Not all Patients with Severe/Critical COVID-19 Pneumonia Benefit from Tocilizumab

Objective: To determine serum IL-6 levels predictive of death during hospitalization for severe COVID-19 pneumonia, to rationalize treatment in resource-limited settings. Study Design: Prospective longitudinal study. Place and Duration of Study: Combined Military Hospital, Peshawar Pakistan from Aug to Sep 2021. Methodology: Patients with severe COVID-19 pneumonia, confirmed by a positive SARS-CoV-2 polymerase chain reaction, who received Tocilizumab between August 2020 and July 2021 were included. Patients with negative polymerase chain reaction for SARS-CoV-2, incomplete data, and those admitted before August 2020 were excluded. Paper medical records of eligible patients were scrutinized to record serum C-reactive protein, ferritin, procalcitonin, and interleukin-6 levels within the 24 hours preceding Tocilizumab administration (one or two doses left at the discretion of the treating physician). In-hospital mortality or discharge status was also noted. Results: Out of 88 patients aged 59.21±14.10 years, 54(61.36%) were males. Twenty-five (28.41%) patients died in the hospital. Area under ROC curve for mortality associated with interleukin-6 levels was 0.719(95% confidence interval 0.603, 0.836; p=0.001). Serum interleukin-6 levels ≥60.28 pg/ml or greater had a sensitivity of 68.00% and specificity of 63.49% for predicting death in hospital. Two doses of Tocilizumab were required in 78(88.64%) patients, and the mortality rate was not different from those receiving only one dose. Conclusion: Tocilizumab should preferably be avoided in patients with serum interleukin-6 levels ≥10 times the normal.