Immunoglobul ins in periapical granulomas: a pre l iminary report

The periapical granuloma, one of the most common forms of dental pathosis, is characterized as a localized mass of chronic granulation tissue formed in response to infection with infiltration of chronic inflammatory cells, chiefly lymphocytes and plasma cells. 1 While this definition is satisfactory to the pathologist, it gives the endodontist no insight into the biological significance of this lesion. Specifically, the textbook description either ignores or sketchily presents the relationship of the described cellular elements to the immune response. Recently, attention has been called to the necessity for investigations of this nature. 2 Immunologists have suspected antigen-antibody relationships in chronic granulamatous lesions. Burnet z said, "It is a good rule that any local accumulation of lymphoc-ytes in the body, especially if plasma ceils are also present, is a sign that immunological activities are going on." The plasma cell, the end of the B-cell line, can be likened to the hedgehog in the aphorism, "The fox knows many things, but the hedgehog knows one big thing." The plasma cell is an efficient protein manufacturing plant that turns out only one produc t -an immunoglobulin of a single type. The immunoglobulin is capable of combining efficiently onIy with the antigen which turned on the specific precursor B cell that has the appropriate receptor sites for that antigen. This is the essence of the clonal-section theory of immunity. Burnet a also noted that the interrelationship of chronic infection with immunological anomalies is one of the potentially important areas of medicine that is almost unexplored. The importance of such lesions to systemic health has been reported by Osserman and others. 4-6 They provided strong inferential evidence that long-standing chronic infections, especially those of the biliary tract, with round cell infiltration may be precursors of monoclonal plasma cell dyscrasias. From the viewpoint of the clinical endodontist, the presence of B cells and humeral antibodies suggests the possibility of clinically evident immediate reactions of hypersensitivity. On the other hand, T cells associated with cellular immunity can be involved in delayed hypersensitivities.~ It seems that the isolation and identification of immunoglobulins in periapicaI granulomas are essential preliminary steps in attacking and solving problems of this nature.