ABSTRACT
The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2), was declared a global pandemic in March 2020 and resulted in more than 6 million deaths worldwide to date. Although several vaccines were produced against COVID-19 and many therapeutic protocols were developed for the management of this respiratory infection, COVID-19 pandemic has still remained an unresolved problem with the emergence of new variants of SARS-CoV-2, especially vaccine-resistant variants. Probably, end of the COVID-19 needs effective and certain treatments which were undiscovered to date. According to immunomodulatory and regenerative properties, mesenchymal stem cells (MSCs) have been considered a therapeutic approach to suppressing cytokine storm caused by SARS-CoV-2 and the treatmet of severe COVID-19. Following intravenous (IV) infusion of MSCs, cells entrap in the lung, guard alveolar epithelial cells, suppress pulmonary fibrosis and improve lung dysfunction. The human menstrual blood-derived stem cells (hMenSCs) as a novel source of MSCs are collected by noninvasive, painless, and easy way without ethical issues. MenScs are an abundant and cheap source with a high proliferation rate and differentiation ability into multiple cell lineages. Regarding immunomodulatory and anti-inflammatory properties, regenerative ability and low immunogenicity, these cells exhibit great potential in the treatment of various diseases. Some clinical trial studies have begun using MenSCs to treat severe COVID-19. According to these trials, MenSC therapy showed promising and encouraging results in treating severe COVID-19. We reviewed published clinical trials and summarized the effects of MenSC therapy on severe COVID-19 with a focus on clinical and laboratory data, immune and inflammatory factors and concluded the advantages and possible risks of this procedure.