Alloimmunization to platelet-specific antigens on glycoproteins IIb-IIIa and Ib/IX in multiply transfused thrombocytopenic patients.
The rate of alloimmunization to platelet-specific antigens associated with platelet glycoproteins (GPs) IIb-IIIa and Ib/IX was studied in 293 multiply transfused thrombocytopenic patients. Antibodies to platelet-specific antigens were measured with a solid-phase assay using platelet GP IIb-IIIa or Ib/IX as the antigenic targets. Nine patients were found to have antibodies to platelet GP IIb-IIIa, and no patients had antibodies to platelet GP Ib/IX. In six of these nine patients, the specificity of the antibody was shown by using GP IIb-IIIa from donors with different platelet-specific antigen phenotypes. In the remaining three patients with antibodies to platelet GP IIb-IIIa, no specificity could be identified. These patients had autoimmune thrombocytopenia in association with lymphoma. The alloimmunization rate to platelet-specific antigens associated with GP IIb-IIIa was 2 percent, whereas the rate of alloimmunization to HLA antigens was 23 percent. Of the patients alloimmunized to HLA antigens, 9 percent also had antibodies to platelet-specific antigens. A poor response to HLA-identical platelet transfusions was observed only in those patients with positive assays in the solid-phase test. These results suggest that the incidence of antibodies to platelet-specific antigens carried on GP IIb-IIIa is low. Platelet-specific antibodies may be found more frequently in patients alloimmunized to HLA antigens than in those not so alloimmunized.
Department of Laboratory Medicine, Johns Hopkins Hospital, Baltimore, Maryland.
T
T
Kickler
S D
SD
Kennedy
H G
HG
Braine
D016824:Antigens, Human Platelet; D001681:Biological Assay; D001803:Blood Transfusion; D005260:Female; D006801:Humans; D007114:Immunization; D039661:Integrin beta3; D007518:Isoantibodies / Q000276:immunology*; D007519:Isoantigens / Q000276:immunology*; D008297:Male; D010980:Platelet Membrane Glycoproteins / Q000276:immunology*; D013921:Thrombocytopenia / Q000097:blood* / Q000276:immunology / Q000628:therapy
C044561:3a alloantigen, human; C057260:4a alloantigen, human; C055973:5b alloantigen, human; D016824:Antigens, Human Platelet; C061248:ITGB3 protein, human; D039661:Integrin beta3; D007518:Isoantibodies; D007519:Isoantigens; D010980:Platelet Membrane Glycoproteins