QUANTIFICATION OF HUMAN MYELOPEROXIDASE IN ORAL FLUIDS

Peroxidase activity in human whole saliva is derived from salivary per oxidase and myeloperoxidase. Present spectrophotometric assays are rel atively nonspecific and influenced by ions present in salivary secreti ons, resulting in an over and/or underestimation of peroxidase activit ies. Specific polyclonal or monoclonal antibodies would greatly simpli fy the identification of salivary peroxidase and myeloperoxidase in hu man saliva and determine the relative contribution of each enzyme to t he total peroxidase activity in human saliva. In the present study, a highly purified preparation of myeloperoxidase was used to raise polyc lonal antibodies against the antigen. The antibodies were purified and extensively characterized in terms of their ability to interact with the antigen, with other mammalian peroxidases, and with other proteins present in salivary fluids. The antibodies recognized only myeloperox idase and did not cross-react with any of the substances tested, showi ng that these antibodies can be used to detect and differentiate myelo peroxidase from other peroxidases in saliva. We have also developed an d tested a sandwich ELISA which can be used in a clinical setting to q uantify myeloperoxidase in whole saliva and gingival crevicular fluid.