Increased plasma nucleosomes are associated with severe sepsis in foals

E M Birckhead; S L Raidal; S Das; S R Raidal

doi:10.1016/j.tvjl.2025.106297

Increased plasma nucleosomes are associated with severe sepsis in foals

Vet J. 2025 Jan 8:106297. doi: 10.1016/j.tvjl.2025.106297. Online ahead of print.

Authors

E M Birckhead¹, S L Raidal², S Das², S R Raidal²

Affiliations

¹ Gulbali Institute, School of Agricultural, Environmental and Veterinary Sciences, Faculty of Science and Health, Charles Sturt University, Locked Bag 588, Booroma St, Wagga Wagga, NSW 2678 Australia. Electronic address: ebirckhead@csu.edu.au.
² Gulbali Institute, School of Agricultural, Environmental and Veterinary Sciences, Faculty of Science and Health, Charles Sturt University, Locked Bag 588, Booroma St, Wagga Wagga, NSW 2678 Australia.

PMID: 39793919
DOI: 10.1016/j.tvjl.2025.106297

Abstract

Sepsis is a main cause of death in neonatal foals. While the syndrome is not completely understood, sepsis is a dysregulated inflammatory response of the host to infection. It can be difficult to diagnose because of varying and non-specific clinical signs and imperfect diagnostic tests. Increased circulating nucleosome levels have been detected in humans and animals with sepsis, but this has not been documented in foals. Nucleosomes are released extracellularly during neutrophil extracellular trap formation, as well as from damaged and dead cells. We analysed plasma samples from clinically healthy (n = 16), sick non-septic (n = 31) and septic (n = 36) foals using an enzyme-linked immunosorbent assay (ELISA) that targeted nucleosomes. Septic foals with evidence of hypoperfusion and/or organ dysfunction were classified as severe sepsis (n = 24). The main objective was to determine if nucleosome levels were increased in foals with sepsis, particularly those with severe sepsis. Our data identified that nucleosome levels in foals with severe sepsis on the day of study entry were increased significantly compared to all other foals. There was not a significant difference in nucleosome levels between sick non-septic or clinically healthy foals. Foal groups were not age-matched and factors associated with the clinical nature of the study may have affected the results. Further research with larger numbers of foals of similar ages, would be necessary to determine if the analysis of nucleosomes and related biomarkers are helpful adjuncts for the assessment and understanding of equine neonatal sepsis.

Keywords: ELISA; Foal; Nucleosomes; Sepsis.