A comparative analysis of systemic and placental ADAMTS-13 levels in preeclampsia and normotensive pregnancy

Preeclampsia is characterized by systemic endothelial dysfunction and remains a major cause of maternal and perinatal morbidity. The von Willebrand factor (VWF)/ADAMTS-13 axis plays a key role in hemostasis; however, its role in preeclampsia, particularly at the placental level, is not fully understood. This study aimed to compare maternal serum and placental ADAMTS-13 levels in late-onset preeclamptic and normotensive pregnancies and to assess their associations with clinical parameters. This prospective case-control study included 100 pregnant women, comprising 50 with late-onset preeclampsia and 50 gestational age-matched normotensive controls. Maternal serum ADAMTS-13 levels were measured by ELISA from blood samples obtained at a median gestational age of 38 weeks in both groups. Placental ADAMTS-13 expression was evaluated by immunohistochemistry and quantified using the semi-quantitative immunohistochemical score (IHC score). Fetal Doppler parameters, including umbilical artery, middle cerebral artery, and uterine artery pulsatility indices, were also recorded. Maternal serum ADAMTS-13 levels were significantly lower in late-onset preeclampsia compared with controls (4.15 ± 1.97 vs. 6.02 ± 2.06 µg/L, p = 0.001). Placental ADAMTS-13 expression was also reduced (median IHC score: 4 vs. 6, p = 0.001). In subgroup analysis, cases with fetal growth restriction (FGR) showed significantly lower placental expression than those without FGR ( p = 0.034), while serum levels were similar. UA and UtA pulsatility indices were significantly higher in late-onset preeclampsia ( p = 0.001). Serum ADAMTS-13 levels were weakly negatively correlated with protein-to-creatinine ratio ( r = − 0.354, p = 0.012). Late-onset preeclampsia is associated with reduced maternal serum ADAMTS-13 concentrations and placental ADAMTS-13 expression. The more pronounced reduction in placental ADAMTS-13 expression observed in pregnancies complicated by FGR suggests a possible association between local ADAMTS-13 alterations and placental insufficiency. However, functional ADAMTS-13 activity and VWF-related parameters were not assessed, and the functional significance of the VWF/ADAMTS-13 axis therefore requires further investigation.