Recently Frazier et al detected SARS-CoV-2 virus in autopsy samples from middle ear and mastoid of COVID-19 deceased. Our article presents an anatomical model for the possible route by which SARS-CoV-2 may pass into the middle ear cavity and hence to the mastoid cavity. The anatomic correlation explained in this article will not only help in explaining the pathological basis of the findings presented by Frazier et al but will also imply for the precautionary measures to be taken while dealing with COVID-19 patients with otolaryngeal problems.
Introduction: Intense immunological dysregulation including immune cell lesions have been characteristically observed in severe cases of Coronavirus Disease-2019 (COVID-19), for which molecular mechanisms are least understood. A study of physiological expressions of SARS-CoV-2 host cell entry related factors in immune system components may help explain molecular mechanisms involved in COVID-19 immunopathology. Materials and Methods: Transcriptomic and proteomic expression metadata for SARS-CoV-2 host cell entry receptor ACE2 and entry associated proteases (TMPRSS2, CTSL, and FURIN) were analysed in silico across immune system components including blood lineage cells. Results: ACE2 was not-detected in any of the studied immune cell components, however, varying transcriptomic and proteomic expressions were observed, for TMPRSS2, CTSL, and FURIN. Conclusions: Non-detectable expressions of SARS-CoV-2 host cell entry receptor ACE2 in immune system components or blood lineage cells indicate it doesn’t mediate immune cell lesions in COVID-19. Alternative mechanisms need to be explored for COVID-19 immuno-pathogenesis.