365: THE USE OF TOCILIZUMAB IN CRITICALLY ILL CHILDREN: A SINGLE PEDIATRIC CENTER EXPERIENCE

Abstract

Introduction: Tocilizumab has been demonstrated to prevent systemic inflammatory responses by inhibiting the inflammatory cytokine interleukin-6 (IL-6). Our objective was to review a single-center experience of the use of tocilizumab in critically ill children and describe its effect on inflammatory markers and platelet counts. Methods: After IRB approval, a retrospective analysis of all inpatients who received tocilizumab from July 2017 to June 2022 was performed, collecting demographic, clinical, and outcome variables. Twenty doses of tocilizumab were given to 14 patients. Chi-square or Fisher’s exact test and Wilcoxon signed-rank test were used to analyze the data. Results: The cohort was mostly male (85.7%), white (78.6%), and Hispanic (78.6%). The mean age was 124±95 months. COVID-19 pneumonia (50%) and cytokine release syndrome (CRS; 28.6%) were two common indications. The mean (range) PRISM3 risk of mortality was 7.1% (0.8-30.3%). The mean LOS and mortality rate in PICU were 50.6 days and 42.9%, respectively. The mortality rate was 0% in COVID-19, 75% in CRS, and 100% in others (p< 0.01). Multiple organ failure (MOF = >2 organ failures) was present in 50%. Individual organ failure included respiratory failure (85.7%), cardiovascular failure (42.9%), liver dysfunction (57.1%), thrombocytopenia, (50%), coagulopathy (21.4%), and acute kidney injury (21.4%). 5 of the 6 patients (83%) with inotropic use died (p=0.026). MOF was present in 71% of patients who died compared to 14% of those who survived (p=0.13). The median (IQR) values of LDH, IL6, CRP, and ferritin before tocilizumab were 1817 (1190-3100), 22.8 (10.9-400), 7.4 (2.3-34.6), and 1175 (615-4095), respectively. The median platelet count increased from 92 (24-178) to 158 (63-278) and CRP decreased from 7.4 (2.3-34.6) to 1.7 (0.5-4.6) within 3 days after tocilizumab (p< 0.001). The median vasoactive infusion score decreased from 46 (2.5-87) to 9 (2.5-46) after tocilizumab (p=0.5). Conclusions: The use of tocilizumab increased with COVID-19 pandemic. The mortality associated with the use of tocilizumab varied with underlying diagnoses and was lowest with COVID-19. Platelet count increased and CRP decreased after administration of tocilizumab. The role of tocilizumab in critically ill children with hypercytokinemia needs further evaluation.