A Study Of The Pathogenesis Of Discogenic Low Back Pain

Objective:To study the pathogenesis of degenerative disc disease such as discogenic low back pain and the difference from disc herniation, prolapse and control group.Method:71 cases disc specimens with degenerative disc disease were collected during operation, including 10 cases in discogenic low back pain,52 cases Disc herniation(30 cases in disc herniation,22 cases in disc prolapse), And nine cases of spinal fractures were collected during anterior approach as normal control group (MRI shows no degeneration), The nucleus pulposus were got during surgery, washed with saline and were immediately placed in-80℃refrigerator after surgery. (1)HE staining, observe the morphology, size and distribution of the nucleus pulposus cells, observe the degree of degeneration of extracellular matrix, inflammatory cells infiltration and small vessel hyperplasia. (2) SP immunohistochemical was used to stain CD68 positive macrophages and CD45RO T cells. (3)Break down the nucleus pulposus tissues, get the supernate, determine the the content of the cytokines of IL-1, IL-6, TNF-a by Elisa. Analyzed with SPSS 13.0 Statistics software.Result:(1) HE staining:In the control group, the nucleus pulposus cells are in the same shape and size, and are well distributed, no obvious cell matrix degeneration can be seen. All of the other groups can see that nucleus pulposus cells became vascuolated, different in size and distribution, there are inflammatory cells and focal small vessels proliferation on the edge of disc prolapse group, herniation group, In discogenic low back pain group the cell matrix became degenerate severely, there are inflammatory cells but there is no significant angiogenesis;(2)Immunohistochemistry CD68-positive macrophages exist in each disease group, positive rate(positive cases/all cases):prolapse group(14/22)>discogenic low back pain group(4/10)> herniation group(8/30)>, there is no positive cells can be seen in control group, Chi-square test reveals that there is significant difference between the four groups (P <0.05), by comparison:There is significant difference between prolapse group and herniation group, as well as prolapse group and control group. positive rate of CD45RO T cells (positive cases/all cases):prolapse group(13/22)>herniation group(4/30), there is no positive cells can be seen in discogenic low back pain group and control group, Chi-square test reveals that there is significant difference between the four groups(P<0.05), by comparison:There is significant difference between prolapse group and discogenic low back pain group, prolapse group and herniation group, prolapse group and control group. (3) Elisa test Mean Content of IL-1(pg/ML) form high to low:discogenic low back pain group12.32>prolapse group11.84> herniation group7.89>control group5.16, Rank sum test demonstrate there is significant difference between the four groups(P<0.05), by comparison:There is significant difference between discogenic low back pain group and herniation group, discogenic low back pain group and control group, prolapse group and herniation group, prolapse group and control group. Mean Content of IL-6(pg/ML) form high to low:prolapse groupl28.02>herniation group17.59>discogenic low back pain group18.6>control group7.03; Rank sum test demonstrate there is significant difference between the four groups(P<0.05), by comparison:There is significant difference between prolapse group and herniation group, prolapse group and control group, discogenic low back pain group and control group. Mean Content of TNF-a(pg/ML) form high to low:prolapse group 15.61>herniation group13.74> discogenic low back pain group 11.54>control group5.40, Rank sum test demonstrate there is significant difference between the four groups (P<0.05), by comparison:There is significant difference between each group and control group.Conclusion:(1)Cell matrix of discogenic low back pain degenerates seriously, there are CD68- positive macrophages and cytokines of IL-1, IL-6, TNF-a in the nucleus pulposus, which suggest inflammatory response and cytokines are important pathoge-nesis. (2) There are macrophages, CD45RO T cells and focal small vessels proliferatio- n on the edge of prolapse group, herniation group; on the edge of low back pain group inflammatory cells are not so many, and there is no small vessels proliferation and CD45RO T cells, which suggest the pathogenesis of discogenic low back pain dose not associated with cellular immunity.