Immune disorders in sepsis and their treatment as a significant problem of modern intensive care

Despite the great advances in the treatment of sepsis over the past 20 years, sepsis remains the main cause of death in intensive care units. In the context of new possibilities of treating sepsis, a comprehensive response of the immune system to the infection, immunosuppression, in particular, has in recent years gained considerable interest. There is vast evidence pointing to the correlation between comorbid immunosuppression and an increased risk of recurrent infections and death. Immune disorders may impact the clinical course of sepsis. This applies in particular to patients with deteriorated clinical response to infections. They usually suffer from comorbidities and conditions accompanied by immunosuppression. Sepsis disrupts innate and adaptive immunity. The key to diagnose the immune disorders in sepsis and undertake targeted immunomodulatory therapy is to define the right biomarkers and laboratory methods, which permit prompt "bedside" diagnosis. Flow cytometry is a laboratory tool that meets these criteria. Two therapeutic methods are currently being suggested to restore the immune homeostasis of sepsis patients. Excessive inflammatory response may be controlled through extracorporeal blood purification techniques, in large part derived from renal replacement therapy. These are such techniques as high-volume haemofiltration, cascade haemofiltration, plasma exchange, coupled plasma filtration and adsorption, high-absorption membranes, high cut-off membranes. The main task of theses techniques is the selective elimination of middle molecular weight molecules, such as cytokines. Pharmacotherapy with the use of such immunostimulants as interleukin 7, granulocyte-macrophage colony-stimulating factor, interferon gamma, PD-1, PD-L1 and CTLA-4 antagonists, intravenous immunoglobulins may help fight immunosuppressive immune disorders.