Studies on the pathophysiology of posttransfusion purpura.
Studies on the pathophysiology of posttransfusion purpura.
复制标题
输血后紫癜的病理生理学研究。
作者：
TS Kickler;P. Ness;J. Herman;W. Bell
输血后紫癜通常发生在PLA1阴性的受血者中，这些受血者之前已经对PLA1抗原进行了免疫。输血后，随着抗PLA1抗体的形成，会出现严重的血小板减少症。由于患者的血小板缺乏PLA1抗原，人们不会指望这种抗体会破坏自体血小板。在这项研究中，我们证明了PLA1抗原存在于储存的血液中，并能与PLA1阴性的血小板结合，使其发生PLA1反应。用PLA1(+)献血者的超速离心血浆孵育PLA1(-)血小板，可以使抗PLA1与PLA1(-)血小板结合。来自PLA1(-)献血员的对照血浆不能导致抗PLA1结合。通过抑制试验，我们发现储存的血液中含有不能通过超速离心法去除的PLA1物质。经Western blotting证实，结合PLA1(-)的物质为PLA1抗原。将含有PLA1抗原的血浆与PLA1(-)血小板孵育后，观察到95000D的反应性。天然PLA1(+)血小板表现出类似的条带。当PLA1(-)血小板与来自PLA1(-)捐献者的血浆孵育时，这条带不存在。这些研究表明，PLA1抗原的一种可溶形式存在于储存的血液中，可以吸收PLA1(-)血小板。因此，抗PLA1可以与这些血小板结合，导致血小板减少。这些观察结果可能解释了输血后紫癜性血小板的自体破坏。
Posttransfusion purpura typically occurs in PLA1 negative blood recipients who have been previously immunized to the PLA1 antigen. Following transfusion, severe thrombocytopenia develops with the formation of anti-PLA1. Since the patients' platelets lack the PLA1 antigen, one would not expect this antibody to destroy autologous platelets. In this study we show that PLA1 antigen exists in stored blood and can absorb to PLA1 negative platelets making them PLA1 reactive. Incubating PLA1 (-) platelets with ultracentrifuged plasma from PLA1 (+) blood donors allowed anti-PLA1 to bind to PLA1 (-) platelets. Control plasma from PLA1 (-) blood donors did not lead to anti-PLA1 binding. Using an inhibition assay, we showed that stored blood contains PLA1 material that was not removed by ultracentrifugation. The material absorbing to PLA1 (-) platelets represented the PLA1 antigen, which was confirmed by Western blotting. After incubating plasma containing PLA1 antigen with PLA1 (-) platelets, reactivity at 95,000 D was observed. Native PLA1 (+) platelets showed a similar band. When PLA1 (-) platelets were incubated with plasma from a PLA1 (-) donor, this band was not present. These studies show that a soluble form of PLA1 antigen exists in stored blood that can absorb to PLA1 (-) platelets. Consequently, anti-PLA1 can bind to these platelets leading to thrombocytopenia. These observations may explain the autologous destruction of platelets in posttransfusion purpura.