IMMUNOHISTOCHEMICAL LOCALIZATION OF PLACENTAL-LIKE ALKALINE-PHOSPHATASE IN TESTIS AND GERM-CELL TUMORS USING MONOCLONAL-ANTIBODIES

  • 1 January 1983
    • journal article
    • research article
    • Vol. 111  (2) , 156-165
Abstract
Six monoclonal antibodies raised against the human placental alkaline phosphatase (ALP) recognizing distinct antigenic determinants on the surface of this isozyme were used for immunohistochemical studies of adult and fetal human testes and testicular germ cell tumors. ALP reacting with all 6 antibodies was defined as placental, whereas ALP reacting with some but not all antibodies was labeled as placental-like. ALP reacting with one of the monoclonal antibodies that recognizes a determinant common to intestinal and placental ALP was tentatively considered probably intestinal, unless it reacted with any other monoclonal placental specific antibody. Using this approach, placental ALP was identified in 4 of 7 seminomas, 3 of 7 tumors composed in part or fully of embryonal carcinoma, and 1 yolk sac carcinoma. Placental-like ALP was identified in 2 additional seminomas and 4 embryonal carcinoma-containing tumors, whereas 1 seminoma and 1 benign teratoma were devoid of either placental or placental-like ALP. Trophoblastic giant cells in 2 seminomas and 3 teratocarcinomas expressed only the antigenic determinant common to placental and intestinal ALP. Testicular tumor cells may express either placental or placental-like ALP and in some instances, the tumor isozyme is antigenically different from ALP found on either fetal or adult testicular germ cells.