Laboratory parameters predicting mortality of adult in-patients with COVID-19 associated cytokine release syndrome treated with high-dose tocilizumab

Trajectories and predictive significance of inflammatory parameters for clinical outcome in COVID-19 patients treated with tocilizumab

PURPOSE

The IL-6 receptor inhibitor tocilizumab reduces mortality and morbidity in severe cases of COVID-19 through its effects on hyperinflammation and was approved as adjuvant therapy. Since tocilizumab changes the levels of inflammatory markers, we aimed to describe these changes in patients treated with tocilizumab, analyse their value in predicting death and bacterial superinfection and determine their influence on mortality rates.

METHODS

A retrospective analysis of 76 patients who were treated with tocilizumab for severe COVID-19 in 2020 and 2021 was conducted. Inflammatory markers (IL-6, C-reactive protein (CRP), procalcitonin) were documented before and up to seven days after tocilizumab administration.

RESULTS

The overall mortality was 25% and 53.8% in patients who required invasive respiratory support. Deceased patients had higher baseline IL-6 (p = 0.026) and peak IL-6 levels after tocilizumab vs those who survived (p < 0.0001). A peak IL-6 value > 1000 pg/dl after tocilizumab administration was a good predictor of mortality (AUC = 0.812). Of the deceased patients 41.1% had a renewed CRP increase after an initial decrease following tocilizumab administration, compared to 7.1% of the surviving patients (p = 0.0011). Documented bacterial superinfections were observed in 35.5% (27/76) of patients, of whom 48.1% (13/27) died.

CONCLUSION

CRP-decline and IL-6 increase after tocilizumab treatment occurs regularly. An increase of IL-6 levels exceeding tenfold of baseline IL-6 levels, an absolute peak of 1000 pg/ml or a renewed increase of CRP are associated with higher mortality. Suppressed CRP synthesis can impede the diagnosis of bacterial superinfections, thus increasing the risk for complications.

Secondary infections and long-term outcomes among hospitalized elderly and non-elderly patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and treated with baricitinib: a comparative study from the national centre of Hungary

Baricitinib is considered a first-line treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected adult patients with an associated cytokine storm syndrome (CSS). Our objective was to compare rates of secondary infections and long-term outcomes of elderly and non-elderly patients who received baricitinib for COVID-19. We conducted a single-centre observational study between November 2020 and September 2023, focusing on hospitalized adult SARS-CoV-2 patients with CSS, categorized as elderly (≥ 65 years) and non-elderly (< 65 years). Enrolment, severity stratification, and diagnosis of infectious complications followed predefined criteria. Outcomes of all-cause mortality and rates of non-severe and severe secondary infections were assessed at 1-year post-treatment initiation. Kaplan-Meier analysis was performed for survival analysis. In total, 490 patients were enrolled (median age 65 ± 23 (21-100) years (years, median ± IQR, min-max); 49.18% elderly; 59.59% male). Elderly patients were admitted to the hospital significantly earlier (7 ± 5 days vs. 8 ± 4 days; p = 0.02), experienced a higher occurrence of severe COVID-19 (121/241, 50.21% vs. 98/249, 39.36%; p = 0.02), and required the use of non-invasive ventilation at baseline (167/225, 74.22% vs. 153/236, 64.83%; p = 0.03). At 1 year, all-cause mortality was significantly higher in the elderly subgroup (111/241, 46.06% vs. 29/249, 11.65%; p < 0.01). At 90 days and 1 year, rates of any severe secondary infection were also more prevalent among the elderly (56/241, 23.24% vs. 37/249 14.86%; p = 0.02 and 58/241, 24.07% vs. 39/249, 15.66%; p = 0.02). In conclusion, elderly SARS-CoV-2-infected patients experience a more severe clinical course, higher secondary infection rates, and increased risk for long-term mortality, regardless of immunomodulatory therapy.

Application of Machine Learning in Hospitalized Patients with Severe COVID-19 Treated with Tocilizumab

Among the IL-6 inhibitors, tocilizumab is the most widely used therapeutic option in patients with SARS-CoV-2-associated severe respiratory failure (SRF). The aim of our study was to provide evidence on predictors of poor outcome in patients with COVID-19 treated with tocilizumab, using machine learning (ML) techniques. We conducted a retrospective study, analyzing the clinical, laboratory and sociodemographic data of patients admitted for severe COVID-19 with SRF, treated with tocilizumab. The extreme gradient boost (XGB) method had the highest balanced accuracy (93.16%). The factors associated with a worse outcome of tocilizumab use in terms of mortality were: baseline situation at the start of tocilizumab treatment requiring invasive mechanical ventilation (IMV), elevated ferritin, lactate dehydrogenase (LDH) and glutamate-pyruvate transaminase (GPT), lymphopenia, and low PaFi [ratio between arterial oxygen pressure and inspired oxygen fraction (PaO₂/FiO₂)] values. The factors associated with a worse outcome of tocilizumab use in terms of hospital stay were: baseline situation at the start of tocilizumab treatment requiring IMV or supplemental oxygen, elevated levels of ferritin, glutamate-oxaloacetate transaminase (GOT), GPT, C-reactive protein (CRP), LDH, lymphopenia, and low PaFi values. In our study focused on patients with severe COVID-19 treated with tocilizumab, the factors that were weighted most strongly in predicting worse clinical outcome were baseline status at the start of tocilizumab treatment requiring IMV and hyperferritinemia.

Association between tocilizumab and emerging multidrug-resistant organisms in critically ill patients with COVID-19: A multicenter, retrospective cohort study

BACKGROUND

Tocilizumab is an IgG1 class recombinant humanized monoclonal antibody that directly inhibits the IL-6 receptor. Several randomized clinical trials have evaluated its safety and efficacy in patients with coronavirus disease 2019 (COVID-19), and these studies demonstrate conflicting results. Our study aimed to determine the association between tocilizumab treatment and microbial isolation and emergence of multidrug-resistant bacteria in critically ill patients with COVID-19.

METHODS

A multicenter retrospective cohort study was conducted at two tertiary government hospitals in Saudi Arabia. All critically ill patients admitted to intensive care units with a positive COVID-19 PCR test between March 1 and December 31, 2020, who met study criteria were included. Patients who received tocilizumab were compared to those who did not receive it.

RESULTS

A total of 738 patients who met our inclusion criteria were included in the analysis. Of these, 262 (35.5%) received tocilizumab, and 476 (64.5%) were included in the control group. Patients who received tocilizumab had higher odds for microbial isolation (OR 1.34; 95% CI 0.91-1.94, p = 0.13); however, the difference was not statistically significant. Development of resistant organisms (OR 1.00; 95% CI 0.51-1.98, p = 0.99) or detection of carbapenem-resistant Enterobacteriaceae (CRE) (OR 0.67; 95% CI 0.29-1.54, p = 0.34) was not statistically significant between the two groups.

CONCLUSIONS

Tocilizumab use in critically ill patients with COVID-19 is not associated with higher microbial isolation, the emergence of resistant organisms, or the detection of CRE organisms.