Institute of Clinical Chemistry and Laboratory Medicine, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.
Thromb Haemost. 2010 Feb;103(2):461-5. doi: 10.1160/TH09-04-0230. Epub 2009 Nov 13.
In vitro D-dimer stability in plasma is widely assumed, but has not yet been documented by systematic studies using samples covering a wide range of D-dimer. We investigated the short- and long-term stability of D-dimer in clinical citrated plasma samples with normal and pathological levels. The short-term stability was analysed by measuring D-dimer fresh, after storage of plasma for 4 hours at room temperature (RT) and after an additional 24 h storage at +2 to +8 degrees C (n=40). Long-term stability samples (n=40) were measured fresh and after storage for 19, 25 and 36 months at < or =-60 degrees C. The effect of repeated freezing was analysed by measuring samples (n=50) fresh and after four consecutive freeze-thaw cycles. D-dimer was measured on the BCS System using the INNOVANCE D-Dimer assay (Siemens Healthcare Diagnostics Products GmbH, Marburg, Germany). D-dimer values at baseline ranged from 0.23-22.2 mg/l FEU. The mean percentage change after storage for 4 hours at RT and additional 24 hours at +2 to +8 degrees C was +3.8% and +2.7%, respectively. The mean percentage change after frozen storage for 19, 25 and 36 months at < or =-60 degrees C was -11.7%, -4.8% and -9.3%, respectively. The small decrease of D-dimer values after frozen storage was not time-dependent. Repeated freezing did not significantly alter D-dimer values (mean change < or =5%). The data demonstrate stability of D-dimer in plasma prior to freezing for up to 4 hours at RT and for up to 24 hours at +2 to +8 degrees C as well as in plasma stored for up to three years at < or =-60 degrees C.
在体外，血浆中的 D-二聚体稳定性被广泛假设，但尚未通过使用涵盖广泛 D-二聚体范围的样本进行系统研究来证明。我们研究了正常和病理水平的临床枸橼酸盐血浆样本中 D-二聚体的短期和长期稳定性。通过测量新鲜、在室温（RT）下储存 4 小时后的血浆以及在 +2 至 +8 摄氏度下额外储存 24 小时后的 D-二聚体（n=40）来分析短期稳定性。长期稳定性样本（n=40）新鲜测量并在 <或=-60°C 下储存 19、25 和 36 个月后进行测量。通过测量新鲜和连续 4 次冻融循环后的样本（n=50）来分析反复冻融的影响。使用 BCS 系统和 INNOVANCE D-Dimer 测定法（德国马堡西门子医疗诊断产品有限公司）测量 D-二聚体。基线时 D-二聚体值范围为 0.23-22.2mg/l FEU。在 RT 下储存 4 小时和在 +2 至 +8 摄氏度下额外储存 24 小时后的平均百分比变化分别为+3.8%和+2.7%。在 <或=-60°C 下储存 19、25 和 36 个月后的平均百分比变化分别为-11.7%、-4.8%和-9.3%。冷冻储存后 D-二聚体值的微小下降与时间无关。反复冻融不会显著改变 D-二聚体值（平均变化<或=5%）。数据表明，在冷冻前，D-二聚体在 RT 下储存长达 4 小时，在 +2 至 +8 摄氏度下储存长达 24 小时，以及在 <或=-60°C 下储存长达 3 年都是稳定的。
