Daily Sepsis Research Analysis
Analyzed 77 papers and selected 3 impactful papers.
Summary
Three studies advance sepsis science across mechanisms, prognosis, and diagnostics: (1) human data show long-term reprogramming of hematopoietic stem/progenitor cells after sepsis, driving myeloid dysfunction; (2) a large, externally validated cohort confirms a nonlinear association between the simple HALP score and in-hospital mortality; (3) ICU metagenomic sequencing (mNGS) links sampling strategy and specific pathogens to outcomes amid high multidrug resistance.
Research Themes
- Long-term immune reprogramming in sepsis survivors
- Pragmatic risk stratification using routine laboratory composites
- Metagenomic pathogen profiling and antimicrobial resistance in ICU sepsis
Selected Articles
1. Sepsis induces long-term reprogramming of human HSPCs and drives myeloid dysregulation in sepsis survivors.
In sepsis survivors, hematopoietic progenitors are durably reprogrammed, with expanded CD38+ and megakaryocyte-erythroid progenitors, impaired granulopoiesis, and macrophages showing metabolic suppression and enhanced type-I IFN/JAK-STAT signaling after LPS. IFNβ exposure recapitulated reduced HSPC proliferation, increased apoptosis, and glycolytic shift, implicating IFN-driven training/tolerance as a targetable axis.
Impact: Provides mechanistic human evidence that sepsis imprints long-lasting changes at the HSPC level, explaining persistent immune dysfunction and identifying IFN/JAK-STAT and metabolic pathways as intervention points.
Clinical Implications: Suggests monitoring and potentially modulating IFN signaling and cellular metabolism in sepsis survivors to restore myelopoiesis and innate immunity; supports development of interventions targeting long-term immunoparesis.
Key Findings
- Sepsis survivors showed expansion of CD38+ progenitors and megakaryocyte-erythroid progenitors with a near significant reduction in mature neutrophils.
- HSPC-derived macrophages from survivors displayed downregulated TCA cycle and glycolysis genes after LPS and enhanced type-I IFN/JAK-STAT signaling.
- IFNβ exposure to healthy HSPCs reduced proliferation, increased apoptosis, and shifted metabolism toward glycolysis, recapitulating survivor phenotypes.
Methodological Strengths
- Human cohort including sepsis survivors, septic shock patients, and healthy donors with functional differentiation assays
- Pathway-level analyses linking metabolic programs and IFN/JAK-STAT signaling to phenotypic changes
Limitations
- Small sample size and cross-sectional design without longitudinal follow-up
- Lack of interventional validation linking pathway modulation to clinical outcomes
Future Directions: Longitudinal survivor cohorts with single-cell multi-omics to map durability and reversibility; early-phase trials targeting IFN/JAK-STAT or metabolic rewiring to restore myelopoiesis.
BACKGROUND: Sepsis is a life-threatening condition characterised by an overwhelming immune response and high fatality. While most research has focused on its acute phase, many sepsis survivors remain immunologically weakened leaving them susceptible to serious complications from even mild infections. The mechanisms underlying this prolonged immune dysregulation remain unclear, limiting effective interventions. Here, we analysed whether sepsis induced long-term "training" in hematopoietic stem and progenitor cells (HSPCs), imprinting changes that persist in their myeloid progeny. RESULTS: Peripheral blood analysis of 8 sepsis survivors, 12 patients with septic shock, and 10 healthy donors revealed a significant expansion of CD38 + progenitors in survivors, with increased megakaryocyte-erythroid progenitors and a near significant reduction in mature neutrophil counts. This shift suggests impaired granulopoiesis, favouring immature, immunosuppressive granulocytes. Differentiated macrophages from survivors' HSPCs exhibited impaired metabolic pathways after lipopolysaccharide stimulation, with downregulation of tricarboxylic acid cycle and glycolysis genes, indicating altered immune metabolism. Pathway analysis revealed enhanced type-I interferon (IFN) and JAK-STAT signalling in survivors' macrophages, reflective of potentially tolerance-prone reprogramming. Finally, exposing healthy donor HSPCs to IFNβ during macrophage differentiation reduced HSPC proliferation, increased apoptosis, and induced a metabolic shift towards glycolysis over mitochondrial respiration. CONCLUSIONS: Together, these findings suggest that sepsis induces lasting reprogramming in HSPCs leading to myeloid progeny with altered immune memory that might drive immune dysregulation in survivors. These data open avenues to explore potential targets to better manage long-term immune alterations in sepsis survivors.
2. Association between HALP score and in-hospital mortality in sepsis patients: a multicenter retrospective cohort study with external validation.
Across 16,625 sepsis patients from two critical care databases, the HALP score showed a validated, nonlinear relationship with in-hospital mortality. Its construction from routine labs supports scalable risk stratification at admission.
Impact: Provides a pragmatic, externally validated prognostic tool using standard labs, enabling early risk stratification without additional testing.
Clinical Implications: Clinicians can incorporate HALP into early assessment to identify high-risk patients and tailor monitoring and resource allocation; decision thresholds may require local calibration due to nonlinear effects.
Key Findings
- Analyzed 16,625 Sepsis-3 patients with consistent, nonlinear associations between HALP and in-hospital mortality across two databases.
- Restricted cubic spline modeling confirmed nonlinearity and robustness in derivation and validation cohorts.
- The HALP score uses routine hemoglobin, albumin, lymphocyte, and platelet values, supporting practical bedside implementation.
Methodological Strengths
- Large sample size with external validation across two independent databases
- Use of restricted cubic splines to capture nonlinear risk relationships
Limitations
- Retrospective design with potential residual confounding and variability in lab timing
- Lack of predefined clinical thresholds for action tied to HALP categories
Future Directions: Prospective implementation studies to define actionable thresholds and assess impact on triage, resource use, and outcomes; integration with multi-marker panels and EHR alerts.
BACKGROUND: The HALP (Hemoglobin, Albumin, Lymphocyte, and Platelet) score integrates key parameters reflecting nutritional and immune status. However, its prognostic value for in-hospital mortality in sepsis patients remains underexplored. OBJECTIVE: To investigate the association between HALP score and in-hospital mortality in sepsis patients using two large critical care databases. METHODS: We conducted a retrospective cohort study including adult patients with Sepsis-3 from the eICU Collaborative Research Database (derivation cohort, RESULTS: A total of 16,625 patients were analyzed. RCS analysis demonstrated significant nonlinear associations between HALP and in-hospital mortality in both cohorts (overall CONCLUSION: The HALP score demonstrates robust prognostic value for predicting in-hospital mortality in sepsis patients, with consistent nonlinear relationships validated across two large databases. Its simplicity and reliance on routine laboratory parameters support potential clinical application in sepsis risk stratification.
3. Comprehensive analysis of microorganisms in severe septic patients in the intensive care unit by mNGS and microbial culture.
In 81 ICU patients (184 samples), RNA mNGS outperformed DNA mNGS for pathogenic detection, particularly in sputum and BAL, and detection patterns (e.g., top-1 DNA pathogen or 4–5 RNA pathogens) correlated with poor outcomes. Specific taxa (R. pickettii, C. difficile, S. enterica) were linked to higher mortality amid widespread multidrug resistance, supporting mNGS plus susceptibility testing to guide therapy.
Impact: Links specimen choice and mNGS modality to prognostically relevant findings in severe sepsis and highlights pervasive multidrug resistance, informing diagnostic and stewardship strategies.
Clinical Implications: Prioritize lower respiratory specimens (sputum/BAL) and consider RNA mNGS to maximize pathogen yield; integrate mNGS with culture-based susceptibility testing to tailor therapy, especially when MDR is likely.
Key Findings
- RNA mNGS detected more pathogenic organisms than DNA mNGS, with higher yields from sputum (83.3%) and BAL (75.0%) than blood.
- Detection patterns (top-1 DNA pathogenic microbe or 4–5 RNA pathogenic microbes) were associated with poorer clinical outcomes.
- Specific pathogens (R. pickettii, C. difficile, S. enterica) correlated with higher mortality; 89.5% had positive cultures with high MDR burden (≥1 resistant organism in all, ≥2 in 45.1%).
Methodological Strengths
- Parallel DNA and RNA mNGS across multiple specimen types with integration of culture and susceptibility testing
- Outcome associations linking specific taxa and detection patterns to prognosis
Limitations
- Single-center observational design with modest sample size
- Potential contamination and variability in sampling timing and indications
Future Directions: Prospective studies testing mNGS-guided therapy algorithms, cost-effectiveness, and standardized thresholds for clinical action by specimen type and readout (DNA vs RNA).
BACKGROUND: Severe sepsis is a life-threatening condition involving dysregulated systemic inflammatory responses and acute organ dysfunctions. Timely and accurate pathogen identification is critical for the effective treatment of severe septic patients in the intensive care unit (ICU). Although metagenomic next-generation sequencing (mNGS) enables the sensitive and unbiased detection of pathogens, its clinical implications in identification of causative pathogens, the association with the outcomes and the development of treatment regimens in such patients remain underexplored. METHODS: 184 clinical samples were collected from 81 severe septic patients and subjected to mNGS analysis. Blood and bronchoalveolar lavage fluid (BAL) samples were collected from the majority of patients, while sputum, cerebrospinal fluid (CSF), pleural effusion (PE), ascites, urine, hydropericardium (HPC) and blister effusion (BE) samples were also collected from select patients. Microorganisms were detected by DNA and RNA mNGS and the top 5 microorganisms detected by mNGS in each sample were used for analysis. Microbes were isolated from most patients and the isolates were tested for drug susceptibility. RESULTS: mNGS identified 183 top 5 microorganisms, with bacteria (92.3%), viruses (3.3%) and fungi (2.7%) as the major detected microbes. Among them, 40, 98 and 45 were pathogenic (21.9%), opportunistic (53.6%) and non-pathogenic (24.6%), respectively. Significantly more pathogenic microbes were detected in the sputum (83.3%) and the bronchoalveolar lavage fluid (BAL; 75.0%) than the blood by RNA mNGS (87.4%) than DNA mNGS (58.2%). Patients having the top-1 pathogenic microorganism detected by DNA mNGS or 4-5 pathogenic microorganisms detected by RNA mNGS had a poor association with clinical outcomes. Moreover, detection of R. pickettii, C. difficile and S. enterica were significantly associated with high mortality. The majority of patients (89.5%) were positive for microbial cultures. Each of these patients had at least one drug-resistant organism and nearly half (45.1%) were infected with two or more drug-resistant strains. CONCLUSIONS: Detection of predominant pathogenic microorganisms or particular bacteria in the sputum or BAL samples by mNGS are associated with poor clinical outcomes among severe septic patients in ICU in this cohort. The high prevalence of multidrug-resistant bacteria among these patients underscores the importance of integration of mNGS with antimicrobial susceptibility assessment in the clinical practice to develop the most effective treatment regimens.