Charline Lenaerts (Presenter)
University of Mons
Bio: Charline Lenaerts has research activities in the field of diagnostic and clinical biology. At present time, she is tempting to develop a diagnostic tool for preeclampsia in pregnant women based on a LC-MS assay of marinobufagenin in plasma. She is also in charge of several teaching tasks at the Faculty of Pharmacy such as the supervising of student's research work or student's lab session.
Authorship: Charline Lenaerts(1), Liz Bond(2), Robin Tuytten(2), Cedric Delporte(3), Van Antwerpen Pierre(3), Bertrand Blankert(1)
(1) Laboratory of Pharmaceutical Analysis, Faculty of Medicine and Pharmacy,UMONS, Belgium; (2)Metabolomic Diagnostics, Cork, Ireland; (3)Analytical Platform, Faculty of Pharmacy, ULB, Belgium
| Short Abstract Marinobufagenin (MBG) is a bufadienolide cardiac inotrope implicated in the early diagnosis of volume expansion-mediated hypertensive states such as preeclampsia. The enhanced production of MBG in preeclamptic patients has been described using poor-specific immunoassays. This demonstrates the need for a sensitive analytical method to detect MBG in plasma at low levels. The identification of marinobufagenin in human plasma (men, non-pregnant women and early-pregnant women) using a sensitive and specific LC-MS assay will be presented, leading to a promising perspective concerning the preeclampsia risk assessment. An observational clinical study is currently designed in order to confirm previous results. |
Long Abstract
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).
Endogenous MBG is an inhibitor of the alpha-1 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 biomarkers for PE.
A sensitive and accurate analytical method is needed to assess MBG as lower as possible in human 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.
Our aim is to develop a specific and sensitive analytical MBG assay by LC-MS/MS with special attention to the limit of quantification (LOQ). An algorithm dealing with the MBG plasma levels might be established in the future, in order to help for prediction of 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 very sensitive and specific LC-MS/MS based assay is now being optimized in order to determine MBG in human plasma. The assay is preceded by an effective extraction step of the plasma on SLE cartridges. Using dihydrotestosterone-d3 as internal standard, the obtained LOQ fully satisfies the need for quantification of MBG plasma levels in pregnancy (nmol/L range). The assay allowed us to confirm the identity of MBG in a man plasma.
Previously, we had the opportunity to authenticate the presence of MBG by LC-MS/MS in non-pregnant and in early-pregnant women. These pioneering preliminary results are giving a promising perspective for early preeclampsia risk assessment in pregnant women. The method will be validated thanks to the accuracy profiles strategy.
At this time, a primary observational clinical study in pregnant women with non-pregnant controls is under design and will allow us to confirm previous results observed in pregnancy and in PE.
References
1. Lopatin, D.A., et al., Circulating bufodienolide and cardenolide sodium pump inhibitors in preeclampsia. Journal of Hypertension, 1999. 17(8): p. 1179-1187.
2. Agunanne, E., et al., Marinobufagenin Levels in Preeclamptic Patients: A Preliminary Report. American Journal of Perinatology, 2011. 28(7): p. 509-514.
3. Vu, H.V., et al., Involvement of Marinobufagenin in a Rat Model of Human Preeclampsia. American Journal of Nephrology, 2005. 25(5): p. 520-528.
4. Abi-Ghanem, D., et al., A CHEMIFLUORESCENT IMMUNOASSAY FOR THE DETERMINATION OF MARINOBUFAGENIN IN BODY FLUIDS. Journal of Immunoassay and Immunochemistry, 2011. 32(1): p. 31-46.
5. Fedorova, O.V., et al., Endogenous Ligand of á1 Sodium Pump, Marinobufagenin, Is a Novel Mediator of Sodium Chloride–Dependent Hypertension. Circulation, 2002. 105(9): p. 1122-1127.
6. Jarvis, Ultra-sensitive analysis of aldosterone in serum using the AB SCIEX Triple QuadTM 6500 LC/MS/MS system, AB SCIEX, 5730212-01
References & Acknowledgements:
| Description | Y/N | Source |
| Grants | no | |
| Salary | no | |
| Board Member | no | |
| Stock | no | |
| Expenses | no |
IP Royalty: no
| Planning to mention or discuss specific products or technology of the company(ies) listed above: | no |