Böer Klas, Deufel Thomas
Institute for Clinical Chemistry and Laboratory Medicine, Friedrich-Schiller-University Jena, Jena, Germany.
Clin Chem Lab Med. 2009;47(5):607-11. doi: 10.1515/CCLM.2009.135.
Samples with limited volume is a common problem in laboratories receiving samples from pediatric patients. Also, pediatric samples may contain nucleated red blood cells (NRBC) which distorts the white blood cell (WBC) count and which can only be measured by some automated cell counting systems. Differential counts are sometimes required, posing the question of validity of flagging depending on age of the patients and on predilutions.
We evaluated the hematology analyzers XE-2100 and XS-800 for their suitability in measuring hematological parameters in such samples.
With the exception of the MCHC and partly the MCH, we observed very good agreement between complete blood counts (CBC) in diluted and undiluted samples. Dilution did not impair sensitivity in the clinically relevant range nor, accuracy of the NRBC count on XE-2100. Flagging was ineffective in undiluted samples from children<1 year of age and in all diluted samples when measuring differential counts.
In summary, while automated measurement of CBC and NRBC is possible in diluted samples, measurement of differential counts is restricted by loss of flagging efficiency. In addition, flagging is also ineffective in children<1 year of age using the analyzers evaluated and should, for diagnostic purposes, be performed manually.
对于接收儿科患者样本的实验室来说,样本量有限是一个常见问题。此外,儿科样本可能含有有核红细胞(NRBC),这会扭曲白细胞(WBC)计数,并且只有一些自动细胞计数系统能够对其进行测量。有时需要进行分类计数,这就引发了根据患者年龄和预稀释情况进行标记有效性的问题。
我们评估了血液分析仪XE - 2100和XS - 800在测量此类样本血液学参数方面的适用性。
除了平均红细胞血红蛋白浓度(MCHC)以及部分平均红细胞血红蛋白含量(MCH)外,我们观察到稀释样本和未稀释样本的全血细胞计数(CBC)之间具有很好的一致性。稀释并未损害临床相关范围内的灵敏度,也未影响XE - 2100上NRBC计数的准确性。在测量分类计数时,标记在1岁以下儿童的未稀释样本和所有稀释样本中均无效。
总之,虽然在稀释样本中可以自动测量CBC和NRBC,但分类计数的测量受到标记效率损失的限制。此外,使用所评估的分析仪对1岁以下儿童进行标记也是无效的,出于诊断目的,应手动进行标记。