Serum Histones in Dogs with Septic Peritonitis as a Prognostic Biomarker

Septic peritonitis (SP) is a life-threating condition. Extracellular histones exert cytotoxic, prothrombotic and proinflammatory effects. Determining prognosis for dogs suffering from SP remains challenging. Our objective was to investigate serum general histones concentrations (sHs) as biomarkers of disease severity and outcome in dogs with naturally occurring SP. Blood samples were collected upon admission and 24 hours post hospitalization from 21 dogs with SP and from 7 healthy controls. Serum general histone concentrations (median;IQR) upon admission were higher in dogs with SP compared to controls (34.2 ng/ml;39.1 ng/ml vs. 7.3 ng/ml;1.7 ng/ml; P  = 0.001) and sHs significantly decreased 24 hours post-hospitalization (34.4 ng/ml; 39.3 ng/ml vs. 24.2 ng/ml; 11 ng/ml; P  = 0.018). Serum histones were higher among survivors compared to non-survivors (45.5 ng/ml;37 ng/ml vs. 24.0 ng/ml;12 ng/ml; P  = 0.03). This data demonstrates that serum general histone concentrations significantly increase in dogs with SP and decrease after hospitalization. Future studies are warranted to investigate the reverse relationship between outcome and sHs.