DI-UMONS : Dépôt institutionnel de l’université de Mons

Recherche transversale
(titres de publication, de périodique et noms de colloque inclus)
2016-01-27 - Colloque/Présentation - poster - Anglais - 1 page(s)

Lenaerts Charline , Tuytten Robin, Bond Liz, Delporte Cédric, Van Antwerpen P., Blankert Bertrand , "Setting up of a LC-MS/MS assay for identification and quantification of MBG in pregnant women for preeclampsia risk evaluation" in HTC-14 ; 14th International Symposium on Hyphenated Techniques in Chromatography and Separation Technology, Ghent, Belgique, 2016

  • Codes CREF : Analyse et contrôle pharmaceutique (DI3450), Chimie analytique (DI1314), Sciences pharmaceutiques (DI3400)
  • Unités de recherche UMONS : Analyse pharmaceutique (M130)
  • Instituts UMONS : Institut des Sciences et Technologies de la Santé (Santé)
  • Centres UMONS : Centre de Recherche UMONS-Ambroise Paré (UMHAP), Centre Interdisciplinaire de Spectrométrie de Masse (CISMA)

Abstract(s) :

(Anglais) Marinobufagenin (MBG) is an endogenous bufadienolide cardiac inotrope which is demonstrating growing interest in the early diagnosis of volume expansion-mediated hypertensive states such as preeclampsia (PE) and end-stage renal disease hypertension. Mammalian MBG is an inhibitor of the α1 isoform of Na+,K+-ATPase with vasoconstrictive and cardiotonic properties,resulting in hypertension and natriuresis. Elevated endogenous MBG levels have been described in pregnant mammals and especially in preeclamptic patients [1-3]. The rise of endogenous MBG appears prior the development of the main symptoms of PE, leading us to consider MBG as one of the potential target in the biomarker panel for PE. A sensitive and accurate analytical method is needed to assess MBG in as lower level as possible in plasma. Currently, only marinobufagenin-like material has been found in humans using two published quantification methods based each on immunoassays [4,5]. These techniques suffer from a lack of specificity due to cross-reactivity and tend to exhibit high variability at low concentrations [6]. Moreover, the two studies that recorded MBG plasma levels in preeclampsia compared to normal pregnancy are in marked discrepancy concerning the values of MBG plasma concentration. No threshold value can be determined from these studies due to the consequent discordance about MBG values. Our aim is to develop a MBG assay using a more specific and easy to access technique, such as LC-MS/MS; above all its limit of quantification (LOQ) will be a crucial key point. Subsequently, an algorithm dealing with the MBG plasma levels might be established by clinicians in the future, in order to predict, in combination with other clinical and biological markers, the risk for preeclampsia in pregnant women. As the major source for MBG is located in the parotid glands of the Bufo marinus toad, we developed a purification method from toad venom in order to get pure MBG standard. The identity of the compound was confirmed using TLC-MS and HPLC-MS/MS. A collaboration with an Irish company called Metabolomic Diagnostics that dispose of a significant pregnant women biobank gave us the opportunity to investigate MBG in non-pregnant healthy volunteers plasma as well as in early pregnant women plasma. The on-place developed analytical method for MBG plasma levels offered preliminary results that allowed us to authenticate the presence of MBG by LC-MS/MS in non-pregnant women as well as in early pregnancy. However they still have to be confirmed, these pioneering observations, are giving the clinicians a promising perspective for early preeclampsia risk assessment in pregnant women. A LC-MS/MS based assay designed to determine MBG in human plasma is being optimized and focused on our main target: to reach the lowest limit of quantification. A SPE procedure on HLB cartridges designed to clean and concentrate the plasma samples prior their analysis has been developed with an extraction recovery of 92 %. The LOQ obtained by our method fully satisfies the need for quantification of MBG plasma levels in pregnancy (nmol/L range). After the method will be subjected to a validation process, pregnant women samples analysis will allow us to confirm previous results observed in pregnancy by immunoassays.

Mots-clés :
  • (Anglais) Marinobufagenin
  • (Anglais) biomarker
  • (Anglais) Preeclampsia
  • (Anglais) Bufo marinus