Relationship Between Dynamic Changes Of Immune Function And Prognosis In Trauma Patients

Objective:Trauma is a major public health problem in today’s society.Sepsis is one of the main causes of hospital deaths after trauma,and the occurrence of sepsis is closely related to immune dysfunction after injury.In this study,we used flow cytometry to detect immune cell surface markers in order to explore the changes of immune function in trauma patients and screen out possible biomarkers for early warning of sepsis.Methods:Peripheral blood of trauma patients with AIS≥3 was collected according to inclusion and exclusion criteria.The dynamic changes of population and function of immune cells in patients at 1st,3rd,5th,7th and 14th day after injury were detected by flow cytometry.Clinical data including physical signs,biochemical test and bacteria culture were collected within 28 days after injury.The changes of the above indexes and their clinical correlation with post-traumatic sepsis and other complications were analyzed.Results:Measured by flow cytometry,results showed that,compared to healthy controls,the proportion of CD4~+T lymphocytes,Tregs and B lymphocytes,CD64 index,CD4~+/CD8~+ratio,and NLR increased,the proportion of CD8~+T lymphocytes,NK cells and the positive rate of HLA-DR in monocytes decreased in trauma patients,with significant differences at one timepoint at least.Within 14 days after injury,the proportion of CD3~+T lymphocytes in septic patients showed a gradually increasing trend,the proportion of B lymphocytes in septic patients showed a gradually decreasing trend,the proportion of CD4~+T lymphocytes and the positive rate of HLA-DR in monocytes in septic patients decreased initially and then increased.Compared to non-sepsis group,the proportion of CD3~+T lymphocytes,proportion of CD4~+T lymphocytes,positive rate of HLA-DR in monocytes and CD4~+/CD8~+ratio decreased in sepsis group,NLR and CD64 index increased in sepsis group,with differences at one timepoint at least.According to ISS,trauma patients were divided into three groups,containing 22 severe trauma patients with ISS greater than 25scores,35 moderate trauma patients with ISS between 16 and 25 scores,and 61mild trauma patients with ISS less than 16 scores.Among different injury groups,at1st day after injury,the proportion of CD3~+T lymphocyte and the positive rate of HLA-DR in monocytes of patients with severe injury were significantly lower than those of patients with mild injury,the proportion of B lymphocytes and NLR of patients with severe injury were significantly higher than those of patients with mild injury,CD64 index of patients with severe injury was significantly higher than that of patients with moderate injury.At 3rd day after injury,the proportion of CD4~+T lymphocytes of patients with severe injury was significantly lower than that of patients with moderate injury.At 5th day after injury,the NLR of patients with severe injury and moderate injury was significantly higher than that of patients with mild injury,CD64 index of patients with severe injury was significantly higher than that of patients with moderate injury.At 7th day after injury,the positive rate of HLA-DR in monocytes of patients with severe injury was significantly lower than that of patients with moderate injury,NLR of patients with severe injury was significantly higher than that of patients with mild injury.At 14th day after injury,the proportion of Tregs of patients with severe injury was significantly higher than that of patients with moderate injury,and NLR of patients with severe injury was significantly higher than that of patients with moderate and mild injury.Correlation analysis showed that the proportion of Tregs and B lymphocytes,NLR was positively correlated with ISS score(P<0.05),while the proportion of CD3~+T lymphocytes and positive rate of HLA-DR in monocytes was negatively correlated with ISS score(P<0.05),the proportion of B lymphocytes were positively correlated with SOFA score(P<0.05),while the proportion of CD3~+T lymphocytes,CD4~+CD28~+T lymphocytes,CD8~+CD28~+T lymphocytes and positive rate of HLA-DR in monocytes were negatively correlated with SOFA score(P<0.05),the proportion of B lymphocytes was positively correlated with APACHEII score(P<0.05),while the proportion of CD4~+CD28~+T lymphocytes and CD8~+CD28~+T lymphocytes was negatively correlated with APACHEII score(P<0.05).Conclusion:Cellular immune biomarkers including NLR,CD64 index and positive rate of HLA-DR in monocytes are correlated with injury severity and prognosis of trauma patients,and may be used as early indicators of sepsis,monitoring these indicators may contribute to the assessment of injury and prognosis of trauma patients.