Intrahepatic cholestasis of pregnancy: Biochemical predictors of adverse perinatal outcomes

Gradual dosing of ursodeoxycholic acid in mothers with intrahepatic cholestasis of pregnancy may improve composite neonatal outcome

INTRODUCTION AND OBJECTIVES

Intrahepatic cholestasis of pregnancy (ICP) is often accompanied by fetal and maternal complications.

MATERIALS AND METHODS

Retrospective review of the clinical course of women with ICP and their neonates treated at our medical center over a 10-year period. Special attention was paid to the maternal and neonatal response to 2 different modes of ursodeoxycholic acid (UDCA) administration.

RESULTS

Neonates of mothers with high total bile acid levels had a poorer composite neonatal outcome. Twenty-seven women who presented at an advanced stage of their pregnancies did not receive UDCA. UDCA was administered in 2 modes: either a full dose at admission (76 women) or a gradually increasing dose until the desired dosage was reached (25 women). The mean gestational age at delivery for the 94 neonates that were exposed to full UDCA dose was the lowest (36±2.3 weeks for the full dose, 37±1.4 weeks for the 30 neonates from the gradually increasing dose, 38±1.6 weeks for the 29 neonates from the no treatment group, p<0.001). The group of neonates that were exposed to full UDCA dose had the highest rate of unfavorable composite neonatal outcome (53% for full dose, 30% for gradually increasing dose, 24% for the no treatment group, p=0.006).

CONCLUSIONS

Compared to the administration of a full UDCA dose, the administration of a gradually increasing dose of UDCA may be associated with a greater gestational age at delivery and fewer events of unfavorable composite neonatal outcomes. These novel findings should be retested prospectively in a large cohort of patients.

Whole-exome sequencing reveals ANO8 as a genetic risk factor for intrahepatic cholestasis of pregnancy

Background

Intrahepatic cholestasis of pregnancy (ICP) is characterized by pruritus and cholestasis in late pregnancy and results in adverse pregnancy outcomes, including preterm delivery and birth weight, which are affected by the genetic and environmental background. However, until now, the genetic architecture of ICP has remained largely unclear.

Methods

Twenty-six clinical data points were recorded for 151 Chinese ICP patients. The data generated from whole-exome sequencing (WES) using the BGISEQ-500 platform were further analyzed by Burrows-Wheeler Aligner (BWA) software, Genome Analysis Toolkit (GATK), ANNOVAR tool, etc. R packages were used to conduct t-test, Fisher’s test and receiver operating characteristic (ROC) curve analyses.

Results

We identified eighteen possible pathogenic loci associated with ICP disease in known genes, covering ABCB4, ABCB11, ATP8B1 and TJP2. The loci Lys386Gln, Gly527Gln and Trp708Ter in ABCB4, Leu589Met, Gln605Pro and Gln1194Ter in ABCB11, and Arg189Ser in TJP2 were novel discoveries. In addition, WES analysis indicated that the gene ANO8 involved in the transport of bile salts is newly identified as associated with ICP. The functional network of the ANO8 gene confirmed this finding. ANO8 contained 8 rare missense mutations that were found in eight patients among the 151 cases and were absent from 1029 controls. Out of the eight SNPs, 3 were known, and the remaining five are newly identified. These variants have a low frequency, ranging from 0.000008 to 0.00001 in the ExAC, gnomAD – Genomes and TOPMED databases. Bioinformatics analysis showed that the sites and their corresponding amino acids were both highly conserved among vertebrates. Moreover, the influences of all the mutations on protein function were predicted to be damaging by the SIFT tool. Combining clinical data, it was found that the mutation group (93.36 µmol/L) had significantly (P = 0.038) higher total bile acid (TBA) levels than the wild-type group (40.81 µmol/L).

Conclusions

To the best of our knowledge, this is the first study to employ WES technology to detect genetic loci for ICP. Our results provide new insights into the genetic basis of ICP and will benefit the final identification of the underlying mutations.

Novel high-coverage targeted metabolomics method (SWATHtoMRM) for exploring follicular fluid metabolome alterations in women with recurrent spontaneous abortion undergoing in vitro fertilization

The complexity of follicular fluid metabolome presents a significant challenge for qualitative and quantitative metabolite profiling, and for discovering the comprehensive biomarkers. In order to address this challenge, a novel SWATHtoMRM metabolomics method was used for providing broad coverage and excellent quantitative capability to discover the human follicular fluid metabolites related to recurrent spontaneous abortion (RSA) after in vitro fertilization and embryo transfer, and to evaluate their relationship with pregnancy outcome. The follicular fluid samples from the spontaneous abortion group (n = 22) and the control group (n = 22) were analyzed using ultra-performance liquid chromatography high-resolution mass spectrometry. A novel, high-coverage, targeted metabolomics method (SWATH to MRM) and a targeted metabolomics method were used to find and validate the differential metabolites between the two groups. A total of 18 follicular fluid metabolites, including amino acids, cholesterol, vitamins, fatty acids, cholic acid, lysophosphatidylcholine and other metabolites, were identified. In the RSA group, 8 metabolites, namely dehydroepiandrosterone, lysoPC(16:0), lysoPC(18:2), lysoPC(18:1), lysoPC(18:0), lysoPC(20:5), lysoPC(20:4), and lysoPC(20:3), were up-regulated, and 10 metabolites, namely phenylalanine, linoleate, oleic acid, docosahexaenoic acid, lithocholic acid, 25-hydroxyvitamin D3, hydroxycholesterol, 13-hydroxy-alpha-tocopherol, leucine, and tryptophan, were down-regulated. These differential metabolites related to RSA may provide a possible diagnostic basis and therapeutic target for RSA, as well as a scientific basis for elucidating the mechanism of RSA.

Bile acid levels and risk of adverse perinatal outcomes in intrahepatic cholestasis of pregnancy: A meta-analysis

AIM

We aimed to determine the association between maternal total bile acid (TBA) levels and the risks of adverse perinatal outcomes in pregnant women with intrahepatic cholestasis of pregnancy (ICP) based on a meta-analysis study.

METHODS

We searched PubMed for articles published from 2000 to 2015 with a focus on ICP and restriction to the English language. The main perinatal outcomes were preterm birth (PTB), meconium-stained amniotic fluid (MSAF), asphyxia, or respiratory distress syndrome (RDS). Relative risk (RR) with 95% confidence intervals (CI) was the summary statistic. We used a random- or fixed-effects model to calculate the pooled RR according to the heterogeneity test. Subgroup analyses were performed by region and study design.

RESULTS

Nine eligible related citations fulfilled the inclusion criteria and were included in this study. Compared with pregnant women with a serum TBA < 40 μmol/L, severe ICP (TBA ≥ 40 μmol/L) was associated with a significantly increased risk of adverse fetal outcomes (pooled RR, 1.96; 95%CI, 1.63-2.35), PTB (pooled RR, 2.23; 95%CI, 1.51-3.29), MSAF (pooled RR, 2.27; 95%CI, 1.81-2.85), and asphyxia or RDS (pooled RR, 1.67; 95%CI, 1.18-2.36). Sensitivity analysis suggested that the study design difference may be a major source of heterogeneity. No publication bias was demonstrated by Begg's test (P > 0.05).

CONCLUSION

This meta-analysis indicates that maternal elevated bile acid levels are significantly associated with increased risks of overall adverse perinatal outcomes, PTB, MSAF, and asphyxia or RDS. Serum TBA levels seem to be a useful predictor for the risk of adverse perinatal outcomes.