Extracellular histones drive thrombo-inflammation in sepsis, stroke, and ARDS, review finds

This systematic review synthesizes existing literature on the role of extracellular histones as damage-associated molecular patterns (DAMPs) in thrombo-inflammation. The review covers conditions including sepsis, stroke, ARDS, COVID-19, and autoimmune disorders, though specific study populations, sample sizes, and settings are not reported. The focus is on the biological mechanisms rather than a specific clinical intervention or comparator.

The main findings describe mechanistic pathways. Histones are released during necrosis, apoptosis, and neutrophil extracellular trap (NET) formation. They engage receptors like Toll-like receptors (TLR2, TLR4, TLR9) to trigger endothelial dysfunction, platelet activation, and cytokine release. Post-translational modifications are noted to modulate their immunogenicity and procoagulant potential. These mechanisms are described as amplifying thrombin generation, impairing anticoagulant pathways, and promoting vascular permeability. Circulating histones and nucleosomes are presented as emerging biomarkers for disease severity and prognosis.

Therapeutic strategies mentioned include neutralizing antibodies, heparin derivatives, PAD inhibitors, and activated protein C, which are described as showing promise in mitigating histone-driven pathology. No safety, tolerability, or adverse event data for these strategies are reported. Key limitations include the review's nature; it summarizes proposed mechanisms and associations from the literature without presenting new primary data, effect sizes, or statistical certainty. Its practice relevance is framed as highlighting mechanistic insights and exploring translational opportunities, not as providing evidence for clinical application.