Studies On The Expression Of Tumor Necrosis Factor-α, Interlukin-6, Interlukin-8 And MRI Characteristics After Acute Spinal Cord Injury

Objective: To observe the expression of tumor necrosis factor- , interlukin-6, interlukin-8 in serum after acute spinal cord injury (ASCI) and evaluate the relationship between these change and degree of SCI. To study the correlation between the hyper signal length in the lesion area on T2WI sagittal plane of MRI and the lesion degree of SCI, and evaluate the relationship between the length and the level of three cytokines as above. Methods: According to ASIA methods, 41 adult ASCI patients were divided into two groups: complete paralysis group (20 cases, 9 cases with cervical SCI involved) and incomplete paralysis group (21 cases, 8 cases with cervical SCI involved), while 19 cases with limbs fracture and 20 healthy individuals were chosen as controls. In each group, TNF- a ,IL-6,IL-8 level in serum at 12h,24h,72h after injury were detected respectively by radioimmunoassay. All cervical SCI patients were performed MRI determination within 7 days after injury. The hyper signal length in the lesion area on T2WI sagittal plane was measured. Results: TNF-a level in serum of SCI patients showed an early flash-like expression immediately after injury. It peaked at 12h postinjury, and then descended gradually. In 72h postinjury, it returned to normal level. The degree of this increase was related to the lesion degree of SCI. IL-6 level in serum of SCI patients showed an early fast expression after injury. It peaked at 12h postinjury, and then descended gradually. In 72h postinjury, its level was still higher than the normal level. No significant difference in the highest concentration was seen between complete paralysis group and incomplete paralysis group. But the former's peak concentration maintained a longer time than the latter's did. IL-8 levels in serum of SCI groups were higher than the one of limbs fracture group and normal control group ateach time point. While the concentration of SCI groups at 24h postinjury were the highest one, IL-8 level at 72h post injury of complete paralysis group was higher than the one of incomplete paralysis group. There were no difference in TNF-a and IL-6 level postinjury between limbs fracture group and normal control group at each time point, and the former's IL-8 level only had a temporary increase. The complete paralysis group's hyper signal length in the lesion area on T2WI sagittal plane of MRI was longer than the incomplete paralysis group's. No correlation between the hyper signal length and the serum level of TNF-a, IL-8, IL-6 at each time point was found. Conclusion: The early flash-like up-regulated expression of TNF-a and the early, fast, lasting up-regulated expression of IL-6,IL-8 in ASCI patients' serum showed that these three cytokines played an important role in the secondary injury of SCI. The degree of the increase of TNF-a serum level after SCI was related to the lesion degree of SCI. According to TNF-a level in serum, degree of the loss of neural-function and prognosis could be judged approximately, which can provide reference for diagnosis and treatment. The correlation between the hyper signal length in the lesion area on T2WI sagittal plane of MRI and the lesion degree of SCI showed that MRI is a well and non-invasive examination method in clinical diagnosis and treatment as well as in study of the secondary injury of SCI, while no correlation between the length and the serum level of TNF-a , IL-8, IL-6 in each SCI group at each time point was found.