Department of Laboratory Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
Ann Lab Med. 2012 Nov;32(6):392-8. doi: 10.3343/alm.2012.32.6.392. Epub 2012 Oct 17.
The reticulocyte count is a good marker of erythropoietic activity of the bone marrow. In the mid-1990s, automated flow cytometric analysis replaced microscopy for the quantification of reticulocytes. Leukocytosis cases with an erroneously high reticulocyte count and a high immature reticulocyte fraction (IRF) have been reported. In this study, we analyzed reticulocyte counts in leukocytosis samples, in an effort to identify a correction method.
The study comprised of 21 samples from 16 leukocytosis patients. Results of reticulocyte analyses obtained using a XE-2100 hematology analyzer (Sysmex, Japan) were compared with those obtained using the supravital staining technique, which is a reference method. If the samples showed erroneously high reticulocyte counts and IRF, they were reanalyzed after serial dilution with isotonic solution.
Five samples from 4 patients showed erroneously elevated reticulocyte counts and/or IRF on the XE-2100 analyzer. They displayed abnormal reticulocyte scattergrams, with 4 of 5 cases indicated by a flag. The white blood cell (WBC) fractions overlapped with the reticulocyte regions, especially with the IRF. Diagnoses and blast counts were variable when such errors occurred; WBC counts varied from 218.19×10(9)/L to 725.14×10(9)/L. The errors were corrected by simple dilution with isotonic solution. However, the corrective WBC counts differed according to individual cases.
When leukocytosis samples exhibit an abnormal reticulocyte scattergram with a flag, or an abnormally high IRF, we recommend the dilution of the sample with isotonic solution to a WBC count of about 100.00×10(9)/L, followed by reanalysis of the reticulocyte count and reticulocyte scattergram.
网织红细胞计数是反映骨髓红细胞生成活性的一个很好的指标。20 世纪 90 年代中期，自动化流式细胞术分析取代了显微镜用于网织红细胞的定量检测。已经报道了白细胞增多症病例中存在网织红细胞计数错误升高和不成熟网织红细胞分数（IRF）升高的情况。在这项研究中，我们分析了白细胞增多症样本中的网织红细胞计数，以努力确定一种校正方法。
该研究包括 16 例白细胞增多症患者的 21 个样本。使用 XE-2100 血液分析仪（Sysmex，日本）获得的网织红细胞分析结果与作为参考方法的活体染色技术获得的结果进行了比较。如果样本显示网织红细胞计数和/或 IRF 错误升高，则用等渗溶液进行连续稀释后重新分析。
4 例患者的 5 个样本在 XE-2100 分析仪上显示出错误升高的网织红细胞计数和/或 IRF。它们显示出异常的网织红细胞散点图，其中 5 个中的 4 个有标记。白细胞（WBC）分数与网织红细胞区域重叠，尤其是与 IRF 重叠。当出现此类错误时，诊断和原始细胞计数会有所不同；WBC 计数从 218.19×10(9)/L 到 725.14×10(9)/L 不等。通过简单的等渗溶液稀释可纠正这些错误。然而，校正后的 WBC 计数因个体情况而异。
当白细胞增多症样本显示异常的网织红细胞散点图和标记，或异常高的 IRF 时，我们建议用等渗溶液将样本稀释至约 100.00×10(9)/L 的 WBC 计数，然后重新分析网织红细胞计数和网织红细胞散点图。
