Zeiler T, Heim M, Dempfle A, Kretschmer V
Institute for Transfusion Medicine and Hemostaseology, University Clinics, Philipps-University, Marburg, Germany.
Transfus Med. 2006 Jun;16(3):176-83. doi: 10.1111/j.1365-3148.2006.00664.x.
The origin of HLA class I molecules on platelets is still under discussion. Adsorption of HLA molecules on platelets using specific experimental conditions has been described. The study presented investigates whether there is a significant elution and adsorption of HLA class I molecules on platelets during storage of pooled random platelet concentrates (PRPC) under routine conditions. Platelet concentrates (PCs) from whole blood were prepared from HLA-A2-positive and HLA-A2-negative donors, pooled and stored under routine conditions. In addition, platelets from HLA-A2-negative donors were pelleted and resuspended in cell-free plasma from HLA-A2-positive donors. HLA-A2-positive PCs (positive control), HLA-A2-negative PCs (negative control) and HLA-A2-negative platelets in plasma from HLA-A2-negative donors were stored simultaneously. Binding of FITC-conjugated monoclonal murine antihuman HLA-A2 antibodies (anti-HLA-A2-mab) was measured during 5-day storage by flow cytometry. An increased binding of anti-HLA-A2-mab during storage was found on HLA-A2-negative platelets (P < 0.005) independently whether they were incubated with cell-free plasma or platelets from HLA-A2-positive donors or autologous HLA-A2-negative cell-free plasma. However, non-specific binding of IgG controls increased equally, whereas anti-HLA-A2-mab binding to platelets from HLA-A2-positive donors did not decrease during storage. This study suggests that there is no significant elution and adsorption of HLA class I antigens of platelets in pooled PCs during storage under the usual conditions for platelet storage. Increased anti-HLA-A2-mab signal was due to non-specific binding. Therefore, HLA class I compatible platelets should maintain their compatibility for an immunized patient when stored in a pool with HLA incompatible platelets and shortened survival after transfusion should not be expected.
血小板上 HLA - I 类分子的来源仍在讨论中。已经描述了在特定实验条件下 HLA 分子在血小板上的吸附情况。本研究探讨在常规条件下储存混合随机血小板浓缩物（PRPC）期间，血小板上是否存在 HLA - I 类分子的显著洗脱和吸附。从 HLA - A2 阳性和 HLA - A2 阴性供体的全血中制备血小板浓缩物（PC），混合并在常规条件下储存。此外，将 HLA - A2 阴性供体的血小板制成沉淀，再悬浮于 HLA - A2 阳性供体的无细胞血浆中。HLA - A2 阳性 PC（阳性对照）、HLA - A2 阴性 PC（阴性对照）以及 HLA - A2 阴性供体血浆中的 HLA - A2 阴性血小板同时储存。在 5 天的储存期间，通过流式细胞术检测异硫氰酸荧光素（FITC）偶联的鼠抗人 HLA - A2 单克隆抗体（抗 - HLA - A2 - mab）的结合情况。发现在储存期间，HLA - A2 阴性血小板上抗 - HLA - A2 - mab 的结合增加（P < 0.005），无论它们是与无细胞血浆、HLA - A2 阳性供体的血小板还是自身 HLA - A2 阴性无细胞血浆孵育。然而，IgG 对照的非特异性结合同样增加，而抗 - HLA - A2 - mab 与 HLA - A2 阳性供体血小板的结合在储存期间并未减少。本研究表明，在血小板储存的常规条件下储存期间，混合 PC 中血小板的 HLA - I 类抗原不存在显著的洗脱和吸附。抗 - HLA - A2 - mab 信号增加是由于非特异性结合。因此，当 HLA - I 类相容的血小板与 HLA 不相容的血小板储存在一起时，对于免疫患者应保持其相容性，并且不应预期输血后存活时间缩短。
