title: Quantification of human platelet antigen-1a antibodies with the monoclonal antibody immobilization of platelet antigens procedure.
abstract: BACKGROUND
  Fetal-neonatal alloimmune thrombocytopenia results from a maternal alloimmunization against fetal platelet (PLT) antigens. In Caucasian persons, human PLT antigen-1a (HPA-1a) is the most frequently implicated antigen. Our aim was to develop a method supported by a mathematical approach to quantify HPA-1a antibodies.
  
  
  METHODS
  The monoclonal antibody immobilization of PLT antigens (MAIPA) protocol was applied on serial dilutions of a serum with high concentration of HPA-1a antibodies used as reference. Two mathematical procedures were used: the standard curve was constructed with a linear and a logistic regression. These regressions were used to calculate the amount of antibody in 14 test serum samples from mothers with detectable anti-HPA-1a.
  
  
  RESULTS
  Similar quantifications were obtained with both mathematical procedures. In 11 serum samples, the results, expressed in arbitrary units (AU), ranged from 62 +/- 4 to 1096 +/- 19 with the linear regression and from 62 +/- 4 to 1117 +/- 38 with the logistic regression. In addition, the linear regression allowed us to measure 3 test serum samples with low antibody concentrations from 4 +/- 2 to 44 +/- 3 AU, whereas the logistic regression was not suitable for the quantification of antibodies in these serum samples.
  
  
  CONCLUSIONS
  A simple quantification method was developed for anti-HPA-1a, based on the MAIPA procedure, allowing further studies concerning correlations between anti-HPA-1a quantification and clinical relevance.
authors.affiliation: Platelet Immunology Unit, INTS, Paris, France.
authors.forename: Gérald
authors.initials: G
authors.lastname: Bertrand
authors.forename: Vincent
authors.initials: V
authors.lastname: Jallu
authors.forename: Maxime
authors.initials: M
authors.lastname: Gouet
authors.forename: Killie Mette
authors.initials: KM
authors.lastname: Kjaer
authors.forename: Patrick
authors.initials: P
authors.lastname: Lambin
authors.forename: Anne
authors.initials: A
authors.lastname: Husebekk
authors.forename: Cécile
authors.initials: C
authors.lastname: Kaplan
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D016824:Antigens, Human Platelet / Q000276:immunology*; D005260:Female; D006801:Humans; D039661:Integrin beta3; D007518:Isoantibodies / Q000097:blood*; D016015:Logistic Models; D008433:Mathematics; D011247:Pregnancy; D012044:Regression Analysis
chemical_list: D000911:Antibodies, Monoclonal; D016824:Antigens, Human Platelet; C061248:ITGB3 protein, human; D039661:Integrin beta3; D007518:Isoantibodies