Christopoulos C G, Kelsey H C, Machin S J
University College, London, UK.
Vox Sang. 1993;64(2):106-15. doi: 10.1111/j.1423-0410.1993.tb02527.x.
Flow cytometry (FC) was used to estimate platelet-surface IgG (PSIgG) by quantifying the fluorescence of platelets incubated with a fluorescein isothiocyanate (FITC)-labelled polyclonal goat anti-human IgG antibody or FITC-labelled non-immune goat IgG. Results were expressed as relative fluorescence intensity (RFI) defined as the ratio of specific fluorescence (mean fluorescence of platelets incubated with the FITC anti-IgG) over non-specific fluorescence (mean fluorescence of platelets incubated with FITC non-immune goat IgG). A normal range was formed by analysing platelets from 71 healthy subjects. Platelets from 16 patients with a firm clinical diagnosis of immune-mediated thrombocytopenia had a mean RFI significantly higher (p < 0.001) than the controls, whereas platelets from 9 patients thought to have non-immune thrombocytopenia had an RFI not significantly different from the normal controls. From a prospectively studied group of 62 patients with no clinically obvious cause for their thrombocytopenia or impaired platelet function 35.5% had raised PSIgG. In order to express the results as number of IgG molecules per platelet, reference curves were created by using FC to measure PSIgG of platelets coated with known amounts of a chimeric IgG (human IgG with murine hypervariable region) monoclonal antibody to the glycoprotein IIb-IIIa complex. Normal platelets had an average 1,463 (SD = 927) molecules of PSIgG. In patients with immune-mediated thrombocytopenia the levels ranged from 690 to 32,328 (mean 11,535) molecules per platelet. Flow-cytometric PSIgG estimation was sensitive, fast and easy to perform and therefore suitable for both research and clinical service purposes.
采用流式细胞术（FC），通过对与异硫氰酸荧光素（FITC）标记的多克隆山羊抗人IgG抗体或FITC标记的非免疫山羊IgG孵育的血小板荧光进行定量，来估计血小板表面IgG（PSIgG）。结果以相对荧光强度（RFI）表示，定义为特异性荧光（与FITC抗IgG孵育的血小板平均荧光）与非特异性荧光（与FITC非免疫山羊IgG孵育的血小板平均荧光）之比。通过分析71名健康受试者的血小板形成正常范围。16例临床确诊为免疫性血小板减少症患者的血小板平均RFI显著高于对照组（p<0.001），而9例疑似非免疫性血小板减少症患者的血小板RFI与正常对照组无显著差异。在一组前瞻性研究的62例血小板减少或血小板功能受损但无明显临床病因的患者中，35.5%的患者PSIgG升高。为了将结果表示为每个血小板的IgG分子数，通过使用FC测量包被有已知量的针对糖蛋白IIb-IIIa复合物的嵌合IgG（具有鼠源高变区的人IgG）单克隆抗体的血小板的PSIgG来创建参考曲线。正常血小板平均有1463个（标准差=927）PSIgG分子。免疫性血小板减少症患者的水平为每血小板690至32328个（平均11535个）分子。流式细胞术估计PSIgG灵敏、快速且易于操作，因此适用于研究和临床服务目的。
