Higher levels of IL‐6 early after tocilizumab distinguish survivors from non‐survivors in COVID‐19 pneumonia: a possible indication for deeper targeting IL‐6

Quartuccio, Luca; Sonaglia, Arianna; Pecori, Davide; Peghin, Maddalena; Fabris, Martina; Tascini, Carlo; De Vita, Salvatore

INTRODUCTION: The most serious COVID‐19 deriving from severe acute respiratory syndrome coronavirus 2 causes cytokine release storm and it is associated with worse outcomes. In COVID‐19 patients, Interleukin (IL)‐6 levels are significantly elevated. Blocking IL‐6 preliminary resulted in the improvement of this hyperinflammatory state. It is unknown which patients could require higher doses of tocilizumab to get out of the cytokine storm. MATERIALS AND METHODS: Twenty‐four patients affected by COVID‐19 pneumonia were included. All the patients underwent tocilizumab 8 mg/kg intravenously and were tested for serum IL‐6 24‐48 hours before and 12‐48 hours after tocilizumab infusion. Comparisons between survivors and non‐survivors were performed. RESULTS: Eighteen patients were discharged, while six patients died, with no clinical or laboratory differences between the two groups at baseline. IL‐6 was not different at baseline (p=0.41), while 24‐48h post‐tocilizumab IL‐6 serum levels were significantly higher in non‐survivors than in survivors [2398.5 (430.5‐9372) pg/mL vs 290.5 (58.5‐1305.5) pg/mL, p=0.022)]. Serum IL‐6 post‐tocilizumab showed a good predictive ability to discriminate survivors from non‐survivors (AUC 0.815 95%CI 0.63‐0.99, p=0.02). CONCLUSION: Repeated measurement of serum level of IL‐6 early after tocilizumab may distinguish non‐survivors from survivors and support the choice of deeper targeting IL‐6 in COVID‐19 pneumonia. This article is protected by copyright. All rights reserved.