Pattern of circulating cell-free DNA in trauma haemorrhagic shock

Background Severe trauma and injury may be associated with the release of inflammatory cytokines and the presence of circulating cell-free DNA (cfDNA). cfDNA is released by tissue damage, cell death, or dying cells in trauma haemorrhagic shock (T/HS) patients. However, the source and mechanism of release of cfDNA in T/HS is not well understood. Neutrophil extra-cellular traps (NETs) are the most common source of cfDNA, released by activated neutrophils during the process of NETosis. We aimed to determine the levels of cfDNA following T/HS at different time points after injury. Methods A prospective cohort study was done at Jai Prakash Narayan Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India, with three groups: T/HS patients, trauma victims without haemorrhagic shock (TVWHS), and healthy controls. Peripheral blood samples were collected and analysed for circulating cfDNA, protein C, myeloperoxidase (MPO, a marker of neutrophil activation), citrullinated histone H3 (a marker of NETosis), cyclophilin, and caspase-cleaved CK18 on hospital admission and follow-up days 3 and 7. Results A total of 60 patients were included, 20 each of T/HS, TVWHS patients and controls. The mean age was 32 years; 10% were women, and 90% were men, and mortality was 35% at 15 days. Circulating cfDNA were elevated in T/HS when compared to TVWHS and controls. Moreover, serum levels of MPO, CK18, and H3Cit were significantly elevated in T/HS patients. Conclusion Our study suggests that elevated circulating levels of cfDNA are present in T/HS patients.