286. Endothelin-1 is elevated prior to the development of term preeclampsia and is exacerbated in established severe early onset preeclampsia

Introduction Preeclampsia (PE) is a serious complication of pregnancy, the pathophysiology remains unclear and diagnosis and treatment strategies are limited. The potent vasoconstrictor endothelin-1 (ET-1) has been implicated in the pathogenesis of PE. Previously we observed ET-1 levels were significantly higher in a cohort of women at high risk of developing PE as early as the first trimester[a]. We set out to measure ET-1 in the circulation in women destined to develop PE, and in women with established severe PE. Methods Plasma samples were collected as part of two separate studies and used to assess ET-1 levels by ELISA. Plasma was collected from women 1) from a case control prospective cohort study (Fetal Longitudinal Assessment of Growth; FLAG) at both 28 (n = 106 Controls and n = 38 PE) and 36 weeks (n = 99 Controls and n = 39 PE) gestation, prior to diagnosis of term PE; and 2) with established severe early onset PE ( Results Plasma ET-1 levels were significantly higher in women destined to develop term PE (FLAG cohort) at 28 (p  Conclusions We identified increased ET-1 levels in women destined to develop term PE and massively elevated levels in women with severe early onset PE. ET-1 may provide a useful biomarker alone or in combination with other markers to predict PE. ET-1 has potent vasoconstrictory activities, and likely plays considerable roles in the pathogenesis of PE; neutralising ET-1 action may offer therapeutic strategies to treat PE. 1 Groom et al., AmJOG, 2017.