The interleukin network in sepsis: from cytokine storm to clinical applications

Background and Objectives: Despite major advances in medical science and critical care, sepsis remains a leading cause of morbidity and mortality worldwide: it arises from dysregulated host response to infections and may culminate in organ dysfunction. A hallmark of its pathogenesis is the cytokine storm, in which interleukins (ILs) serve as central mediators of both protective and deleterious immune responses. This review summarizes the current knowledge on the role of ILs in sepsis, emphasizing their potential as biomarkers and therapeutic targets. Material and Methods: We analyzed recent clinical and experimental studies focusing on the most studied ILs—including IL-1, IL-6, IL-10, IL-8, IL-12, IL-18, and IL-17—in the pathophysiology of sepsis. Attention was given to mechanistic insights, prognostic significance, and therapeutic strategies targeting IL pathways. Results: IL-1 and IL-6 emerged as key pro-inflammatory mediators, amplifying vascular permeability, coagulation activation, and shock, with IL-6 validated as a robust prognostic biomarker. IL-10 was identified as a pivotal anti-inflammatory cytokine, limiting tissue injury but fostering immunosuppression and secondary infections. Other ILs, such as IL-8, IL-12, IL-18, and IL-17, contributed to neutrophil recruitment, Th1/Th17 activation, organ-specific injury, and sepsis susceptibility. Therapeutic interventions targeting ILs, including the IL-1 receptor antagonist anakinra and IL-6 receptor blockade with tocilizumab, have shown promise in selected patient subgroups. Conclusions: ILs are central to the immunopathology of sepsis, acting both as drivers of hyperinflammation and mediators of immunosuppression. Their dual role underscores the relevance of ILs as diagnostic and prognostic biomarkers, as well as context-dependent therapeutic targets. Future approaches should prioritize precision immunomodulation aligned with the principles of personalized medicine to improve clinical outcomes in sepsis.