Tocilizumab is associated with reduced delirium and coma in critically ill patients with COVID-19.

Recent preclinical studies demonstrate a direct pathological role for the interleukin-6 (IL-6) pathway in mediating structural and functional delirium-like phenotypes in animal models of acute lung injury. Tocilizumab, an IL-6 pathway inhibitor, has shown reduced duration of ventilator dependency and mortality in critically ill patients with COVID-19. In this study, we test the hypothesis that tocilizumab is associated with reduced delirium/coma prevalence in critically ill patients with COVID-19. 253 patients were included in the study cohort, 69 in the tocilizumab group and 184 in the historical control group who did not receive tocilizumab. Delirium was assessed using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) with a positive score indicating delirium. Coma was defined as a Richmond Agitation-Sedation Scale score of - 4 or - 5. Tocilizumab was associated with significantly greater number of days alive without delirium/coma (tocilizumab [7 days (IQR: 3-9 days)] vs control [3 days (IQR: 1-8 days)]; p < 0.001). These results remained significant after adjusting for age, sex, sepsis, Charlson Comorbidity Index, Sequential Organ Failure Assessment score, and median daily dose of analgesics/sedatives ( ß ^ = 0.671, p = 0.010). There were no significant differences in mortality ( ß ^ = - 0.204, p = 0.561), ventilator duration ( ß ^ = 0.016, p = 0.956), and ICU or hospital length of stay ( ß ^ = - 0.134, p = 0.603; ß ^ = 0.003, p = 0.991, respectively). Tocilizumab use was associated with significantly increased number of days without delirium/coma. Confirmation of these findings in randomized prospective studies may inform a novel paradigm of pharmacological amelioration of delirium/coma during critical illness.

Comparison of SAT and SBT Conduct During the ABC Trial and PILOT Trial.

BACKGROUND: Implementation of the "B" element-both spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs)-of the ABCDEF bundle improves the outcomes for mechanically ventilated patients. In 2021, the Pragmatic Investigation of optimal Oxygen Targets (PILOT) trial investigating optimal oxygenation targets in patients on mechanical ventilation was completed. OBJECTIVES: To compare SAT and SBT conduct between a randomized controlled trial and current clinical care. METHODS: The 2008 Awakening and Breathing Controlled (ABC) Trial (2003-2006) randomized mechanically ventilated patients to paired SATs and SBTs versus sedation per usual care plus SBTs. The PILOT trial (2018-2021) enrolled patients years later where SAT + SBT conduct was observed. We compared SAT and SBT conduct in ABC's interventional group (SAT + SBT; n = 167, 1140 patient days) to that in PILOT (n = 2083, 8355 patient days). RESULTS: Spontaneous awakening trial safety screens were done in all 1140 ABC patient-days on sedation and/or analgesia and in 3889 of 4228 (92%) in PILOT. Spontaneous awakening trial safety screens were passed in 939 of 1140 (82%) instances in ABC versus only 1897 of 3889 (49%) in PILOT. Interestingly, SAT was performed in ≥95% of passed SAT safety screens in both trials and was passed in 837 of 895 (94%) in ABC versus 1145 of 1867 (61%) in PILOT. SBT safety screens were performed in all 983 ABC instances and 8031 of 8370 (96%) in PILOT. SBT safety screens were passed in 647 of 983 (66%) in ABC versus 4475 of 8031 (56%) in PILOT. Spontaneous breathing trial was performed in ≥93% of passed SBT safety screens in both trials and was passed in 319 of 603 (53%) in ABC versus 3337 of 4454 (75%) in PILOT. CONCLUSION: This study compared SAT/SBT conduction in an ideal setting to real-world practice, 13 years later. Performance of SAT/SBT safety screens, SATs, and SBTs between a definitive clinical trial (ABC) as compared to current clinical care (PILOT) remained high.

Medication Changes and Diagnosis of New Chronic Illnesses in COVID-19 Intensive Care Unit Survivors.

BACKGROUND: Currently, there is limited literature on the impact of the COVID-19 infection on medications and medical conditions in COVID-19 intensive care unit (ICU) survivors. Our study is, to our knowledge, the first multicenter study to describe the prevalence of new medical conditions and medication changes at hospital discharge in COVID-19 ICU survivors. OBJECTIVE: To determine the number of medical conditions and medications at hospital admission compared to at hospital discharge in COVID-19 ICU survivors. METHODS: Retrospective multicenter observational study (7 ICUs) evaluated new medical conditions and medication changes at hospital discharge in patients with COVID-19 infection admitted to an ICU between March 1, 2020, to March 1, 2021. Patient and hospital characteristics, baseline and hospital discharge medication and medical conditions, ICU and hospital length of stay, and Charlson comorbidity index were collected. Descriptive statistics were used to describe patient characteristics and number and type of medical conditions and medications. Paired t-test was used to compare number of medical conditions and medications from hospital discharge to admission. RESULTS: Of the 973 COVID-19 ICU survivors, 67.4% had at least one new medical condition and 88.2% had at least one medication change. Median number of medical conditions (increased from 3 to 4, P < .0001) and medications (increased from 5 to 8, P < .0001) increased from admission to discharge. Most common new medical conditions at discharge were pulmonary disorders, venous thromboembolism, psychiatric disorders, infection, and diabetes. Most common therapeutic categories associated with medication change were cardiology, gastroenterology, pain, hematology, and endocrinology. CONCLUSION AND RELEVANCE: Our study found that the number of medical conditions and medications increased from hospital admission to discharge. Our results provide additional data to help guide providers on using targeted approaches to manage medications and diseases in COVID-19 ICU survivors after hospital discharge.

KDM6A Lysine Demethylase Directs Epigenetic Polarity of MDSCs during Murine Sepsis.

Sepsis-induced myeloid-derived suppressor cells (MDSCs) increase mortality risk. We previously identified that long non-coding RNA Hotairm1 supports myeloid precursor shifts to Gr1+CD11b+ MDSCs during mouse sepsis. A major unanswered question is what molecular processes control Hotairm1 expression. In this study, we found by a genetic deletion that a specific PU.1-binding site is indispensable in controlling Hotairm1 transcription. We then identified H3K4me3 and H3K27me3 at the PU.1 site on the Hotairm1 promoter. Controlling an epigenetic switch of Hotairm1 transcription by PU.1 was histone KDM6A demethylase for H3K27me3 that derepressed its transcription with possible contributions from Ezh2 methyltransferase for H3K27me3. KDM6A knockdown in MDSCs increased H3K27me3, decreased H3K4me3, and inhibited Hotairm1 transcription activation by PU.1. These results enlighten clinical translation research of PU.1 epigenetic regulation as a potential sepsis immune-checkpoint treatment site.

Long Non-Coding RNA Hotairm1 Promotes S100A9 Support of MDSC Expansion during Sepsis.

Myeloid-derived suppressor cells (MDSCs) expand during mouse and human sepsis, but the mechanism responsible for this is unclear. We previously reported that nuclear transport of S100A9 protein programs Gr1+CD11b+ myeloid precursors into MDSCs in septic mice. Here, we show that long non-coding RNA Hotairm1 converts MDSCs from an activator to a repressor state. Mechanistically, increased Hotairm1 expression in MDSCs in mice converted S100A9 from a secreted proinflammatory mediator to an immune repressor by binding to and shuttling it from cytosol to nucleus during late sepsis. High Hotairm1 levels were detected in exosomes shed from MDSCs from late septic mice. These exosomes inhibited lipopolysaccharide-stimulated secretion of S100A9 from early sepsis Gr1+CD11b+ cells. Importantly, Hotairm1 knockdown in late sepsis Gr1+CD11b+ MDSCs prevented S100A9 cytosol to nuclear transfer and decreased repression of proimmune T cells. Notably, ectopic expression of Hotairm1 in early sepsis Gr1+CD11b+ cells shuttled S100A9 to the nucleus and promoted the MDSC repressor phenotype. In support of translating the mechanistic concept to human sepsis, we found that Hotairm1 binds S100A9 protein in CD33+CD11b+HLA-DR- MDSCs during established sepsis. Together, these data support that Hotairm1 is a plausible molecular target for treating late sepsis immune suppression in humans and its immune repressor mechanism may be cell autonomous.

HuR promotes miRNA-mediated upregulation of NFI-A protein expression in MDSCs during murine sepsis.

Myeloid-derived suppressor cells (MDSCs) contribute to high mortality rates during sepsis, but how sepsis induces MDSCs is unclear. Previously we reported that microRNA (miR)-21 and miR-181b reprogram MDSCs in septic mice by increasing levels of DNA binding transcription factor, nuclear factor 1 (NFI-A). Here, we provide evidence that miR-21 and miR-181b stabilize NFI-A mRNA and increase NFI-A protein levels by recruiting RNA-binding proteins HuR and Ago1 to its 3' untranslated region (3'UTR). We also find that the NFI-A GU-rich element (GRE)-binding protein CUGBP1 counters miR-21 and miR-181b dependent NFI-A mRNA stabilization and decreases protein production by replacing 3'UTR bound Ago1 with Ago2. We confirmed the miR-21 and miR-181b dependent reprogramming pathway in MDSCs transfected with a luciferase reporter construct containing an NFI-A 3'UTR fragment with point mutations in the miRNA binding sites. These results suggest that targeting NFI-A in MDSCs during sepsis may enhance resistance to uncontrolled infection.

S100A9 maintains myeloid-derived suppressor cells in chronic sepsis by inducing miR-21 and miR-181b.

Myeloid-derived suppressor cells (MDSC) expand during sepsis, suppress both innate and adaptive immunity, and promote chronic immunosuppression, which characterizes the late/chronic phase of sepsis. We previously reported that the transcription factors Stat3 and C/EBPß synergize to induces the expression of microRNA (miR)-21 and miR-181b to promote MDSC expansion in a mouse model of polymicrobial sepsis that progresses from an early/acute proinflammatory phase to a late/chronic immunosuppressive stage. We also showed that Gr1+CD11b+ cells, the precursors of MDSCs, from mice genetically deficient in the inflammatory protein S100A9 lack miR-21 or miR-181b in late sepsis, and are not immunosuppressive. In the present study, we show that S100A9 induces miR-21 and miR-181b during the late sepsis phase. We find that S100A9 associates with and stabilizes the Stat3-C/EBPß protein complex that activates the miRNA promoters. Reconstituting Gr1+CD11b+ cells from S100A9 knockout mice with late sepsis with S100A9 protein restores the Stat3-C/EBPß protein complex and miRNA expressions, and switches the Gr1+CD11b+ cells into the immunosuppressive, MDSC phenotype. Importantly, we find that this process requires IL-10 mediated signaling, which induces S100A9 translocation from the cytosol to the nucleus. These results demonstrate that S100A9 promotes MDSC expansion and immunosuppression in late/chronic sepsis by inducing the expression of miR-21 and miR-181b.