A new platelet-specific alloantigen Bra. Report of 4 cases with neonatal alloimmune thrombocytopenia.
Sera obtained from 4 mothers of children with neonatal alloimmune thrombocytopenia contained a platelet-specific alloantibody, anti-Bra, which defined an antigen apparently different from all known platelet alloantigens. All 4 fathers were Bra positive, whereas all mothers were Bra negative. The minimal postnatal values of platelet counts ranged from 19 X 10(9) to 75 X 10(9)/1. Family studies showed that the Bra antigen is inherited as an autosomal, codominant trait. Its antigen frequency in the German population is 20% (21 of 105 unrelated donors were positive). The estimated gene frequency is 0.11. The antibodies were identified by a glycoprotein-specific enzyme immunoassay using monoclonal antibodies for antigen immobilization, while they could not reliably be detected by binding assays employing whole platelets (platelet immunofluorescence, indirect competitive ELISA).
Kiefel
V
V
Institute for Clinical Immunology, Justus Liebig University, Giessen, FRG.
Santoso
S
S
Katzmann
B
B
Mueller-Eckhardt
C
C
D000328:Adult; D016824:Antigens, Human Platelet; D001792:Blood Platelets / Q000276:immunology*; D005260:Female; D005799:Genes, Dominant; D006801:Humans; D007231:Infant, Newborn; D007518:Isoantibodies / Q000276:immunology; D007519:Isoantigens / Q000235:genetics / Q000276:immunology*; D008297:Male; D010375:Pedigree; D011247:Pregnancy; D013921:Thrombocytopenia / Q000097:blood* / Q000235:genetics / Q000276:immunology
C055973:5b alloantigen, human; D016824:Antigens, Human Platelet; D007518:Isoantibodies; D007519:Isoantigens