Chikako Hirashima

Hydroxysteroid (17-β) Dehydrogenase 1 Is Dysregulated by Mir-210 and Mir-518c That Are Aberrantly Expressed in Preeclamptic Placentas: A Novel Marker for Predicting Preeclampsia

In this study, to search for novel preeclampsia (PE) biomarkers, we focused on microRNA expression and function in the human placenta complicated with PE. By comprehensive analyses of microRNA expression, we identified 22 microRNAs significantly upregulated in preeclamptic placentas, 5 of which were predicted in silico to commonly target the mRNA encoding hydroxysteroid (17-&bgr;) dehydrogenase 1 (HSD17B1), a steroidogenetic enzyme expressed predominantly in the placenta. In vivo HSD17B1 expression, at both the mRNA and protein levels, was significantly decreased in preeclamptic placentas. Of these microRNAs, miR-210 and miR-518c were experimentally validated to target HSD17B1 by luciferase assay, real-time PCR, and ELISA. Furthermore, we found that plasma HSD17B1 protein levels in preeclamptic pregnant women reflected the decrease of its placental expression. Moreover, a prospective cohort study of plasma HSD17B1 revealed a significant reduction of plasma HSD17B1 levels in pregnant women at 20 to 23 and 27 to 30 weeks of gestation before PE onset compared with those with normal pregnancies. The sensitivities/specificities for predicting PE at 20 to 23 and 27 to 30 weeks of gestation were 0.75/0.67 (cutoff value=21.9 ng/mL) and 0.88/0.51 (cutoff value=30.5 ng/mL), and the odds ratios were 6.09 (95% CI: 2.35–15.77) and 7.83 (95% CI: 1.70–36.14), respectively. We conclude that HSD17B1 is dysregulated by miR-210 and miR-518c that are aberrantly expressed in preeclamptic placenta and that reducing plasma level of HSD17B1 precedes the onset of PE and is a potential prognostic factor for PE.

Alterations in Placental Growth Factor Levels before and after the Onset of Preeclampsia Are More Pronounced in Women with Early Onset Severe Preeclampsia

It has been established that the serum placental growth factor (PlGF) decreases and the soluble fms-like tyrosine kinase-1 (sFlt-1) increases in women with preeclampsia. However, there have been no studies on the relation between preeclampsia onset time and the changes in PlGF and sFlt-1. Furthermore, the PlGF and sFlt-1 levels have not been evaluated using their reference values specific to each gestational age. In this study we reevaluated the serum PlGF and sFlt-1 levels before and after the clinical manifestation of early and late onset severe preeclampsia using the new reference values developed in our recent longitudinal study. Blood specimens were obtained immediately after the clinical manifestation of severe preeclampsia in 34 referred women, and both before and after the clinical manifestation in 8 women receiving a routine checkup at our institute. Both women with early and those with late preeclampsia showed decreased PlGF and increased sFlt-1 levels compared to normotensive controls at 28 and 37 weeks (n=68). However, those with early onset preeclampsia had a higher incidence of low PlGF (<5th percentile on the reference values) and high sFlt-1 (≥95th percentile) than those with late onset (low PlGF: 93% vs. 55%; high sFlt-1: 100% vs. 60%). log10PlGF (r=0.574, p<0.001) and log10(sFlt-1/PlGF) (r=−0.556, p<0.001) were correlated with the week of onset of preeclampsia. Before the onset of preeclampsia, the incidence rate of low PlGF in the women with early onset preeclampsia was 100% (5/5), whereas that in the women with late onset preeclampsia was 0% (0/2) (p=0.048). Therefore, alterations in the PlGF levels both before and after the onset of preeclampsia may be more pronounced in women with early onset than those with late onset severe preeclampsia.

Evaluation of a new and automated electrochemiluminescence immunoassay for plasma sFlt-1 and PlGF levels in women with preeclampsia.

The first commercial automated immunoassays specific for soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) (Elecsys sFlt-1 and Elecsys PlGF, respectively) have recently been introduced. We constructed reference range values of plasma levels of sFlt-1 and PlGF, and the sFlt-1/PlGF ratio using Elecsys sFlt-1 and Elecsys PlGF during the second half of pregnancy and evaluated their sensitivity and specificity for the diagnosis of preeclampsia. Plasma samples were collected from 144 normal pregnant women at 19–25, 27–31 and 34–38 weeks of gestation and from 34 women with preeclampsia. The most appropriate reference range curves for plasma levels of sFlt-1 and PlGF, and the sFlt-1/PlGF ratio are presented as quadratic curves after logarithmic transformation. The sFlt-1/PlGF ratio showed the best diagnostic power for both early-onset and late-onset preeclampsia. In addition, a cutoff value of 45 for the sFlt-1/PlGF ratio resulted in the best sensitivity and specificity for the diagnosis of all preeclampsia (97 and 95%, respectively), and for the diagnosis of early-onset preeclampsia (100 and 95%, respectively). Using another 50 pairs of serum and plasma samples, including those from normal pregnant women and preeclamptic women, the plasma recovery rates of sFlt-1 and PlGF were 0.89 and 0.85, respectively; the correlation determinations between serum and plasma samples were 0.999 for sFlt-1, 0.990 for PlGF and 0.987 for sFlt-1/PlGF ratio. In conclusion, measurement of the plasma sFlt-1/PlGF ratio determined by Elecsys sFlt-1 and Elecsys PlGF and using a cutoff value of 45 might assist in the diagnosis of preeclampsia, especially for early-onset preeclampsia.

Normal and High-Normal Blood Pressures, but Not Body Mass Index, Are Risk Factors for the Subsequent Occurrence of Both Preeclampsia and Gestational Hypertension: A Retrospective Cohort Study

Blood pressure (BP) levels and body mass index (BMI) are known as risk factors for preeclampsia and gestational hypertension. However, there have been few investigations regarding the effects of BP and BMI levels on preeclampsia and gestational hypertension in the same cohort. In the present study, we conducted a retrospective cohort study using multiple logistic regression analysis. The cohort included 1,518 patients without nephritis. The unadjusted odds ratios (ORs) of preeclampsia and gestational hypertension were increased in pregnant women with normal BP (120–129 mmHg systolic or 80–84 mmHg diastolic), high-normal BP and hypertension in the second trimester compared to those with optimal BP. The unadjusted ORs of preeclampsia and gestational hypertension were also increased in obese women in the pre-pregnancy period compared to women with normal range BMI. When adjustment was made for both the BP levels and pre-pregnancy BMI levels, the ORs (95% confidence intervals) of normal BP, high-normal BP, hypertension and obesity for the subsequent occurrence of preeclampsia were 5.1 (2.2–12), 8.3 (3.1–22), 16 (5.0–50) and 2.0 (0.67–5.9), and those for the subsequent occurrence of gestational hypertension were 7.0 (2.6–19), 7.4 (2.1–25), 22 (6.1–83) and 1.3 (0.33–4.8), respectively. For the subsequent occurrence of preeclampsia or gestational hypertension, normal BP, high-normal BP and hypertension in the second trimester may be independent risk factors. Obesity in the pre-pregnancy period, however, may not be an independent risk factor.

Threshold of Soluble Fms-Like Tyrosine Kinase 1/Placental Growth Factor Ratio for the Imminent Onset of Preeclampsia

It has not been clarified whether thresholds of soluble fms-like tyrosine kinase 1 (sFlt-1), placental growth factor (PlGF), soluble endoglin, and the sFlt-1/PlGF ratio for the imminent onset of preeclampsia (PE) exist. We hypothesized that onset thresholds for the imminent onset of PE could be determined by the distributions of these 4 markers just after the onset of PE. Study subjects were 51 PE after the onset of PE; 36 of PE, 20 of gestational hypertension, 142 of a small-for-gestational-age infant, and 400 of normal pregnant controls at 19 to 25 and 27 to 31 weeks of gestation in a prospective cohort study. The current data supported our hypothesis that onset thresholds of sFlt-1 and the sFlt-1/PlGF ratio exist. The onset thresholds of the sFlt-1/PlGF at 26 to 31 weeks of gestation were useful for detecting imminent PE with the onset at <36 weeks of gestation, showing sensitivity of 0.36 and a positive likelihood ratio and 95th percent CIs of 38 (11–132); when positive, PE occurred at 2.2±0.6 weeks (range: 1.4–3.0 weeks) after the measurement of the sFlt-1/PlGF ratio. The combination of sFlt-1 at 26 to 31 weeks of gestation, past history of gestational hypertension or PE, prepregnancy body mass index, and mean blood pressure at 16 to 23 weeks of gestation was useful for detecting PE with onset of <36 weeks of gestation, showing sensitivity of 0.82, and a positive likelihood ratio (95% CI) of 42 (20–88). In conclusion, the onset threshold of sFlt-1/PlGF existed and might be useful for detecting the imminent onset of PE.

Establishing Reference Values for Both Total Soluble Fms-Like Tyrosine Kinase 1 and Free Placental Growth Factor in Pregnant Women

It has been reported that the concentration of free placental growth factor (PlGF) is decreased and that of soluble fms-like tyrosine kinase 1 (sFlt-1) is increased before the onset of preeclampsia. However, no study has determined the reference values for sFlt-1 and free PlGF during pregnancy using a commercially available enzyme-linked immunosorbent assay (ELISA) kit. This longitudinal cohort study was undertaken to address this issue. Serum samples were collected from 148 women at 10, 18, 28, and 37 weeks of gestation. Preeclampsia occurred in 6 women: 4 women who delivered at <37 weeks of gestation, and 2 women who delivered at ≥37 weeks. The average and 90% confidence interval (90% CI) of the serum concentration of both sFlt-1 and free PlGF were determined in a total of 433 specimens from 148 subjects with 1 to 4 collections at 7 to 39 weeks of gestation, and were represented as quadric curves. The mean values (90% CI) of sFlt-1 (pg/ml) at 10, 18, 28, and 37 weeks of gestation were 413 (174–981), 296 (125–704), 413 (174–982), and 1,130 (477–2,690), respectively. The mean values (90% CI) of free PlGF (pg/ml) were 36 (14–89), 206 (83–515), 518 (207–1,290), and 354 (142–884), respectively. We also established the reference values for the ratio of sFlt-1/PlGF. These values may be useful for predicting the subsequent occurrence of preeclampsia.

Alteration of serum soluble endoglin levels after the onset of preeclampsia is more pronounced in women with early-onset.

It has been established that serum soluble endoglin (sEng) increases in women with preeclampsia. However, sEng levels have not been evaluated using a normal reference value specific to each gestational age. First, we established the normal reference value for sEng using 85 pregnant controls without preeclampsia, from whom serum samples were collected three times at 20–23, 27–30, and 36–38 weeks of gestation. Second, we evaluated the serum sEng levels after the onset of preeclampsia in 56 preeclamptic patients. In three women (3.5%) with normal pregnancies, sustained high sEng levels (>15 ng/mL) were observed. We calculated the reference value for sEng using the remaining 82 normal controls. The log10sEng was almost normally distributed at each gestational week during 20–38 weeks, and the mean log10sEng was represented as a quadratic curve of gestational week. The SD of log10sEng was represented as a linear equation of gestational week. The mean log10sEng significantly and gradually increased from 20–23 weeks to 27–30 weeks of gestation and then rapidly increased at 36–38 weeks of gestation. Ninety-three percent of preeclamptic women showed sEng≥95th percentile of the reference value. The log10sEng levels and the SD score (SDS) of log10sEng in women with early-onset preeclampsia (onset<32 weeks of gestation) were significantly higher than those in women with late-onset preeclampsia (onset≥32 weeks of gestation) (1.97±0.23 vs. 1.78±0.28, 9.94±2.61 vs. 4.47±2.06, respectively). In conclusion, alteration of serum sEng levels after the onset of preeclampsia was more pronounced in women with early-onset preeclampsia compared to those with late onset.

Onset threshold of the plasma levels of soluble fms-like tyrosine kinase 1/placental growth factor ratio for predicting the imminent onset of preeclampsia within 4 weeks after blood sampling at 19–31 weeks of gestation

Our aim was to evaluate the onset threshold of plasma levels of the soluble fms-like tyrosine kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio for predicting the imminent onset of preeclampsia (PE) within 4 weeks after blood sampling. We prospectively measured the plasma levels of sFlt-1 and PlGF by an automated electrochemiluminescence immunoassay at 19–25 weeks of gestation in 1199 women and at 26–31 weeks of gestation in 798 women. The onset threshold of the sFlt-1/PlGF ratio was determined as the 2.5th percentile of the 95th confidence interval (CI) of a regression line between the onset gestational weeks of PE and the standard deviation score of log10(sFlt-1/PlGF), using 25 samples taken within 1 week after the onset of PE. The imminent onset of PE was identified in 2 (0.2%) women recruited at 19–25 weeks and in 6 (0.8%) women recruited at 26–31 weeks. The onset threshold of plasma levels of the sFlt-1/PlGF ratio at 19–25 weeks showed a sensitivity (SE) of 1.00, a specificity (SP) of 1.00, a positive likelihood ratio (LR+) of ∞ and a positive predictive value (PPV) of 1.00; the onset threshold of plasma levels of the sFlt-1/PlGF ratio at 26–31 weeks showed a SE of 0.83, a SP of 0.994, a LR+ of 132 (95% CI: 51–339) and a PPV of 0.50. In conclusion, the onset threshold of plasma levels of the sFlt-1/PlGF ratio was shown to be a highly sensitive and a highly specific screening method for detecting the imminent onset of PE within 4 weeks after blood sampling at 19–31 weeks.

Serum sFlt1:PlGF Ratio, PlGF, and Soluble Endoglin Levels in Gestational Proteinuria

Objective: It was recently reported that both a high soluble fms-like tyrosine kinase 1 (sFlt1): placental growth factor (PlGF) ratio (sFlt1:PlGF ratio) and high soluble endoglin (sEng) levels are related to the later occurrence of preeclampsia. We compared the serum sFlt1:PlGF ratio, PlGF and sEng levels in women with gestational proteinuria (GP) to those in women with preeclampsia. Methods: Seven women with GP and 34 women with preeclampsia were recruited in this study. The 95th percentile values in the reference curves of sFlt1, sFlt1:PlGF ratio and sEng, and the 5th percentile values in the reference curve of PlGF were respectively set as the cutoff values. Results: The incidence rates of a high sFlt1:PlGF ratio, low PlGF and high sEng in women with GP were 57%, 29% and 86%, respectively, whereas those in women with preeclampsia were 94%, 77%, and 88%, respectively (p = 0.028, p = 0.024, and p = 1.000, respectively). The incidence rates of a both high sFlt1:PlGF ratio and high sEng in women with GP and preeclampsia were 57% and 88%, respectively (p = 0.082). Conclusion: The majority of women with GP showed both increases of the sFlt1:PlGF ratio and sEng, thus suggesting some women with GP may represent subclinical preeclampsia. In addition, women with GP showed a significantly lower sFlt1:PlGF ratio and higher PlGF level than those with preeclampsia, suggesting that the PlGF level is a key regulator for developing hypertension in some pregnant women, even with increases of both sFlt1:PlGF ratio and sEng levels.

Antinuclear Antibody Reduces the Pregnancy Rate in the First IVF‐ET Treatment Cycle but Not the Cumulative Pregnancy Rate without Specific Medication

Problem: It has been shown that the presence of antinuclear antibody (ANA) might reduce pregnancy rates after in vitro fertilization‐embryo transfer (IVF‐ET). However, the mechanism of implantation failure by ANA has not yet been clarified. This study was performed to investigate the impact of ANA on pregnancy rates after IVF‐ET, and the necessity of specific medication for infertile women who have ANA in their sera.