Daily Sepsis Research Analysis

Time-course monitoring of blood biomarkers with rapid turnaround has the potential to revolutionize the diagnosis, stratification of phenotypes, and therapeutic/prognostic approaches for various acute inflammatory diseases in both clinical and preclinical studies. Current approaches, however, are hampered by slow turnaround times and large sample volume requirements, limiting the exploration of disease mechanisms and therapeutic strategies. Here, we developed a microfluidic digital ELISA platform prototype, combining single-molecule counting with whole blood assay capability for the first time from small animal models. This platform is semi-automated and enables repeated, rapid biomarker monitoring with just 3.5 μL of whole blood collected from the tail. Our platform demonstrated high sensitivity and multiplexity, allowing real-time cytokine profiling within a 2-h turnaround. Using a murine sepsis model, we achieved precise temporal monitoring of cytokine levels, demonstrating prognostic capability by correlating early-stage cytokine levels with a liver-injury biomarker. This microfluidic platform enables high temporal resolution and rapid monitoring of biomarker dynamics in a single mouse using freshly collected whole blood, significantly reducing the number of animals needed for preclinical studies. This technology has strong potential to transform ICU therapeutic strategies and preclinical research, enabling personalized treatment based on real-time biomarker profiles.

BACKGROUND: Serial measurements of C-reactive protein (CRP) are often taken in hospitals to assess recovery from infection, but their utility remains debated. Previous studies, including our development of CRP centile reference charts for suspected bloodstream infections (BSI), suggest variability in CRP responses across infection types. Here we investigated the association between serial CRP percentile changes, antibiotic prescribing patterns, and patient outcomes in a large cohort with suspected infection, acknowledging that CRP is one of multiple factors in clinical decision-making. METHODS: We analysed 51,544 suspected infection episodes (defined by blood culture collection) from 36,578 patients in Oxfordshire, UK (2016-2021). Episodes were categorised by blood culture results: Gram-positive, Gram-negative, polymicrobial, contaminants, or culture-negative (having previously shown that 51% culture-negatives have CRP responses indistinguishable from culture-positives). The spectrum of antibiotic prescriptions and their changes over time were tracked. Multinomial logistic regression, adjusted for clinical covariates, assessed the association between CRP percentile changes and subsequent prescribing decisions. Linear mixed models evaluated CRP trajectories post-prescribing, and logistic regression associations between early CRP changes (days 1-4) and 5-30-day mortality. RESULTS: Broad-spectrum antibiotics were predominantly used within the first three days after blood culture collection, followed by a notable shift to narrow-spectrum antibiotics for Gram-positive infections, but with slower de-escalation for Gram-negative and polymicrobial infections. CRP percentile changes were modestly associated with subsequent antibiotic adjustments; in particular, suboptimal recovery, indicated by an increase in CRP centiles, was associated with a higher rate of antibiotic escalation (16.5% vs. 10.7% in expected recovery) and, conversely, faster than expected recovery in CRP was associated with de-escalation (23.6% vs. 17.2%). However, 61.8% of decisions were unchanged despite CRP trends. The relationship between various prescribing decisions and subsequent CRP percentile changes was complex and challenging to estimate, likely due to testing bias. CRP percentile changes during the 4 days post blood culture collection were strongly associated with 5-30-day mortality, highlighting their potential utility as a prognostic indicator. CONCLUSIONS: While CRP monitoring can inform antibiotic stewardship, its association with prescribing decisions is probably only modest, underscoring the need to integrate a range of clinical factors to optimise infection management.

INTRODUCTION: Neutrophil extracellular traps (NETs) play a critical role in inflammation and coagulation imbalance. Recent studies have demonstrated that activation of gasdermin D (GSDMD) protein and its pore-forming activity are essential drivers of NET generation. This study investigated the association between GSDMD-NETs axis activation and sepsis-induced coagulopathy (SIC), as well as the potential association with glycocalyx damage. MATERIALS AND METHODS: A prospective cohort of 70 sepsis patients (35 with SIC, 35 non-SIC) admitted to a respiratory intensive care unit was analyzed. This study was registered at the Chinese Clinical Trial Registry (ChiCTR) with the registration number ChiCTR2500100284. The trial can be accessed at https://www.chictr.org.cn/bin/project/edit?pid=266738. Plasma levels of GSDMD-NETs biomarkers (N-GSDMD, MPO-DNA) and glycocalyx injury markers (syndecan-1, MMP-9) were measured via ELISA. Clinical outcomes, thrombotic/hemorrhagic events, and biomarker correlations were evaluated using logistic regression, ROC analysis, and Pearson's correlation. RESULTS: Compared to non-SIC patients, the SIC group exhibited higher rates of viral infections (31.4% CONCLUSION: The activation of the GSDMD-NETs axis is strongly associated with the development of SIC, glycocalyx injury, and adverse clinical outcomes in sepsis, potentially contributing to these pathological processes. Plasma N-GSDMD and MPO-DNA serve as predictive biomarkers for SIC severity and mortality, highlighting their potential role in targeted therapeutic strategies.