Study On The Effect And Mechanism Of Neutrophils Extracellular Traps In Lower Limb Deep Venous Thrombosis

Objective: Deep venous thrombosis(DVT)is the most common complication in patients with traumatic fractures.In addition to exerting an antibacterial effect,the neutrophil extracellular trap(NETs)also promotes thrombus formation.In this prospective study,we investigated the role of NETs in thrombosis in patients with traumatic fractures and whether NETs biomarkers can be used to assisted diagnosis thrombosis risk in patients.Methods: Traumatic fractures patients were enrolled in this prospective observational cohort study from December 2018 to September 2019.Patients with traumatic fractures were divided into two groups according to whether or not thrombosis was formed.Vascular surgery patients who have developed thrombosis and normal people who have not formed thrombosis are also included.Plasma samples from all patients enrolled in the study were collected and NETs biomarker levels of Citrullinated Histone H3(H3Cit),cell-free DNA(cf DNA)and nucleosomes in the plasma were determined.The D-dimer level and FDP level in plasma was measured using the Sysmex CS-5100;a conventional coagulation test instrument in the laboratory.Statistical analysis of the test results was performed to assess changes in NETs biomarker levels during thrombosis in patients with traumatic fractures.Results: The H3 Cit levels in DVT group 1.88(1.11,3.35)ng/ml was significantly higher than Trauma non-DVT group 0.38(0.10,1.17)ng/ml(P<0.05).Trauma DVT group H3 Cit is 0.87(0.32,2.21)g/ml,which is higher than Trauma non-DVT group but there is no statistical difference.The level of cf DNA was significantly increased in patients with traumatic fractures,and it was higher after thrombosis than before.The cf DNA level in the DVT group was 216.15(185.76,253.53)ng/ml,the Trauma non-DVT group was 185.56(155.15,211.60)ng/ml,and the Trauma DVT group was 165.70(147.66,203.62),which were higher than the Control group at 135.08(117.90,153.74)ng/ml(P<0.05).The nucleosomes ratio was not statistically different between the groups.Similar to cf DNA,the levels of D-dimer in DVT group,Trauma DVT group,Trauma non-DVT group are 5.11(3.97,8.11)mg/l,6.12(2.59,18.49)mg/l,2.99(0.99,9.02)mg/l Higher than Control group was 0.18(0.08,0.24)mg/l(P<0.05).The distribution of FDP levels in each group was similar to that of D-dimer.The level of FDP in the DVT group,Trauma DVT group and Trauma non-DVT group was higher than that in the control group.Conclusions: NETs released by neutrophils are involved in the formation of DVT in patients with traumatic fractures.H3 Cit and cf DNA can assist the diagnosis of DVT in patients with traumatic fractures.