Identity of the neoplastic alkaline phosphatase as revealed with monoclonal antibodies to the placental form of the enzyme.

A panel of six monoclonal antibodies and a conventional polyclonal antibody raised against human placental alkaline phosphatase (ALP) were used to characterize the alkaline phosphatase detected by means of histochemistry on tumors of breast, ovary, lung, gastrointestinal tract, and kidney. Complete antigenic identity between the tumor ALP and the placental ALP was found only in one lung tumor. However, ten tumors reacted with the polyclonal antibody and some monoclonal antibodies, thus exhibiting partial identity with the placental ALP.