[Criteria for the optimal use of interleukin-6 receptor blockers in patients with COVID-19]

To determine the criteria for the optimal use of IL-6 receptor blockers in patients with COVID-19 community-acquired pneumonia based on predictors of adverse outcomes.

The single-center, non-randomized prospective study included 190 patients with community-acquired pneumonia caused by coronavirus 2 between the beginning of March and the end of May 2020. Of these, 89 patients received tocilizumab and 101 patients received sarilumab. The study inclusion criterion for the patient was indications for initiating therapy with one of the inhibitors of IL-6 receptors (anti-IL-6R) according to the Interim guidelines (versions 4 and 5). The exclusion criterion was the need to re-prescribe genetically engineered biological therapy (GEBT). The severity of the patient's condition was assessed according to the early warning score (NEWS2), the volume of lung tissue lesions was assessed according to computed tomography (CT). Laboratory monitoring included counting the absolute (abs) number of lymphocytes, serum levels of C-reactive protein (CRP), interleukin 6 (IL-6), D-dimer, lactate dehydrogenase, fibrinogen. Statistical data processing was conducted by nonparametric methods using the IBM SPSS Statistics V-22 software.

The phenotype of a patient with a negative outcome prognosis was described: a male patient over 50 years of age with aggravated premorbid background (with cardiovascular diseases, obesity and/or chronic renal disease), lung lesion CT 34, saturation less than 93% upon inhalation of atmospheric air, persisting for 2448 hours after GEBT. According to the blood test, lymphopenia was below 1000 U/L and CRP levels were above 50 mg/L. The laboratory parameters and clinical picture of the patient progressively worsened after 911 days of illness, regardless of the use of Anti-IL-6R. The features of patients monitoring when administering IL-6 receptor blockers have been determined.

IL-6 receptor blockers should be administered to patients hospitalized with severe COVID-19 before the development of hyperinflammatory reactions. The optimal "therapeutic window" is 78 days of illness.