HIF1A and MIF as potential predictive mRNA biomarkers of pre-eclampsia: a longitudinal prospective study in high risk population

Background: Pre-eclampsia (PE) is a hypertensive multisystem disorder, causing significant fetal-maternal mortality and morbidity worldwide. This study aims to define possible longitudinal predictive mRNA markers involved in the main pathogenic pathways of PE: inflammation [macrophage migration inhibitory factor (MIF)], hypoxia and oxidative stress [hypoxia inducible factor 1-alpha subunit (HIF1A) and beta-site APP-cleaving enzyme-2 (BACE2)] and endothelial dysfunction [endoglin (ENG), fms-related tyrosine kinase-1 (FLT1) and vascular endothelial growth factor (VEGF)]. Methods: Peripheral blood was collected from 33 singleton pregnancies characterized by a high cardiovascular profile risk sampled consecutively at 6-16; 17-23; 24-30; 31-34; >= 35 weeks followed by the Obstetrics and Gynecology Unit of the San Raffaele Hospital in Milan. A real-time quantitative PCR reaction was performed on plasma RNA. Results: Of the 33 women enrolled, nine developed PE. Until 23 weeks HIF1A was significantly higher in women who later developed PE compared to women who did not (p=0.049 and p=0.012 in the first and second blood collection). In the third time interval MIF (p=0.0005), FLT1 (p=0.024), ENG (p=0.0034) and BACE2 (p=0.044) appeared to be significantly increased while HIF1A was elevated even from 24 week onwards but not reaching the statistical significance. In the fourth time interval ENG mRNA still remained increased (p=0.037). Conclusions: HIF1A, marker of hypoxia and oxidative stress, and MIF, marker of inflammation, seemed to be the most promising RNA markers, suggesting that hypoxia, principally, and inflammation may play an important role in PE pathogenesis.