Abstract P298: Excretion of Urinary Marinobufagenin And Angiogenic Factors in Pregnancies With Increased Risk for Preeclampsia: A Pilot Study

Background: Previous work has shown an increase in urinary excretion of marinobufagenin (MBG) in patients with preeclampsia (preE) compared to normal pregnancy at delivery. MBG is a novel urinary marker for preE; however, it is unknown how MBG levels fluctuate during gestation. Hypothesis: Shifts in MBG and angiogenic factors during early pregnancy identify cytotrophoblast’s dysfunction, contributing to reduced vascular development with impaired perfusion and preE. Methods: In this study, we prospectively enrolled two groups of patients; 50 patients in each group total of 100 patients for serial collection of urine and serum during each trimester and at delivery. These groups are: (1) Pregnant women at risk for development of preE; and (2) Pregnant women at low risk for development of preE. Risks were calculated for each pregnancy using the sum of relative risk values. Urine samples from 100 subjects (100 in first trimester, 67 in second trimester, 67 third trimester, and 67 at delivery) were assayed using ELISA for MBG (Panorama Research, Inc.), sENG, VEGF, PIGF, sFlt-1 expressed as pg/mg creatinine and the calculated uFP (log of 10x sFLT-1/PIGF ratio). The angiogenic factors were analyzed by commercially available kits. Results: Of 100 subjects, 50 had no risk for preE and 50 had relative risks on the average of 6.6 with a range of 1.4 to 16.6. There were no associations between relative risk and any of the 6 angiogenic measures during the first trimester (p > 0.36) and second trimester (p > 0.22) using linear regression. However, during the second trimester, the high risk cohort had lower PIGF levels than the no risk cohort (p < 0.05 using Mann-Whitney U test). Comparing the serial values of 6 angiogenic measures in 67 subjects during the first, second, third trimesters and at deliveries, only MBG and PIGF varied significantly (p < 0.05) with MBG. Conclusions: MBG increases with progression of pregnancy and the levels of MBG are the highest during delivery. We conclude that MBG levels increase during normal pregnancy, however, the differential levels of MBG in normal and preE pregnancies are now underway. Relationships to development of preE symptoms and MBG levels are pending with the addition of patients and additional sample.