Lucas G F, Holburn A M
Br J Haematol. 1987 Jan;65(1):111-5. doi: 10.1111/j.1365-2141.1987.tb06144.x.
Blood anticoagulated with solid K2EDTA had platelet associated IgG (PAIgG) levels five-fold greater than citrated blood when the platelets were harvested by differential centrifugation but identical PAIgG levels when the platelets were harvested by Percoll density gradient. Furthermore, blood anticoagulated with increasing amounts of solid K2EDTA demonstrated a proportionate increase in both PAIgG and haemolysis whereas the same blood sample anticoagulated with aqueous K2EDTA exhibited neither of these effects. Coulter Counter analysis of platelet poor plasma (PPP) prepared from blood anticoagulated with solid K2EDTA revealed particles with a mean volume greater than normal RBC; such particles were not found in the PPP prepared from citrated blood. While some of these particles could be sedimented through plasma, those remaining were sufficiently buoyant to resist sedimentation unless the plasma was diluted with buffer. Studies with FITC conjugated antisera revealed that the particles could be classified into two types. Type I particles reacted strongly with a monoclonal anti-RBC antibody, weakly with anti-IgG antibody and had the appearance of stroma. Type II particles lacked any apparent biological structure, reacted strongly with anti-IgG antibody but not with monoclonal anti-RBC antibody. Thus, the buoyant IgG-rich particles found in blood anticoagulated with solid K2EDTA appear to contribute to the high PAIgG levels associated with this anticoagulant. Consequently, solid K2EDTA should not be used to anticoagulate blood destined for PAIgG measurement.
当通过差速离心法采集血小板时，用固体K2EDTA抗凝的血液中血小板相关IgG（PAIgG）水平比枸橼酸盐抗凝的血液高五倍，但当通过Percoll密度梯度法采集血小板时，PAIgG水平相同。此外，随着固体K2EDTA用量增加而抗凝的血液，PAIgG和溶血均呈相应增加，而用液体K2EDTA抗凝的同一血样则未出现这些效应。对用固体K2EDTA抗凝的血液制备的血小板贫乏血浆（PPP）进行库尔特计数器分析，发现有平均体积大于正常红细胞的颗粒；在枸橼酸盐抗凝血液制备的PPP中未发现此类颗粒。虽然其中一些颗粒可通过血浆沉淀，但剩余颗粒具有足够的浮力以抵抗沉淀，除非用缓冲液稀释血浆。用异硫氰酸荧光素（FITC）偶联抗血清进行的研究表明，这些颗粒可分为两类。I型颗粒与单克隆抗红细胞抗体强烈反应，与抗IgG抗体反应较弱，外观呈基质状。II型颗粒缺乏任何明显的生物学结构，与抗IgG抗体强烈反应，但不与单克隆抗红细胞抗体反应。因此，在用固体K2EDTA抗凝的血液中发现的富含IgG的浮力颗粒似乎导致了与这种抗凝剂相关的高PAIgG水平。因此，固体K2EDTA不应被用于抗凝用于PAIgG测量的血液。
