[Primary observational study of tocilizumab in children with severe acute necrotizing encephalopathy]

Objective: To investigate the efficacy and safety of tocilizumab in the treatment of critically ill children with acute necrotizing encephalopathy (ANE). Methods: It is a retrospective cohort study. The children with ANE admitted to the pediatric intensive care unit of 4 Chinese tertiary hospitals from December 2022 to November 2023 were divided into conventional treatment group and tocilizumab group, and the comparison between groups was performed by using Mann - Whitney U test or Chi-square test. Results: Among 21 cases of severe ANE, there were 11 males with the onset age of 65 (27, 113) months. The duration from onset to PICU admission was 2 (1, 2) days. There were 13 cases of ultra-high fever (greater than 40 ℃), including 18 cases of convulsions, and 19 cases with a GCS score of less than 8 points. The causative agent was novel coronavirus Omicron in 7 cases and influenza A in 14 cases. All cases had central respiratory failure requiring mechanical ventilation. Of the 21 cases, 18 were shock, 15 were coagulopathy, 10 were kidney injury and 13 were liver dysfunction. Of these hospitalized patients, 8 children with ANE were treated with tocilizumab. Eight cases received continuous blood purification (CBP) treatment, 5 of them were combined with plasmapheresis. Serum cytokine levels were elevated in 21 children with ANE, including (interleukin, IL)-6 and IL-8 (61 (22, 1 513) and 68 (5, 296) ng/L). There were 14 cases (67%) deaths, including 11 cases in the conventional treatment group and 3 cases in the tocilizumab group. There was no significant difference in the mortality rate between the two groups (P=0.056). Tocilizumab-related rash or other adverse events were not observed. Conclusions: The motality of critically ill ANE patients was high. The combination of Tocilizumab with conventional treatment did not reduce the motality of severe ANE patients, and no adverse reactions of tocilizumab were observed.