Plasma HMGB1 levels in postoperative delirium

Editor—Animal models of short-term perioperative neurocognitive disorders (PNDs) have emphasised changes in damage-associated molecular patterns (DAMPs) such as high mobility group box protein 1 (HMGB1). 1 Terrando N. Yang T. Wang X. et al. Systemic HMGB1 Neutralization prevents postoperative neurocognitive dysfunction in aged rats. Front Immunol. 2016; 7: 441 Crossref PubMed Scopus (67) Google Scholar ,2 Vacas S. Degos V. Tracey K.J. Maze M. High-mobility group box 1 protein initiates postoperative cognitive decline by engaging bone marrow-derived macrophages. Anesthesiology. 2014; 120: 1160-1167 Crossref PubMed Scopus (107) Google Scholar The innate immune response to trauma is activated by HMGB1, which leads to the downstream release of proinflammatory cytokines, blood–brain barrier disruption, and postoperative cognitive decline. 3 Saxena S. Kruys V. De Jongh R. Vamecq J. Maze M. High-mobility group box-1 and its potential role in perioperative neurocognitive disorders. Cells. 2021; 10: 2582 Crossref Scopus (5) Google Scholar Suppression of HMGB1 has been shown to prevent surgery-induced PNDs in rats 1 Terrando N. Yang T. Wang X. et al. Systemic HMGB1 Neutralization prevents postoperative neurocognitive dysfunction in aged rats. Front Immunol. 2016; 7: 441 Crossref PubMed Scopus (67) Google Scholar and mice. 2 Vacas S. Degos V. Tracey K.J. Maze M. High-mobility group box 1 protein initiates postoperative cognitive decline by engaging bone marrow-derived macrophages. Anesthesiology. 2014; 120: 1160-1167 Crossref PubMed Scopus (107) Google Scholar Although the half-life of HMGB1 is very short, elevated HMGB1 levels have been reported up to 24 h after surgery in rodents. 1 Terrando N. Yang T. Wang X. et al. Systemic HMGB1 Neutralization prevents postoperative neurocognitive dysfunction in aged rats. Front Immunol. 2016; 7: 441 Crossref PubMed Scopus (67) Google Scholar We sought to ascertain whether postoperative day 1 increases in HMGB1 are associated with acute delirium, a type of PND. 4 Subramaniyan S. Terrando N. Neuroinflammation and perioperative neurocognitive disorders. Anesth Analg. 2019; 128: 781-788 Crossref PubMed Scopus (151) Google Scholar