Russell bodies: a light and electron microscopic immunoperoxidase study.

Russell bodies have been previously regarded as aggregates of immunoglobulin. Light and electron microscopic immunoperoxidase studies show no detectable immunoglobulin determinants in the Russell body cores. Denaturation of antigens during tissue preparation appears to be an unlikely explanation, since immunoglobulins in the cytoplasm of plasma cells are clearly demonstrated. The presence of immunoglobulins on the surface of small intracellular Russell bodies may represent the immunoglobulin determinants in the surrounding rough endoplasmic reticulum. It seems likely that Russell bodies contain non-immunoglobulin molecules, by-products of immunoglobulin synthesis, or some altered form of immunoglobulins that no longer can be recognized by the anti-immunoglobulin antibody. The non-uniform dye staining pattern of Russell bodies further suggests that Russell bodies may be heterogenous in nature.