title: Development, characterization, and use of monoclonal antibodies made to antigens expressed on the surface of fetal nucleated red blood cells.
abstract: BACKGROUND
  Current methods for obtaining fetal cells for prenatal diagnosis are invasive and carry a small (0.5-1.0%) but definite risk of miscarriage. An attractive alternative would be isolation of fetal cells from peripheral maternal blood using antibodies with high specificity and avidity.
  
  
  METHODS
  To generate antibodies, we purified nucleated red blood cells (NRBCs) from fetal livers and used them as the immunogen to generate monoclonal antibodies (mAbs) directed against surface antigens.
  
  
  RESULTS
  The four antibodies recognized at least two conformationally sensitive epitopes of the transferrin receptor. Isolation of NRBCs from 252 maternal blood samples using these antibodies in magnetic activated cell sorting after an initial density gradient centrifugation yielded 0-419 NRBCs per 25 mL of maternal blood. One antibody, 2B7.4, not only isolated the highest number of NRBCs (>10 in 90% of the samples) but also isolated these NRBCs in 78 consecutive maternal samples.
  
  
  CONCLUSIONS
  Antibody 2B7.4 shows promise for the isolation of NRBCs from maternal blood and should allow studies concerning the source of these cells, fetal vs maternal, and the factors controlling their prevalence.
authors.affiliation: Servicio de Análisis Clínicos, Hospital San Agustín, Aviles 33400 Asturias, Spain. falvarez@arrrakis.es
authors.forename: F V
authors.initials: FV
authors.lastname: Alvarez
authors.forename: J
authors.initials: J
authors.lastname: Olander
authors.forename: D
authors.initials: D
authors.lastname: Crimmins
authors.forename: B
authors.initials: B
authors.lastname: Prieto
authors.forename: A
authors.initials: A
authors.lastname: Paz
authors.forename: R
authors.initials: R
authors.lastname: Alonso
authors.forename: S
authors.initials: S
authors.lastname: Porter
authors.forename: J
authors.initials: J
authors.lastname: Hess
authors.forename: R D
authors.initials: RD
authors.lastname: Crist
authors.forename: Y
authors.initials: Y
authors.lastname: Landt
authors.forename: J H
authors.initials: JH
authors.lastname: Ladenson
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis; D000939:Epitopes; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D005312:Fetal Blood / Q000166:cytology* / Q000276:immunology; D006801:Humans; D008099:Liver / Q000166:cytology; D051379:Mice; D011247:Pregnancy; D011990:Receptors, Transferrin / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D011990:Receptors, Transferrin