EXTRACTION OF AMYLOID-LIKE FIBRILS FROM CHRONICALLY INFLAMED PERIODONTAL TISSUES

Immunohistological studies have established an association between the deposition of the amyloid P protein and disease status in chronically inflamed periodontal tissues. The aim of this study was to determine if amyloid-like fibrils could be extracted from these tissues. Biopsie s were homogenised and extracted exhaustively in saline before serial extraction in distilled water. Electrophoretic analysis revealed the p resence of previously undetected protein bands in the fifth water extr action. These were probed and were found to react with antisera to kap pa and lambda immunoglobulin light chains but not with antisera to mu, gamma or alpha heavy chains. Electron microscopic study indicated fib rils of 9.7 nm diameter. These bound Congo Red and exhibited green bir efringence under polarised light. The results supported the presence o f an amyloid-like matrix composed of immunoglobulin light chains in th e lesions of chronic periodontitis. This could explain the persistence of foci of degenerate plasma cells and the paucity of granulation tis sue formation in the disease process.