Immunocytochemical localization of immunoglobulins in disc herniations

Study Design. Disc herniation and control discs were studied for the presence of immunoglobulins immunocytochemically. Objectives. To study a possible presence of immunoglobulin complexes in herniated disc tissue and to locate them at the tissue level by immunocytochemistry; to compare immunohistologic findings with those obtained in control disc tissue; and to compare the prevalences of immunoglobulin M and immunoglobulin G. Summary of Background Data. In herniated disc tissue, high activity of inflammatory phospholipase A(2) was previously demonstrated, and inflammatory cells were noted immunohistochemically. Immunoglobulins G and M were observed biochemically but have not been located at the tissue level. Methods. Fifty-two disc herniations and three macroscopically normal fresh cadaver discs were managed by an identical immunocytochemical protocol, using monoclonal antihuman antibodies to immunoglobulins M and G. Results. In 29 of 52 disc herniations (56%), immunoglobulin M deposits were observed, and in 18 of 52 disc herniations (35%) immunoglobulin G could be demonstrated. Almost all the disc herniations where immunoglobulin G was present also contained immunoglobulin M deposits (except for two). In the control discs studied, neither immunoglobulin could be observed immunohistochemically. The immunoglobulin deposits were noted in areas where blood vessels were also present. Morphologically, immunoglobulin immunoreactivity resembling immune complexes was observed. Conclusions. The results lend support to previous suggestions of inflammation and immune reaction in disc herniations, including previous biochemical studies suggesting immunoglobulin deposition. The exact role of the demonstrated immunoglobulins in disc tissue pathophysiology will have to be clarified further.