Daily Sepsis Research Analysis
Three impactful studies advanced sepsis science across genetics, epidemiology, and mechanism. A multi-cohort GWAS/Mendelian randomization study identified a novel susceptibility locus (GALNTL6) and implicated obesity and lipid traits as potential causal contributors to sepsis-associated AKI. An ECIL systematic review quantified rising Gram-negative resistance in hematologic malignancy/HCT patients and clarified trade-offs of fluoroquinolone prophylaxis, while an experimental study revealed KLF6-
Summary
Three impactful studies advanced sepsis science across genetics, epidemiology, and mechanism. A multi-cohort GWAS/Mendelian randomization study identified a novel susceptibility locus (GALNTL6) and implicated obesity and lipid traits as potential causal contributors to sepsis-associated AKI. An ECIL systematic review quantified rising Gram-negative resistance in hematologic malignancy/HCT patients and clarified trade-offs of fluoroquinolone prophylaxis, while an experimental study revealed KLF6-driven ferroptosis via NCOA4 as a targetable pathway in septic AKI.
Research Themes
- Genetic susceptibility and metabolic causality in sepsis-associated AKI
- Antimicrobial resistance trends and prophylaxis trade-offs in immunocompromised patients
- Mechanistic pathways (ferroptosis) driving organ injury in sepsis
Selected Articles
1. Obesity- and Lipid-Related Traits May Causally Contribute to Sepsis-Associated Acute Kidney Injury.
A discovery GWAS with two-sample Mendelian randomization identified GALNTL6 as a novel susceptibility locus for septic AKI and implicated obesity and VLDL-related lipid traits as potential causal contributors. Findings replicated across two independent septic shock cohorts, and several lipid classes showed strong associations, supporting metabolic pathways in S-AKI pathogenesis.
Impact: This is one of the first multi-cohort genetic causality studies linking cardiometabolic traits to septic AKI, offering a mechanistic bridge between host metabolism and organ injury. It provides targets for risk stratification and therapeutic exploration.
Clinical Implications: Supports incorporating obesity and lipid profiles into S-AKI risk stratification for septic patients and motivates trials testing metabolic interventions (e.g., lipid modulation) to mitigate AKI risk.
Key Findings
- Discovery GWAS (4,584 cases vs 7,090 controls) identified a novel S-AKI locus at GALNTL6 (rs149773593; OR 2.18; p=3.0×10−8)
- Two-sample MR implicated obesity and VLDL-related lipid traits as potential causal contributors to S-AKI
- Associations for multiple lipid classes (cholesterol ester, lysophosphatidylcholine, phosphatidylcholine, phosphatidylethanolamine) replicated across FinnGen and two septic shock cohorts
- Higher BMI associated with increased serum creatinine in two independent septic shock cohorts (p<0.0001)
Methodological Strengths
- Multi-cohort design with discovery and replication across independent septic shock cohorts
- Use of two-sample Mendelian randomization to infer causality and mitigate confounding
Limitations
- Case-control GWAS design may be susceptible to selection bias and phenotype misclassification of sepsis/AKI
- Pleiotropy in MR instruments cannot be fully excluded; functional validation of GALNTL6 is pending
Future Directions: Functional studies to elucidate GALNTL6 biology in kidney and immune cells; prospective trials of lipid-modulating or weight-loss interventions to reduce S-AKI in high-risk septic patients.
OBJECTIVES: Acute kidney injury (AKI) is a major complication of sepsis resulting in substantial morbidity and mortality. We used genome-wide association study (GWAS) data together with Mendelian randomization (MR) analysis in multiple cohorts of different ancestries to identify traits potentially contributing to sepsis-associated AKI (Septic-AKI). DESIGN: Natural experiment and case-control study. SETTING: ICU patients, FinnGen ( finngen.fi ), and U.K. Biobank participants. PATIENTS: Adults with sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We conducted a discovery GWAS in the U.K. Biobank by selecting, after quality control, 4584 European Septic-AKI patients as cases, and 7090 European sepsis patients without AKI as controls. Causal inference analyses using two sample MR combined these GWAS results with Integrative Epidemiology Unit Open Genome-Wide Association Studies results for 118 clinical risk factors and 386 metabolites and, separately, for 13 lipid classes from FinnGen GWAS results. We tested for replication of positive findings in two independent genotyped septic shock cohorts (Vasopressin and Septic Shock Trial [VASST] cohort n = 632 and Japanese Septic Shock Cohort [Chiba] cohort n = 536). Variants in the GALNTL6 gene were associated with Septic-AKI (rs149773593; odds ratio = 2.18; p = 3.0 × 10 -8 ) in U.K. Biobank patients. GALNTL6 is associated with cardiometabolic traits, which we then focused on. Increased body mass index was associated with increased serum creatinine in both septic shock cohorts ( p < 0.0001). Obesity and metabolic traits, most frequently related to very low-density lipoprotein, were identified as potentially causal contributors to Septic-AKI. Combining these GWAS results with FinnGen GWAS results identified associations with Septic-AKI, which replicated in both independent septic shock cohorts, for cholesterol ester ( p = 4.8 × 10 -44 ), lysophosphatidylcholine ( p = 8.5 × 10 -54 ), phosphatidylcholine ( p = 2.7 × 10 -39 ), and phosphatidylethanolamine ( p = 2.1 × 10 -28 ). CONCLUSIONS: For Septic-AKI, GWAS identified a novel genetic susceptibility locus ( GALNTL6 ), which is also associated with cardiometabolic traits. We then further found that obesity- and lipid-related traits are possible contributors to the pathogenesis of Septic-AKI.
2. Epidemiology of resistant bacterial infections in patients with hematological malignancies or undergoing hematopoietic cell transplantation in Europe: A systematic review by the European Conference on Infections in Leukemia (ECIL).
Across 40 studies in 12 European countries, Gram-negative resistance in hematologic malignancy/HCT patients was high (FQ-R 55%, ESBL/3GCR 30%, CR and MDR 13%), with notable elevations in Pseudomonas and Klebsiella. Fluoroquinolone prophylaxis reduced overall and GN BSI incidence but increased FQ-R and ESBL/3GCR infections in adults, underscoring complex stewardship trade-offs.
Impact: Provides a PRISMA-registered, Europe-wide synthesis informing empirical therapy and prophylaxis strategies in a high-risk population where sepsis is common and lethal. Quantifies geographic gradients and temporal resistance trends critical for guideline updates.
Clinical Implications: Encourages center- and region-specific empirical regimens, cautions on indiscriminate fluoroquinolone prophylaxis in adults, and supports rapid diagnostics and stewardship to balance infection prevention with resistance mitigation.
Key Findings
- Median resistance among Gram-negative BSIs: FQ-R 55%, ESBL/3GCR 30%, carbapenem-resistant 13%, MDR 13%
- Carbapenem resistance reached 26% in Pseudomonas aeruginosa and 38% in Klebsiella pneumoniae
- Fluoroquinolone prophylaxis reduced overall and Gram-negative BSI incidence but increased FQ-R and ESBL/3GCR infections in adults
- Southeastern Europe showed higher resistance; temporal increases corroborated by ECDC/EARS-Net data
Methodological Strengths
- PRISMA-compliant, registered systematic review with dual independent extraction
- Integrated analysis with European surveillance (ECDC/EARS-Net) to contextualize trends
Limitations
- Predominantly observational data with heterogeneity across centers and time
- Limited and inconclusive pediatric resistance data, especially in HCT
Future Directions: Prospective, multicenter studies to evaluate tailored prophylaxis and empiric therapy strategies; implement and assess rapid diagnostics and stewardship programs, especially in high-resistance regions.
BACKGROUND: Patients with hematological malignancies (HM) or undergoing hematopoietic cell transplantation (HCT) face high risk of bloodstream infections (BSI) during febrile neutropenia. Rising antimicrobial resistance (AMR), especially among Gram-negative (GN) bacteria, challenges effective empirical antibiotic therapy (EAT) selection. This ECIL-10 systematic review updates European resistance epidemiology since the 2011 ECIL-4 guidelines publication to inform clinical recommendations. METHODS: We conducted a systematic review (ID: CRD42025638003) of bacterial epidemiology and resistance in HM/HCT patients across Europe, from June 2011 to September 2024, using PubMed, Embase, and Web of Science according to PRISMA guidelines. We included studies reporting BSI or colonization rates and resistance patterns, including extended-spectrum beta-lactamase-producing/third-generation cephalosporin-resistant (ESBL/3GCR), fluoroquinolone-resistant (FQ-R) carbapenem-resistant (CR), and multidrug-resistant (MDR) for GN bacteria; methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) for Gram-positive (GP) bacteria. Two reviewers independently extracted data with ECDC/EARS-Net surveillance 2011 and 2022 data providing supporting analysis. We examined fluoroquinolone prophylaxis (FQ-P) impact on BSI rate and resistance. RESULTS: Analysis included 40 studies (33,387 patients/febrile episodes from observational studies and 21,402 patients from one meta-analysis) across 12 European countries. BSI prevalence averaged 30% (range, 15-59%), with 42% GN and 51% GP distribution. Median resistance rates among GN BSI were: 55% for FQ-R, 30% for ESBL/3GCR, 13% for both CR and MDR. CR reached 26% in P. aeruginosa (PsA) and 38% in K. pneumoniae (KPn). Among GP BSI resistance was 3% for MRSA and 1% for VRE. Colonization studies demonstrated 20% ESBL/3GCR and 5% CR rates. We identified a southeastern European resistance gradient and significant temporal increase in ESBL/3GCR, CR KPn, and MDR PsA, confirmed in ECDC/EAR-Net analysis. FQ-P reduced overall and GN BSI incidence but increased FQ-R and ESBL/3GCR GN infections in adults. In children, FQ-P reduced BSI in leukemia but not in HCT and data on resistance were inconclusive. ECIL-10 proposed resistance reporting aligned with ESCMID/IDSA guidelines. CONCLUSIONS: AMR presents an escalating challenge in febrile neutropenic HM/HCT patients with geographical variability and increasing resistance trends. These findings strongly support the need for updated guidelines, antimicrobial stewardship programs, rapid diagnostics implementation, and prospective studies to optimize effective empirical therapy strategies.
3. KLF6 enhances ferroptosis in S-AKI through the NCOA4/ACSL4/LPCAT3 axis.
In murine CLP sepsis and in vitro models, KLF6 upregulation aggravated kidney injury by promoting ferroptosis via transcriptional activation of NCOA4. AAV9-mediated KLF6 knockdown and pharmacologic KLF6 inhibition reduced lipid peroxidation and injury, positioning the KLF6–NCOA4 axis as a therapeutic target in septic AKI.
Impact: Reveals a previously unrecognized transcriptional control point for ferroptosis in septic AKI, supported by complementary genetic and pharmacologic interventions. Identifies a tractable pathway for drug development.
Clinical Implications: Suggests that targeting KLF6 or its downstream NCOA4-mediated ferritinophagy/ferroptosis could mitigate septic kidney injury; informs biomarker exploration and timing of antioxidant or ferroptosis-modulating therapies.
Key Findings
- KLF6 expression increased in renal injury models; overexpression aggravated, while AAV9-mediated knockdown alleviated septic kidney injury
- KLF6 directly bound the NCOA4 promoter, increasing NCOA4 and promoting ferroptosis; NCOA4 knockdown mitigated KLF6-induced injury
- Pharmacologic inhibition of KLF6 reduced lipid peroxidation and ferroptosis in S-AKI mice
Methodological Strengths
- Mechanistic validation across in vivo (CLP model) and in vitro systems
- Multiple orthogonal assays (ChIP-qPCR, luciferase reporter, TEM) and both genetic and pharmacologic perturbations
Limitations
- Preclinical mouse and cell models may not fully recapitulate human S-AKI
- Sample sizes and dosing regimens are not detailed for translational scaling; off-target effects of inhibitors cannot be excluded
Future Directions: Validate KLF6–NCOA4 signaling and ferroptosis markers in human septic AKI samples; develop/select selective KLF6 modulators; test combination with iron/ROS-targeting strategies in translational models.
BACKGROUND: Septic acute kidney injury (S-AKI) is a major cause of acute kidney injury (AKI), but no effective therapies exist to prevent or treat it. Although KLF6 is linked to various pathophysiological processes, its exact role in S-AKI is not yet fully understood. METHODS: The role of KLF was investigated using both the mouse CLP model and in vitro systems. To identify the transcriptional targets regulated by KLF6, ChIP-qPCR and luciferase reporter assays were carried out. Biochemical and cellular techniques were employed to assess cellular injury and lipid peroxidation levels. The extent of ferroptosis was evaluated through transmission electron microscopy (TEM). RESULTS: KLF6 levels were significantly increased in a renal IRI model. Knockdown of KLF6 using AAV9 reduced kidney injury in both in vitro and in vivo models, while KLF6 overexpression aggravated injury. Overexpression of KLF6 promoted ferroptosis, whereas its knockdown reduced lipid peroxidation and ferroptosis. KLF6 regulates NCOA4 expression by binding to its promoter, controlling ferroptosis. Knockdown of NCOA4 in vitro alleviated ferroptosis and cellular damage caused by KLF6 overexpression. Pharmacological inhibition of KLF6 reduced kidney injury and ferroptosis in S-AKI mice. CONCLUSION: Our study uncovered a previously unrecognized role for KLF6 in S-AKI. By facilitating NCOA4 transcription, KLF6 intensified ferroptosis, which, in turn, aggravated septic AKI.