Effect Of Coblation Nucleoplasty On Inflammation And Immune Response Of Degenerative Intervertebral Discs

Objective:1.To investigate the effect of coblation nucleoplasty on inflammatory factor expression of degenerative intervertebral disc.1.To evaluate the influence of coblation nucleoplasty on immune response of degenerative intervertebral disc.Methods:1.Thirty New Zealand white rabbits were selected and the rabbit lumbar 2-6 discs were randomly divided into four groups:control group(C group),sham operation group(S group),normal-operation group(N group),and degeneration-operation group(D group).The disc degeneration model was prepared using a ring of acupuncture in the disc segments of the D group.After the model was successfully established,different surgical treatments were performed according to the grouping and 6 animals were sacrificed immediately after surgery,7d,14d,21d,and 28d.2.HE staining was used to evaluate the changes of vascular,collagen and histomorphology of the IVD.Immunohistochemical staining was used to analyze the expression levels of matrix metalloproteinases in the discs at different time points.The content of IL-1 and TNF-αof intervertebral discs at different time points were quantitatively analyzed by enzyme-linked immunosorbent assay(ELISA).3.Immunofluorescence staining was used to semi-quantitatively analyze the expression levels of CD4~+T cells,CD8~+T cells,IgG,and IgM at different time points in each experimental group.Results:1.HE staining showed that the anulus fibrosus was intact,the collagen fibers and cartilage cells were evenly distributed,and no inflammatory cell infiltration was observed at different time points in C group.The nucleus pulposus tissue structure was disordered,the rare cartilage cells and confusion collagen fibers were observed,a large number of red blood cells infiltration and gradually increased over time in the S group.There were burning necrosis-like substances,disordered nucleus structure,less chondrocytes and some clumpy aggregated collagen fibers in D and N group.A small amount of red blood cells were infiltrated in the nucleus pulposus in D and N group.2.The results of immunohistochemical staining showed that the positive rate of MMP-1 and MMP-3 was decreased from 100%immediately after operation to 50%and 55%respectively at postoperative 28 days in the D group,while the positive rate of MMP-1 and MMP-3 was range from 0%to 10%at different time point in the C group.Although in N group the expression of MMP-1 and MMP-3 were on the rise,at postoperative 28 days,the positive rates of the two indexes were 65%and 55,respectively,which were significantly different from those in the sham operation group at same time piont.3.The results of ELISA showed that:in group C,the expression of IL-1 and TNF-αin the nucleus pulposus was stable and low at different time points;CN could significantly reduce the expression level of inflammatory factors in the degenerative intervertebral disc;IL-1 and TNF-αwas decreased from 43.91±2.82ng/L,50.00±4.22ng/L immediately after operation to 31.76±1.34ng/L and 34.14±3.50ng/L at postoperative 28 days,respectively.The two indexes were no statistically significant difference between N and D groups.4.Immunofluorescence staining showed that there was no obvious immunoglobulin and immune cell infiltration in the nucleus pulposus of group C.The immune index in group D decreased significantly at 28 days after surgery compared with immediate after operation,the number of CD4~+T cells and CD8~+T cells per high magnification decreased from 22.39±6.79,28.22±7.81 to 16.50±5.82 and 20.22±5.79,respectively.The gray values under the green channel of IgG and IgM per high magnification decreased from 49.08±7.99,44.94±10.70 to 25.53±6.04 and 25.41±7.95,respectively.The difference was statistically significant.Conclusion1.Coblation nucleoplasty could significantly decrease the expression of inflammatory factors and inhibit the local immune response of degenerative intervertebral disc.2.Coblation nucleoplasty may relieve pain symptoms in patients with degenerative intervertebral disc by inhibiting local inflammation and immune response.3.After coblation nucleoplasty surgery,immunocyte infiltration,inflammatory factor secretion and matrix metalloproteinase expression were observed in normal intervertebral disc.This may be one of the reasons why the mechanical compression of patients after coblation nucleoplasty is light but the clinical symptoms are repeated.