Anna Glantz

Intrahepatic cholestasis of pregnancy: Relationships between bile acid levels and fetal complication rates.

Intrahepatic cholestasis of pregnancy (ICP), characterized by pruritus in the second half of pregnancy, entails an increased risk to the fetus. This study was designed to determine the incidence and fetal complication rates in ICP, and to define groups at increased risk. In an prospective cohort study conducted between February 1, 1999, and January 31, 2002, all 45,485 pregnancies in a defined region of Sweden (Västra Götaland) were screened for ICP, defined as otherwise unexplained pruritus of pregnancy in combination with fasting serum bile acid levels ≥10 μmol/L. Pruritus was reported by 937 (2.1%) women, and ICP was diagnosed in 693 (1.5%). Simple logistic regression analyses showed that the probability of fetal complications (spontaneous preterm deliveries, asphyxial events, and meconium staining of amniotic fluid, placenta, and membranes) increased by 1%–2% per additional μmol/L of serum bile acids. Complementary analyses showed that fetal complications did not arise until bile acid levels were ≥40 μmol/L. Gallstone disease and a family history of ICP were significantly (P < .001) more prevalent in the group of ICP patients with higher bile acid levels. In conclusion, we found an incidence of ICP in our population of 1.5%. From complication rates recorded prospectively, we could define a mild (81%) and a severe (19%) form of ICP, the latter with bile acid levels ≥40 μmol/L. No increase in fetal risk was detected in ICP patients with bile acid levels < 40 μmol/L, and we propose that these women be managed expectantly, which would significantly reduce the costs of medical care. (HEPATOLOGY 2004;40:467–474.)

Intrahepatic cholestasis of pregnancy: molecular pathogenesis, diagnosis and management

Frank Lammert, Hanns-Ulrich Marschall1, Anna Glantz2 and Siegfried Matern Department of Internal Medicine III, Aachen University of Technology – RWTH, Aachen, Germany, 1Karolinska Institutet, Department of Medicine, Division of Gastroenterology and Hepatology, Huddinge University Hospital, Stockholm, and 2Department of Obstetrics and Gynecology, Sahlgren’s University Hospital, East, Göteborg, Sweden

Intrahepatic cholestasis of pregnancy: A randomized controlled trial comparing dexamethasone and ursodeoxycholic acid†

Intrahepatic cholestasis of pregnancy (ICP) is characterized by troublesome maternal pruritus, elevated serum bile acids (≥10 μmol/L) and increased fetal risk. Recently we determined a cutoff level of serum bile acids, ≥40 μmol/L, to be associated with impaired fetal outcome. We have now studied the effects of ursodeoxycholic acid (UDCA) and dexamethasone on pruritus, biochemical markers of cholestasis, and fetal complication rates in a double‐blind, placebo‐controlled trial. For this purpose, 130 women with ICP were randomly allocated to UDCA (1 g/day for three weeks), or dexamethasone (12 mg/day for 1 week and placebo during weeks 2 and 3), or placebo for 3 weeks. Pruritus and biochemical markers of cholestasis were analyzed at inclusion and after 3 weeks of treatment. Fetal complications (spontaneous preterm delivery; asphyxial events; and meconium staining of amniotic fluid, placenta, and membranes) were registered at delivery. An intention‐to‐treat analysis showed significant reduction of alanine aminotransferase (ALT) (P = .01) and bilirubin (P = .002) in the UDCA group only. In a subgroup analysis of ICP women with serum bile acids ≥40 μmol/L at inclusion (n = 34), UDCA had significant effects on pruritus (−75%), bile acids (−79%), ALT (−80%), and bilirubin (−50%) as well, but not on fetal complication rates. Dexamethasone yielded no alleviation of pruritus or reduction of ALT and was less effective than UDCA at reducing bile acids and bilirubin. In conclusion, 3 weeks of UDCA treatment improved some biochemical markers of ICP irrespective of disease severity, whereas significant relief from pruritus and marked reduction of serum bile acids were only found in patients with severe ICP. (HEPATOLOGY 2005;42:1399–1405.)

Contribution of Variant Alleles of ABCB11 to Susceptibility to Intrahepatic Cholestasis of Pregnancy.

Background: Intrahepatic cholestasis of pregnancy (ICP) has a complex aetiology with a significant genetic component. ABCB11 encodes the bile salt export pump (BSEP); mutations cause a spectrum of cholestatic disease, and are implicated in the aetiology of ICP. Methods: ABCB11 variation in ICP was investigated by screening for five mutant alleles (E297G, D482G, N591S, D676Y and G855R) and the V444A polymorphism (c.1331T>C, rs2287622) in two ICP cohorts (n = 333 UK, n = 158 continental Europe), and controls (n = 261) for V444A. PCR primers were used to amplify and sequence patient and control DNA. The molecular basis for the observed phenotypes was investigated in silico by analysing the equivalent residues in the structure of the homologous bacterial transporter Sav1866. Results: E297G was observed four times and D482G once. N591S was present in two patients; D676Y and G855R were not observed. The V444A polymorphism was associated with ICP (allelic analysis for C vs T: OR 1.7 (95% CI 1.4 to 2.1, p<0.001)). In addition, CC homozygotes were more likely to have ICP than TT homozygotes: OR 2.8 (95% CI 1.7 to 4.4 p<0.0001). Structural analyses suggest that E297G and D482G destabilise the protein fold of BSEP. The molecular basis of V444A and N591S was not apparent from the Sav1866 structure. Conclusions: Heterozygosity for the common ABCB11 mutations accounts for 1% of European ICP cases; these two mutants probably reduce the folding efficiency of BSEP. N591S is a recurrent mutation; however, the mechanism may be independent of protein stability or function. The V444A polymorphism is a significant risk factor for ICP in this population.

Efficacy of ursodeoxycholic acid in treating intrahepatic cholestasis of pregnancy: a meta-analysis.

BACKGROUND & AIMS We performed a meta-analysis to evaluate the effects of ursodeoxycholic acid (UDCA) on pruritus, liver test results, and outcomes of babies born to women with intrahepatic cholestasis of pregnancy (ICP). METHODS We performed a systematic review of 9 published, randomized controlled trials (3 double blinded) that compared the effects of UDCA to other drugs, placebo, or no specific treatment (controls) in patients with ICP. We analyzed data from 454 patients: 207 received only UDCA, 70 received only placebo, 42 received cholestyramine, 36 received dexamethasone for 1 week and then placebo for 2 weeks, 65 received S-adenosyl-methionine, and 34 received no specific treatment. To achieve consistency among end points, a standard questionnaire was sent to all corresponding authors. For each end point, we performed pooled analysis that compared the effects of UDCA with those of all controls and UDCA with those of placebos. RESULTS In pooled analyses that compared UDCA with all controls, UDCA was associated with total resolution of pruritus (odds ratio [OR], 0.23; 95% confidence interval [CI], 0.07-0.74; P < .01), reduced pruritis (OR, 0.27; 95% CI, 0.13-0.55; P < .0001), normalization of serum levels of alanine aminotransferase (ALT) (OR, 0.23; 95% CI, 0.10-0.50; P < .001), decreased serum level of ALT (OR, 0.24; 95% CI, 0.11-0.52; P < .0001), reduced serum levels of bile acids (OR, 0.37; 95% CI, 0.19-0.75; P < .001), fewer premature births (OR, 0.44; 95% CI, 0.24-0.79; P < .01), reduced fetal distress (OR, 0.46; 95% CI, 0.25-0.86; P < .01), less frequent respiratory distress syndrome (OR, 0.30; 95% CI, 0.12-0.74; P < .01), and fewer neonates in the intensive care unit (OR, 0.49; 95% CI, 0.25-0.98; P = .046). In pooled analyses that compared the effects of UDCA with placebo, UDCA reduced pruritus (OR, 0.21; 95% CI, 0.07-0.62; P < .01), normalized (OR, 0.18; 95% CI, 0.06-0.52; P < .001) or decreased serum levels of ALT (OR, 0.12; 95% CI, 0.05-0.31; P < .0001), and reduced serum levels of bile acids (OR, 0.30; 95% CI, 0.12-0.73; P < .01). CONCLUSIONS Based on a meta-analysis, UDCA is effective in reducing pruritus and improving liver test results in patients with ICP; UDCA therapy might also benefit fetal outcomes.

Intrahepatic cholestasis of pregnancy: the severe form is associated with common variants of the hepatobiliary phospholipid transporter ABCB4 gene

Background: Intrahepatic cholestasis of pregnancy (ICP) is characterised by troublesome maternal pruritus, raised serum bile acid levels and increased fetal risk. Mutations of the ABCB4 gene encoding the hepatobiliary phospholipid transporter have been identified in a small proportion of patients with cholestasis of pregnancy. In a recent prospective study on 693 patients with cholestasis of pregnancy, a cut-off level for serum bile acid (⩾40 μmol/l) was determined for increased risk of fetal complications. Objectives: To investigate whether common combinations of polymorphic alleles (haplotypes) of the genes encoding the hepatobiliary ATP-binding cassette (ABC) transporters for phospholipids (ABCB4) and bile acids (ABCB11) were associated with this severe form of cholestasis of pregnancy. Methods: For genetic analysis, 52 women with bile acid levels ⩾40 μmol/l (called cases) and 52 unaffected women (called controls) matched for age, parity and geographical residence were studied. Gene variants tagging common ABCB4 and ABCB11 haplotypes were genotyped and haplotype distributions were compared between cases and controls by permutation testing. Results: In contrast with ABCB11 haplotypes, ABCB4 haplotypes differed between the two groups (p = 0.019), showing that the severe form of cholestasis of pregnancy is associated with the ABCB4 gene variants. Specifically, haplotype ABCB4_5 occurred more often in cases, whereas haplotypes ABCB4_3 and ABCB4_7 were more common in controls. These associations were reflected by different frequencies of at-risk alleles of the two tagging polymorphisms (c.711A: odds ratio (OR) 2.27, p = 0.04; deletion intron 5: OR 14.68, p = 0.012). Conclusion: Variants of ABCB4 represent genetic risk factors for the severe form of ICP in Sweden.

Intrahepatic cholestasis of pregnancy: Amelioration of pruritus by UDCA is associated with decreased progesterone disulphates in urine

Intrahepatic cholestasis of pregnancy (ICP) is characterized by pruritus, elevated bile acids, and, specifically, elevated disulphated progesterone metabolites. We aimed to study changes in these parameters during treatment with dexamethasone or ursodeoxycholic acid (UDCA) in 40 out of 130 women included in the Swedish ICP intervention trial (26 randomized to placebo or UDCA, 14 randomized to dexamethasone). Serum bile acid profiles and urinary steroid hormone metabolites were analyzed using isotope‐dilution gas chromatography–mass spectrometry and electrospray–mass spectrometry. We found that all patients displayed ICP‐typical serum bile acid profiles with >50% cholic acid at baseline but almost 80% UDCA upon treatment with this bile acid. In UDCA‐treated patients, relative amounts of disulphated progesterone metabolites in urine decreased by 34%, 48% (P < 0.05), and 55% (P < 0.05) after 1, 2, and 3 weeks of treatment, respectively, which was significantly correlated to improvements of pruritus scores but not to serum bile acid levels. In contrast, in patients randomized to dexamethasone or placebo, no changes in steroid metabolites or pruritus scores were observed. Conclusion: UDCA treatment in ICP decreased urinary excretion of disulphated progesterone metabolites, suggesting that amelioration of pruritus is connected to stimulation of hepatobiliary excretion of progesterone disulphates. (HEPATOLOGY 2008.)

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 Armitages 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.