Expression of the drug-dependent antigen for quinine-dependent antiplatelet antibodies on GP IIIa but not that on GPIb, IIb or IX on human endothelial cells.
In quinine- and quinidine-induced thrombocytopenic purpura IgG antibodies are known to react in a drug-dependent manner with different combinations of surface glycoproteins (GP) Ib, IIb, IIIa and IX. Because endothelial cells share a number of properties of platelets, including the presence of GP IIIa and GPIb-like proteins, we have compared these two cell types for their quinine-dependent IgG binding abilities. By immunoblotting of endothelial cells, quinine-dependent IgG binding from four patient sera was observed only to a 93 kDa component corresponding to GP IIIa. Strong IgG binding independent of the drug was found at 170-180 kDa. Thus endothelial cells express the GP IIIa quinine-dependent epitope on platelet GP IIIa, but not those on other platelet glycoproteins.
Pfueller
S L
SL
Department of Medicine, Monash University Medical School, Alfred Hospital, Prahran, Victoria, Australia.
Bilston
R A
RA
Jane
S
S
Gibson
J
J
D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000096:biosynthesis*; D001792:Blood Platelets / Q000187:drug effects / Q000276:immunology*; D004730:Endothelium, Vascular / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000276:immunology; D010980:Platelet Membrane Glycoproteins / Q000187:drug effects / Q000276:immunology*; D011803:Quinine / Q000494:pharmacology*
D001323:Autoantibodies; D001324:Autoantigens; D007074:Immunoglobulin G; D010980:Platelet Membrane Glycoproteins; D011803:Quinine