title: An autoanalyzer test for the quantitation of platelet-associated IgG.
abstract: A new quantitative antiglobulin consumption (QAC) test for the measurement of platelet-associated IgG is described. In this test washed platelets are incubated with anti-IgG at a final dilution of 1:2 million. The unneutralized fraction of anti-IgG remaining in solution is then measured with an Autoanalyzer and soluble IgG is used for calibration. The dose-response curves depicting the percent neutralization of anti-IgG by platelets and by soluble IgG were compared in detail and found to be nearly identical, indicating that platelet-associated IgG can be accurately quantitated by this method. The mean IgG values were 2,287 molecules/platelet for normal adults and 38,112 molecules/platelet for ITP patients. The Autoanalyzer QAC test is a sensitive and reproducible assay for the quantitation of platelet-associated IgG.
mesh_terms: D001322:Autoanalysis / Q000379:methods; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism*; D003298:Coombs Test; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis*; D007700:Kinetics; D011485:Protein Binding; D011696:Purpura, Thrombocytopenic / Q000097:blood / Q000175:diagnosis; D011947:Receptors, Antigen, B-Cell / Q000032:analysis*
chemical_list: D007074:Immunoglobulin G; D011947:Receptors, Antigen, B-Cell