New Decade, Old Debate: Blocking the Cytokine Pathways in Infection-Induced Cytokine Cascade

OBJECTIVES: Our understanding of the immunopathogenesis of coronavirus disease 2019 is evolving; however, a “cytokine storm” has been implicated. Ongoing clinical trials are evaluating the value of anticytokine therapies to treat patients with coronavirus disease 2019. This review summarizes the existing literature evaluating the efficacy and safety of anticytokine therapy to tackle the dysregulated immune response to infectious pathogens, discusses potential reasons for failure, applicability to coronavirus disease 2019, and future direction. DATA SOURCES: Medline, PubMed, ClinicalTrials.gov, and media reports. STUDY SELECTION: The studies were included by author consensus. DATA EXTRACTION: Data were selected for inclusion after reviewing each study by author consensus. DATA SYNTHESIS: “Cytokine storm” is a nonspecific term, encompassing systemic inflammatory response to infectious pathogens, autoimmune conditions, cancers, trauma, and various chemotherapies. Like bacterial sepsis, viral pathogens may fuel immunopathogenesis by inducing a dysregulated autoamplifying cytokine cascade, ultimately leading to organ injury. This narrative review discusses what we know of the immune milieu of coronavirus disease 2019 versus noncoronavirus disease 2019 sepsis and/or acute respiratory distress syndrome, summarizes the existing literature on cytokine inhibitors in patients with sepsis and/or acute respiratory distress syndrome, and discusses possible reasons for recurrent failure. In doing so, it aims to assist decisions regarding the use of anticytokine therapy in patients with coronavirus disease 2019, as many regions of the world confront the second wave of the pandemic. CONCLUSIONS: As ongoing clinical trials determine the efficacy and safety of anticytokine therapy in patients with coronavirus disease 2019, clinicians should uphold caution when incorporating it into treatment protocols, while maintaining focus on established evidence-based practices and the mantra of “less is more.”