Daily Sepsis Research Analysis
Three advances stand out today: a conserved 42-gene immune dysregulation signature (SoM) that stratifies infection severity and predicts treatment response (including potential harm from hydrocortisone in sepsis); a high-performing machine learning model that predicts pediatric sepsis onset daily using EMR data; and preclinical evidence that pro-dermcidin and PEGylated derivatives protect against lethal experimental sepsis via LC3-associated phagocytosis.
Summary
Three advances stand out today: a conserved 42-gene immune dysregulation signature (SoM) that stratifies infection severity and predicts treatment response (including potential harm from hydrocortisone in sepsis); a high-performing machine learning model that predicts pediatric sepsis onset daily using EMR data; and preclinical evidence that pro-dermcidin and PEGylated derivatives protect against lethal experimental sepsis via LC3-associated phagocytosis.
Research Themes
- Precision immunology to stratify sepsis risk and therapy
- AI-driven early detection of pediatric sepsis
- Host-directed immunotherapies enhancing antibacterial phagocytosis
Selected Articles
1. A conserved immune dysregulation signature is associated with infection severity, risk factors prior to infection, and treatment response.
Across 68 cohorts (12,026 blood samples), a conserved 42-gene Severe-or-Mild (SoM) immune signature linked baseline risk factors to infection severity and was modifiable by drugs and lifestyle. The SoM score predicted sepsis patients likely to be harmed by hydrocortisone and was associated with all-cause mortality, suggesting utility for precision immunotherapy and trial stratification.
Impact: This work unifies diverse risk factors under a single immune dysregulation signature that predicts treatment harm/benefit and mortality, enabling precision sepsis therapeutics and better trial design.
Clinical Implications: The SoM score could guide corticosteroid use in sepsis (identifying patients at risk of harm), inform selection of immunomodulatory therapies, and enable baseline immune state profiling for risk stratification.
Key Findings
- Integrated 12,026 blood samples across 68 cohorts to analyze immune dysregulation.
- A 42-gene SoM signature associated with age, sex, obesity, smoking, and comorbidities before infection.
- The SoM signature is modifiable by immunomodulatory drugs and lifestyle changes.
- The SoM score predicted sepsis patients harmed by hydrocortisone and was associated with all-cause mortality.
Methodological Strengths
- Large, multi-cohort integration of single-cell, bulk transcriptomic, and proteomic data (n=12,026 across 68 cohorts).
- Cross-disease validation linking baseline immune state to severity and treatment response.
Limitations
- Observational and integrative design limits causal inference.
- Heterogeneity across cohorts; prospective interventional validation is needed for clinical deployment.
Future Directions: Prospective trials to test SoM-guided corticosteroid and immunomodulator use; embed SoM scoring into EHR pipelines; explore temporal dynamics and responsiveness monitoring.
Older age, being male, obesity, smoking, and comorbidities (e.g., diabetes, asthma) are associated with an increased risk for severe infections. We hypothesized that there is a conserved common immune dysregulation across these risk factors. We integrated single-cell and bulk transcriptomic data and proteomic data from 12,026 blood samples across 68 cohorts to test this hypothesis. We found that our previously described 42-gene Severe-or-Mild (SoM) signature was associated with each of these risk factors prior to infection. Furthermore, this conserved immune signature was modifiable using immunomodulatory drugs and lifestyle changes. The SoM score predicted the individuals with sepsis who would be harmed by hydrocortisone treatment and individuals with asthma who would not respond to monoclonal antibody treatment. Finally, the SoM score was associated with all-cause mortality. The SoM signature has the potential to redefine the immunologic framing of the baseline immune state and response to chronic, subacute, and acute illnesses.
2. Pro-dermcidin and derivatives as potential therapeutics for lethal experimental sepsis.
Antibody-mediated suppression of pro-dermcidin exacerbated sepsis, whereas supplementation with pro-DCD or PEGylated derivatives conferred protection even when administered 2–24 hours after onset. Benefits correlated with reduced inflammatory biomarkers, tissue injury, and bacteremia, mediated via activation of LC3-associated phagocytosis rather than direct bactericidal activity.
Impact: Introduces a host-directed therapeutic class for sepsis with a clinically relevant treatment window and a defined mechanism (LC3-associated phagocytosis).
Clinical Implications: Pro-DCD-derived agents could complement antibiotics by enhancing LC3-associated bacterial clearance, offering a host-directed strategy for patients with overwhelming inflammation and bacteremia.
Key Findings
- Antibody suppression of pro-DCD worsened sepsis-induced inflammation and liver injury.
- Pro-DCD or PEGylated derivatives protected against sepsis even when given 2–24 hours post-onset.
- Protection correlated with reduced inflammatory biomarkers, tissue damage, and bacteremia.
- Mechanism involved activation of LC3-associated phagocytosis, not direct bactericidal effects.
Methodological Strengths
- Both loss-of-function (antibody suppression) and gain-of-function (supplementation) approaches support causality.
- Demonstrated efficacy with delayed dosing and multi-parametric readouts (cytokines, tissue injury, bacterial counts).
Limitations
- Preclinical animal models; human safety, dosing, and pharmacokinetics are unknown.
- Short-term outcomes; durability of protection and effects in polymicrobial or comorbid settings remain to be tested.
Future Directions: Conduct GLP toxicology, PK/PD, and dose-ranging studies; evaluate efficacy in polymicrobial and comorbidity models; explore combination with antibiotics and immunomodulators; identify biomarkers of response.
A 110-amino acid precursor of dermcidin (pre-dermcidin, pre-DCD) with a 19-residue N-terminal leader signal sequence can be secreted by human eccrine sweat glands as a leader-less pro-domain-containing peptide (pro-DCD), which is enzymatically cleaved to generate C-terminal anti-microbial peptides (dermcidin-1, DCD-1) capable of killing various bacteria. Previously, it was unknown whether pro-DCD could be pharmacologically developed as potential therapeutics for lethal sepsis. Here, we demonstrated that pharmacological suppression of pro-DCD with polyclonal antibodies worsened sepsis-induced inflammation and liver injury, whereas supplementation of pro-DCD or its PEGylation derivatives significantly protected against sepsis, even when given 2-24 h after disease onset. These protective effects were associated with a significant reduction in circulating levels of surrogate biomarkers [e.g., Granulocyte Colony Stimulating Factor (G-CSF), Interleukin-6 (IL-6), keratinocytes-derived chemokine (KC), Monocyte Chemoattractant Protein 1 (MCP-1), Macrophage Inflammatory Protein-2 (MIP-2), and Soluble Tumor Necrosis Factor Receptor I (sTNFRI)], tissue injury, and blood bacterial counts. Although pro-DCD or its PEGylation derivatives failed to directly kill bacteria across a wide range of concentrations, they were able to activate microtubule-associated protein 1A/1B-light chain 3 (LC3), a marker of autophagy and phagosome maturation in LC3-associated bacterial phagocytosis. Our findings suggest that pro-DCD-derived agents hold promise as potential therapies for clinical sepsis.
3. Machine learning model for daily prediction of pediatric sepsis using Phoenix criteria.
Using 63,875 PICU encounters from two units, a CatBoost model using routinely available EMR variables achieved AUROC 0.98 and AUPRC 0.83 for daily prediction of Phoenix-defined pediatric sepsis. This tool could automate early recognition and prompt management to mitigate organ dysfunction and mortality.
Impact: Demonstrates near-perfect discrimination for pediatric sepsis onset using readily available EMR data across two PICUs, providing a scalable pathway to earlier interventions.
Clinical Implications: Integration into PICU workflows could trigger earlier sepsis bundles, targeted diagnostics, and antimicrobial therapy, potentially reducing organ dysfunction and mortality.
Key Findings
- Analyzed 63,875 PICU encounters; 5,248 met Phoenix Sepsis criteria.
- CatBoost achieved AUROC 0.98 and AUPRC 0.83 for daily sepsis prediction using EMR variables.
- Features included vital signs, labs, demographics, medications, and organ dysfunction scores across two PICUs.
Methodological Strengths
- Large, multi-institution dataset with validation across two PICUs.
- Use of routinely available EMR variables enhances implementability.
Limitations
- Single health system; generalizability beyond two PICUs is uncertain.
- Phoenix criteria dependency and lack of prospective impact evaluation may limit clinical translation.
Future Directions: Prospective implementation studies to measure time-to-antibiotics and outcomes, external validation across diverse PICUs, fairness auditing, and clinician-in-the-loop deployment.
BACKGROUND: Early sepsis diagnosis is essential for initiating prompt treatment, preventing the progression of organ failure, and improving the survival rate of critically ill children. The aim of this study was to develop and validate a machine learning sepsis prediction model for patients admitted to a pediatric intensive care unit (PICU) who met the Phoenix Sepsis Score Criteria using EMR data. METHODS: Data were obtained from two PICUs within the same healthcare system. Readily available variables were used to develop and validate machine learning models predicting the onset of sepsis in critically ill children. RESULTS: A total of 63,875 PICU encounters were included, of which there were 5248 who met the criteria for Phoenix Sepsis. We trained and tested 4 machine learning models using vital signs, laboratory tests, demographic data, medications, and organ dysfunction scores. The Categorical Boosting (CatBoost) model had the best performance with an AUROC of 0.98 (95% CI, 0.98-0.98), and an AUPRC of 0.83 (95% CI, 0.82-0.83). CONCLUSIONS: The implementation of our model capable of predicting the onset of sepsis defined by the Phoenix Sepsis Score criteria may help clinicians recognize and manage children with sepsis more efficiently to reduce morbidity and mortality. IMPACT: Sepsis is a life-threatening condition with high rates of morbidity and mortality in children, especially in pediatric critical care units. However, there is no validated model using readily available variables in the electronic medical record data to identify critically ill patients with sepsis. The use of machine learning and electronic medical health records data to develop a predictive model can automate the identification of patients at high risk for sepsis-related organ dysfunction. The implementation of this tool can improve recognition of sepsis and prevent the progression of sepsis-related organ dysfunction leading to death.