Possible Unexplored Aspects of Covid-19 Pathogenesis: The Role of Carboxypeptidase A3

Background: Coronavirus disease 2019 (COVID-19) is a contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). First reported in 2019, it has already caused more than 500 million cases worldwide. The problem of COVID-19 treatment is still relevant, and it is necessary to study in detail the pathogenesis of COVID-19, including the involvement of different immune cells and their mediators. There is increasing evidence of the important role of mast cells (MCs) and their specific protease carooxypeptidase A3 (CPA3) in the pathogenesis of COVID-19. MCs chymase and tryptase are already well studied, while CPA3 is of growing interest. The aim of this review is to study the CPA3 features and mechanisms of its participation in the pathogenesis of COVID-19 and some other infectious and non-infectious diseases. Methods and Results: A literature search was carried out using Scopus, Web of Science, PubMed, Medlin, and E-Library databases. Of the158 articles analyzed, 33 were included in the review. CPA3, expressed by MCs in various organs, including human lungs, plays a role in the pathogenesis of COVID-19 by indirectly causing pulmonary fibrosis, associating with levels of inflammatory cytokines and chemokines, and severity of COVID-19.