anosmia COVID-19 Olfaction disorders Smell |
| title | Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review |
| title_full | Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review |
| title_fullStr | Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review |
| title_full_unstemmed | Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review |
| title_short | Pathophysiological relationship between COVID-19 and olfactory dysfunction: A systematic review |
| title_sort | pathophysiological relationship between covid 19 and olfactory dysfunction a systematic review |
| topic | SARS-CoV-2 Anosmia COVID-19 Olfaction disorders Smell |
| url | http://www.sciencedirect.com/science/article/pii/S1808869421000732 |
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