title: Production and characterization of monoclonal antibodies against pregnancy-associated plasma protein A.
abstract: Pregnancy-associated plasma protein A (PAPP-A) was found to be a good first trimester maternal serum marker, together with free beta-human chorionic gonadotrophin (HCG) subunits, for the biochemical screening of fetal trisomy 21 (Down's syndrome). We have raised monoclonal antibodies (mAbs) against PAPP-A purified from human pregnancy serum. The different antibodies were characterized biochemically by Western blot analysis and in terms of specificity (reaction with non-pregnant and male serum). Their performance in Down's syndrome screening was assessed in comparison with an existing enzyme-linked immunosorbent assay method after labelling of the different mAbs with biotin or horseradish peroxidase. A pair of mAbs was eventually chosen for a double-antibody sandwich protocol. The selected combination was found to have a significantly increased specificity (P = 0.0116) over the method using (purified) polyclonal antibodies, together with slightly increased sensitivity. In our limited number of Down's syndrome pregnancy samples (n = 17) and controls (n = 18), the medians as well as the multiples of the median values (for the affected cases) were comparable between the two methods described.
authors.affiliation: Department of Obstetrics and Gynaecology, University of Berne, Schanzeneckstrasse 1, Berne CH-3012, Switzerland.
authors.forename: N A
authors.initials: NA
authors.lastname: Bersinger
authors.forename: A
authors.initials: A
authors.lastname: Meisser
authors.forename: T
authors.initials: T
authors.lastname: Bessou
authors.forename: P
authors.initials: P
authors.lastname: Seguin
authors.forename: M H
authors.initials: MH
authors.lastname: Birkhäuser
authors.forename: P
authors.initials: P
authors.lastname: Bischof
mesh_terms: D000911:Antibodies, Monoclonal; D015153:Blotting, Western / Q000379:methods; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D004314:Down Syndrome / Q000175:diagnosis* / Q000196:embryology*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D011247:Pregnancy; D011261:Pregnancy Trimester, First / Q000097:blood*; D011266:Pregnancy-Associated Plasma Protein-A / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D011296:Prenatal Diagnosis / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D018997:Chorionic Gonadotropin, beta Subunit, Human; D011266:Pregnancy-Associated Plasma Protein-A