Department of Laboratory Medicine, College of Medicine, Ewha Womans University, Seoul, Republic of Korea.
Scand J Clin Lab Invest. 2020 Dec;80(8):644-648. doi: 10.1080/00365513.2020.1824298. Epub 2020 Sep 25.
During the evaluation of the DxH 900 hematology analyzer (Beckman Coulter, Miami, FL), we noted that some patient samples produced a false positive white blood cell (WBC) flag, neutrophil blasts (NE-blast), despite the absence of abnormal cells. We investigated whether storage time or anticoagulants such as K2- or K3-ethylenediaminetetraacetic acid (EDTA) would affect complete blood count (CBC) tests on the DxH 900. Sixty-four whole blood samples were collected in K3-EDTA tubes, and 44 were simultaneously drawn in K2-EDTA tubes. Samples were tested at the following two intervals: within 30 min of collection (0 min) and after an additional 30 min of roller-mixing at room temperature (30 min). WBC differential dataplots in 0-min K3-EDTA tubes showed a mixed cell population between lymphocytes and neutrophils in 22 patients presenting the NE-blast flag. All 22 samples revealed normal WBC differential dataplots after 30 min of roller-mixing. The significantly lower mean neutrophil volume in specimens of 0-min K3-EDTA tubes than those of 0-min K2-EDTA, 30-min K2-EDTA and 30-min K3-EDTA tubes appear to be the cause of the false flag. Unlike blood cell counts, mean platelet volume (MPV) was significantly higher at 30 min using both EDTA tubes than that at 0 min. In conclusion, K3-EDTA can produce a false positive flag, NE-blast, on the DxH 900. MPV increases over time irrespective of EDTA salt type.
在评估 DxH 900 血液分析仪（贝克曼库尔特，迈阿密，佛罗里达州）时，我们注意到一些患者样本尽管没有异常细胞，但产生了白细胞（WBC）假阳性标志、中性粒细胞原始细胞（NE-blast）。我们研究了储存时间或抗凝剂（如 K2-或 K3-乙二胺四乙酸（EDTA））是否会影响 DxH 900 的全血细胞计数（CBC）测试。将 64 份全血样本采集于 K3-EDTA 管中，同时采集 44 份于 K2-EDTA 管中。样本在以下两个时间间隔进行测试：采集后 30 分钟内（0 分钟）和在室温下额外 30 分钟滚瓶混合后（30 分钟）。0 分钟 K3-EDTA 管中的 WBC 差异数据图显示，在出现 NE-blast 标志的 22 名患者中，淋巴细胞和中性粒细胞之间存在混合细胞群。所有 22 个样本在 30 分钟滚瓶混合后，WBC 差异数据图均恢复正常。0 分钟 K3-EDTA 管标本的中性粒细胞体积明显低于 0 分钟 K2-EDTA、30 分钟 K2-EDTA 和 30 分钟 K3-EDTA 管标本，这似乎是产生假阳性标志的原因。与血细胞计数不同，使用两种 EDTA 管时，30 分钟时的平均血小板体积（MPV）明显高于 0 分钟时。总之，K3-EDTA 可在 DxH 900 上产生白细胞假阳性标志、NE-blast。MPV 随时间推移而增加，与 EDTA 盐类型无关。
