Background and importance Levels of interleukin-6 (IL-6) in patients with coronavirus disease 2019 (COVID-19) are particularly relevant before treatment with tocilizumab. According to the protocol established in our centre, levels of IL-6 above 40 pg/mL are required to start treatment with tocilizumab. Assessing the role of dexamethasone in the evolution of IL-6 during the first hours of the patient’s hospital admission could help prevent premature use of tocilizumab.

Aim and objectives Assessing the evolution of IL-6 after the use of dexamethasone in patients diagnosed with COVID-19 and IL-6 >40 pg/mL.

Material and methods Descriptive, retrospective, observational study carried out between November 2020 and January 2021 in a second-level hospital. All patients with determinations of IL-6 were located. Those with IL-6 levels above 40 pg/mL were selected. Through a review of medical histories, COVID-19 patients who were treated with dexamethasone and with determination of IL-6 levels, both at the admission and within the following 96 hours, were chosen. Exclusion criteria: prescription of dexamethasone at least 24 hours before the first determination and use of tocilizumab before the first determination or between determinations. Data were subjected to Wilcoxon’s test.

Results 41 patients met the criteria. 28 of them were men (66.7%) with a median age of 64 years (IQR 23). The median time between determinations was 48 hours (IQR 48). The median level of IL-6 at the time of the hospital admission was 85.6 pg/mL (IQR 110.9) and after being treated with dexamethasone it was 24.2 pg/mL (IQR 33.1). The median of differences was –66.1 pg/mL (IQR 67.3) and 87.8% of the patients experienced a decrease, observing a statistical association (p<0.01). 75.6% of the patients showed levels below 40 pg/mL and 21.9% showed levels within the reference range (<7 pg/mL). 12 patients (29.3%) were finally treated with tocilizumab, of which 7 (58.3%) still presented levels of IL-6 >40 pg/mL.

Conclusion and relevance Dexamethasone treatment reduced IL-6 levels to below 40 pg/mL in most patients in 48 hours.

IL-6 monitoring after dexamethasone treatment could help prevent inadequate use of tocilizumab.

It is necessary to research the benefits of tocilizumab for patients with low levels of IL-6.

Conflict of interest No conflict of interest