Objective: Sepsis causes millions of deaths on a global scale annually. Activation of peptidylarginine deiminase (PAD) enzymes in sepsis causes citrullination of histones, which results in neutrophil extracellular trap formation and sepsis progression. This study evaluates pan-PAD inhibitor, Cl-amidine, in a model of lipopolysaccharide (LPS)-induced endotoxic shock in rabbits. We hypothesized that Cl-amidine would improve survival and attenuate kidney injury.

Methods: In the survival model, rabbits were injected injected intravenously with 1 mg/kg of LPS, and then randomly assigned either to receive dimethyl sulfoxide (DMSO; 1 mcL/g) or Cl-amidine (10 mg/kg diluted in 1 mcL/g DMSO). They were then monitored for 14 days to evaluate survival. In the non-survival experiment, the same insult and treatment were administered, however; the animals were euthanized 12 hours after LPS injection for kidney harvest. Acute kidney injury (AKI) scoring was performed by a histopathologist who was blinded to the group assignment. Serial blood samples were also collected and compared.

Results: Rabbits that received Cl-amidine had a higher survival (72%) compared with the rabbits that received DMSO (14%; p < 0.05). Cl-amidine–treated rabbits had lower (p < 0.05) histopathologic AKI scores, as well as plasma creatinine and blood urea nitrogen (BUN) levels 12 hours after insult.

Conclusions: Pan-PAD inhibitor Cl-amidine improves survival and attenuates kidney injury in LPS-induced endotoxic shock in rabbits.