Specificity of antibodies present in human periapical lesions.

Various classes of immunoglobulins have been found in human periapical lesions. The specificity of secreted antibodies against antigens egressing from the root canal system has yet to be thoroughly investigated. The purpose of this study was to test the specificity of antibodies present in human periapical lesions. Human periapical biopsies were removed and cultured as organ culture explants. Antibodies present in the lesions were extracted in the cell culture fluids. A modified enzyme-linked immunosorbent assay was used to determine the presence, type, and concentration of different classes of antibodies against a number of commonly found bacterial species present in the root canal system. The data show the presence of specific antibodies (IgG, IgM, and IgA) against all 16 microorganisms tested. Peptostreptococcus micros, Actinomyces israelii, Staphylococcus intermedius, and Fusobacterium nucleatum produced significantly high levels of IgG antibodies in these lesions.