Department of Dermatology, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke 329-0498, Tochigi, Japan.
Int J Mol Sci. 2022 Oct 14;23(20):12260. doi: 10.3390/ijms232012260.
COVID-19 is a recently emerged viral infection worldwide. SARS-CoV-2, the causative virus, is believed to have emerged from bat coronaviruses, probably through host conversion. The bat coronavirus which has the highest gene homology to SARS-CoV-2 specifically infects deep forest bats in China whose habitat extends through the Middle East to Southern Europe. Host conversion might have occurred due to the deforestation by humans exposing wild bats to the environment they had never encountered before. SARS-CoV-2 infects cells through two mechanisms: through its receptor ACE2 with the help of enzyme TMPRSS and through membrane fusion with the help of elastases in the inflammatory condition. Obesity, hypertension, diabetes mellitus, and pulmonary diseases cause poor prognosis of COVID-19. Aging is another factor promoting poor prognosis. These diseases and aging cause low-level and persistent inflammation in humans, which can promote poor prognosis of COVID-19. Psoriasis and atopic dermatitis are the major inflammatory skin diseases. These inflammatory skin conditions, however, do not seem to cause poor prognosis for COVID-19 based on the epidemiological data accumulated so far. These mechanisms need to be elucidated.
新型冠状病毒肺炎（COVID-19）是一种新出现的全球病毒性传染病。目前认为，引发 COVID-19 的病原体 SARS-CoV-2 可能来源于蝙蝠冠状病毒，通过宿主转换而出现。与 SARS-CoV-2 基因同源性最高的蝙蝠冠状病毒，主要感染中国的深山蝙蝠，其栖息地从中东延伸到南欧。人类砍伐森林，使野生蝙蝠暴露于前所未有的环境中，可能导致了宿主转换。SARS-CoV-2 通过两种机制感染细胞：一种是通过其受体 ACE2 并在酶 TMPRSS 的帮助下，另一种是在炎症条件下通过弹性蛋白酶帮助膜融合。肥胖、高血压、糖尿病和肺部疾病导致 COVID-19 的预后不良。衰老也是导致预后不良的另一个因素。这些疾病和衰老导致人类发生低度和持续的炎症，从而可能导致 COVID-19 的预后不良。银屑病和特应性皮炎是主要的炎症性皮肤病。然而，根据迄今为止积累的流行病学数据，这些炎症性皮肤疾病似乎不会导致 COVID-19 的预后不良。这些机制需要进一步阐明。
