Spontaneous Production of Monocyte Chemoattractant Protein-1 and Interleukin-8 by the Human Lumbar Intervertebral Disc

Study Design. Scoliotic and herniated human intervertebral disc tissue obtained intraoperatively was cultured, and the medium was analyzed for the production of monocyte chemoattractant protein-1 and interleukin-8. Objectives. This study was conducted to determine whether the human intervertebral disc is capable of spontaneous production of the chemokines monocyte chemoattractant protein-1 and interleukin-8. Summary of Background Data. Lumbar disc herniations undergo spontaneous regression with time. This is believed to occur via macrophage-mediated phagocytosis of herniated disc material. Monocyte chemoattractant protein-1, a chemotactic agent for macrophages, has recently been identified in rat intervertebral disc tissue. Methods. Disc material obtained from patients undergoing surgery for scoliosis and sciatica was cultured using a serumless technique, and the medium was subsequently analyzed for levels of monocyte chemoattractant protein-1 and interleukin-8. Results. Monocyte chemoattractant protein-1 and IL-8 were detected in both control and herniated disc specimens. Noncontained herniations produced higher levels of chemokines than those with an intact anulus. Conclusions. Human intervertebral disc tissue is capable of spontaneously producing the proinflammatory chemokines monocyte chemoattractant protein-1 and interleukin-8. These are chemotactic for macrophages and capillaries and may explain the ingrowth of granulation tissue seen in spontaneous disc herniation resorption.