Diagnostic significance of serum free DNA human telomerase reverse transcriptase quantitative determination on spinal cord injury

Objective To investigate the relationship between the content of human telomerase reverse transcriptase (hTERT) and its clinical features in serum free DNA in patients with different degree of spinal cord injury. Methods From December 2013 to December 2016, inpatients of the Central Hospital of Bazhong, Sichuan Province were enrolledand divided into the experimental group, the disease control group and the negative control group. For the experimental group: 46 patients with spinal cord injury were graded according to the criteria of the American Association of Spinal Cord Injury (ASIA), including 12 cases of grade A, 10 cases of grade B, 10 cases of grade C, 7 cases of grade D and 7 cases of grade E; for the disease control group: 15 patients with spinal fractures (without spinal cord injury) at the same period were included; and for the negative control group: 20 healthy adult volunteers aged 18-50 years were selected.Real-time fluorescence quantitative PCR and immunoblotting were performed to detect the content of hTERT in serum free DNA both in patients and healthy controls and to compare the difference between them. The results of the somatosensory evoked potential (SEP) of all patients were compared and analyzed.The receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of hTERT content in serum free DNA in patients with spinal cord injury. Results Comparison of serum free DNA hTERT content: in the experimental group, the serum free DNA hTERT content of grade A, B, C, D, E was (99.63±8.23), (76.24±4.37), (46.07±5.43), (16.30±0.95) and (15.74±1.12)μg/L, respectively.While it was (15.01±1.39)μg/L in the disease control group and (14.54±1.03)μg/L in the negative control group. The total difference was statistically significant between patients of each group and the control group (F=857.917, P<0.001). Comparison of the protein content of TERT: in the experimental group, the protein content of TERT of grade A, B, C, D, E was 0.736±0.214, 0.641±0.172, 0.606±0.184, 0.411±0.132 and 0.307±0.152, respectively.The protein content of TERT in the disease control group and the negative control group was about 0.312±0.098 and 0.322±0.177, the difference between patients of each group and the control group was statistically significant (F=62.461, P<0.001). Detection results of surface evoked potential (SEP) showed that in the experimental group, level A patients all had conduction block.Two cases of level B patients had conduction block and 8 cases had delayed conduction.Among level C patients, 1 case had conduction block, 9 cases had delayed conduction.Among level D patients and patients from the control group and the negative control group, SEP detection all had no conduction block. Conclusion The detection of the hTERT content in serum free DNA in patients with spinal cord injury has a certain guiding significance for the diagnosis of spinal cord injury and the degree of injury. Key words: Spinal cord injury; DNA; Polymerase chain reaction; Reverse transcriptase