title: [Monoclonal antibodies directed against the beta hCG subunit and against a synthetic peptide analog of the carboxyl-terminal end. Clinical use in vivo and in vitro].
abstract: In order to detect specifically the beta-hCG, we have produced monoclonal antibodies (Mabs), using as immunogens hCG, beta hCG or a totally synthetic molecule (109-145 peptide) analogous to the beta-subunit carboxyl terminus. 34 fusion experiments were performed and led to 8 Mabs which presented a high reactivity to 125I beta hCG in the screening test. Mab D1E8 was directed to the 1-115 region of beta hCG and was cross reactive with hLH (greater than 60%). Mabs 702, 1032, and 1211 were directed against three different epitopes located in the 109-145 region and were specific for the beta hCG. The in vivo localization of tumors containing beta hCG ty tomoscintigraphy (SPECT) was evaluated in 5 patients by injecting 131I-Mab D1E8, selected for imaging because of its high affinity to beta hCG (Ka = 1.9 X 10(9)). SPECT was performed 48 h and 96 h after injection: 2 patients with proven tumor sites had positive "immunoscintigraphy" results. One patient, simultaneously injected with 125I non-specific IgG, had a tumor resection: the count ratio between normal and tumoral tissues revealed a low specific uptake. Two and three-site immunoradiometric assays (IRMA) were performed with monoclonal antibodies purified from nude mice ascitic fluids. IRMA were based upon two or three Mabs, with D1E8 on a solid phase and 125I Mab 702 or a mixing of 125I-702 and 125I-1032 as tracer. The specificity of IRMA was demonstrated by the absence of binding with increasing amount of hLH, hFSH and hTSH up to 5000 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin / Q000032:analysis / Q000276:immunology*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D010446:Peptide Fragments / Q000032:analysis / Q000276:immunology*; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000000981:diagnostic imaging*; D013736:Testicular Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D014055:Tomography, Emission-Computed; D014328:Trophoblastic Neoplasms / Q000000981:diagnostic imaging*; D014594:Uterine Neoplasms / Q000000981:diagnostic imaging*
chemical_list: D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D000939:Epitopes; D010446:Peptide Fragments
vernacular_title: Anticorps monoclonaux dirigés contre la sous-unité beta hCG et contre un peptide synthétique analogue de l'extrémité carboxyl-terminale: utilisation clinique in vivo et in vitro.