Corticosteroids induce an early but limited decrease in IL-6 dependent pro-inflammatory responses in critically ill COVID-19 patients.

BACKGROUND: Corticosteroids have become standard of care for COVID-19 but their effect on the systemic immune-inflammatory response has been little investigated. METHODS: Multicenter prospective cohort, including critically ill COVID-19 patients between March and November 2020. C-reactive protein (CRP), lymphocyte count and fibrinogen levels were collected upon hospital admission before initiation of steroid treatment and at ICU admission, three days and seven days later, along with interleukin (IL)-6, IL-10 and tumor necrosis factor-alpha (TNF-α) plasma levels. RESULTS: A hundred and fifty patients were included, 47 received corticosteroids, 103 did not. Median age was 62 [53-70], and 96 (65%) patients were mechanically ventilated. Propensity score matching rendered 45 well-balanced pairs of treated and non-treated patients, particularly on pre-treatment CRP levels. Using a mixed model, CRP (P=0.019), fibrinogen (P=0.003) and lymphocyte counts (P=0.006) remained lower in treated patients over ICU stay. Conversely, there was no significant difference over the ICU stay for Il-6 (P=0.146) and IL-10 (0.301), while TNF- α levels were higher in the treated group (P=0.013). Among corticosteroid-treated patients, CRP (P=0.012), fibrinogen (P=0.041) and lymphocyte count (P=0.004) over time were associated with outcome, whereas plasma cytokine levels were not. CONCLUSIONS: Steroid treatment was associated with an early and sustained decrease in the downstream IL-6-dependent inflammatory signature but an increase in TNF-α levels. In corticosteroid-treated patients, CRP and lymphocyte count were associated with outcome, conversely to plasma cytokine levels. Further research on using these biomarker's kinetics to individualize immunomodulatory treatments is warranted.

Delayed inflammation decrease is associated with mortality in Tocilizumab-treated critically ill SARS-CoV-2 patients: A retrospective matched-cohort analysis.

Little is known about the immuno-inflammatory response to Tocilizumab and its association with outcome in critically-ill SARS-CoV2 pneumonia. In this multicenter retrospective cohort of SARS-CoV-2 patients admitted to three intensive care units between March and April 2020, we matched on gender and SAPS II 21 Tocilizumab-treated patients to 42 non-treated patients. Need for mechanical ventilation was 76% versus 79%. IL-6, C-reactive protein, and fibrinogen had been collected within the first days of admission (T1), 3 d (T2) and 7 d (T3) later. Tocilizumab-treated patients had persistently higher IL-6 plasma levels and persistently lower C-Reactive protein and fibrinogen levels. Among Tocilizumab-treated patients, baseline levels of inflammatory biomarkers were not different according to outcome. Conversely, C-reactive protein and fibrinogen decrease was delayed in non-survivors. C-Reactive protein decreased at T1 in survivors (45 [30-98] vs 170 [69-204] mg/l, P < 0.001) but only at T2 in non-survivors (37 [13-74] vs 277 [235-288], P = 0.03). Fibrinogen decreased at T2 in survivors (4.11 [3.58-4.69] vs 614 [5.61-7.85] g/l, P = 0.005) but not in non-survivors (4.79 [4.12-7.58] vs 7.24 [6.22-9.24] g/l, P = 0.125). Tocilizumab treatment was thus associated with a persistent both increase in plasma IL-6, and decrease in C-reactive protein and fibrinogen. Among Tocilizumab-treated patients, the decrease in inflammatory biomarkers was delayed in non-survivors.

Proof of principle for transfusion of in vitro-generated red blood cells.

In vitro RBC production from stem cells could represent an alternative to classic transfusion products. Until now the clinical feasibility of this concept has not been demonstrated. We addressed the question of the capacity of cultured RBCs (cRBCs) to survive in humans. By using a culture protocol permitting erythroid differentiation from peripheral CD34(+) HSC, we generated a homogeneous population of cRBC functional in terms of their deformability, enzyme content, capacity of their hemoglobin to fix/release oxygen, and expression of blood group antigens. We then demonstrated in the nonobese diabetes/severe combined immunodeficiency mouse that cRBC encountered in vivo the conditions necessary for their complete maturation. These data provided the rationale for injecting into one human a homogeneous sample of 10(10) cRBCs generated under good manufacturing practice conditions and labeled with (51)Cr. The level of these cells in the circulation 26 days after injection was between 41% and 63%, which compares favorably with the reported half-life of 28 ± 2 days for native RBCs. Their survival in vivo testifies globally to their quality and functionality. These data establish the proof of principle for transfusion of in vitro-generated RBCs and path the way toward new developments in transfusion medicine. This study is registered at http://www.clinicaltrials.gov as NCT0929266.