Risk of obstetric cholestasis in sisters of index patients

Intrahepatic cholestasis of pregnancy - Diagnosis and management: A consensus statement of the Society of Obstetric Medicine of Australia and New Zealand (SOMANZ): Executive summary

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy liver disease, characterised by pruritus and increased total serum bile acids (TSBA), Australian incidence 0.6-0.7%. ICP is diagnosed by non-fasting TSBA ≥19 μmol/L in a pregnant woman with pruritus without rash without a known pre-existing liver disorder. Peak TSBA ≥40 and ≥100 μmol/L identify severe and very severe disease respectively, associated with spontaneous preterm birth when severe, and with stillbirth, when very severe. Benefit-vs-risk for iatrogenic preterm birth in ICP remains uncertain. Ursodeoxycholic acid remains the best pharmacotherapy preterm, improving perinatal outcome and reducing pruritus, although it has not been shown to reduce stillbirth.

Familial clustering of intrahepatic cholestasis of pregnancy: A nationwide population-based study in Denmark

BACKGROUND AND AIMS

Genetics plays a role in the pathogenesis of intrahepatic cholestasis of pregnancy (ICP); however, empirical evidence on familial clustering of ICP is scarce. We aimed to assess the extent of familial recurrence of ICP.

APPROACH AND RESULTS

This population-based cohort study included all 668,461 primiparous women who gave birth between 1995 and 2018 in Denmark. Women diagnosed with ICP were included to the index cohort. Kinship with index women was determined with the Danish Civil Registration System. Log-binomial regression was used to calculate the relative recurrence risk (RRR) of ICP in relatives of index women. A total of 6722 (1.0%) primiparous women were diagnosed with ICP. In co-twins (n=57), first-degree (n=2279), second-degree (n=1373), and third-degree (n=1758) relatives of the index women, the incidence of ICP reached 5.3%, 2.6%, 0.7%, and 1.4%, respectively, corresponding to adjusted RRRs of 4.82 (95% CI, 1.60-14.48), 2.54 (1.98-3.26), 0.81 (0.44-1.51), and 1.15 (0.77-1.71), respectively. The first-degree relatives of women who had recurrent ICP or first-trimester ICP seemed to be at higher risks [RRR, 4.30 (2.85-6.48), 3.04 (1.93-4.77), respectively]. A minor increased risk was observed in nonbiological relatives [RRR, 1.35 (1.05-1.73); n=4274, including women's full-brothers' partner and women's husbands' full sisters].

CONCLUSIONS

Co-twins and first-degree relatives of ICP patients were at ~5- and ~2.5-fold increased risk of ICP, respectively. No increased risk was observed in second-degree and third-degree relatives. Recurrent ICP and first-trimester ICP might indicate a higher degree of family clustering. Further investigation is needed to investigate the increased risk of ICP in nonbiological relatives.

Recognizing, Diagnosing, and Managing Pregnancy Dermatoses

Pregnancy dermatoses are inflammatory skin disorders that occur during pregnancy or immediately postpartum. This heterogenous group of disorders includes pemphigoid gestationis, polymorphic eruption of pregnancy, intrahepatic cholestasis of pregnancy, atopic eruption of pregnancy, and pustular psoriasis of pregnancy. In this article, we provide a comprehensive literature review of each condition focusing on nomenclature, epidemiology, pathogenesis, clinical presentation, diagnosis, differential diagnosis, maternal risk, fetal risk, and treatment. We aim to increase awareness and help clinicians recognize, diagnose, and manage these unique conditions.

Whole-exome sequencing expands the roles of novel mutations of organic anion transporting polypeptide, ATP-binding cassette transporter, and receptor genes in intrahepatic cholestasis of pregnancy

Background: Intrahepatic cholestasis of pregnancy (ICP) is associated with a high incidence of fetal morbidity and mortality. Therefore, revealing the mechanisms involved in ICP and its association with fetal complications is very important.

Methods: Here, we used a whole-exome sequencing (WES) approach to detect novel mutations of organic anion transporting polypeptide (OTAP) genes, ATP-binding cassette transporter (ABC) genes, and receptor genes associated with ICP in 249 individuals and 1,029 local control individuals. Two available tools, SIFT and PolyPhen-2, were used to predict protein damage. Protein structuremodeling and comparison between the reference and modified protein structures were conducted by SWISS-MODEL and Chimera 1.14rc software, respectively.

Results: A total of 5,583 mutations were identified in 82 genes related to bile acid transporters and receptors, of which 62 were novel mutations. These novel mutations were absent in the 1,029 control individuals and three databases, including the 1,000 Genome Project (1000G_ALL), Exome Aggregation Consortium (ExAC), and Single-Nucleotide Polymorphism Database (dbSNP). We classified the 62 novel loci into two groups (damaging and probably damaging) according to the results of SIFT and PolyPhen-2. Out of the 62 novel mutations, 24 were detected in the damaging group. Of these, five novel possibly pathogenic variants were identified that were located in known functional genes, including ABCB4 (Ile377Asn), ABCB11 (Ala588Pro), ABCC2 (Ile681Lys and Met688Thr), and NR1H4 (Tyr149Ter). Moreover, compared to the wild-type protein structure, ABCC2 Ile681Lys and Met688Thr protein structures showed a slight change in the chemical bond lengths of ATP-ligand binding amino acid side chains. The combined 32 clinical data points indicate that the mutation group had a significantly (p = 0.04) lower level of Cl ions than the wild-type group. Particularly, patients with the 24 novel mutations had higher average values of alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bile acids (TBA), high-density lipoprotein (HDL), and low-density lipoprotein (LDL) than patients with the 38 novel mutations in the probably damaging group and the local control individuals.

Conclusion: The present study provides new insights into the genetic architecture of ICP involving these novel mutations.

Pregnancy-Associated Liver Diseases

The liver disorders unique to pregnancy include hyperemesis gravidarum, intrahepatic cholestasis of pregnancy, acute fatty liver of pregnancy, and preeclampsia-associated hepatic impairment, specifically hemolysis, elevated liver enzymes, and low platelet count syndrome (HELLP). Their importance lies in the significant maternal and fetal/neonatal morbidity and mortality. Expeditious diagnosis and clinical evaluation is critical to ensure timely, appropriate care and minimize risks to the pregnant woman and her fetus/baby. A multidisciplinary approach is essential, including midwives, maternal-fetal-medicine specialists, anesthetists, neonatologists, and hepatologists.

Whole-exome sequencing identifies novel mutations in ABC transporter genes associated with intrahepatic cholestasis of pregnancy disease: a case-control study

Background

Intrahepatic cholestasis of pregnancy (ICP) can cause premature delivery and stillbirth. Previous studies have reported that mutations in ABC transporter genes strongly influence the transport of bile salts. However, to date, their effects are still largely elusive.

Methods

A whole-exome sequencing (WES) approach was used to detect novel variants. Rare novel exonic variants (minor allele frequencies: MAF < 1%) were analyzed. Three web-available tools, namely, SIFT, Mutation Taster and FATHMM, were used to predict protein damage. Protein structure modeling and comparisons between reference and modified protein structures were performed by SWISS-MODEL and Chimera 1.14rc, respectively.

Results

We detected a total of 2953 mutations in 44 ABC family transporter genes. When the MAF of loci was controlled in all databases at less than 0.01, 320 mutations were reserved for further analysis. Among these mutations, 42 were novel. We classified these loci into four groups (the damaging, probably damaging, possibly damaging, and neutral groups) according to the prediction results, of which 7 novel possible pathogenic mutations were identified that were located in known functional genes, including ABCB4 (Trp708Ter, Gly527Glu and Lys386Glu), ABCB11 (Gln1194Ter, Gln605Pro and Leu589Met) and ABCC2 (Ser1342Tyr), in the damaging group. New mutations in the first two genes were reported in our recent article. In addition, compared to the wild-type protein structure, the ABCC2 Ser1342Tyr-modified protein structure showed a slight change in the chemical bond lengths of ATP ligand-binding amino acid side chains. In placental tissue, the expression level of the ABCC2 gene in patients with ICP was significantly higher (P < 0.05) than that in healthy pregnant women. In particular, the patients with two mutations in ABC family genes had higher average values of total bile acids (TBA), aspartate transaminase (AST), direct bilirubin (DBIL), total cholesterol (CHOL), triglycerides (TG) and high-density lipoprotein (HDL) than the patients who had one mutation, no mutation in ABC genes and local controls.

Conclusions

Our present study provide new insight into the genetic architecture of ICP and will benefit the final identification of the underlying mutations.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03595-x.

Hepatitis B infection and intrahepatic cholestasis of pregnancy: A systematic review and meta-analysis

BACKGROUND

Viral hepatitis type B is caused by hepatitis B virus (HBV) infection. Several studies have linked HBV infection to a higher risk of developing intrahepatic cholestasis of pregnancy (ICP), although some give contradictory results. To investigate the association and estimated risk of ICP in patients with HBV infection, we conducted this meta-analysis to summarize all available evidence.

METHODS

This study consists of 2 meta-analyses. A literature search was performed using MEDLINE and EMBASE from inception to July 2019. The first study included studies that reported associations between HBV infection and the risk of ICP. The second analysis included studies comparing the risk of HBV infection in ICP patients with those without ICP. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using a random-effect, inverse variance method.

RESULTS

Four studies were included in both analyses. The OR of ICP in HBV-infected pregnant women compared with non-HBV pregnant women was 1.68 (95% CI 1.43-1.97; I = 0%). The OR of HBV infection among ICP patients compared with non-ICP patients was 1.70 (95% CI 1.44-2.01; I = 0%).

CONCLUSIONS

Our meta-analysis demonstrates not only a higher risk of ICP among HBV-infected pregnant women but also an increased risk of HBV infection among ICP patients. These findings suggest that HBV is a high-risk factor for ICP and screening for hepatitis B in women with ICP symptoms may be beneficial.

Pharmacological interventions for treating intrahepatic cholestasis of pregnancy

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder that can develop in pregnancy. It occurs when there is a build-up of bile acids in the maternal blood. It has been linked to adverse maternal and fetal/neonatal outcomes. As the pathophysiology is poorly understood, therapies have been largely empiric. As ICP is an uncommon condition (incidence less than 2% a year), many trials have been small. Synthesis, including recent larger trials, will provide more evidence to guide clinical practice. This review is an update of a review first published in 2001 and last updated in 2013.

OBJECTIVES

To assess the effects of pharmacological interventions to treat women with intrahepatic cholestasis of pregnancy, on maternal, fetal and neonatal outcomes.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (13 December 2019), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials, including cluster-randomised trials and trials published in abstract form only, that compared any drug with placebo or no treatment, or two drug intervention strategies, for women with a clinical diagnosis of intrahepatic cholestasis of pregnancy.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed trials for eligibility and risks of bias. We independently extracted data and checked these for accuracy. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included 26 trials involving 2007 women. They were mostly at unclear to high risk of bias. They assessed nine different pharmacological interventions, resulting in 14 different comparisons. We judged two placebo-controlled trials of ursodeoxycholic acid (UDCA) in 715 women to be at low risk of bias. The ten different pharmacological interventions were: agents believed to detoxify bile acids (UCDA) and S-adenosylmethionine (SAMe); agents used to bind bile acids in the intestine (activated charcoal, guar gum, cholestyramine); Chinese herbal medicines (yinchenghao decoction (YCHD), salvia, Yiganling and Danxioling pill (DXLP)), and agents aimed to reduce bile acid production (dexamethasone) Compared with placebo, UDCA probably results in a small improvement in pruritus score measured on a 100 mm visual analogue scale (VAS) (mean difference (MD) -7.64 points, 95% confidence interval (CI) -9.69 to -5.60 points; 2 trials, 715 women; GRADE moderate certainty), where a score of zero indicates no itch and a score of 100 indicates severe itching. The evidence for fetal distress and stillbirth were uncertain, due to serious limitations in study design and imprecision (risk ratio (RR) 0.70, 95% CI 0.35 to 1.40; 6 trials, 944 women; RR 0.33, 95% CI 0.08 to 1.37; 6 trials, 955 women; GRADE very low certainty). We found very few differences for the other comparisons included in this review. There is insufficient evidence to indicate if SAMe, guar gum, activated charcoal, dexamethasone, cholestyramine, Salvia, Yinchenghao decoction, Danxioling and Yiganling, or Yiganling alone or in combination are effective in treating women with intrahepatic cholestasis of pregnancy.

AUTHORS' CONCLUSIONS

When compared with placebo, UDCA administered to women with ICP probably shows a reduction in pruritus. However the size of the effect is small and for most pregnant women and clinicians, the reduction may fall below the minimum clinically worthwhile effect. The evidence was unclear for other adverse fetal outcomes, due to very low-certainty evidence. There is insufficient evidence to indicate that SAMe, guar gum, activated charcoal, dexamethasone, cholestyramine, YCHD, DXLP, Salvia, Yiganling alone or in combination are effective in treating women with cholestasis of pregnancy. There are no trials of the efficacy of topical emollients. Further high-quality trials of other interventions are needed in order to identify effective treatments for maternal itching and preventing adverse perinatal outcomes. It would also be helpful to identify those women who are mostly likely to respond to UDCA (for example, whether bile acid concentrations affect how women with ICP respond to treatment with UDCA).

An expanded role for heterozygous mutations of ABCB4, ABCB11, ATP8B1, ABCC2 and TJP2 in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) affects 1/140 UK pregnancies; with pruritus, hepatic impairment and elevated serum bile acids. Severe disease is complicated by spontaneous preterm delivery and stillbirth. Previous studies have reported mutations in hepatocellular transporters (ABCB4, ABCB11). High throughput sequencing in 147 patients was performed in the transporters ABCB4, ABCB11, ATP8B1, ABCC2 and tight junction protein 2 (TJP2). Twenty-six potentially damaging variants were identified with the following predicted protein changes: Twelve ABCB4 mutations - Arg47Gln, Met113Val, Glu161Gly, Thr175Ala, Glu528Glyfs*6, Arg590Gln, Ala601Ser, Glu884Ter, Gly722Ala, Tyr775Met (x2), Trp854Ter. Four potential ABCB11 mutations - Glu297Gly (x3) and a donor splice site mutation (intron 19). Five potential ATP8B1 mutations - Asn45Thr (x3), and two others, Glu114Gln and Lys203Glu. Two ABCC2 mutations - Glu1352Ala and a duplication (exons 24 and 25). Three potential mutations were identified in TJP2; Thr62Met (x2) and Thr626Ser. No patient harboured more than one mutation. All were heterozygous. An additional 545 cases were screened for the potential recurrent mutations of ATP8B1 (Asn45Thr) and TJP2 (Thr62Met) identifying three further occurrences of Asn45Thr. This study has expanded known mutations in ABCB4 and ABCB11 and identified roles in ICP for mutations in ATP8B1 and ABCC2. Possible novel mutations in TJP2 were also discovered.

Management of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease during pregnancy, characterized by otherwise unexplained pruritus in late second and third trimester of pregnancy and elevated bile acids and/or transaminases. ICP is associated with an increased risk of adverse perinatal outcomes for the fetus and the later development of hepatobiliary disease for the mother. Bile acids should be monitored throughout pregnancy since fetal risk is increased at serum bile acids >40 µmol/l. Management of ICP consists of treatment with ursodeoxycholic acid, which reduces pruritus. Early elective delivery is common practice but should be performed on an individualized basis as long as strong evidence supporting this practice is lacking. Mothers should be followed-up for normalization of liver function tests 6-12 weeks after delivery. Future research in large-scale studies is needed to address the impact of ursodeoxycholic acid and early elective delivery on fetal outcome.

Intrahepatic Cholestasis of Pregnancy (ICP) in U.S. Latinas and Chileans: Clinical features, Ancestry Analysis, and Admixture Mapping

In the Americas, women with Indigenous American ancestry are at increased risk of intrahepatic cholestasis of pregnancy (ICP), relative to women of other ethnicities. We hypothesized that ancestry-related genetic factors contribute to this increased risk. We collected clinical and laboratory data, and performed biochemical assays on samples from U.S. Latinas and Chilean women, with and without ICP. The study sample included 198 women with ICP (90 from California, U.S., and 108 from Chile) and 174 pregnant control women (69 from California, U.S., and 105 from Chile). SNP genotyping was performed using Affymetrix arrays. We compared overall genetic ancestry between cases and controls, and used a genome-wide admixture mapping approach to screen for ICP susceptibility loci. We identified commonalities and differences in features of ICP between the 2 countries and determined that cases had a greater proportion of Indigenous American ancestry than did controls (p = 0.034). We performed admixture mapping, taking country of origin into account, and identified one locus for which Native American ancestry was associated with increased risk of ICP at a genome-wide level of significance (P = 3.1 x 10(-5), Pcorrected = 0.035). This locus has an odds ratio of 4.48 (95% CI: 2.21-9.06) for 2 versus zero Indigenous American chromosomes. This locus lies on chromosome 2, with a 10 Mb 95% confidence interval which does not contain any previously identified hereditary 'cholestasis genes.' Our results indicate that genetic factors contribute to the risk of developing ICP in the Americas, and support the utility of clinical and genetic studies of ethnically mixed populations for increasing our understanding of ICP.

Intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy is the most common pregnancy-specific liver disease that typically presents in the third trimester. The clinical features are maternal pruritus in the absence of a rash and deranged liver function tests, including raised serum bile acids. Intrahepatic cholestasis of pregnancy is associated with an increased risk of adverse perinatal outcomes, including spontaneous preterm delivery, meconium staining of the amniotic fluid, and stillbirth. It is commonly treated with ursodeoxycholic acid. There is accumulating evidence to suggest that intrahepatic cholestasis of pregnancy has a lasting influence on both maternal and fetal health. We review the etiology, diagnosis, and management of this intriguing condition.

A comprehensive analysis of common genetic variation around six candidate loci for intrahepatic cholestasis of pregnancy

OBJECTIVES

Intrahepatic cholestasis of pregnancy (ICP) has a complex etiology with a significant genetic component. Heterozygous mutations of canalicular transporters occur in a subset of ICP cases and a population susceptibility allele (p.444A) has been identified in ABCB11. We sought to expand our knowledge of the detailed genetic contribution to ICP by investigation of common variation around candidate loci with biological plausibility for a role in ICP (ABCB4, ABCB11, ABCC2, ATP8B1, NR1H4, and FGF19).

METHODS

ICP patients (n=563) of white western European origin and controls (n=642) were analyzed in a case-control design. Single-nucleotide polymorphism (SNP) markers (n=83) were selected from the HapMap data set (Tagger, Haploview 4.1 (build 22)). Genotyping was performed by allelic discrimination assay on a robotic platform. Following quality control, SNP data were analyzed by Armitage's trend test.

RESULTS

Cochran-Armitage trend testing identified six SNPs in ABCB11 together with six SNPs in ABCB4 that showed significant evidence of association. The minimum Bonferroni corrected P value for trend testing ABCB11 was 5.81×10(-4) (rs3815676) and for ABCB4 it was 4.6×10(-7)(rs2109505). Conditional analysis of the two clusters of association signals suggested a single signal in ABCB4 but evidence for two independent signals in ABCB11. To confirm these findings, a second study was performed in a further 227 cases, which confirmed and strengthened the original findings.

CONCLUSIONS

Our analysis of a large cohort of ICP cases has identified a key role for common variation around the ABCB4 and ABCB11 loci, identified the core associations, and expanded our knowledge of ICP susceptibility.

Interventions for treating cholestasis in pregnancy

BACKGROUND

Obstetric cholestasis has been linked to adverse maternal and fetal/neonatal outcomes. As the pathophysiology is poorly understood, therapies have been empiric. The first version of this review, published in 2001, and including nine randomised controlled trials involving 227 women, concluded that there was insufficient evidence to recommend any of the interventions alone or in combination. This is the first update.

OBJECTIVES

To evaluate the effectiveness and safety of therapeutic and delivery interventions in women with cholestasis of pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (20 February 2013) and reference lists of identified studies.

SELECTION CRITERIA

Randomised controlled trials that compared two intervention strategies for women with a clinical diagnosis of obstetric cholestasis.

DATA COLLECTION AND ANALYSIS

The review authors independently assessed trials for eligibility and risk of bias. We independently extracted data and checked these for accuracy.

MAIN RESULTS

We included 21 trials with a total of 1197 women. They were mostly at moderate to high risk of bias. They assessed 11 different interventions resulting in 15 different comparisons.Compared with placebo, ursodeoxycholic acid (UDCA) showed improvement in pruritus in five (228 women) out of seven trials. There were no significant differences in instances of fetal distress in the UDCA groups compared with placebo (average risk ratio (RR) 0.67; 95% confidence interval (CI) 0.22 to 2.02; five trials, 304 women; random-effects analysis: T² = 0.74; I² = 48%). There were significantly fewer total preterm births with UDCA (RR 0.46; 95% CI 0.28 to 0.73; two trials, 179 women). The difference for spontaneous preterm births was not significant (RR 0.99; 95% CI 0.41 to 2.36, two trials, 109 women).Two trials (48 women) reported lower (better) pruritus scores for S-adenosylmethionine (SAMe) compared with placebo, while two other trials of 34 women reported no significant differences between groups.UDCA was more effective in improving pruritus than either SAMe (four trials; 133 women) or cholestyramine (one trial; 84 women), as was combined UDCA+SAMe when compared with placebo (one trial; 16 women) and SAMe alone (two trials; 68 women). However, combined UDCA+SAMe was no more effective than UDCA alone in regard to pruritus improvement (one trial; 53 women) and two trials (80 women) reported data were insufficient to draw any conclusions from. In one trial comparing UDCA and dexamethasone (83 women), a significant improvement with UDCA was seen only in a subgroup of women with severe obstetric cholestasis (23 women).Danxiaoling significantly improved pruritus in comparison to Yiganling. No significant differences were seen in pruritus improvement with other interventions.Eight trials reported fetal or neonatal deaths, with two deaths reported overall (both in the placebo groups).Women receiving UDCA and cholestyramine experienced nausea, vomiting and diarrhoea. Guar gum caused mild abdominal distress, diarrhoea and flatulence during the first days of treatment. Women found charcoal suspension unpleasant to swallow. Dexamethasone caused nausea, dizziness and stomach pain in one woman.One trial (62 women) looked at the timing of delivery intervention. There were no stillbirths or neonatal deaths in 'early delivery' or the 'await spontaneous labour' group. There were no significant differences in the rates of caesarean section, meconium passage or admission to neonatal intensive care unit between the two groups.

AUTHORS' CONCLUSIONS

Different approaches to assessing and reporting pruritus precluded pooling of trials comparing the effects of UDCA versus placebo on pruritus, but examination of individual trials suggests that UDCA significantly improves pruritus, albeit by a small amount. Fewer instances of fetal distress/asphyxial events were seen in the UDCA groups when compared with placebo but the difference was not statistically significant. Large trials of UDCA to determine fetal benefits or risks are needed.A single trial was too small to rule in or out a clinically important effect of early term delivery on caesarean section.There is insufficient evidence to indicate that SAMe, guar gum, activated charcoal, dexamethasone, cholestyramine, Salvia, Yinchenghao decoction (YCHD), Danxioling and Yiganling, or Yiganling alone or in combination are effective in treating women with cholestasis of pregnancy.

Intrahepatic cholestasis of pregnancy is common among patients' first-degree relatives

Intrahepatic cholestasis of pregnancy has been shown to have a genetic predisposition. We studied whether Finnish women who had suffered from the disorder reported their first-degree relatives to have had liver dysfunction during their pregnancies. Questionnaires were sent in autumn 2010 to a total of 544 former intrahepatic cholestasis of pregnancy patients and 1235 controls, all having delivered during 1969-1988. The response rate was 66.2%. The incidence of intrahepatic cholestasis is 0.5-1.5% of pregnancies in Finland. In our survey, altogether 12.8% of mothers (odds ratio 9.2), 15.9% of sisters (odds ratio 5.3) and 10.3% of daughters (odds ratio 4.8) of women who had suffered from intrahepatic cholestasis of pregnancy had had liver dysfunction during pregnancy. Our findings strengthen the earlier knowledge of the genetic component in intrahepatic cholestasis of pregnancy. We suggest that all pregnant women are asked about their family history regarding liver dysfunction during pregnancy.

Advances in pathogenesis and treatment of pruritus

The pathogenesis of itch during cholestasis is largely unknown and treatment options are limited. Lysophosphatidate, female steroid hormones, and endogenous opioids are among the agents discussed as potential pruritogens in cholestasis. The itch-alleviating action of guideline-based therapeutic interventions with anion exchanger resins, rifampicin, opioid antagonists, and serotonin reuptake inhibitors are studied to unravel the molecular pathogenesis of itch. Still, a considerable part of the patients is in need of alternative experimental therapeutic approaches (eg, UV-B phototherapy, extracorporeal albumin dialysis, nasobiliary drainage), providing additional information about the enigmatic pathophysiology of cholestatic pruritus.

Effects of 17α-ethynylestradiol-induced cholestasis on the pharmacokinetics of doxorubicin in rats: reduced biliary excretion and hepatic metabolism of doxorubicin

1. Since the prevalent hormonal combination therapy with estrogen analogues in cancer patients has frequency and possibility to induce the cholestasis, the frequent combination therapy with 17α-ethynylestradiol (EE, an oral contraceptive) and doxorubicin (an anticancer drug) might be monitored in aspect of efficacy and safety. Doxorubicin is mainly excreted into the bile via P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (Mrp2) in hepatobiliary route and metabolized via cytochrome P450 (CYP) 3A subfamily. Also the hepatic Mrp2 (not P-gp) and CYP3A subfamily levels were reduced in EE-induced cholestatic (EEC) rats. Thus, we herein report the pharmacokinetic changes of doxorubicin with respect to the changes in its biliary excretion and hepatic metabolism in EEC rats. 2. The pharmacokinetic study of doxorubicin after intravenous administration of its hydrochloride was conducted along with the investigation of bile flow rate and hepatobiliary excretion of doxorubicin in control and EEC rats. 3. The significantly greater AUC (58.7% increase) of doxorubicin in EEC rats was due to the slower CL (32.9% decrease). The slower CL was due to the reduction of hepatic biliary excretion (67.0% decrease) and hepatic CYP3A subfamily-mediated metabolism (21.9% decrease) of doxorubicin. These results might have broader implications to understand the altered pharmacokinetics and/or pharmacologic effects of doxorubicin via biliary excretion and hepatic metabolism in experimental and clinical estrogen-induced cholestasis.

Dexamethasone in the treatment of obstetric cholestasis: A case series

Twelve women with obstetric cholestasis were given dexamethasone after failure to respond to ursodeoxycholic acid. Clinical improvement was achieved in eight cases, without complete resolution of symptoms. Biochemical response was achieved in seven cases. All but two cases had good correlation between clinical and biochemical response. Women of Asian and South American origin were more likely to respond to dexamethasone than Caucasians. There were no reported maternal or fetal side-effects. However, the subsequent consequences of dexamethasone treatment for the mother and fetus have not been thoroughly evaluated. Therefore, even in Asian and South American women, larger studies of dexamethasone are required before this treatment can be recommended as a universally safe and effective treatment for obstetric cholestasis.

Intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder characterized by maternal pruritus in the third trimester, raised serum bile acids and increased rates of adverse fetal outcomes. The etiology of ICP is complex and not fully understood, but it is likely to result from the cholestatic effects of reproductive hormones and their metabolites in genetically susceptible women. Equally unclear are the mechanisms by which the fetal complications occur. This article reviews the epidemiology, clinical features, diagnosis, etiology and management of ICP.

Sequencing and functional assessment of hPXR (NR1I2) variants in intrahepatic cholestasis of pregnancy

1. The purpose of this study was to evaluate the role of coding variation in hPXR (NR1I2) in intrahepatic cholestasis of pregnancy (ICP) and to functionally asses the response of PXR variants to ligands of interest in ICP. 2. The coding region of hPXR was sequenced in a cohort of 121 Caucasian ICP patients and exon 2 was sequenced in an additional 226 cases. Reporter assays were used to evaluate the function of all known hPXR variants in response to the secondary bile acid lithocholic acid and therapeutic agents rifampicin, ursodeoxycholic acid and dexamethasone. 3. Two coding single nucleotide polymorphisms (C79T and G106A) were detected in the ICP cohort at frequencies consistent with healthy populations. These do not alter hPXR function in response to ligands of interest to ICP. Analysis of all known coding hPXR variants demonstrates that while subtle changes in experimental design mask or may unveil the functional effects of genetic variation, these are not maintained in a standard functional assay. 4. Coding genetic variation in hPXR does not contribute to the aetiology of ICP in Caucasian populations.

The molecular genetics of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP), also known as obstetric cholestasis, causes maternal pruritus and liver impairment, and may be complicated by spontaneous preterm labour, fetal asphyxial events and intrauterine death. Our understanding of the aetiology of this disease has expanded significantly in the last decade due to a better understanding of the role played by genetic factors. In particular, advances in our knowledge of bile homeostasis has led to the identification of genes that play a considerable role in susceptibility to ICP. In this review we consider these advances and discuss the disease in the context of bile synthesis and metabolism, focusing on the genetic discoveries that have shed light on the molecular aetiology and pathophysiology of the condition.

Reduced antidiabetic effect of metformin and down-regulation of hepatic Oct1 in rats with ethynylestradiol-induced cholestasis

PURPOSE

To investigate the effect of 17alpha-ethynylestradiol (EE)-induced cholestasis on the expression of organic cation transporters (Octs) in the liver and kidney, as well as the pharmacokinetics and pharmacodynamics of metformin in rats.

METHODS

Octs mRNA and protein expression were determined. The pharmacokinetics and tissue uptake clearance of metformin were determined following iv administration (5 mg/kg). Uptake of metformin, glucagon-mediated glucose production, and AMP-activated protein kinase (AMPK) activation were measured in isolated hepatocytes. The effect of metformin (30 mg/kg) on blood glucose levels was tested using the iv glucose tolerance test (IVGTT).

RESULTS

The mRNAs of hepatic Oct1, renal Oct1, and Oct2 were decreased by 71.1%, 37.6%, and 94.5%, respectively, by EE cholestasis. The hepatic Oct1 and renal Oct2 proteins were decreased by 30.6% and 60.2%, respectively. The systemic and renal clearance of metformin were decreased. The in vitro hepatocyte uptake of metformin was decreased by 86.4% for V (max). Suppression of glucagon-stimulated glucose production and stimulation of AMPK activation in hepatocytes by metformin were diminished. In addition, metformin did not demonstrate a glucose-lowering effect during IVGTT in EE cholestasis.

CONCLUSION

The antidiabetic effect of metformin may be diminished in diabetic patients with EE cholestasis, due to impaired hepatic uptake of the drug via OCT1.

Association of the multidrug-resistance-associated protein gene (ABCC2) variants with intrahepatic cholestasis of pregnancy

BACKGROUND/AIMS

We hypothesized that common genetic variation at ABCC2 influences ICP susceptibility. Hence we studied the association of single nucleotide polymorphisms (SNPs) of promoter, coding and non-coding regions of ABCC2 and intrahepatic cholestasis of pregnancy (ICP).

METHODS

70 ICP patients and 112 healthy pregnant women in the third trimester of their pregnancies were included in a cross sectional study. Four tag SNPs (rs717620 A/G; rs2756105 C/T; rs2002042 C/T; rs3740066 A/G) encompassing 70 kb in chr.10 and representing 46 polymorphic sites (r(2) > 0.8) were genotyped. Besides, 2 additional SNPs (rs17222723 A/T and rs8187710 G/A) were included.

RESULTS

In univariate analysis, rs2002042 and rs3740066 were significantly associated with ICP (p < 0.04 and 0.01, respectively) but after multiple testing correction, only rs3740066 remained significantly associated with disease status (p < 0.03). We also observed a positive association between the rs3740066 and ALT, AST, alkaline phosphatase and total and conjugated bilirubin concentrations. Consistent with the analysis of individual markers, we observed that haplotype frequency of the ABCC2 gene in ICP patients significantly differed from controls (p < 0.03).

CONCLUSIONS

We found an association between the rs3740066 in exon 28 of ABCC2 gene and ICP. The risk of disease for homozygous AA carriers is 4-fold higher (OR 4.44 CI 95% 1.83-10.78, p < 0.001) in comparison with GG carriers.

Intrahepatic cholestasis of pregnancy: review of the literature and evaluation of current evidence

OBJECTIVE

To provide an overview of the epidemiology, etiology, pathogenesis, diagnosis, and management of intrahepatic cholestasis of pregnancy.

METHODS

We searched the Medline and PubMed database using the key words intrahepatic cholestasis of pregnancy, obstetric cholestasis, diagnosis, management, and complications.

RESULTS

Intrahepatic cholestasis of pregnancy, or obstetric cholestasis, is a liver condition that develops during pregnancy. It is associated with increased perinatal morbidity and mortality. Pruritus and risk of postpartum hemorrhage are the main causes of maternal morbidity. Intrahepatic cholestasis of pregnancy is a diagnosis of exclusion. The current management policies depend on regular fetal and maternal monitoring and delivery at fetal maturity. The analysis of the quality of previous studies provided in this review highlights the areas of deficiency in evidence-based knowledge of this subject.

CONCLUSIONS

More research is required into the etiology, pathogenesis, and monitoring modalities that can specifically predict fetal outcome in intrahepatic cholestasis of pregnancy. Clinical trials are required to identify the most suitable drugs for treatment.

Functional variants of the central bile acid sensor FXR identified in intrahepatic cholestasis of pregnancy

BACKGROUND AND AIMS

Intrahepatic cholestasis of pregnancy (ICP) is characterized by liver impairment, pruritus, and elevated maternal serum bile acids. It can cause premature delivery and intrauterine death. Bile acid synthesis, metabolism, and transport are regulated by the bile acid sensor FXR, and we hypothesized that genetic variation in FXR confers susceptibility to ICP.

METHODS

The coding regions and intron/exon boundaries of FXR were sequenced in 92 British ICP cases of mixed ethnicity. Subsequently, a case-control study of allele frequencies of these variants in 2 independent cohorts of Caucasian ICP patients and controls was performed. Variants were cloned into an FXR expression plasmid and tested in functional assays.

RESULTS

We identified 4 novel heterozygous FXR variants (-1g>t, M1V, W80R, M173T) in ICP. W80R was not present in Caucasians and M1V was detected uniquely in 1 British case. M173T and -1g>t occur both in Caucasian cases and controls, and we found a significant association of M173T with ICP (OR, 3.2; 95% confidence interval, 1.1-11.2; P = .02) when the allele frequencies of both Caucasian cohorts were analyzed together. We demonstrate functional defects in either translation efficiency or activity for 3 of the 4 variants (-1g>t, M1V, M173T).

CONCLUSIONS

This is the first report of functional variants in FXR. We propose that these variants may predispose to ICP, and because FXR has a central role in regulating bile and lipid homeostasis they may be associated with other cholestatic and dyslipidemic disorders.

Short communication: Consensus on the management of obstetric cholestasis: National UK survey

An anonymous questionnaire was sent to the lead consultant obstetricians and the midwives in charge of the antenatal clinics of all maternity units in UK to determine their current views on the diagnosis and management of obstetric cholestasis (OC). The response rate was 60%. Management policies were broadly similar and consistent with those recommended in the current literature. However, the survey highlighted areas for improvement. Based on the findings of this survey, a consensus view of the management of OC in UK is achievable.

A case of impetigo herpetiformis associated with intrahepatic cholestasis of pregnancy

We herein reported a 26-year-old primigravida with impetigo herpetiformis and intrahepatic cholestasis of gestation. She was in gestation for 34 weeks. She had a 5-month history of pustules on the trunk and limbs that had exacerbated from 1 month before. The jaundice had also emerged lately with increased levels of serous transaminase, bilirubin and bile acid. The histopathology of the lesion confirmed the diagnosis of impetigo herpetiformis. After cesarean section and administration of glucocorticoid, the patient totally recovered.

Maternal midtrimester free beta-HCG and AFP serum levels in spontaneous singleton pregnancies complicated by gestational diabetes mellitus, pregnancy-induced hypertension or obstetric cholestasis

OBJECTIVES

The present study aims at finding out whether a connection exists between altered serum free beta-hCG and/or alpha-fetoprotein (AFP) levels and the manifestation of specific pregnancy complications [i.e. gestational diabetes mellitus (GDM), pregnancy induced hypertension (PIH) or intrahepatic cholestasis of pregnancy (ICP)].

METHODS

We compared free beta-hCG and AFP multiples of median (MoM) values in singleton pregnancies. The study population consisted of 117 pregnancies with GDM, 107 with PIH and 24 with ICP. The control group consisted of 1148 singleton pregnancies without any pregnancy complications. All were spontaneously conceived.

RESULTS

In the group with GDM, both the free beta-hCG (0.72 MoM) and AFP MoM values (0.93) were significantly lower than in controls (beta-hCG 0.97 MoM, p = 0.0063 and AFP 1.01 MoM, p = 0.01). No statistically significant differences in the marker levels were observed between the ICP pregnancies and the control group.

CONCLUSIONS

GDM has an impact on maternal midtrimester free beta-hCG and AFP levels and may change the DS screening result.

Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (or obstetric cholestasis) is a liver disorder that occurs in late pregnancy. Despite the potential adverse maternal and fetal/neonatal outcomes, cholestasis of pregnancy is often neglected and treated expectantly. More research is needed to improve the molecular and genetic understanding of the disease and to define a safe and effective medical treatment that improves clinical outcome. Ursodeoxycholic acid is considered to be a safe treatment option in the third trimester, but further randomized controlled trials are needed before ursodeoxycholic acid treatment can be generally recommended. Ursodeoxycholic acid is preferentially administered to patients with severe cholestasis (onset before week 33 or serum bile acid levels > 70 mmol/L) or to patients with a history of sudden fetal death, while maintaining close obstetric and regular biochemical surveillance (transaminases, bilirubin, and bile acid levels). Ursodeoxycholic acid can decrease pruritus and ameliorate liver tests, but effects on obstetric complications are ambiguous. S-Adenosylmethionine, dexamethasone, and cholestyramine can provide some relief of itching. Because none of these drugs have been shown to be harmful to mother or fetus, the individual woman and her clinician may decide whether to try one of the treatments described.

Microsatellite marker association at chromosome region 2p13 in Finnish patients with preeclampsia and obstetric cholestasis suggests a common risk locus

The pathophysiology of preeclampsia is incompletely understood, but the familial nature of the disease has long been recognized. Recent genome-scan studies have indicated linkage at the p23 region of chromosome 2. We have previously reported microsatellite marker association at chromosome region 2p13 in patients with obstetric cholestasis. We conducted population-based association screening with microsatellite markers to find potential preeclampsia-associated loci on chromosome region 2p13-p12 and to test whether preeclampsia and obstetric cholestasis share a single risk locus. The study was carried out among 115 unrelated control women, 133 preeclamptic women and 57 cholestatic women. Screening with microsatellite markers at the 2p13-p12 region revealed that the marker D2S286 was significantly associated with obstetric cholestasis in the overall association analysis (P=0.03), while it revealed only borderline association with preeclampsia (P=0.08). However, single allele association analysis indicated that both preeclampsia and obstetric cholestasis showed a statistically significant association with a common allele (P < 0.05), which was overrepresented in both the obstetric cholestasis (0.42) and preeclamptic (0.37) groups when compared with the control group (0.28). In conclusion, These findings suggest a possible genetic link between chromosome region 2p13-p12, preeclampsia and obstetric cholestasis. More specifically, these data suggest that there may be a common risk locus associated with both obstetric complications located in the vicinity of the 2p13-p12 association region.

Cholestatic syndromes

Further insights into the molecular regulation of bile acid transport and metabolism have provided the basis for a better understanding of the pathogenesis of cholestatic liver diseases. Novel insights into the mechanisms of action of ursodeoxycholic acid should advance our understanding of the treatment of cholestatic liver diseases. Mutations of transporter genes can cause hereditary cholestatic syndromes in both infants and adults as well as cholesterol gallstone disease. Important studies have been published on the pathogenesis, clinical features, and treatment of primary biliary cirrhosis, drug-induced cholestasis, and cholestasis of pregnancy.