Severe COVID-19 Pneumonia Treated with Tocilizumab in a Pakistani Population: Variables Impacting Outcomes

Abstract

Background: The association of severity of COVID-19 with raised Interleukin-6 (IL-6) levels led to Tocilizumab (TCZ) approval for treatment based on its IL-6 inhibiting mechanism of action. Treatment outcomes reported have been variable, with little data from Pakistan. Objective: To identify demographic, clinical, and laboratory variables impacting outcomes (recovery or death) of patients with severe COVID-19 pneumonia treated with intravenous tocilizumab in a Pakistani hospital setting. Methodology: A single-center, retrospective, descriptive case series was conducted at the National Hospital Postgraduate Training and Medical Centre, Lahore from April to December 2020. Severe COVID-19 pneumonia (oxygen saturation below 90%, chest HRCT severity score more than 15) administered intravenous tocilizumab was included. Not fulfilling the above inclusion criteria. Data was analysed to identify significant differences between expired patients and those discharged after recovery. Results: Forty-nine patients were admitted to intensive care/ high dependency units (ICU/HDU) with severe COVID pneumonia and treated with intravenous tocilizumab during the study period. The mean age was 61 years, with male predominance. Of the 49 patients, 23 expired. In the expired group lactate dehydrogenase (LDH), and neutrophil to lymphocyte ratio (NLR) were significantly higher throughout the admission course, while D-Dimers plus the last available white blood cell (WBC) count, were significantly higher post-TCZ, as was odds of co-infection evidenced by positive blood cultures. Conclusion: Mortality correlated with increased inflammatory markers LDH and NLR ratio. Post TCZ raised D-Dimers may be indicators of fibrin microthrombi and prophylactic anticoagulation with TCZ may benefit such patients. High odds of secondary bacterial infection post-TCZ had a significant negative impact on recovery.