Presence and distribution of antigen-antibody complexes in the herniated nucleus pulposus

Study Design. Herniated tissue was studied by immunohistochemistry in eight patients with lumbar disc herniation. The results were compared with those of control subjects. Objective. To assess the presence and distribution of possible antigen-anti body complexes in herniated disc tissue. Summary of Background Data. It has been suggested that the nucleus pulposus may be recognized as a foreign-body by the immune system and that this wil l lead to secondary nerve root disturbance. Such immunologic events should be initiated by binding of antibodies to a specific antigen in the disc tis sue. However, the presence of antigen-antibody complexes in the herniated d isc tissue has not been assessed. Methods. Amplification of the peroxidase reaction produced in avidin-biotin -peroxidase complex immunostaining by diaminobenzidine was used to visualiz e antigen-antibody complexes in the herniated tissue. The authors used hern iated tissue from eight patients with lumbar disc herniation and nucleus pu lposus from five control subjects with nonlumbar disc herniation. Thin para ffin sections, prefixed in 4% paraformaldehyde, were incubated with anti-hu man IgG antibody to allow visualization of antigen-antibody complexes in th e specimens. Results. A brown deposit, indicating antigen-antibody complexes, could be o bserved in the pericellular capsule in herniated disc tissue but not in con trol discs or in the residual discs of the herniation patients. Conclusion. Antigen-antibody complexes seem to be commonly present in herni ated disc tissue, but not in healthy discs. However, the pathophysiologic a nd clinical significance of this observation has to be elucidated further.