D-dimer is an important marker of different coagulation diseases, such as venous thromboembolism (including deep vein thrombosis and pulmonary embolism) and disseminated intravascular coagulation. Though it is frequently used in many clinical diagnostic situations, the D-dimer assays currently lack standardization due to its inherent heterogeneity which makes the antibody-based methods have different quantitative results and cutoffs to define an abnormal value. In this study, we report the first antibody-free D-dimer quantification method. In the method, a cross-linked peptide of fibrin D domain carboxyl terminal cross-linked by the factor XIIIa was used to represent the D-dimer. By using a filter-aided sample preparation and a nickel immobilized metal affinity chromatography enrichment strategy, the complexity of the plasma sample was significantly reduced, and the cross-linked peptide was enriched effectively for analysis with parallel reaction monitoring in mass spectrometry. The linear range of this method was 3.125–400 nmol/L which spans over two magnitudes. Recovery and reproducibility of the method were found to be good. To further demonstrate the performance of our method, D-dimer concentrations of 25 human plasma samples were analyzed, and the results had a good correlation between with the commercial D-dimer assay kit used in hospitals. This method was completely antibody-free and has the potential to promote the standardization of D-dimer analysis.

中文翻译：

---

基于质谱的无抗体方法可实现血浆中D-二聚体的定量分析。

D-二聚体是不同凝血疾病的重要标志，例如静脉血栓栓塞（包括深静脉血栓形成和肺栓塞）和弥散性血管内凝血。尽管D-二聚体测定法经常用于许多临床诊断情况，但由于其固有的异质性，目前缺乏标准化，这使得基于抗体的方法具有不同的定量结果和定义异常值的临界值。在这项研究中，我们报告了第一个无抗体的D-二聚体定量方法。在该方法中，使用通过因子XIIIa交联的血纤蛋白D结构域羧基末端的交联肽代表D-二聚体。通过使用助滤剂制备的样品和固定化镍的金属亲和色谱富集策略，血浆样品的复杂性显着降低，有效地富集了交联肽，可通过质谱中的平行反应监控进行分析。该方法的线性范围为3.125–400 nmol / L，跨越两个量级。发现该方法的回收率和重现性良好。为了进一步证明我们方法的性能，分析了25个人血浆样品中D-二聚体的浓度，结果与医院使用的商业D-二聚体测定试剂盒有很好的相关性。该方法完全不含抗体，具有促进D-二聚体分析标准化的潜力。125–400 nmol / L，跨两个量级。发现该方法的回收率和重现性良好。为了进一步证明我们方法的性能，分析了25个人血浆样品中D-二聚体的浓度，结果与医院使用的商业D-二聚体测定试剂盒有很好的相关性。该方法完全不含抗体，具有促进D-二聚体分析标准化的潜力。125–400 nmol / L，跨两个量级。发现该方法的回收率和重现性良好。为了进一步证明我们方法的性能，分析了25个人血浆样品中D-二聚体的浓度，结果与医院中使用的商业D-二聚体测定试剂盒有很好的相关性。该方法完全不含抗体，具有促进D-二聚体分析标准化的潜力。