Bo Tian, n/a: No financial relationships to disclose
Objectives: To investigate the changes of immune microenvironment caused by annulus fibrosus rupture in Intervertebral Disc Degeneration (IDD).
Methods: Patients diagnosed with intervertebral disc herniation and underwent surgical treatment in the Orthopedics Department of the Second Affiliated Hospital of Soochow University from September 2020 to July 2021 were enrolled. According to the annulus rupture or not, patients were divided into Annulus Intact (AI) group and annulus rupture (AR) group. The nucleus pulposus were collected and then flow cytometry, real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) to detect the levels of inflammatory factors. Immunohistochemical was used to observe the expression of CD68, F4/80 and IL-1β in immune cells.
Results: . The number of macrophages and T cells were significantly elevated in AR group detected by flow cytometry. The mRNA expression levels of TNF-α, IL-1β, IL-4 and IL-6 in AR group were higher than those in AI group (8.73±1.56 vs. 1.00±0.04, t=8.57, P0.01; 5.68±0.70 vs. 1.00±0.02, t=11.55, P0.01; 2.33±0.77 vs. 1.00±0.05, t=3.01, P0.05; 16.97±1.81 vs. 1.00±0.06, t=8.83, P0.01). The levels of TNF-α and IL-1β detected by ELISA were also significantly increased in AR group (12.20±4.56 vs. 5.55±3.74, t=2.66, P0.05; 10.57±1.58 vs. 6.32±2.61, t=3.41, P0.05). Immunohistochemical showed that the positive cells of CD68, F4/80 and IL-1β in AR group were significantly increased.
Conclusions: Annulus fibrosus Rupture can aggravate the inflammatory response around the nucleus pulposus tissue, leading to inflammatory cell infiltration and increased levels of inflammatory factors. The local inflammatory response plays an important role in the pathophysiological process of intervertebral disc degeneration.
