Daily Sepsis Research Analysis
Three papers reshape sepsis and critical care thinking across mechanisms, ventilation strategy, and trial design. A mechanistic study uncovers an oxPL–AKT–methionine cycle–EZH2 axis that epigenetically silences IL-10 and drives lethal inflammation, a large multicohort analysis suggests personalizing tidal volume to predicted FVC rather than PBW, and a translational study shows combined pyroptosis–ferroptosis biomarker signatures identify the sickest ICU patients for enrichment of emerging interv
Summary
Three papers reshape sepsis and critical care thinking across mechanisms, ventilation strategy, and trial design. A mechanistic study uncovers an oxPL–AKT–methionine cycle–EZH2 axis that epigenetically silences IL-10 and drives lethal inflammation, a large multicohort analysis suggests personalizing tidal volume to predicted FVC rather than PBW, and a translational study shows combined pyroptosis–ferroptosis biomarker signatures identify the sickest ICU patients for enrichment of emerging interventions.
Research Themes
- Epigenetic checkpoints of inflammation in sepsis
- Precision ventilation using predicted forced vital capacity
- Biomarker-driven enrichment for cell-death–targeted therapies
Selected Articles
1. Epigenetic silencing of interleukin-10 by host-derived oxidized phospholipids supports a lethal inflammatory response to infections.
This mechanistic study shows that host-derived oxidized phospholipids form during infection and amplify inflammation by inhibiting AKT, enhancing the methionine cycle and EZH2 activity, which epigenetically silences IL-10. Targeting oxPLs or downstream nodes could restore anti-inflammatory balance and prevent lethal immunopathology in sepsis.
Impact: Identifies a previously unappreciated oxPL–AKT–EZH2 checkpoint that epigenetically suppresses IL-10 and drives fatal inflammation, offering concrete, targetable nodes for intervention.
Clinical Implications: While preclinical, the data support development of diagnostics (oxPL/EZH2/IL-10 axis) and therapeutics (oxPL neutralization, AKT modulation, EZH2 inhibition) to prevent hyperinflammation in sepsis without impairing pathogen control.
Key Findings
- Host-derived oxidized phospholipids (oxPLs) are generated after infection in mice and humans.
- oxPLs exacerbate inflammation without altering pathogen burden.
- Mechanistically, oxPLs bind and inhibit AKT, augmenting the methionine cycle and EZH2 activity.
- EZH2 epigenetically suppresses IL-10, contributing to host mortality.
- Prophylactic or therapeutic targeting of oxPLs mitigates deranged inflammation and immunopathology.
Methodological Strengths
- Integrated mouse and human evidence with mechanistic dissection linking oxPLs to AKT–EZH2–IL-10.
- Demonstrated causality with pathway perturbation enabling therapeutic targeting.
Limitations
- Preclinical study; absence of interventional human trials.
- Heterogeneity of infection contexts may limit immediate generalizability.
Future Directions: Validate the oxPL–AKT–EZH2–IL-10 axis in prospective human sepsis cohorts, develop assays for clinical oxPL/EZH2 activity, and test targeted interventions in early-phase trials.
Phagocytes initiate immunity to invading microorganisms by detecting pathogen-associated molecular patterns via pattern recognition receptors. Pathogen encounter and consequent activation of the immune system cause tissue damage and the release of host-derived damage-associated molecular patterns, contributing to shape immunity. However, how self-derived factors are sensed by phagocytes and impact the immune response remains poorly understood. Here, we demonstrated that host-derived oxidized phospholipids (oxPLs) are formed after microbial encounter in both mice and humans. oxPLs exacerbated inflammation without affecting pathogen burden. Mechanistically, oxPLs bound and inhibited AKT, potentiating the methionine cycle and the activity of the epigenetic writer EZH2. EZH2 epigenetically dampened the pluripotent anti-inflammatory cytokine IL-10, contributing to the death of the host. Overall, we found that host-derived oxPLs set the balance between protective and detrimental antimicrobial responses and that they can be prophylactically or therapeutically targeted to protect the host against deranged inflammation and immunopathology.
2. Evaluating the generalisability of formulas used to set tidal volumes in mechanically ventilated patients: an observational, multicohort, retrospective study.
Across MIMIC-IV and eICU-CRD cohorts (n≈21,500), predicted FVC varied systematically by age, sex, and race at the same PBW, and a higher PBW:PFVC ratio correlated with higher mortality. These findings challenge PBW-based tidal volume normalization and support personalizing Vt to lung capacity (PFVC).
Impact: Proposes a physiologically grounded alternative to PBW-based tidal volume setting with reproducible mortality associations across two large, independent ICU datasets.
Clinical Implications: Consider incorporating predicted FVC into tidal volume targets to avoid relative overdistension in patients with smaller lung capacity at a given PBW, especially common in older, female, and non-White patients.
Key Findings
- In two large ICU cohorts (MIMIC-IV n=9152; eICU-CRD n=12,420), PFVC varied by age, sex, and race at the same PBW.
- A 1 SD increase in the PBW:PFVC ratio was associated with 1.43-fold higher odds of death in MIMIC-IV, with similar results in eICU-CRD.
- Results challenge PBW-only Vt normalization and support tailoring tidal volume to PFVC.
Methodological Strengths
- Replication across two large, heterogeneous cohorts with consistent findings.
- Use of standardized GLI 2012 reference equations for PFVC estimation.
Limitations
- Retrospective design limits causal inference and is subject to residual confounding.
- PFVC is estimated (not measured), potentially introducing model-based error.
Future Directions: Prospective trials testing PFVC-based tidal volume targets versus PBW-based targets on patient-centered outcomes (e.g., ventilator-free days, mortality) in ARDS and sepsis.
BACKGROUND: Lung-protective mechanical ventilation with low tidal volume (V METHODS: In this observational, multicohort, retrospective study we compared ARMA PBW with PFVC estimated with the Global Lung Initiative 2012 reference equations for two cohorts: Medical Information Mart for Intensive Care-IV (MIMIC-IV), a cohort of patients from a single academic medical centre in Boston, MA, USA, and electronic Intensive Care Unit Collaborative Research Database (eICU-CRD), a cohort of patients from 208 hospitals in the USA. Patients who had lung-protective ventilation, hypoxaemia, and height in the range 150-210 cm were included. The data were collected from publicly available, deidentified datasets. We then studied the association between normalised V FINDINGS: 9152 patients were included from MIMIC-IV (3064 [33·5%] female and 6088 [66·5%] male; 645 [7·0%] Black, 5885 [64·3%] White, and 2622 [28·6%] other race; mean age 63 years [SD 16]) and 12 420 patients were included from eICU-CRD (4262 [34·3%] female and 8158 [65·7%] male; 1023 [8·2%] Black, 10 093 [81·3%] White, and 1304 [10·5%] other race; mean age 62 years [SD 16]). Patients who were younger, male, and White had greater PFVCs than patients who were older, female, and non-White with the same PBW. A 1 SD increase in PBW:PFVC ratio was associated with 1·43-fold (95% CI 1·17-1·76) higher odds of death in MIMIC-IV and similar results were observed in the eICU-CRD cohort. INTERPRETATION: Adjusting V FUNDING: National Heart, Lung, and Blood Institute.
3. Potential of biomarker-based enrichment strategies to identify critically ill patients for emerging cell death interventions.
In ICU patients, concurrent pyroptosis and ferroptosis biomarker signatures identified the group with the lowest survival, marked by elevated IL-1Ra, IL-18, GDF15 (pyroptosis) and MDA, catalytic iron (ferroptosis). These data support biomarker-based enrichment to select high-risk patients for emerging interventions targeting cell death pathways.
Impact: Connects mechanistic cell death programs to pragmatic biomarker panels with prognostic separation, enabling precision enrollment for forthcoming pyroptosis/ferroptosis-targeted sepsis trials.
Clinical Implications: Hospitals could develop panels (e.g., IL-1Ra, IL-18, GDF15, MDA, catalytic iron) to identify patients most likely to benefit from cell-death–modulating therapies and to stratify risk in sepsis-related MODS.
Key Findings
- ICU patients with both pyroptosis- and ferroptosis-positive signatures had the lowest survival probability.
- Pyroptosis biomarkers (IL-1Ra, IL-18, GDF15) and ferroptosis biomarkers (MDA, catalytic iron) were significantly elevated in this group.
- Findings support biomarker-based enrichment to select candidates for therapies targeting regulated cell death pathways.
Methodological Strengths
- Biologically grounded selection of complementary cell-death biomarkers with consistent prognostic association.
- Translational orientation linking mechanistic pathways to clinical stratification.
Limitations
- Observational design; causality cannot be inferred.
- Cohort size and external validation details are not specified in the abstract.
Future Directions: Prospective validation and adaptive trial designs using pyroptosis/ferroptosis panels to enrich enrollment for targeted interventions; evaluate whether panel-guided therapy improves outcomes.
Critically ill patients admitted to the intensive care unit (ICU) frequently suffer from sepsis and severe multiple organ dysfunction with underlying widespread cell death. Pyroptosis and ferroptosis are regulated cell death forms that may serve as potential therapeutic targets. Pyroptosis is a major detrimental factor driving sepsis, which typically results in excessive oxidative stress potentially inducing ferroptotic organ injury. Here, we show that ICU patients with simultaneous pyro- and ferroptosis-positive signatures have the lowest survival probability. This is reflected by significantly elevated levels of pyroptosis-related biomarkers interleukin-1 receptor antagonist (IL-1Ra), IL-18, and growth and differentiation factor-15 (GDF15), as well as the ferroptosis-related biomarkers malondialdehyde (MDA) and catalytic iron (Fe