Corresponding author:
Department of laboratory diagnostics, Children's hospital Zagreb, Zagreb, Croatia.
Biochem Med (Zagreb). 2018 Feb 15;28(1):010707. doi: 10.11613/BM.2018.010707. Epub 2018 Jan 10.
Laboratories often modify procedures recommended by the European Urinalysis Guidelines for urine sediment analysis. The aim of this study was to compare the recommended protocol with our routine laboratory procedure and to evaluate the possible impact of modifications in the relative centrifugal force, type of tube, method of supernatant aspiration and urine volume on patient's results.
Firstly, relative centrifugal force was investigated using 20 pairs of samples examined after centrifugation at 400xg and 1358xg. In phase two, 110 samples were examined, paired as: round bottom conical tube (N = 46), decanting suction of supernatant (N = 100) and 10 mL 5 mL of urine sample (N = 101).
The number of erythrocytes, leukocytes and squamous epithelial cells was significantly lower after centrifugation at 400xg (P = 0.001, 0.002 and 0.004, respectively). The number of leukocytes was significantly lower in conical tubes (P = 0.010), after the suction of supernatant (P = 0.045) and in 5 mL urine (P < 0.001). The number of squamous epithelial cells was significantly lower after the suction of supernatant (P < 0.001) and in 5 mL urine (P < 0.001). The number of erythrocytes (P < 0.001), total non-hyaline casts (P < 0.001) and the frequency of granular casts (P = 0.039) was significantly lower in 5 mL urine.
Lower results of leukocytes, erythrocytes, squamous cells and non-hyaline casts were recorded in recommended procedures (centrifugation at 400xg, suction of supernatant, conical tube, 5 mL of sample) than in routine procedure (centrifugation at 1358xg, decanting of supernatant, round bottom tube, 10 mL) used in our laboratory.
实验室经常会修改欧洲尿液分析指南中推荐的尿液沉淀物分析程序。本研究旨在比较推荐方案与我们常规实验室程序的差异，并评估相对离心力、试管类型、上清液抽吸方式和尿液量的改变对患者结果的可能影响。
首先，使用 20 对离心后分别在 400xg 和 1358xg 下离心的样本，研究相对离心力。在第二阶段，检查了 110 个配对样本，分为：圆底锥形管（N = 46）、倾析上清液抽吸（N = 100）和 10 mL 5 mL 尿液样本（N = 101）。
离心力为 400xg 时，红细胞、白细胞和鳞状上皮细胞的数量明显较低（P = 0.001、0.002 和 0.004）。锥形管（P = 0.010）、上清液抽吸后（P = 0.045）和 5 mL 尿液中（P < 0.001）白细胞数量明显较低。上清液抽吸后（P < 0.001）和 5 mL 尿液中（P < 0.001）鳞状上皮细胞数量明显较低。红细胞（P < 0.001）、总非透明管型（P < 0.001）和颗粒管型的频率（P = 0.039）在 5 mL 尿液中明显较低。
与我们实验室常规程序（离心力 1358xg，倾析上清液，圆底管，10 mL 样本）相比，推荐程序（离心力 400xg，上清液抽吸，锥形管，5 mL 样本）中白细胞、红细胞、鳞状细胞和非透明管型的结果较低。
