title: False-positive rubella hemagglutination-inhibition (HAI) titers in neonates and children with conjugated hyperbilirubinemia.
abstract: Two neonates, one with extrahepatic biliary atresia and one with cystic fibrosis, and a 9-year-old child with atresia of the common bile duct had conjugated hyperbilirubinemia and elevated rubella HAI titers when kaolin pretreatment of serum was used. A beta-lipoprotein fraction of the serum that is frequently found in association with biliary obstruction was shown to be the probable source of the rubella HAI inhibitor. This beta-lipoprotein was not removed by standard kaolin treatment of serum, but was removed almost completely by dextran sulfate--calcium chloride treatment. In the presence of conjugated hyperbilirubinemia, routine kaolin pretreatment of serum is an inadequate measure for the removal of interfering substances, as false-positive rubella HAI results are obtained consistently.
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis; D001797:Blood Protein Electrophoresis; D002648:Child; D005189:False Positive Reactions; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D006932:Hyperbilirubinemia / Q000276:immunology*; D007223:Infant; D007231:Infant, Newborn; D007616:Kaolin; D008074:Lipoproteins / Q000097:blood; D012409:Rubella / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D008074:Lipoproteins; D007616:Kaolin