Specific interference with the determination of the tumour-associated glycoprotein 72 by human anti-idiotypic antibodies formed after treatment with the anti-tumour-associated glycoprotein 72 antibody B72.3.
Recorded concentrations of the tumour-associated glycoprotein 72 (TAG-72) in ovarian cancer patients after repeated infusion of the antibody B72.3 were found to be falsely elevated when measured with an homologous immunometric assay involving the anti-TAG-72 antibody B72.3 (Test 1), or with an heterologous assay involving CC49 capture and B72.3 detector antibodies (Test 2). Test 1 yielded falsely elevated values up to 10(4) kU/l. Test 2 gave slightly false positive elevations up to 10(2) kU/l for only some of the samples with very high false-positive values in Test 1. The interfering serum components bound to Protein G-Sepharose and could be precipitated with perchloric acid or by heating serum samples to 100 degrees C. Addition of non-specific murine immunoglobulins only partly suppressed false-positive values in both tests. Our results suggest that this interference is caused by human anti-B72.3 IgG induced by B72.3 application, which to some extent specifically binds to determinants of the B72.3 antibody. Heat extraction of serum samples effectively eliminated interferences probably caused by anti-idiotypic antibodies, but did not affect real TAG-72.
Reinsberg
J
J
Zentrum für Frauenheilkunde und Geburtshilfe, Universität Bonn, Germany.
Gast
B
B
Schmolling
J
J
Wagner
U
U
Krebs
D
D
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000096:biosynthesis / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000627:therapeutic use*; D000918:Antibody Specificity; D000937:Antigen-Antibody Reactions; D000951:Antigens, Neoplasm / Q000276:immunology / Q000378:metabolism*; D002846:Chromatography, Affinity; D005260:Female; D005500:Follow-Up Studies; D006023:Glycoproteins / Q000276:immunology / Q000378:metabolism*; D006358:Hot Temperature; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood* / Q000737:chemistry / Q000302:isolation & purification; D007167:Immunotherapy; D016014:Linear Models; D051379:Mice; D010051:Ovarian Neoplasms / Q000628:therapy*; D010472:Perchlorates / Q000737:chemistry
D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D006023:Glycoproteins; D007074:Immunoglobulin G; D010472:Perchlorates; C047052:tumor-associated antigen 72