Tocilizumab Therapy in Gram-Positive and Gram-Negative Pediatric Septic Shock: A Comparative Pilot Study

Background: Elevated interleukin-6 (IL-6) is strongly associated with disease severity and mortality in pediatric septic shock. This study investigated whether adjunctive tocilizumab, a humanized anti-IL-6 receptor antibody, improves clinical outcomes in children with Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB) septic shock. Methods: This retrospective cohort study included 58 children with septic shock (32 receiving adjunctive tocilizumab and 26 historical controls). We evaluated mortality rates, shock duration, and intensive care unit (ICU) length of stay, with further stratification by pathogen type. Results: Baseline demographics and initial disease severity were comparable between the groups. Tocilizumab administration was associated with a significantly shorter median shock duration (84 vs. 240 hours; p < 0.001), reduced ICU stay (6 vs. 14 days; p = 0.002), and lower mortality (18.7% vs. 46.1%; p = 0.02) compared to controls. In subgroup analyses, tocilizumab significantly decreased mortality in GNB sepsis (23.8% vs. 56.2%; p = 0.04) and improved 28-day survival (log-rank p = 0.023). Notably, although tocilizumab-treated GNB patients had markedly higher initial IL-6 levels (median 7531 vs. 294 pg/mL; p = 0.014) and PRISM III scores than GPB patients, post-treatment mortality did not differ significantly between these cohorts (23.8% vs. 9.0%; p = 0.31). Conclusions: Adjunctive tocilizumab is associated with improved survival and shortened shock duration in pediatric septic shock. Targeted IL-6 blockade effectively neutralizes the hyperinflammatory surge, narrowing the clinical outcome gap typically driven by severe GNB infections.