作者：Dzik WH, Cserti-Gazdewich CM, Ssewanyana I, Delelys M, Preffer FI.

来源：Cytometry B Clin Cytom. 2010 Mar;78(2):81-7.

摘要 背景：使用流式细胞仪可检测单核细胞表面CD36抗原，CD36与糖尿病，心血管疾病，血脂异常，血小板同种免疫和易感恶性疟原虫疟疾等疾病相关。CD36又称为血小板糖蛋白IV，在血小板表面也有很强的表达。

方法：将含相同单核细胞浓度的全血样本的血小板含量调节到20,000/ul到600,000/ul范围之间，用荧光标记的抗CD36染色，通过流式细胞仪分析。

结果：单核细胞表面的CD36平均荧光强度（MFI）随样本中血小板浓度增加而较血小板值正常时降低超过50%。即使使用更大剂量的单克隆抗体和不同克隆的抗CD36试剂，结果并没有改观。这个发现与血小板竞争CD36抗体试剂的说法非常相符。在HLA-I类抗体中也有类似的发现。在规定的条件下，单核细胞表面的CD36 MFI值下降与血小板浓度升高形成了可预测的逆线性关系。

结论：通过流式细胞仪测量全血样本中单核细胞表面CD36的表达受血小板计数的影响。当对比不同个体单核细胞表面的CD36表达，我们的方法可以用来消除样品中血小板浓度对该样品单核细胞表面CD36表达的影响。当使用全血分析且目标抗原在血小板和白细胞中都有较强表达时，血小板竞争单克隆抗体试剂的情况也可能发生。

When monocytes and platelets compete: The effect of platelet count on the flow cytometric measurement of monocyte CD36

Dzik WH, Cserti-Gazdewich CM, Ssewanyana I, Delelys M, Preffer FI.

Cytometry B Clin Cytom. 2010 Mar;78(2):81-7.

Abstract BACKGROUND: Flow cytometric measurement of monocyte surface CD36 is relevant to several conditions including diabetes, cardiovascular disease, lipid disorders, platelet isoimmunization, and susceptibility to P falciparum malaria. CD36 is also strongly expressed on platelets where it is also known as platelet glycoprotein IV.

METHODS: Whole blood samples, containing identical monocyte concentrations, were adjusted to contain platelets ranging from 20,000/uL to 600,000/uL, were stained with fluorescent-labeled anti-CD36, and analyzed by flow cytometry.

RESULTS: CD36 median fluorescent intensity (MFI) observed on monocytes decreased as the platelet concentration in the sample increased with more than a 50% decline in monocyte MFI over the normal range of platelet values. The effect was not abolished by using larger volumes of monoclonal antibody and was observed with different clones of reagent anti-CD36. The findings were most consistent with competition by platelets for the CD36 reagent. Similar findings were observed with antibody to class I HLA. Under defined assay conditions, monocyte CD36 MFI declined with rising platelet concentration in a predictable fashion following an inverse linear relationship.

CONCLUSIONS: Measurement of CD36 expression on monocytes by flow cytometry in whole blood samples is affected by the sample platelet count. When comparing the monocyte CD36 expression among different individuals, our approach can be used to adjust measured monocyte CD36 expression for the effect of the platelet concentration in the sample. Competition by platelets for monoclonal reagents may occur in other settings when whole blood assays are used and when the target antigen is strongly expressed on both platelets and leukocytes.

翻译：何保仁 校对：周燕