Quantification of NLRP3-caspase-1 complex assembly reveals a non-linear association with 30-day mortality in sepsis: a proof-of-concept pilot study.

@article{mehl2026quantification,
  title = {{Quantification of NLRP3-caspase-1 complex assembly reveals a non-linear association with 30-day mortality in sepsis: a proof-of-concept pilot study.}},
  author = {Fabian Mehl and Willy J Chedjou and Andrea Witowski and Katharina Rump and Birte Dyck and Lars Bergmann and Christian Putensen and Dietrich Henzler and Michael Adamzik and Björn Koos and Patrick Thon and Tim Rahmel},
  journal = {Intensive care medicine experimental},
  year = {2026},
  month = oct,
  doi = {10.1186/s40635-026-00992-4},
  url = {https://europepmc.org/article/MED/42955163},
  note = {CC BY},
}

TY  - JOUR
TI  - Quantification of NLRP3-caspase-1 complex assembly reveals a non-linear association with 30-day mortality in sepsis: a proof-of-concept pilot study.
AU  - Fabian Mehl
AU  - Willy J Chedjou
AU  - Andrea Witowski
AU  - Katharina Rump
AU  - Birte Dyck
AU  - Lars Bergmann
AU  - Christian Putensen
AU  - Dietrich Henzler
AU  - Michael Adamzik
AU  - Björn Koos
AU  - Patrick Thon
AU  - Tim Rahmel
PY  - 2026
DA  - 2026/10/29
JO  - Intensive care medicine experimental
DO  - 10.1186/s40635-026-00992-4
UR  - https://europepmc.org/article/MED/42955163
AB  - 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.
SN  - 2197-425X
ER  -