title: Phenotypes of placental-type alkaline phosphatase in seminoma sera as defined by monoclonal antibodies.
abstract: PLAP-like enzymes could be detected in serum of patients with primary testicular tumors, in particular seminomas. The use of a panel of monoclonal antibodies (MAbs) permitted typing into 6 different testicular serum phenotypes, of which one appeared similar to a placental type (II) and 2 have not been previously described. Most tumor sera belonged to type I, as described for seminoma tissues. With a more advanced tumor the mean serum PLAP-like levels increased. After operation, after radiotherapy or with no evidence of disease lower or non-detectable enzyme levels were found. In typing the tissue PLAP-like antigen in serum of the same patient or sera from recurrences of a seminoma in the same patient, the same phenotypes of PLAP-like antigen were usually but not always found. None of the 6 phenotypes appeared to confer a poorer prognosis. We conclude that the expression of PLAP-like antigen is eutopic and is enhanced by testicular malignancy, especially in seminoma cells.
mesh_terms: D000328:Adult; D000469:Alkaline Phosphatase; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D004407:Dysgerminoma / Q000201:enzymology*; D058851:GPI-Linked Proteins; D006801:Humans; D007527:Isoenzymes / Q000097:blood* / Q000276:immunology; D008297:Male; D009362:Neoplasm Metastasis; D010641:Phenotype; D011379:Prognosis; D011817:Rabbits; D013736:Testicular Neoplasms / Q000201:enzymology*
chemical_list: D000911:Antibodies, Monoclonal; D058851:GPI-Linked Proteins; D007527:Isoenzymes; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental