Tan Kok Hian, Tan Soon Sim, Ng Mor Jack, Tey Wan Shi, Sim Wei Kian, Allen John Carson, Lim Sai Kiang
Department of Maternal Fetal Medicine, KK Women's and Children's Hospital, Singapore, Singapore.
Paracrine Therapeutics Pte Ltd, Singapore, Republic of Singapore.
J Extracell Vesicles. 2017 Dec 13;6(1):1408390. doi: 10.1080/20013078.2017.1408390. eCollection 2017.
Circulating extracellular vesicles (EVs) such as cholera toxin B chain (CTB)- or annexin V (AV)-binding EVs were previously shown to be rich sources of biomarkers. Here we test if previously identified pre-eclampsia (PE) candidate biomarkers, TIMP-1 in CTB-EVs (CTB-TIMP) and PAI-1 in AV-EVs (AV-PAI) complement plasma PlGF in predicting PE in a low-risk obstetric population. Eight hundred and forty-three prospectively banked plasma samples collected at 28 + 0 to 32 + 0 gestation weeks in the Neonatal and Obstetrics Risk Assessment (NORA) cohort study were assayed by sandwich ELISAs for plasma PlGF, CTB-TIMP1 and AV-PAI1. Nineteen patients subsequently developed PE 7.3 (±2.9) weeks later at a mean gestational age of 36.1 ± 3.5 weeks. The biomarkers were assessed for their predictive accuracy for PE using stepwise multivariate logistic regression analysis with Firth correction and Areas under the curve (AUC). To achieve 100% sensitivity in predicting PE, the cut-off for plasma PlGF, CTB-TIMP1 & AV-PAI1 were set at <1235, ≤300 or >1300 and <10,550 pg/mL plasma, respectively. The corresponding AUCs, specificity and PPV at a 95% confidence interval were 0.92, 52.1% and 4.7%; 0.72, 44.5% and 4.0%; and 0.69, 21.5% and 2.9%, respectively. At 100% sensitivity, the three biomarkers had a combined AUC of 0.96, specificity of 78.6%, and PPV of 9.9%. This is the first large cohort validation of the utility of EV-associated analytes as disease biomarkers. Specifically, EV biomarkers enhanced the predictive robustness of an existing PE biomarker sufficiently to justify PE screening in a low-risk general obstetric population.
循环细胞外囊泡（EVs），如霍乱毒素B亚基（CTB）或膜联蛋白V（AV）结合的EVs，此前已被证明是生物标志物的丰富来源。在此，我们测试先前鉴定的子痫前期（PE）候选生物标志物，即CTB-EVs中的金属蛋白酶组织抑制因子-1（TIMP-1，CTB-TIMP）和AV-EVs中的纤溶酶原激活物抑制剂-1（PAI-1，AV-PAI），是否能与血浆胎盘生长因子（PlGF）互补，以预测低风险产科人群中的PE。在新生儿和产科风险评估（NORA）队列研究中，对妊娠28 + 0至32 + 0周前瞻性采集并储存的843份血浆样本，采用夹心酶联免疫吸附测定法检测血浆PlGF、CTB-TIMP1和AV-PAI1。19名患者随后在平均孕周36.1±3.5周时，于7.3（±2.9）周后发生PE。使用带Firth校正的逐步多变量逻辑回归分析和曲线下面积（AUC）评估这些生物标志物对PE的预测准确性。为了在预测PE时达到100%的敏感性，将血浆PlGF、CTB-TIMP1和AV-PAI1的截断值分别设定为<1235、≤300或>1300以及<10,550 pg/mL血浆。在95%置信区间下，相应的AUC、特异性和阳性预测值分别为0.92、52.1%和4.7%；0.72、44.5%和4.0%；以及0.69、21.5%和2.9%。在100%敏感性时，这三种生物标志物的联合AUC为0.96，特异性为78.6%，阳性预测值为9.9%。这是首次对EV相关分析物作为疾病生物标志物的效用进行的大型队列验证。具体而言，EV生物标志物充分增强了现有PE生物标志物的预测稳健性，足以证明在低风险普通产科人群中进行PE筛查的合理性。
