Shin Young Kim

Effective Prediction of Preeclampsia by a Combined Ratio of Angiogenesis-Related Factors

OBJECTIVE: Imbalance between angiogenesis-related factors is closely related to the development of preeclampsia. The objective was to estimate the most effective and accurate predictive biomarker among levels and ratios of angiogenesis-related factors, including soluble fms-like tyrosine kinase 1 (sFlt-1), soluble endoglin, placental growth factor (PlGF), and transforming growth factor-&bgr;1 (TGF-&bgr;1), in women who subsequently developed preeclampsia. METHODS: A nested cohort study was conducted to estimate the levels of sFlt-1, soluble endoglin, PlGF, and TGF-&bgr;1 in plasma collected in the second trimester from 40 women who subsequently developed preeclampsia and 100 contemporaneous normotensive women. RESULTS: Levels of sFlt-1 and soluble endoglin were significantly higher in women with preeclampsia than in normotensive women, whereas levels of PlGF and TGF-&bgr;1 were lower (P<.001). In women with preeclampsia, sFlt-1/PlGF, soluble endoglin/TGF-&bgr;1, and the combined ratio of (sFlt-1+soluble endoglin)/(PlGF+TGF-&bgr;1) were significantly higher than in normotensive women (P<.001) and even greater in severe preeclampsia with preterm delivery compared with mild preeclampsia with term delivery (P<.05). At equivalent sensitivity (85%), the false-positive rate was 45% for sFlt-1, 41% for soluble endoglin, 33% for sFlt-1/PlGF, 21% for soluble endoglin/TGF-&bgr;1, and 10% for the combined ratio. After adjusting for potential confounding factors, the risks for developing preeclampsia were as follows: odds ratio (OR) 6.9 [95% confidence interval 2.3-20.7] for sFlt-1 level, 7.1 [2.3-21.7] for soluble endoglin level, 6.8 [2.4-19.4] for sFlt-1/PlGF, 38.8 [9.8-154.3] for soluble endoglin/TGF-&bgr;1, and 74.8 [17.6-316.7] for the combined ratio. CONCLUSION: The combined ratio of angiogenesis-related factors showed the lowest false-positive rate and the highest OR for prediction of preeclampsia, indicating that it may provide more effective prediction of development of preeclampsia. LEVEL OF EVIDENCE: II

Genetic polymorphism of catechol-O-methyltransferase and cytochrome P450c17 in preeclampsia.

Objective Catechol-O-methyltransferase (COMT) and cytochrome P450c17α (CYP17A1) are key enzymes involved in the metabolism of steroid hormones; genetic polymorphisms in these genes affect enzyme activity. Recently, functional polymorphisms in the COMT and CYP17A1 genes have been suggested as a susceptible marker for intrauterine fetal growth restriction, a typical complication of preeclampsia. Moreover, a close association between COMT and preeclampsia was reported. We therefore investigated the relationships between COMT and CYP17A1 polymorphisms and the risk of preeclampsia. Methods A total of 164 preeclamptic women and 182 normotensive women were enrolled. COMT (Val158Met) and CYP17A1 (-34T/C) polymorphisms were genotyped by quantitative fluorescent-polymerase chain reaction. Multiple logistic regression analysis was used to estimate the risks of preeclampsia according to genotypes. Results The adjusted odds ratios (adjOR) for the risks of preeclampsia, severe preeclampsia and preeclampsia for small-for-gestational-age (SGA) infants were 1.97 [95% confidence interval (CI): 1.02–3.83], 3.29 (95% CI: 1.60–6.77), and 4.05 (95% CI: 1.78–9.22), respectively, in women homozygous for the variant COMT allele. No significant differences were observed between the two groups with respect to CYP17A1 polymorphisms, indicating that variants of this gene have no effects on preeclampsia. The highest risks of preeclampsia were found among women with homozygous variant genotypes of both genes [adjOR (95% CI): 4.58 (1.92–22.81)]. Moreover, the adjOR for preeclamptic complications in those women was 5.09 (95% CI: 1.93–27.88) for severe preeclampsia and 15.65 (95% CI: 3.19–76.82) for SGA preeclampsia. Conclusion These findings suggest that homozygosity for the variant allele of the maternal COMT gene may increase susceptibility to preeclampsia.

Soluble endoglin and transforming growth factor‐β1 in women who subsequently developed preeclampsia

This study aimed to analyze the differences of soluble endoglin (sEng) and transforming growth factor‐beta1 (TGF‐β1) according to preeclamptic complications and to investigate the correlation between these factors and the clinical symptoms of preeclampsia.

Association Between MTHFR 1298A>C Polymorphism and Spontaneous Abortion with Fetal Chromosomal Aneuploidy

Citation Kim SY, Park SY, Choi JW, Kim DJ, Lee SY, Lim JH, Han JY, Ryu HM, Kim MH. Association between MTHFR 1298A>C polymorphism and spontaneous abortion with fetal chromosomal aneuploidy. Am J Reprod Immunol 2011; 66: 252–258

Non-Invasive Epigenetic Detection of Fetal Trisomy 21 in First Trimester Maternal Plasma

Background Down syndrome (DS) is the most common known aneuploidy, caused by an extra copy of all or part of chromosome 21. Fetal-specific epigenetic markers have been investigated for non-invasive prenatal detection of fetal DS. The phosphodiesterases gene, PDE9A, located on chromosome 21q22.3, is completely methylated in blood (M-PDE9A) and unmethylated in the placenta (U-PDE9A). Therefore, we estimated the accuracy of non-invasive fetal DS detection during the first trimester of pregnancy using this tissue-specific epigenetic characteristic of PDE9A. Methodology/Principal Findings A nested, case-control study was conducted using maternal plasma samples collected from 108 pregnant women carrying 18 DS and 90 normal fetuses (each case was matched with 5 controls according to gestational weeks at blood sampling). All pregnancies were singletons at or before 12 weeks of gestation between October 2008 and May 2009. The maternal plasma levels of M-PDE9A and U-PDE9A were measured by quantitative methylation-specific polymerase chain reaction. M-PDE9A and U-PDE9A levels were obtained in all samples and did not differ between male and female fetuses. M-PDE9A levels did not differ between the DS cases and controls (1854.3 vs 2004.5 copies/mL; P = 0.928). U-PDE9A levels were significantly elevated in women with DS fetuses compared with controls (356.8 vs 194.7 copies/mL, P<0.001). The sensitivities of U-PDE9A level and the unmethylation index of PDE9A for non-invasive fetal DS detection were 77.8% and 83.3%, respectively, with a 5% false-positive rate. In the risk assessment for fetal DS, the adjusted odds ratios of U-PDE9A level and UI were 46.2 [95% confidence interval: 7.8–151.6] and 63.7 [95% confidence interval: 23.2–206.7], respectively. Conclusions Our findings suggest that U-PDE9A level and the unmethylation index of PDE9A may be useful biomarkers for non-invasive fetal DS detection during the first trimester of pregnancy, regardless of fetal gender.

Maternal Serum and Amniotic Fluid Inhibin A Levels in Women who Subsequently Develop Severe Preeclampsia

The purpose of this study was to evaluate whether maternal serum (MS) and amniotic fluid (AF) inhibin A levels are elevated in patients who subsequently develop severe preecalmpsia, and to investigate the correlation between MS and AF inhibin A levels in the second trimester. The study included 40 patients who subsequently developed severe preecalmpsia and 80 normal pregnant women. Inhibin A levels in MS and AF were measured with enzyme-linked immunosorbent assay (ELISA). The MS and AF inhibin A levels in patients who developed severe preeclampsia were significantly higher than those in the control group (both for p<0.001). There was a positive correlation between MS and AF inhibin A levels in patients who developed severe preeclampsia (r=0.397, p=0.011), but not in the control group (r=0.185, p=0.126). The best cutoff values of MS and AF inhibin A levels for the prediction of severe preeclampsia were 427 pg/mL and 599 pg/mL, respectively; the estimated ORs that were associated with these cut-off values were 9.95 (95% CI 3.8-25.9, p<0.001) and 6.0 (95% CI 2.3-15.8, p<0.001). An elevated level of inhibin A in MS and AF at the time of second trimester amniocentesis may be a risk factor for the subsequent development of severe preeclampsia.

Effective detection of fetal sex using circulating fetal DNA in first-trimester maternal plasma

The aim of this study was to develop a simple and effective method for noninvasively detecting fetal sex using circulating fetal DNA from first‐trimester maternal plasma. A study was conducted with maternal plasma collected from 203 women between 5 and 12 wk of gestation. The presence of circulating fetal DNA was confirmed by a quantitative methylationspecific polymerase chain reaction of the unmethyla‐ted‐PDE9A gene (U‐PDE9A). Multiplex real‐time PCR was used to simultaneously quantify the amount of DYS14 and GAPDH in maternal plasma. The results were confirmed by phenotype at birth. Pregnancy outcomes and U‐PDE9A concentrations were obtained in all cases, including 99 male‐bearing and 104 female‐bearing participants. At equivalent specificity (100%), the false‐negative rate was 9.1% for DYS14 quantification cycle, 7.1% for DYS14 concentration, and 0.0% for the concentration ratio of DYS14/GAPDH, respectively. In male‐bearing participants, DYS14, U‐PDE9A, and GAPDH concentrations were significantly lower in the false‐negative case than in correct case (P< 0.001 in all). Moreover, DYS14, U‐PDE9A, and GAPDH concentrations showed significantly positive associations with each other (P≤0.001 in all). The ratio of DYS14/ GAPDH in maternal plasma was an effective biomarker for noninvasive fetal sex detection during the first trimester, indicating that it could be useful for clinical application.—Lim, J. H., Park, S. Y., Kim, S. Y., Kim, D. J., Choi, J. E., Kim, M. H., Choi, J. S., Kim, M. Y., Yang, J. H., Ryu, H. M. Effective detection of fetal sex using circulating fetal DNA in first‐trimester maternal plasma. FASEB J. 26, 250–258 (2012). www.fasebj.org

Early Prediction of Hypertensive Disorders of Pregnancy Using Cell-Free Fetal DNA, Cell-Free Total DNA, and Biochemical Markers.

Objective: To evaluate the predictive value of separate and combined tests using cell-free fetal DNA (cffDNA), cell-free total DNA (cfDNA), and biochemical markers for the early detection of pregnancies with hypertensive disorders. Methods: A nested case-control study was conducted with 135 singleton pregnancies including 17 gestational hypertension cases, 34 preeclampsia (PE) cases, and 84 controls. We performed real-time quantitative PCR to measure levels of DSCR3 and RASSF1A as cffDNA markers and HYP2 as a cfDNA marker in the first and early second trimesters. Levels of pregnancy-associated plasma protein A (PAPP-A), α-fetoprotein, β-human chorionic gonadotropin, unconjugated estriol, and inhibin A were also determined. Results: Compared with controls, the median levels and multiples of the median (MoM) values of HYP2 were significantly higher in the PE and hypertensive disorders of pregnancy (HDP) groups at 6-14 and 15-23 weeks. Frist-trimester PAPP-A MoM was significantly lower in PE and HDP than in controls. For PE and HDP, the best model included the first-trimester DSCR3, HYP2, and PAPP-A MoM values achieving detection rates of 67 and 58% at a fixed 10% false-positive rate, respectively [area under the receiver operating characteristic curve 0.832 (95% CI 0.689-0.928) for PE; 0.751 (0.607-0.863) for HDP]. Discussion: The study demonstrates the potential utility of combined first-trimester cffDNA, cfDNA, and PAPP-A for the early prediction of PE.

Non-Invasive Prenatal Testing of Trisomy 18 by an Epigenetic Marker in First Trimester Maternal Plasma

Background Quantification of cell-free fetal DNA by methylation-based DNA discrimination has been used in non-invasive prenatal testing of fetal chromosomal aneuploidy. The maspin (Serpin peptidase inhibitor, clade B (ovalbumin), member 5; SERPINB5) gene, located on chromosome 18q21.33, is hypomethylated in the placenta and completely methylated in maternal blood cells. The objective of this study was to evaluate the accuracy of non-invasive detection of fetal trisomy 18 using the unmethylated-maspin (U-maspin) gene as a cell-free fetal DNA marker and the methylated-maspin (M-maspin) gene as a cell-free total DNA marker in the first trimester of pregnancy. Methodology/Principal Findings A nested case-control study was conducted using maternal plasma collected from 66 pregnant women, 11 carrying fetuses with trisomy 18 and 55 carrying normal fetuses. Median U-maspin concentrations were significantly elevated in women with trisomy 18 fetuses compared with controls (27.2 vs. 6.7 copies/mL; P<0.001). Median M-maspin concentrations were also significantly higher in women with trisomy 18 fetuses than in controls (96.9 vs. 19.5 copies/mL, P<0.001). The specificities of U-maspin and M-maspin concentrations for non-invasive fetal trisomy 18 detection were 96.4% and 74.5%, respectively, with a sensitivity of 90.9%. Conclusions Our results suggest that U-maspin and M-maspin concentrations may be useful as potential biomarkers for non-invasive detection of fetal trisomy 18 in the first trimester of pregnancy, irrespective of the sex and genetic variations of the fetus.

ORIGINAL ARTICLE: Transforming Growth Factor‐Beta1 Gene Polymorphisms in Korean Patients with Pre‐eclampsia

Citation Kim SY, Lim JH, Park SY, Yang JH, Kim MY, Kim MH, Ryu HM. Transforming growth factor‐beta1 (TGF‐β1) gene polymorphisms in Korean patients with pre‐eclampsia. Am J Reprod Immunol 2010; 63: 291–298