| Autor: |
Kieffer, Nelly, Boizard, Bernadette, Didry, Dominique, Wautier, Jean-Luc, Nurden, Alan T. |
| Zdroj: |
Blood; December 1984, Vol. 64 Issue: 6 p1212-1219, 8p |
| Abstrakt: |
We report the immunochemical characterization of a new platelet-specific alloantigen detected using an IgG antibody isolated from the serum of a patient with posttransfusion purpura (PTP). In indirect immunoprecipitation experiments, the antibody, termed anti-Lek8, predominantly precipitated glycoprotein (GP) IIb from Triton X-100 lysates of normal human platelets. In an immunoblot procedure, which involved the transfer of platelet polypeptides separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to nitrocellulose membrane, anti-Lek8bound exclusively to GP IIb. Under identical conditions, four anti-PIA1antibodies each reacted with GP IIIa. No binding of anti-LekaIgG occurred to Leka(–) platelets or to their separated polypeptides although GP IIb was normally detected by Coomassie blue staining. After electrophoresis of reduced platelet proteins, the Lekadeterminant was localized to the IIbαchain. Thus, unlike the PIA1antigen, the Lekadeterminant was not destroyed by disulfide reduction. Analysis of platelets from a patient with Glanzmann’s thrombasthenia revealed little or no binding in the GP IIb position. Anti-Lekapermitted the identification of 76,000 and 60,000 dalton fragments of GP IIb retained by the platelet following chymotrypsin treatment. Our results further highlight the immunogenicity of the GP IIb-IIIa complex. They also suggest that antibodies against GP IIb can cause the thrombocytopenia observed in PTP and that anti-PIA1antibodies do not account exclusively for the pathophysiology of this immune disorder. |
| Databáze: |
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