Åsberg Arne, Løfblad Lena, Felic Amela, Hov Gunhild Garmo
a Department of Clinical Chemistry , Trondheim University Hospital , Trondheim , Norway.
Scand J Clin Lab Invest. 2019 Feb-Apr;79(1-2):50-57. doi: 10.1080/00365513.2018.1550810. Epub 2019 Feb 14.
Calprotectin in plasma and blood might prove to be a useful biomarker of inflammation and infection; however, automated methods for analysing the concentration of calprotectin in those materials are lacking. We have validated a fully automated turbidimetric method and present health-related reference limits. Calprotectin was measured by Siemens Advia XPT with the Bühlmann fCAL® turbo test (Bühlmann Laboratories AG, Schönenbuch, Switzerland), a particle enhanced turbidimetric immunoassay for quantification of calprotectin in fecal extracts. Plasma and serum samples were analysed directly, while whole blood was first extracted with M-PER® Mammalian Protein Extraction Reagent (ThermoFisher) and diluted with B-CAL-EX (Bühlmann). We studied analytical imprecision, estimated health-related reference limits and examined the correlation between neutrophil-calprotectin (blood-calprotectin adjusted for plasma-calprotectin) and the neutrophil count. The intermediate ('day-to-day') coefficient of variation was 3.5 and 1.0% for heparin-plasma-calprotectin at 0.52 mg/L and 3.53 mg/L, respectively, and 4.9% for heparin-blood-calprotectin at 50.2 mg/L. Health-related reference limits were 0.470-3.02 mg/L for calprotectin in heparin-plasma, 50.8-182 mg/L for calprotectin in heparin-blood, 0.534-2.41% for the ratio between them and 24.7-33.3 pg for the mean amount of calprotectin per neutrophil. Compared to heparin-plasma, calprotectin concentrations were significantly lower in EDTA-plasma and higher in serum (p < .05). Correlation between neutrophil-calprotectin and the neutrophil count was excellent. We have shown that the Bühlmann fCAL® turbo test can be used to measure calprotectin in plasma and blood.
血浆和血液中的钙卫蛋白可能是炎症和感染的有用生物标志物；然而，目前缺乏用于分析这些物质中钙卫蛋白浓度的自动化方法。我们验证了一种全自动比浊法，并给出了与健康相关的参考限值。使用西门子Advia XPT和Bühlmann fCAL® turbo检测（瑞士舍嫩布赫的Bühlmann Laboratories AG）测定钙卫蛋白，这是一种颗粒增强比浊免疫测定法，用于定量粪便提取物中的钙卫蛋白。血浆和血清样本直接进行分析，而全血首先用M-PER®哺乳动物蛋白提取试剂（赛默飞世尔科技公司）提取，并用B-CAL-EX（Bühlmann）稀释。我们研究了分析不精密度，估计了与健康相关的参考限值，并检查了中性粒细胞钙卫蛋白（根据血浆钙卫蛋白调整后的血液钙卫蛋白）与中性粒细胞计数之间的相关性。对于肝素血浆钙卫蛋白，在0.52mg/L和3.53mg/L时，中间精密度（“日间”）变异系数分别为3.5%和1.0%，对于肝素血液钙卫蛋白，在50.2mg/L时变异系数为4.9%。肝素血浆中钙卫蛋白与健康相关的参考限值为0.470-3.02mg/L；肝素血液中钙卫蛋白为50.8-182mg/L；两者之间的比率为0.534-2.41%；每个中性粒细胞中钙卫蛋白的平均含量为24.7-33.3pg。与肝素血浆相比 EDTA血浆中的钙卫蛋白浓度显著降低，血清中的钙卫蛋白浓度显著升高（p<0.05）。中性粒细胞钙卫蛋白与中性粒细胞计数之间的相关性极佳。我们已经证明，Bühlmann fCAL® turbo检测可用于测量血浆和血液中的钙卫蛋白。
