Benefits of Tocilizumab in patients with a severe form of SARS-CoV-2 infection: Experience of the intensive care unit of the Mohammed VI university hospital, Oujda.

BACKGROUND

COVID-19 is a new disease that appeared in December 2019. Millions of people have been infected and died from this infection. Until today, the pathophysiology and treatment of this infection remain unknown, but a lot of studies are trying to solve the mystery. The trail of inflammation remains the most convincing, especially the Interleukin 6 (IL-6) which could play an important role in a reaction cascade leading to a cytokine storm. According to studies, although few in number, the Tociluzimab (TCZ), which is an anti-IL6, could prevent or even suppress this storm, leading to a less severe clinical state of the disease and a faster recovery. This could decrease the use of oxygen, avoid the risk of intubation and mortality.

PATIENTS AND METHODS

This single-center retrospective observational case review brought together 557 COVID-19 seriously ill patients (pulmonary involvement> 25% + SatOAA <90%) admitted to the intensive care unit of our university hospital from March 1, 2020 to February 28, 2021. They were divided into 2 groups a Tociluzimab group (TCZ group) and a Non Tociluzimab group (NON TCZ) to facilitate the comparison. The aim of the study was to compare the length of hospital stay, the use of mechanical ventilation and the mortality in the TCZ group versus the NON TCZ group.

RESULTS

The average age of our patients was 62,05 years (±13.51) and 62.61 years (±16.33) respectively in the TCZ versus NON TCZ group. 76 (76%) were men while 24 were women (24%) in the TCZ group; and there was 313 (68.49%) men and 144 (31.51%) women in the NON TCZ group. Their average BMI was 28 kg/m2 (±4.52) in the TCZ group versus 27.89 kg/m2 (±4.73) in the NON TCZ group. Among them, the TCZ group included 38 (38%) diabetic patients, 38 hypertensive (38%), 12 heart disease (12%) and 2 chronic renal failure (2%), while the NON TCZ group regrouped 35 (7.65%) diabetics, 33 (7.22%) hypertensive, 12 heart disease (2.67%), and 5 chronic renal failure (1.09%) patients. The mean time to consultation of patients was almost similar in the two groups: 8.86 (±7,28) days for TCZ and 8.83 (±7,03) days for NON TCZ group. The mean length of ICU hospital stay was 9 days (4,94) for the TCZ group and 8,75 days (4,73) for the other one. The saturation at admission was at 74.92% (10.45) for the TCZ group ranging from 40% to 92%, and at 73,56% for the NON TCZ group. Lung damage from COVID-19 was extensive in 12%, severe in 32%, and critical in 56% of TCZ group enrolled cases. Meanwhile it was extensive in 23.63%, severe in 41,35%, and critical in 35,01% of the NON TCZ group. The biological findings found average of white blood cells at 12256/12082 e/mm, lymphocytes at 761/842 e/mm, CRP at 181/199 mg/L, ferritin at 1747/528 μg/L, and fibrinogen at 6.92/6.27 g/L for the TCZ group versus NON TCZ group. Medical care was based on isolation, oxygenotherapy, azithromycin, vitamin C, zinc, vitamin D, salicylic acid, dexamethasone followed with methylprednisolone, and anticoagulation for all hospitalized patients. The TCZ group received at least 1 course of Tociluzimab dosed at 400 mg (2 patients received 2 doses and 1 patient received 3 doses). The indication of a Tociluzimab course in our department was based on a set of arguments: an increase in oxygen requirements, a progression of lesions on chest-computed tomography and an increase in inflammation markers including IL-6, CRP, ferritin, fibrinogen, and a decrease in the percentage of lymphocytes. The invasive mechanical ventilation was indicated for 4 (4%) patients in the TCZ group versus 192 (42,01%) in the NON TCZ. Among the 100 patients included in our cohort in the TCZ group, 40% died in intensive care unit and 60% had a favorable evolution with a decrease of the biological markers of inflammation. However, in the NON TCZ group, 197 (43,10%) passed away.

CONCLUSION

The use of Tociluzimab in ICU patients with severe COVID-19 pneumonia did not contribute to a significant difference in the reduction of hospital stay. However, the invasive mechanical ventilation was less needed in patients receiving Tociluzimab than the others. Moreover, there was a mortality benefit associated with the use of Tociluzimab, but only before 10 days of hospitalization.