Desfechos clínicos de pacientes com COVID-19 grave que fizeram uso de tocilizumabe (Anti-IL-6): coorte retrospectiva

Abstract

The rapid expansion of the COVID-19 acute respiratory pandemic has impacted all areas of daily life, with vaccination being the main intervention to slow the spread of the disease. Given the urgent circumstances imposed by the pandemic, many efforts were directed toward ensuring patients' access to the most effective and lowest-cost treatment. Accordingly, drug repositioning became the most widely used approach for treating COVID-19, making it essential to analyze and compare the different strategies employed. Considering that the State of Amazonas was one of the regions most affected by the COVID-19 pandemic worldwide, having already experienced two growth waves in 2020 and 2021, this study aimed to evaluate the influence of tocilizumab on all-cause mortality in patients with severe COVID-19 admitted to a private hospital in Manaus, Amazonas, Brazil. For this purpose, an observational, longitudinal cohort study with a retrospective arm was conducted as part of the FOLLOW COVID-19 project, which included data from adult patients hospitalized with severe COVID-19 between March 2020 and March 2022 in a private hospital in southern Manaus. A total of 1,155 patients were studied, with the following socioeconomic and clinical characteristics: mean illness duration of 9.01 (± 5.96) days; mean age of 53 (± 15.4) years; mean length of stay of 12.5 (± 14.9) days; 728 (63%) male patients; and 630 (54.5%) patients with comorbidities. Sample data were described using absolute (N) and relative (%) frequencies, with a significance level of p < 0.05 and the Mann-Whitney test used for comparisons. Clinical variables associated with death were assessed by multivariate Multiple Logistic Regression analysis. Predictor variables regarding the influence of tocilizumab on ventilator-free days were analyzed by Multivariate Linear Regression, with results reported as mean ± standard deviation (SD), median, maximum, and minimum. The predictor variables considered were: age over 60 years, presence of comorbidities, male sex, corticosteroid therapy, and tocilizumab use. Fisher's exact test was used to assess the dependence between two nominal categorical variables, and Pearson's correlation coefficient was used to evaluate the degree of relationship between two quantitative variables. The significance level was set at 0.05. The study showed that tocilizumab increased the number of ventilator-free days by 3.35 times, and that the association between tocilizumab and corticosteroid therapy showed no statistically significant relationship with mortality. In contrast, age over 60 years and the presence of comorbidities were strongly associated with death from severe COVID-19. Thus, this study corroborates previous findings in the literature on the efficacy of tocilizumab in treating severe COVID-19 patients when combined with corticosteroids, while also contributing novel data on patients from Amazonas — a region severely affected by the pandemic yet still underrepresented in this line of research. Overall, this study reaffirms tocilizumab as a valid therapeutic alternative for severe COVID-19, maintaining its efficacy across different populations.