Autoimmunity, COVID-19 Omicron Variant, and Olfactory Dysfunction: A Literature Review

Bibliographic Details
Title: Autoimmunity, COVID-19 Omicron Variant, and Olfactory Dysfunction: A Literature Review
Authors: Yonatan Shneor Patt, Lior Fisher, Paula David, Moriah Bergwerk, Yehuda Shoenfeld
Source: Diagnostics, Vol 13, Iss 4, p 641 (2023)
Publisher Information: MDPI AG, 2023.
Publication Year: 2023
Collection: LCC:Medicine (General)
Subject Terms: SARS-CoV-2, COVID-19, Omicron variant, smell, olfactory dysfunction, anosmia, Medicine (General), R5-920
More Details: Smelling is a critical sense utilized daily. Consequently, smelling impairment or anosmia may lead to a reduction in life quality. Systemic diseases and particular autoimmune conditions can impair olfactory function; among others are Systemic Lupus Erythematosus, Sjögren Syndrome, and Rheumatoid Arthritis. Interactions between the olfactory process and the immune systems cause this phenomenon. Alongside autoimmune conditions, in the recent COVID-19 pandemic, anosmia was also described as a prevalent infection symptom. Nevertheless, the occurrence of anosmia is significantly less common in Omicron-infected patients. Several theories have been proposed to explain this phenomenon. One possibility is that the Omicron variant preferentially enters host cells via endocytosis, rather than plasma cell membrane fusion. This endosomal pathway is less dependent on the activation of Transmembrane serine protease 2 (TMPRSS2), expressed at the olfactory epithelium. As a result, the Omicron variant may have reduced efficiency in penetrating the olfactory epithelium, leading to a lower prevalence of anosmia. Furthermore, olfactory changes are known to be associated with inflammatory conditions. The Omicron variant elicits a less robust autoimmune and inflammatory response, believed to reduce the probability of anosmia. This review elaborates on the commonalities and differences in autoimmune and COVID-19 omicron-associated anosmia.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2075-4418
Relation: https://www.mdpi.com/2075-4418/13/4/641; https://doaj.org/toc/2075-4418
DOI: 10.3390/diagnostics13040641
Access URL: https://doaj.org/article/4102c1631b5f4dd2a4035d8d1e4da155
Accession Number: edsdoj.4102c1631b5f4dd2a4035d8d1e4da155
Database: Directory of Open Access Journals
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More Details
ISSN:20754418
DOI:10.3390/diagnostics13040641
Published in:Diagnostics
Language:English