Potential Predictors of the Outcome of Tocilizumab Treatment in Patients with COVID-19-Associated Hyperinflammation

Objective: During the COVID-19 pandemic, a subset of patients developed COVID-19-
associated hyperinflammation (HIC), which resulted in increased mortality. While early and
effective anti-inflammatory therapies, such as glucocorticoids and tocilizumab, improved
survival, tools to predict treatment response remained lacking. This study aimed to identify
predictors of clinical outcomes in patients who received tocilizumab for HIC.
Materials and Methods: We retrospectively analyzed the records of hospitalized adult patients
with COVID-19 treated between March and December 2020. Patients who received
tocilizumab for HIC constituted the study cohort. Dynamic changes in the laboratory parameters
were analyzed, and the HIC scores (≥35) were calculated to assess disease severity
and treatment response.
Results: Out of 961 hospitalized COVID-19 patients, 150 who received tocilizumab were
identified. Among them, 124 were treated with only tocilizumab in the first phase of the
pandemic (from March to September 2020). After this period, 26 patients also received
glucocorticoids, typically initiated 2–3 days prior to tocilizumab administration. Anakinra
treatment was given to 22 patients whose inflammatory parameters did not resolve with
tocilizumab. Findings of HIC were treated in 122 patients (84%), with a significant reduction
in C-reactive protein (CRP) levels (from 121.8 ± 8.2 to 9.8 ± 2.8 mg/L). Despite tocilizumab
treatment, no effective resolution of the CRP response was observed (from 172 ± 22.8
to 53 ± 8 mg/L by Day 5) among non-survivors, alongside increasing trends in neutrophil
count, D-dimer, lactate dehydrogenase (LDH), troponin, and creatine kinase. The composite
HIC scores progressively decreased in survivors until the last day of hospitalization but increased
in non-survivors (33.8 ± 0.14 vs. 72.3 ± 0.13).