Abstract Background Direct, cell-resolved quantification of NLRP3 inflammasome activation in clinical patients has not been feasible. Previous studies have relied on indirect surrogates such as downstream cytokines, which are influenced by inflammasome-independent pathways and systemic clearance kinetics, potentially explaining the inconsistent prognostic findings reported in the literature. We applied a proximity ligation assay (PLA) to directly visualise NLRP3-caspase-1 complex formation in peripheral blood mononuclear cells of septic patients, providing a cell-specific, in situ readout of inflammasome assembly at the single-cell level. Methods In this prospective, multicentre proof-of-concept pilot study, 78 patients fulfilling Sepsis-3 criteria were enrolled across three university hospitals. The PLA was validated in THP-1-derived macrophages against established readouts of canonical inflammasome activation prior to clinical application. Patients were stratified into low (n = 28), intermediate (n = 23), and high (n = 27) NLRP3 inflammasome activity groups. Results Median age was 64 years (IQR: 56-78), 63% were male, and median Sequential Organ Failure Assessment score was 8 (IQR: 4-12). Baseline characteristics, disease severity scores, and routine inflammatory biomarkers did not differ across activity groups. Kaplan-Meier analysis revealed a non-linear pattern of 30-day survival, with the most favourable outcomes in the intermediate activity group. Both low and high activity were associated with increased mortality (log-rank p = 0.003). In adjusted Cox regression, low inflammasome activity (HR 7.88, 95% CI 1.79-34.65; p = 0.006) and high inflammasome activity (HR 4.35, 95% CI 1.01-19.88; p = 0.048) remained associated with 30-day mortality. Modelling PLA activity as a continuous variable using restricted cubic splines confirmed a significant non-linear association with 30-day mortality, independent of the tertile-based categorisation (p for non-linearity = 0.015). Conclusions This proof-of-concept pilot study demonstrates that direct in situ quantification of NLRP3–caspase-1 complex assembly is feasible in septic patients and reveals a non-linear association with 30-day survival. These findings indicate that PLA-based profiling captures immune heterogeneity beyond routine inflammatory biomarkers. Larger independent cohorts are needed to validate these findings before clinical application or patient stratification can be considered.
Abstract Background Septic shock due to streptococcal infection (SRSS) carries a high mortality and is in part driven by toxin-mediated inflammation. Therapeutic plasma exchange (TPE) may modulate the septic host responses by removing injurious mediators while replenishing protective plasma factors, but data specific to SRSS is lacking. We performed a retrospective, multicenter, cohort study of adults with SRSS between 2012–2024. Methods Patients from three tertiary care ECMO centers in Germany and Switzerland were included requiring (i) streptococcal spp. detected in blood or primary focus and (ii) septic shock according to sepsis-3 definition. Adjunctive TPE with fresh frozen plasma at the intensivists` discretion was compared with standard of care (SOC). The primary outcome was 90-day-hospital mortality. Key exploratory outcomes included 24-h kinetics of vasoactive-inotropic score(VIS) and lactate, as well as SRSS-related complications. Results were validated in a 1:1 propensity score–matched (PSM) cohort. Results Of 149 patients, 31 (20.8%) received TPE and 118 (79.2%) SOC. TPE patients were more severely ill at baseline: SOFA 14 (IQR 13.5–15) vs 11 (IQR 8–14) (p<0.001); lactate 6.4 vs 2.8 mmol/L (p<0.001); Vasoactive-Inotropic-Score (VIS) 70.7 vs 23.3 (p<0.001); more frequent invasive ventilation (87% vs 65%), VV-ECMO (36% vs 19%), and renal replacement therapy (96.8% vs 52.5%). Overall, 90-day hospital mortality was 27.5% (TPE 29.0%, SOC 27.1%). Following SOFA-score adjustment, TPE was associated with lower mortality risk (aHR 0.67 [95% CI 0.5–0.9]; p=0.009). This was validated in the PSM cohort, with an aHR for TPE of 0.44 (95% CI 0.3–0.8); p=0.002. Mixed-effects modeling demonstrated a significant VIS reduction only with TPE (fixed effect 24-h change, p=0.027) and improved lactate decrease versus SOC. Conclusion In SRSS, adjunctive TPE was associated with rapid hemodynamic stabilization and improved lactate kinetics. Exploratory adjusted survival analyses support prospective evaluation of TPE in SRSS.
Pancreatic stone protein (PSP) has been proposed as a prognostic biomarker in sepsis, but its comparative performance versus C-reactive protein (CRP) and procalcitonin (PCT) remains uncertain. We performed a meta-analysis of direct within-study paired AUC comparisons between PSP and CRP and/or PCT in critically ill adults with sepsis, septic shock, or acute infection-related conditions in whom sepsis development or clinically relevant adverse outcomes were prospectively evaluated. Differences in AUC (ΔAUC) were pooled using random-effects models. The principal conservative analysis included one comparison per independent cohort and comparator. Seven studies comprising 803 unique participants contributed 21 paired comparisons. In the principal conservative analysis, PSP showed a higher prognostic AUC than CRP, with a pooled ΔAUC of 0.179 (95
Abstract Mechanical ventilation–associated acute kidney injury (AKI) represents a complex manifestation of lung–kidney cross-talk driven by hemodynamic alterations, neurohumoral activation, systemic inflammation and disturbances in gas exchange and acid–base homeostasis. Beyond static ventilatory settings, increasing evidence suggests that dynamic fluctuations in airway and perfusion parameters, including static driving pressure (ΔP), positive end-expiratory pressure (PEEP), mean airway pressure (P mean ), and effective renal perfusion pressure (eRPP) may substantially influence renal vulnerability during mechanical ventilation. This comprehensive narrative review synthesizes current mechanistic and clinical evidence on the relationship between mechanical ventilation and AKI and proposes an integrated framework for future research on the interplay between ventilatory stress, venous congestion, renal perfusion, and inflammatory injury. Emerging bedside tools such as renal Doppler indices, venous excess ultrasound score (VExUS), and kidney injury biomarkers are discussed as components of an integrated physiologic approach for early recognition and risk stratification of ventilator-associated AKI. We further propose a multimodal conceptual framework integrating respiratory mechanics, congestion assessment, perfusion monitoring, and biomarkers to support individualized kidney-protective ventilation strategies. Future research should prioritize standardized physiologic monitoring, time-varying exposure analyses, causal mediation approaches, and prospective multicenter studies to better define renal-protective ventilatory targets and advance precision critical care.
