Patt Yonatan Shneor, Fisher Lior, David Paula, Bergwerk Moriah, Shoenfeld Yehuda
Zabludowicz Center for Autoimmune Diseases, Sheba Medical Center, Tel Hashomer, Ramat Gan 5265601, Israel.
Department of Medicine 'B', Sheba Medical Center, Tel Hashomer, Ramat Gan 5262100, Israel.
Diagnostics (Basel). 2023 Feb 9;13(4):641. doi: 10.3390/diagnostics13040641.
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.
嗅觉是日常使用的一种关键感官。因此，嗅觉受损或嗅觉丧失可能会导致生活质量下降。全身性疾病和特定的自身免疫性疾病会损害嗅觉功能；其中包括系统性红斑狼疮、干燥综合征和类风湿性关节炎。嗅觉过程与免疫系统之间的相互作用导致了这种现象。除了自身免疫性疾病外，在最近的新冠疫情中，嗅觉丧失也被描述为一种常见的感染症状。然而，嗅觉丧失在感染奥密克戎的患者中明显不那么常见。已经提出了几种理论来解释这一现象。一种可能性是，奥密克戎变种优先通过内吞作用进入宿主细胞，而不是通过浆细胞膜融合。这种内体途径较少依赖于在嗅觉上皮表达的跨膜丝氨酸蛋白酶2（TMPRSS2）的激活。因此，奥密克戎变种穿透嗅觉上皮的效率可能会降低，导致嗅觉丧失的发生率较低。此外，已知嗅觉变化与炎症状况有关。奥密克戎变种引发的自身免疫和炎症反应较弱，据信这会降低嗅觉丧失的可能性。这篇综述阐述了自身免疫性和新冠奥密克戎相关嗅觉丧失的共性和差异。
