The role of immune checkpoint inhibitors in the development and treatment of infectious processes

Abstract

The incidence and prevalence of oncological diseases, which are the second most frequent cause of death, is steadily increasing among the population of the Russian Federation. The advances in translational medicine, including immunotherapy, have revolutionized the cancer treatment strategies. A particular breakthrough has been achieved in two areas of immunotherapy that have modernized the cancer treatment: chimeric T-cell receptors and antibodies known as immune checkpoint inhibitors, which block cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein-1 (PD-1) and ligand programmed cell death receptor (PD-L1). Immune checkpoint inhibitors enhance the immune response of the tumor and can cause adverse effects as a result of hyperactivation of T cells. In turn, immunosuppressive drugs, which are often prescribed to mitigate the side effects associated with immune checkpoint inhibitors, are a risk factor for the development of infectious processes. The purpose of this review is to analyze the possible relationships between immune checkpoint inhibitors and the risk of infection, as well as to discuss the possible benefits of immune checkpoint inhibitors as a treatment for various types of infections, including viral, parasitic and fungal infections, as well as sepsis. Although immune checkpoint inhibitors have demonstrated the ability to significantly increase the life expectancy of patients with advanced cancer, they often lead to adverse events, which often require a treatment with immunosuppressive drugs, including corticosteroids, anti-TNF and other biological agents. The overall effect of immune checkpoint inhibitors on human infections remains poorly understood. Further research is needed to understand the basic mechanisms of the immunological effects of immune checkpoint inhibitors on various types of infections, since in some cases such effects may be beneficial.