RESUMEN
OBJECTIVE: To compare circulating levels of vascular endothelial growth factor receptor 3 (VEGFR-3) in women with pregnancy-induced hypertension (PIH) and in non-pregnant (NP) and healthy pregnant (HP) women. METHODS: We conducted a case-control study including PIH (n = 135), HP (n = 68), and NP (n = 49) women from southeastern Brazil. PIH were diagnosed according to international guidelines, and defined as gestational hypertension (GH, n = 61) or pre-eclampsia (n = 74). VEGFR-3 was measured in plasma using ELISA. RESULTS: Plasma VEGFR-3 was increased in HP (1207 pg/mL) compared with NP (133 pg/mL) women; however, PIH (729 pg/mL) patients exhibited lower levels than HP women (both p < 0.05). In addition, plasma VEGFR-3 was decreased in pre-eclampsia compared with GH (537 versus 980 pg/mL; p < 0.05). When pre-eclampsia was classified according to different clinical presentations, plasma VEGFR-3 was further decreased in the cases identified as pre-eclampsia with severe features, preterm pre-eclampsia, and pre-eclampsia accompanied by small for gestational age (all p < 0.05). CONCLUSION: Our data indicate reduced circulating VEGFR-3 levels in patients with PIH, specifically in those diagnosed with pre-eclampsia. Moreover, decreased VEGFR-3 was associated with adverse clinical outcomes in pre-eclampsia. These findings expand previous evidence of reduced VEGFR-3 expression in pre-eclampsia. Future studies should investigate whether it can be used as a predictive biomarker and/or therapeutic target for pre-eclampsia.
RESUMEN
Hypertensive disorders of pregnancy (HDP), comprising gestational hypertension (GH) and pre-eclampsia (PE), are leading causes of maternal and perinatal morbidity and mortality. Both GH and PE are characterized by new-onset hypertension, but PE additionally includes proteinuria and/or end-organ damage. Impaired nitric oxide (NO) bioavailability may lead to endothelial dysfunction in GH and PE, and the primary source of vascular NO is endothelial NO synthase (eNOS). However, no previous study has investigated plasma eNOS concentrations in patients with GH and PE. In this study, we compared plasma eNOS concentrations in healthy pregnancies and HDP in two independent cohorts. The primary study included 417 subjects, with 43 non-pregnant (NP) and 156 healthy pregnant (HP) women and 122 patients with GH and 96 with PE. The replication study included 85 pregnant women (41 healthy and 44 pre-eclamptic). Plasma concentrations of eNOS were measured using a commercial ELISA kit provided by R&D Systems, and plasma nitrite concentrations were assessed using two ozone-based chemiluminescence assays. Correlations between plasma eNOS concentrations and plasma nitrite concentrations, as well as clinical and biochemical parameters, were evaluated by either Spearman's or Pearson's tests. In the primary study, NP women and HDP had significantly lower plasma eNOS concentrations compared to HP; concentrations were even lower in PE compared to GH. Plasma eNOS concentrations were reduced but not significant in early-onset PE, PE with severe features, preterm birth, and intrauterine growth restriction. No correlation was observed between plasma eNOS and nitrite levels. In HDP, there was a significant positive correlation between levels of eNOS and hemoglobin (r = 0.1496, p = 0.0336) as well as newborn weight (r = 0.1487, p = 0.0316). Conversely, a negative correlation between eNOS levels and proteinuria was observed (r = -0.2167, p = 0.0179). The replication study confirmed significantly reduced plasma concentrations of eNOS in PE compared to HP. Our findings provide evidence of reduced plasma eNOS concentrations in HDP; they were particularly lower in PE compared to GH and HP in two independent studies.