Dai Jincheng, Zhang Xiaoyu, Zhou Jing, Pan Wei, Yu Fei
Department of Clinical Laboratory, Children's Hospital of Nanjing Medical University, Nanjing, China.
Transl Pediatr. 2023 Jan 31;12(1):20-30. doi: 10.21037/tp-22-661. Epub 2023 Jan 16.
Laboratory detection of high values of serum amyloid A (SAA) is impaired by the hook effect. In response to this problem, Mindray has launched the new generation BC-7500CS automated hematology analyzer with an SAA autodilution (SAA-D) function. The present study aimed to verify the performance of the SAA module.
Venous whole-blood specimens anticoagulated with EDTA-K2 were randomly collected from outpatients and inpatient of the Children's Hospital of Nanjing Medical University (CH). Background, repeatability, precision, linear range, intermode comparison, and interference of the SAA module of the Mindray BC-7500CS were evaluated, and the performance of the SAA-D function was verified.
The Mindray BC-7500CS showed an SAA background of 0.14 mg/L, well below that claimed by the manufacturer. Repeatability of SAA with standard deviation (SD) <0.6 mg/L and coefficient of variation (CV) <6%, the quality control (QC) precision was less than 8%. The measured value of the linear range was essentially consistent with the theoretical value, and the maximum measured values could reach 1932.38 mg/L. The deviation between whole-blood mode and micro-whole-blood mode was small (r=0.999), and the SAA module displayed high anti-interference ability. In addition, the measured results of specimens with high SAA concentration diluted by SAA-D were close to those after manual dilution (r=0.993).
The SAA module of the Mindray BC-7500CS had excellent performance, and the SAA-D function was highly accurate at measuring specimens with high SAA concentration, enabling reliable SAA detection in the laboratory and clinical practice.
血清淀粉样蛋白A（SAA）高值的实验室检测受钩状效应影响。针对这一问题，迈瑞推出了具有SAA自动稀释（SAA-D）功能的新一代BC-7500CS全自动血液分析仪。本研究旨在验证SAA模块的性能。
从南京医科大学附属儿童医院（CH）的门诊和住院患者中随机采集用乙二胺四乙酸钾（EDTA-K2）抗凝的静脉全血标本。对迈瑞BC-7500CS的SAA模块的背景、重复性、精密度、线性范围、模式间比较和干扰进行评估，并验证SAA-D功能的性能。
迈瑞BC-7500CS的SAA背景值为0.14 mg/L，远低于制造商声称的值。SAA的重复性标准差（SD）<0.6 mg/L，变异系数（CV）<6%，质量控制（QC）精密度小于8%。线性范围的测量值与理论值基本一致，最大测量值可达1932.38 mg/L。全血模式和微量全血模式之间的偏差很小（r=0.999），SAA模块显示出高抗干扰能力。此外，用SAA-D稀释的高SAA浓度标本的测量结果与手工稀释后的结果接近（r=0.993）。
迈瑞BC-7500CS的SAA模块具有优异的性能，SAA-D功能在测量高SAA浓度标本时高度准确，能够在实验室和临床实践中实现可靠的SAA检测。
