ABSTRACT
Here, we review thematic publications in available literature sources of the databases PubMed, Scopus, Web of Science, eLibrary, 49 of which were dated of the years 1997-2022. Analysis of such reports is aimed at assessing features of cytokine storm-induced hyperinflammatory reaction with signs of immunosuppression accompanied by pronounced lymphopenia and lowered count of CD4(+)T helpers during severe COVID-19. The prognostic factor for unfavorable prognosis was based on the marker of systemic inflammatory reaction correlating with the disease severity - the soluble IL-2 receptor as well as the neutrophil-to-lymphocyte ratio and the lymphocyte subset imbalance. An immunosuppressive therapy of severe forms of COVID-19, aimed at weakening the inflammatory response, exacerbates immune dysfunction by suppressing the T cell function, mainly due to Th1 lymphocytes involved in recognizing and eliminating intracellular pathogens particularly viruses. Upon that, cell-mediated immunity becomes compromised that relies on cytotoxic T-lymphocytes, natural killer cells and macrophages. Timely and targeted immunocorrection is required to prevent or reduce the immunosuppression that accompanies a severe disease course and leads to serious and prolonged complications, as well as to association of secondary infections. In fight against the cytokine storm, it is important not to miss a time point of developing immunosuppressive condition that transitions into immunoparalysis as follows from recent publications covering the tactics of treating immune-mediated complications of coronavirus infection. The review discusses opportunities for immunosuppressive therapy along with glucocorticosteroids and monoclonal antibodies blocking IL-6 or cognate receptors. Studies using mesenchymal stem cells (MSCs) to reduce systemic inflammatory response at COVID-19 are outlined in the review. The use of antigen-specific Treg and their combinations with antagonists of tumor necrosis factor-alpha (TNF alpha), interferon-gamma (IFN gamma) as well as low-dose IL-2 in patients with SARS-CoV-2 infection were analyzed. The prognostic perspectives for CAR-T cells and CAR-NK cells technology have been considered as novel therapeutic approaches aimed at "training" effector cells to recognize the surface SARS-CoV-2 virus spike-like (S) protein. The feasibility of a therapeutic approach is also emphasized by comparatively analyzed of efficacy of using IL-7 or IL-15 during lymphopenia in patients with COVID-19. Here, side effects complicating immunocorrection come to the fore. Critical evaluation of corrected immunosuppressive conditions in patients with COVID-19 in the post-COVID-19 period by using low-dose IL-2 therapy revealed its ability to repair cellular immune response. As a result, a low-dose IL-2 therapy is recommended as a cytokine replacement therapy in such patients with COVID-19 during hyper-to-hypo-inflammatory phase transition in immune response.