The Dynamic Change Of Serum Erythropoietin Receptor And Its Clinical Significance In Trauma Patients

Background Trauma has become the fourth leading cause of death, the first cause of death in young people. The number of traffic injury in the past10years has went up by81%. WTO expects that, to2020, the number of road traffic injuries to death and disability will be increased by60%in the world, and the rank will jump from the ninth in1990to the third place. Therefore, trauma has been the focus of study both at home and abroad.Traumatic brain injury (TBI) and traumatic shock are the main causes of of death in acute trauma. Research has shown that erythropoietin (Epo) can reduce damage of trauma, improve prognosis. Erythropoietin receptor (EpoR) is an important mediator. EpoR is an acrossing membrane protein composed of508amino acids, with82%homology between human and rats.The structure can be divided into three parts:part outside boundaries, cross inside the cell membrane area, part of the district. The combination of Epo and EpoR promote EpoR crosslinking to dimers, leading EpoR related tyrosine kinase JAK-2phosphorylation, making more signal way phosphorylation, finally starting a series of antiapoptotic mechanisms. EpoR combinated with Epo can induce cells with ubiquitin-proteasome change, and EpoR will be degradated by protease and lysosome. There are few EpoR can recycling in the cell membrane. The animal studies show that post-traumatic EpoR concentration maintains at high levels for a long time, and it may be relevant to the degree of damage. The level and the dynamic change meaning of EpoR in human are unclear. In this paper, we study the dynamic change of serum erythropoietin receptor and its clinical significance in trauma patients of different severity, type and prognosis.Objective To measure the dynamic change of serum erythropoietin receptor in trauma patients and evaluate its significance.Method It is a prospective observation study. The concentration of serum erythropoietin receptor in47trauma patients was detected at hours0,24and day7after injury. In the meantime, white blood cell, hemoglobin,blood sugar were measured and recorded; injury severity score(ISS), Glasgow coma score(GCS), and APACHE II at hours0were also recorded. The patients were divided into TBI and shock groups according to the nature of injury, and moderate and severe injury group according to the ISS score. Survial and death groups were divided based on the28day outcome.Peripheral venous blood specimens were collected at corresponding time.20healthy adults were used as normal controls. The collected blood samples were rested for1hour at room temperature, and centrifuged at3000RPM for10min.The serum were stored at-80℃until testing. ELISA method (ELISA) was used to test EpoR serum concentrations.Statistical software SPSS16.0was used, the dynamic change of serum EpoR concentration was analyzed. We studied the dynamic change of serum erythropoietin receptor and its clinical sigificance in trauma patients of different damage degree, types and different prognosis. The characteristics and differences EpoR serum concentration in trauma patients of different damage degree, types and different prognosis were compared. The correlation of the serum erythropoietin receptor concentration with whether there was chest trauma, whether there were limbs or spine fracture, ISS, GCS, APACHE Ⅱ, WBC, hemoglobin and blood glucose was investigated. The we possible clinical significance of EpoR was evaluated.Results EpoR concentration of trauma patients after injury increased significantly, with the peak at24th hour, and slow down gradually. The serum erythropoietin receptor concentration between24th hour and7th day had little difference. The serum erythropoietin receptor concentration in both shock and TBI groups were increased after injury with the peak at the24th hour, and stayed in high level at the7th day. The serum erythropoietin receptor concentration in shock group was higher compare to TBI group at the24th hour and7th day. The serum erythropoietin receptor concentration in moderate and severe TBI groups were increased at all time points, the levels reached peak at the24th hour. In mildly injured group (ISS<16), EpoR concentration at0th hour had no difference with normal control group, the concentration at24th hour and7th day is significantly higher than concentration at0th hour, but concentration at24th hour had no difference with concentration7th day. In severely injured group(ISS^16), EpoR concentration were significantly higher than normal control group at each time point.The concentration at24th hour and7th day were significantly higher than concentration at0th hour, but concentration at24th hour had no obvious difference with concentration at7th day. Erythropoietin concentration in severely injuried group at the same time point (0h,24h,7d) were significantly higher than that in mildly injured group. The serum erythropoietin receptor concentration in death group at7th day was still high, while it was decreased in the survival group. The level in death group was higher than that in survival group at all time points. The serum erythropoietin receptor concentration were positively correlated with ISS, APACHEII score and blood sugar level at all time points. It was correlated with white blood cell counts, chest trauma, limbs or spine fracture at0th hour and24th hour. While the serum erythropoietin receptor concentration was negatively correlated with hemoglobin at7th day, and had no correlation with chest trauma, limbs or spine fracture at7th day.Conclusions It is suggestted that the increased EpoR concentration indicates severe injury, and persistent high level indicates poor outcome. The dynamic changes of serum erythropoietin receptor concentration in trauma patients can be used as an simple and effective marker to evaluate the severity of injury and predict the prognosis of severe trauma patients.