Hezzell Melanie J, Boswood Adrian, Lötter Nicola, Elliott Jonathan
Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, United Kingdom.
Department of Clinical Science and Services, The Royal Veterinary College, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, United Kingdom.
J Vet Cardiol. 2015 Mar;17(1):34-41. doi: 10.1016/j.jvc.2014.10.002. Epub 2014 Dec 23.
The study aims were to assess the temporal stability following storage at room temperature, the effect of up to 4 freeze-thaw cycles and the effect of simulated freezer failure on measurements of canine N-terminal pro-B-type natriuretic peptide (NT-proBNP) in serum and protease-inhibited (PI) plasma.
Twenty-five blood samples were collected from 16 dogs with myxomatous mitral valve disease.
Aliquots of canine serum and PI plasma were stored at room temperature (17-26 °C) for 30 min, 6, 24, 48 and 72 h, respectively. Further aliquots were subjected to between 1 and 4 freeze-thaw cycles. A further aliquot was transferred to storage at 4 °C for 24 h while a paired aliquot remained at -80 °C. All samples were returned to storage at -80 °C until subsequent analysis. N-terminal pro-B-type natriuretic peptide was measured in serum and PI plasma samples using first- and second-generation versions of a commercially-available ELISA. Repeated measures models were used to assess change in NT-proBNP measurements. Wilcoxon signed ranks were used to compare paired measurements.
N-terminal pro-B-type natriuretic peptide concentrations declined over time in all samples stored at room temperature. Of the four situations tested, the rate of decrease was lowest for PI plasma samples measured using the second-generation assay. N-terminal pro-B-type natriuretic peptide is stable in samples subjected to up to 4 freeze-thaw cycles and in previously-frozen samples stored at 4 °C for 24 h.
Use of the second-generation assay, compared with the first-generation, resulted in significantly higher recovery of NT-proBNP measured in PI plasma stored at room temperature. Transport of serum at room temperature for NT-proBNP measurement is not recommended.
本研究旨在评估室温储存后的时间稳定性、多达4次冻融循环的影响以及模拟冷冻机故障对犬血清和蛋白酶抑制（PI）血浆中N端前脑钠肽（NT-proBNP）测量值的影响。
从16只患有黏液瘤性二尖瓣疾病的犬采集了25份血样。
将犬血清和PI血浆的等分试样分别在室温（17 - 26°C）下储存30分钟、6小时、24小时、48小时和72小时。另外的等分试样进行1至4次冻融循环。将另一等分试样转移至4°C储存24小时，而配对的等分试样保持在 - 80°C。所有样品返回 - 80°C储存直至后续分析。使用市售ELISA的第一代和第二代版本测量血清和PI血浆样品中的N端前脑钠肽。采用重复测量模型评估NT-proBNP测量值的变化。使用Wilcoxon符号秩检验比较配对测量值。
在室温下储存的所有样品中，N端前脑钠肽浓度随时间下降。在测试的四种情况中，使用第二代检测方法测量的PI血浆样品下降速率最低。N端前脑钠肽在进行多达4次冻融循环的样品以及先前冷冻后在4°C储存24小时的样品中稳定。
与第一代检测方法相比，使用第二代检测方法可使在室温下储存的PI血浆中测量的NT-proBNP回收率显著更高。不建议在室温下运输血清用于NT-proBNP测量。
