Sundet Birgitte K, Sugulle Meryam, Jacobsen Daniel P, Bratseth Vibeke, Palmero Sheryl, Kindberg Kristine M, Helseth Ragnhild M, Lekva Tove, Ueland Thor, Balakumaran Shahana, Fjeldstad Heidi E, Lunde Ida G, Staff Anne Cathrine
Faculty of Medicine, University of Oslo, Oslo, Norway; Division of Obstetrics and Gynecology, Oslo University Hospital, Oslo, Norway.
Oslo Center for Clinical Heart Research, Department of Cardiology Ullevaal, Oslo University Hospital Oslo, Oslo, Norway.
Am J Obstet Gynecol. 2025 Oct 15. doi: 10.1016/j.ajog.2025.10.003.
Neutrophil extracellular traps consist of DNA and protein and are secreted by neutrophils upon activation. They are stable structures but may be degraded by deoxyribonucleases. Neutrophil extracellular traps can induce endothelial dysfunction, an important feature of the preeclampsia pathophysiology. However, the levels of neutrophil extracellular traps biomarkers and deoxyribonuclease in the maternal circulation during preeclampsia, gestational hypertension, and fetal growth restriction, as well as potential associations to placental dysfunction, remain to be elucidated.
We aimed to investigate levels of circulating neutrophil extracellular traps biomarkers and deoxyribonuclease in women with early-onset and late-onset preeclampsia, gestational hypertension, and isolated fetal growth restriction compared to clinically healthy pregnancies. Additionally, we aimed to compare these biomarkers with circulating placental dysfunction biomarkers and maternal as well as fetal clinical proxies of placental dysfunction in women with preeclampsia.
Plasma and serum samples from women categorized as having early-onset preeclampsia (n=49), late-onset preeclampsia (n=202), gestational hypertension (n=105), isolated fetal growth restriction (n=50), and normotensive, euglycemic controls (n=1126) were analyzed by immunoassays for the circulating neutrophil extracellular traps biomarkers citrullinated histone H3 and myeloperoxidase-DNA and deoxyribonuclease and for the placental dysfunction biomarkers soluble fms-like tyrosine kinase-1 and placental growth factor. The Kruskal-Wallis H test was used to compare biomarker levels across groups. Post hoc pairwise comparisons were conducted using Dunn's test, with Bonferroni correction applied to adjust for multiple comparisons. In women with early-onset and late-onset preeclampsia, the residuals were not normally distributed. Therefore, univariable and multivariable quantile (median) regression for estimating models for the conditional median function were used to study associations between our biomarkers of interest and proxies for placental dysfunction. A 2-sided P value of <.05 was considered statistically significant.
Women with early-onset and late-onset preeclampsia, but not gestational hypertension or isolated fetal growth restriction, had lower median levels of circulating citrullinated histone H3 (both adjusted P<.001) and deoxyribonuclease (both adjusted P<.001) compared to controls. Women with late-onset preeclampsia had lower myeloperoxidase-DNA (adjusted P<.001) compared to controls. Univariable regression analyses within the preeclampsia group revealed positive associations between citrullinated histone H3 and placental growth factor (P=.004) and negative associations between citrullinated histone H3 and soluble fms-like tyrosine kinase-1 (P=.034) and between deoxyribonuclease and soluble fms-like tyrosine kinase-1 (P=.038). In multivariable regression analyses, citrullinated histone H3 and placental growth factor (P=.009) and deoxyribonuclease and gestational age at blood sampling (P=.001) were positively associated, whereas citrullinated histone H3 (P=.027) and deoxyribonuclease (P=.034) were negatively associated with systolic blood pressure. Finally, citrullinated histone H3 was associated with newborn weight ≤10th percentile, representing a fetal proxy for placental dysfunction (P=.036).
The lower levels of circulating neutrophil extracellular traps and deoxyribonuclease in women with preeclampsia, but not in gestational hypertension or isolated fetal growth restriction, as well as associations between citrullinated histone H3 and biomarkers of placental dysfunction may indicate that neutrophil extracellular traps play a role in the placental dysfunction that exclusively characterizes preeclampsia. Additionally, the association between low citrullinated histone H3, low deoxyribonuclease, and high maternal blood pressure may suggest that insufficient presence of circulating deoxyribonucleases contributes to the excessive vascular inflammation in women with preeclampsia.
中性粒细胞胞外诱捕网由DNA和蛋白质组成，在中性粒细胞激活时分泌。它们是稳定的结构，但可被脱氧核糖核酸酶降解。中性粒细胞胞外诱捕网可诱导内皮功能障碍，这是子痫前期病理生理学的一个重要特征。然而，子痫前期、妊娠期高血压和胎儿生长受限孕妇循环系统中中性粒细胞胞外诱捕网生物标志物和脱氧核糖核酸酶的水平，以及与胎盘功能障碍的潜在关联仍有待阐明。
我们旨在研究早发型和晚发型子痫前期、妊娠期高血压和单纯性胎儿生长受限女性与临床健康妊娠女性相比，循环中性粒细胞胞外诱捕网生物标志物和脱氧核糖核酸酶的水平。此外，我们旨在将这些生物标志物与子痫前期女性的循环胎盘功能障碍生物标志物以及胎盘功能障碍的母体和胎儿临床指标进行比较。
对分类为早发型子痫前期（n = 49）、晚发型子痫前期（n = 202）、妊娠期高血压（n = 105）、单纯性胎儿生长受限（n = 50）以及血压正常、血糖正常的对照组（n = 1126）的女性血浆和血清样本进行免疫分析，检测循环中性粒细胞胞外诱捕网生物标志物瓜氨酸化组蛋白H3和髓过氧化物酶-DNA以及脱氧核糖核酸酶，以及胎盘功能障碍生物标志物可溶性fms样酪氨酸激酶-1和胎盘生长因子。采用Kruskal-Wallis H检验比较各组生物标志物水平。使用Dunn检验进行事后两两比较，并应用Bonferroni校正以调整多重比较。在早发型和晚发型子痫前期女性中，残差分布不呈正态。因此，使用单变量和多变量分位数（中位数）回归来估计条件中位数函数模型，以研究我们感兴趣的生物标志物与胎盘功能障碍指标之间的关联。双侧P值<.05被认为具有统计学意义。
与对照组相比，早发型和晚发型子痫前期女性循环瓜氨酸化组蛋白H3（均为校正后P<.001）和脱氧核糖核酸酶（均为校正后P<.001）的中位数水平较低，但妊娠期高血压或单纯性胎儿生长受限女性并非如此。与对照组相比，晚发型子痫前期女性的髓过氧化物酶-DNA较低（校正后P<.001）。子痫前期组内的单变量回归分析显示，瓜氨酸化组蛋白H3与胎盘生长因子呈正相关（P =.004），瓜氨酸化组蛋白H3与可溶性fms样酪氨酸激酶-1呈负相关（P =.034），脱氧核糖核酸酶与可溶性fms样酪氨酸激酶-1呈负相关（P =.038）。在多变量回归分析中，瓜氨酸化组蛋白H3与胎盘生长因子（P =.009）以及脱氧核糖核酸酶与采血时的孕周（P =.001）呈正相关，而瓜氨酸化组蛋白H3（P =.027）和脱氧核糖核酸酶（P =.034）与收缩压呈负相关。最后，瓜氨酸化组蛋白H3与新生儿体重≤第10百分位数相关，这代表胎盘功能障碍的胎儿指标（P =.036）。
子痫前期女性循环中性粒细胞胞外诱捕网和脱氧核糖核酸酶水平较低，但妊娠期高血压或单纯性胎儿生长受限女性并非如此，以及瓜氨酸化组蛋白H3与胎盘功能障碍生物标志物之间的关联可能表明，中性粒细胞胞外诱捕网在子痫前期特有的胎盘功能障碍中起作用。此外，低瓜氨酸化组蛋白H3、低脱氧核糖核酸酶与高母体血压之间的关联可能表明，循环脱氧核糖核酸酶的不足导致子痫前期女性过度的血管炎症。
