| Objective: To explore the changes of telomere length in peripheral blood mononuclearleukocyte during acute trauma and investigate possible mechanisms for the dynamicchanges. Researches concerning telomere length change in trauma patients could helpreveal the molecular mechanisms of acute injury. And these studies could build a bridgefor the trauma surgeons to get to know more about the molecular biology and traumaticimmunology. Inspirations and enlightenments of prevention and treatment of trauma andposttraumatic complications could also be achieved through similar researches.Methods and materials: From September2012to November2013,74patients, aged30-50years, with trauma or multiple trauma were enrolled in our study. Patients withprevious operations, physical and psychological trauma were excluded. Patients withmedical history of chronic morbidities(diabetes mellitus, coronary heart disease), obesity,smoking history, pregnancy, autoimmune disease and receiving of long-term oralGlucocorticoids were not included. All patients were assessed by using injury severityscore(ISS) and were divided into three subgroups including minor trauma, severe traumaand critical trauma group. Another128healthy people were selected as control group.Peripheral blood samples were collected respectively on the day patients were hospitalizedand discharged. Extra blood samples on the day of surgery were also collected in some ofthe severe trauma patients. Standard procedures were used to extract DNA from the frozenblood samples and telomere length calculation was performed by using a quantitativereal-time PCR (Q-PCR) technique. SPSS16.0was used for statistical analysis.Continuous variables were expressed as mean±SD. Statistically significant differencebetween two groups were conducted by using paired t test and one-way ANOVA test. Therelation between changes of telomere length and severity of trauma was investigated. Dynamic change of telomere length during trauma was recorded. We intended to figureout the possible factors that could be related to the changes of telomere length in traumapatients and its relevance to the peripheral blood cells.Results:1. Patients characteristics: Mean age of74trauma patients was39.65±3.86years.According to ISS assessment,74patients were classified into minor trauma group (24patients, ISS<16), severe trauma group (42patients,16≤ISS<25) and critical trauma group(8patients,ISS>25).14severe trauma group patients received emergency operation.6critical trauma patients die on the first hospital day after injury and2other patients in thisgroup were treated with conservative treatment and survived. Mean age of the controlgroup was39.84±3.46years. The characteristics between the trauma group and controlgroup were comparative.2.Comparison of posttraumatic telomere length in different groups and subgroups.Telomere length on the first hospital day of mild trauma group and control group were(1.158±0.193) and (1.098±0.136). There was no statistical difference between the twogroups (t=0.833,P>0.05). However, statistical significant shortening of telomere lengthwas observed in severe trauma group (t=3.340,P<0.05). Telomere length on the firsthospital day of severe trauma group and control group were (0.902±0.313)and(1.098±0.136). Similar result was achieved in critical trauma group(t=5.329,P<0.01).Telomere length in critical trauma group and control group were(0.460±0.118) and(1.098±0.136), respectively.Telomere length on the day of discharge in minor and severe trauma group were(1.181±0.186) and (1.185±0.224). Comparison between minor group and control groupshowed no significant difference of telomere length (t=0.246,P>0.05). We comparedtelomere length of severe group with the control group as well,(t=0.130,P>0.05).14of42patients in severe trauma group were operated and telomere length collected onthe day of operation were calculated(1.251±0.203) and compared with those on the day of discharge(1.232±0.141). No significant difference was found (P>0.05). But whencompared with those on the first hospital day(1.123±0.131), shortening of telomere lengthon the trauma day was seen.(P<0.05).3. Relevance of dynamic change between posttraumatic telomere length and number ofgranulocyte, lymphocyte in peripheral blood.Number of lymphocyte in peripheral blood in severe and critical trauma groupin early stage after injury (within6hours of injury) were (3.68±0.136)*109/L and(3.99±0.043)*109/L. Number of lymphocyte in mild group was only (2.34±0.10)*109/L.Statistical significant increase of lymphocyte was found in severe and critical traumapatients in early stage(P<0.01). Blood samples were drawn again after6hours of injury.Number of lymphocyte in severe and minor group were (0.63±0.029)*109/L and(1.21±0.146)*109/L, decrease of lymphocyte in the two groups were recorded(P<0.01)We also calculated lymphocyte/WBC ratio. The ratio of the patients from severe andcritical trauma group in early stage were (0.312±0.014) and (0.319±0.016). Whencompared with the value in minor trauma group(0.223±0.011), statistical significantincrease of the ratio was noticed(P<0.01). But after6hours of injury, lymphocyte/WBCratio in severe group (0.038±0.002) declined significantly when compared with minortrauma group (0.083±0.012) and P<0.01.Thus we concluded in early stage of trauma (within6hours of injury), telomere lengthwas negatively correlated with number of lymphocyte and lymphocyte/WBC ratio. After6hours of trauma, no obvious correlation could be established.Conclusions:1. Shortening of telomere length in peripheral blood mononuclear leukocyte collected onday of trauma was relevant to the severity of injury.2. Telomere length on the day of discharge in trauma patients were comparative to thoseof the control group. 3. In early stage of trauma (within6hours of injury), the increase of lymphocyte waspositively correlated with the severity of injury and shortening of telomere length wasobvious in severe and critical trauma patients. In severe trauma group patients, an earlyincrease and a late decrease of lymphocyte in peripheral blood were observed. |
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