Intrahepatic cholestasis of pregnancy: molecular pathogenesis, diagnosis and management

Molecular pathogenesis of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) occurs mainly in the third trimester and is characterised by pruritus and elevated serum bile acid levels. ICP is associated with an increased perinatal risk and higher rates of foetal morbidity and mortality. Although the pathogenesis of this disease is unknown, a genetic hypersensitivity to female hormones (oestrogen and/or progesterone) or their metabolites is thought to impair bile secretory function. Recent data suggest that mutations or polymorphisms of genes expressing hepatobiliary transport proteins or their nuclear regulators may contribute to the development and/or severity of ICP. Unidentified environmental factors may also influence pathogenesis of the disease. This review summarises current knowledge on the potential mechanisms involved in ICP at the molecular level.

Mechanisms of cholestasis

This article gives an overview of the molecular and cellular mechanisms of cholestasis. Topics reviewed include the pathomechanisms of hereditary cholestasis syndromes, such as progressive familial intrahepatic cholestasis, and hepatocellular transporter defects encountered in various acquired cholestatic disorders, such as intrahepatic cholestasis of pregnancy, drug-induced cholestasis, inflammatory cholestasis, primary sclerosing cholangitis, and primary biliary cirrhosis. In addition, current concepts regarding adaptive hepatocellular mechanisms counteracting cholestatic liver damage are discussed.

Medical treatment of cholestatic liver disease

In most cholestatic liver diseases the cause of the disease is not known and therapy can only be directed toward suppression of the pathogenetic processes and amelioration of the consequences of cholestasis. The recognition of adaptive-compensatory responses to cholestasis has become of major importance. They tend to minimize retention of bile acids and other potentially toxic solutes in the hepatocyte by limiting hepatocellular uptake, reducing bile acid synthesis, stimulating detoxification, and up-regulating alternative pathways for excretion. Some of the drugs used for the treatment of cholestatic liver diseases in an empiric way turned out to be modulators of nuclear receptors, which regulate these adaptive-compensatory responses. New drugs are being designed and tested along these lines and may be regarded as treatment opportunities of the future.

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.

Predictors of premature delivery in patients with intrahepatic cholestasis of pregnancy

AIM: To evaluate the predictive value of clinical symptoms and biochemical parameters for prematurity in intrahepatic cholestasis of pregnancy (ICP).

METHODS: Sixty symptomatic patients with ICP were included in this retrospective analysis. Preterm delivery was defined as delivery before 37 wk gestation. Predictors of preterm delivery were disclosed by binary multivariate logistic regression analysis.

RESULTS: Mean time of delivery was 38.1 ± 1.7 wk. No stillbirths occurred. Premature delivery was observed in eight (13.3%) patients. Total fasting serum bile acids were higher (47.8 ± 15.2 vs 41.0 ± 10.0 μmol/L, P < 0.05), and pruritus tended to start earlier (29.0 ± 3.9 vs 31.6 ± 3.3 wk, P = 0.057) in patients with premature delivery when compared to those with term delivery. Binary multivariate logistic regression analysis revealed that early onset of pruritus (OR 1.70, 95% CI 1.23-2.95, P = 0.038) and serum bile acid (OR 2.13, 95% CI 1.13-3.25, P = 0.013) were independent predictors of preterm delivery.

CONCLUSION: Early onset of pruritus and high levels of serum bile acids predict preterm delivery in ICP, and define a subgroup of patients at risk for poor neonatal outcome.

Intrahepatic cholestasis occurring with prurigo of pregnancy

A 23-year-old woman presented to our polyclinic complaining of itching, generalized dermatitis, and jaundice. She was in her 31st gestational week and had developed pruritus and the dermatitis since the first month of pregnancy; her jaundice started about a month before presentation. Her history included similar complaints in a previous pregnancy, which resulted in premature birth of a baby with a permanent brain defect. One of her sisters had had jaundice and itching in her 27th gestational week and delivered a healthy baby; a second sister had experienced itching and dermatitis in her second trimester and delivered a healthy baby. Physical examination of the patient showed that her eyes were jaundiced (Figure 1); skin examination revealed generalized erythematous excoriated papules, symmetrically distributed all over her body (Figure 2 Figure 3). Laboratory analyses revealed the following results: leukocyte count, 14.30/mm(3) (3.8-10.3/mm(3)); erythrocyte sedimentation rate, 25 mm/h (<20 mm/h); aspartate aminotransferase, 44 U/L (5-40 U/L); alanine aminotransferase, 63 U/L (5-40 U/L); lactate dehydrogenase, 1158 U/L (220-450 U/L); total bilirubin, 6.88 mg/dL (<1.10 mg/dL); and direct bilirubin, 3.27 mg/dL (<0.35 mg/dL). Urinalysis results were positive for bilirubin and urobilinogen. Positive serologic findings included rubella immunoglobulin G, 93 AU/mL (<15) and cytomegalovirus, 188 AU/mL (<10); negative findings included herpes simplex virus type 2 and hepatitis. Histopathologic examination of material collected from the left breast via punch biopsy showed parakeratosis, acanthosis, and perivascular lymphocyte infiltration in dermal vessels. Treatment with 2 g/d cholestyramine and a topical corticosteroid was effective in the patient, who was diagnosed with intrahepatic cholestasis of pregnancy and prurigo of pregnancy based on the clinical, histopathologic, and laboratory findings. To the authors' knowledge, this is the first such reported case in the literature.

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.

Low phospholipid associated cholelithiasis: association with mutation in the MDR3/ABCB4 gene

Low phospholipid-associated cholelithiasis (LPAC) is characterized by the association of ABCB4 mutations and low biliary phospholipid concentration with symptomatic and recurring cholelithiasis. This syndrome is infrequent and corresponds to a peculiar small subgroup of patients with symptomatic gallstone disease. The patients with the LPAC syndrome present typically with the following main features: age less than 40 years at onset of symptoms, recurrence of biliary symptoms after cholecystectomy, intrahepatic hyperechoic foci or sludge or microlithiasis along the biliary tree. Defect in ABCB4 function causes the production of bile with low phospholipid content, increased lithogenicity and high detergent properties leading to bile duct luminal membrane injuries and resulting in cholestasis with increased serum gamma-glutamyltransferase (GGT) activity. Intrahepatic gallstones may be evidenced by ultrasonography (US), computing tomography (CT) abdominal scan or magnetic resonance cholangiopancreatography, intrahepatic hyperechogenic foci along the biliary tree may be evidenced by US, and hepatic bile composition (phospholipids) may be determined by duodenoscopy. In all cases where the ABCB4 genotyping confirms the diagnosis of LPAC syndrome in young adults, long-term curative or prophylactic therapy with ursodeoxycholic acid (UDCA) should be initiated early to prevent the occurrence or recurrence of the syndrome and its complications. Cholecystectomy is indicated in the case of symptomatic gallstones. Biliary drainage or partial hepatectomy may be indicated in the case of symptomatic intrahepatic bile duct dilatations filled with gallstones. Patients with end-stage liver disease may be candidates for liver transplantation.

Intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder characterized by (i) pruritus with onset in the second or third trimester of pregnancy, (ii) elevated serum aminotransferases and bile acid levels, and (iii) spontaneous relief of signs and symptoms within two to three weeks after delivery. ICP is observed in 0.4–1% of pregnancies in most areas of Central and Western Europe and North America, while in Chile and Bolivia as well as Scandinavia and the Baltic states roughly 5–15% and 1–2%, respectively, of pregnancies are associated with ICP. Genetic and hormonal factors, but also environmental factors may contribute to the pathogenesis of ICP. Intrahepatic cholestasis of pregnancy increases the risk of preterm delivery (19–60%), meconium staining of amniotic fluid (27%), fetal bradycardia (14%), fetal distress (22–41%), and fetal loss (0.4–4.1%), particularly when associated with fasting serum bile acid levels > 40 μmol/L. The hydrophilic bile acid ursodeoxycholic acid (10–20 mg/kg/d) is today regarded as the first line treatment for intrahepatic cholestasis of pregnancy. Delivery has been recommended in the 38^th week when lung maturity has been established.

Randomized prospective comparative study of ursodeoxycholic acid and S-adenosyl-L-methionine in the treatment of intrahepatic cholestasis of pregnancy

AIM

To compare the efficacy of the ursodeoxycholic acid (UDCA) and S-adenosyl-L-methionine (SAMe) monotherapy with their combined effect on intrahepatic cholestasis of pregnancy (ICP).

PATIENTS AND METHODS

We studied singleton pregnancies at <36 weeks with a moderate or severe form of ICP between January 1999 and March 2004. Patients were randomized to either oral UDCA 3x250 mg daily or 500 mg SAMe twice daily in slow running infusion for twelve days followed by oral administration of 500 mg twice daily until delivery. Intensive hematological, biochemical and fetal monitoring were carried out.

RESULTS

Of the 78 women enrolled, 25 received SAMe monotherapy, 26 received UDCA, and 27 received combined therapy. Groups were initially comparable in terms of gestational age, duration of therapy, parity and biochemical characteristics. All therapies improved the pruritus. The combined therapy and the monotherapy with UDCA (later) led to improving of the serum concentrations of bile acids and transaminases compared with SAMe monotherapy (P<0.01). Combined therapy led to a faster decrease of serum concentrations of bile acids and transaminases compared with UDCA monotherapy (borderline significance). Gestational ages were similar in all groups. No adverse effects were noted on the fetuses or neonates with either therapy.

CONCLUSIONS

UDCA is an effective drug in the treatment of ICP, and combined with SAMe, has probably a synergistic effect on biochemical parameters. This mode of treatment seems more effective but the effect of the successful treatment on the fetus is unclear. Therefore, the ante- and intrapartum monitoring of the fetus should be part of the management of severe forms of ICP. The project is supported by IGA MZ CR (No. NH/7376-3).

Cholestasis in pregnancy associated with ciclosporin therapy in renal transplant recipients

Obstetric cholestasis (OC) presents with pruritus in the second half of pregnancy and is associated with increased risk of foetal distress, intra-uterine death and premature delivery. From a tertiary referral, renal-obstetric clinic, we report the occurrence of OC in 5/23 pregnancies of women with renal transplants maintained on ciclosporin treatment (European incidence 0.1-1.5% of pregnancies). All required premature delivery for foetal reasons at 33-37/40 (median 34/40). Ciclosporin, at therapeutic concentrations, inhibits bile salt excretion pump (BSEP) function in rats and humans. We propose that OC developed in our patients because the mild inhibition of the canalicular pumps by ciclosporin was only revealed in pregnancy when increases in progesterone metabolites overwhelmed pump function. We suggest that all pregnant women receiving ciclosporin should be closely monitored from the second trimester for the development of OC. If detected, enhanced foetal and maternal monitoring to optimize time of delivery and pregnancy outcome is required.

The prevalence of intrahepatic cholestasis of pregnancy in a primarily Latina Los Angeles population

OBJECTIVE

To establish the prevalence of intrahepatic cholestasis of pregnancy (ICP) in a primarily Latina population in the United States.

STUDY DESIGN

Over a period of 16 months, a convenience sample of subjects admitted to labor and delivery in the third trimester was enrolled. Each subject completed a questionnaire rating their severity of pruritus on a numeric scale of 1 to 10. Serum was analyzed via radioimmunoassay for total bile acid concentration. ICP was defined as pruritus score >4 and a total serum bile acid concentration of >or=20 micromol/l. Ethnicity was determined from hospital record demographic data.

RESULTS

All invited participants enrolled in the study. Three hundred and forty subjects were enrolled. Three hundred and sixteen subjects (93%) were identified as Latina. The serum bile acid concentration range for the entire study population was 1 to 580 micromol/l with a mean of 10.4+/-34.9 micromol/l. Twenty-four (7.1%) subjects had a serum bile acid concentration >or=20 micromol/l. A pruritus score >4 was found in 19.7% (67/340). Of the 24 subjects with a bile acid concentration >or=20 micromol/l, 19 also had a pruritus score >4. Thus, the prevalence of ICP in this population was 5.6% (19/340). In subjects with ICP, the mean serum bile acid concentration was 89.5+/-124.0 micromol/l. When controlling for confounders, women with ICP were associated with higher rates of chorioamnionitis (P=0.043) and their fetuses had higher rates of thick meconium (P=0.053).

CONCLUSIONS

The overall prevalence of ICP in this population was 5.6%, 10 to 100 times higher than previously reported data from the United States. Larger studies of perinatal morbidity examining the diagnostic criteria of cholestasis need to be conducted.

Combined mutations of canalicular transporter proteins cause severe intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a cholestatic disorder that usually develops in the third trimester of pregnancy and persists until delivery. The cause of ICP remains elusive, but there is evidence that mutations in the canalicular ABC transporter phospholipid flippase (MDR3) and in the bile salt export pump (BSEP) can predispose for the development of ICP. MDR3 and BSEP were investigated by gene sequencing and immunofluorescence microscopy in a patient with severe ICP of early onset. ICP was diagnosed in a patient in the first trimester of pregnancy with severe pruritus, elevated levels of bile salts, and 48-fold elevation of transaminase levels. A liver biopsy specimen showed diminished canalicular expression of the bile salt export pump BSEP, while the expression and localization of the phospholipid flippase MDR3 was normal. Gene sequencing revealed a homozygous MDR3 gene mutation (S320F). The patient was also homozygous for the common BSEP polymorphism V444A. Treatment with ursodeoxycholate normalized transaminase levels but could not prevent further elevation of bile salt levels and preterm delivery. The combined homozygous alterations of the canalicular transporters may explain the early onset and severity of ICP in this patient. The common BSEP polymorphism V444A accounts for the reduced canalicular BSEP expression. Reduced bile salt secretion through BSEP may explain the persistence of elevated bile salt levels and incomplete efficacy of ursodeoxycholate treatment.

Genetics of familial intrahepatic cholestasis syndromes

Bile acids and bile salts have essential functions in the liver and in the small intestine. Their synthesis in the liver provides a metabolic pathway for the catabolism of cholesterol and their detergent properties promote the solubilisation of essential nutrients and vitamins in the small intestine. Inherited conditions that prevent the synthesis of bile acids or their excretion cause cholestasis, or impaired bile flow. These disorders generally lead to severe human liver disease, underscoring the essential role of bile acids in metabolism. Recent advances in the elucidation of gene defects underlying familial cholestasis syndromes has greatly increased knowledge about the process of bile flow. The expression of key proteins involved in bile flow is tightly regulated by transcription factors of the nuclear hormone receptor family, which function as sensors of bile acids and cholesterol. Here we review the genetics of familial cholestasis disorders, the functions of the affected genes in bile flow, and their regulation by bile acids and cholesterol.

Intrahepatic cholestasis of pregnancy and neonatal respiratory distress syndrome

OBJECTIVES

We sought to verify the association between maternal intrahepatic cholestasis of pregnancy (ICP) and neonatal respiratory distress syndrome (RDS) and to determine how bile acids levels alter the risk of developing neonatal RDS.

METHODS

We extracted data from our divisional database about all of the newborns born during the years 2000-2004. We compared 77 neonates born from pregnancies complicated by ICP with 427 neonates in the same range of gestational age born from noncomplicated pregnancies. We studied maternal bile acids levels immediately before delivery in mothers with ICP and measured bile acid levels during the first 24 hours of life in their newborns.

RESULTS

The incidence of RDS in newborns from cholestatic pregnancies was twice that the reference population (28.6% vs 14%). The multivariate analysis showed that the risk of RDS in these newborns was approximately 2.5 times higher than in control infants. Within the ICP group, maternal and neonatal bile acid levels of infants affected by RDS were not significantly higher than those of healthy infants. The multivariate analysis showed that a low gestational age was the most important risk factor, but the probability of respiratory distress syndrome also increased by 2 per thousand for every additional micromole of the interaction term "neonatal by maternal bile acids level."

CONCLUSIONS

Maternal ICP is significantly associated with the occurrence of RDS in the newborn. We hypothesize that bile acids can produce surfactant depletion in the alveoli reverting the reaction of phospholipase A2. This hypothesis could potentially be confirmed by bronchoalveolar lavage study.

Intrahepatic cholestasis of pregnancy as an indicator of liver and biliary diseases: a population-based study

Intrahepatic cholestasis of pregnancy (ICP) is a liver disorder, thought to be specific for pregnancy and to spontaneously resolve after delivery. Increased rates of gallstone formation and hepatitis C have previously been associated with ICP. However, there are no longitudinal studies to determine its significance as an indicator of subsequent liver or biliary diseases. In this retrospective cohort study with cases and controls we assessed the risk of liver and biliary diseases in 21,008 women, 10,504 with a history of ICP during the years 1972-2000 (cases) and 10,504 with a normal pregnancy (controls). Cases and controls were matched for age, time of delivery, and place of delivery. The diagnoses of liver and biliary disease were traced from the Finnish Hospital Discharge Register with an almost 100% coverage. Several liver and biliary diseases were found to have a significantly higher incidence in patients with ICP than in controls. The rate ratio for hepatitis C was 3.5 (CI 1.6-7.6; P < .001), for nonalcoholic liver cirrhosis 8.2 (CI 1.9-35.5; P < .05), for gallstones and cholecystitis 3.7 (CI 3.2-4.2; P < .001) and for nonalcoholic pancreatitis 3.2 (CI 1.7-5.7; P < .001). In conclusion, there is an association of ICP with several liver and biliary diseases. Some patients with ICP are at risk of the subsequent development of cirrhosis and other severe chronic diseases. Contrary to what has been previously thought, follow-up may need to be considered for these patients.

Is a leaky gut involved in the pathogenesis of intrahepatic cholestasis of pregnancy?

Increased gastrointestinal permeability has been demonstrated in several liver diseases. It may facilitate the absorption of gut-derived endotoxin-stimulating Kupffer cells to release proinflammatory cytokines or other potentially hepatotoxic compounds. We examined gastrointestinal permeability, plasma levels of anti-lipopolysacharides (anti-LPS), and four proinflammatory cytokines in 20 patients with intrahepatic cholestasis of pregnancy (ICP) compared with 22 normal pregnant and 29 non-pregnant women. Urinary excretion of sucrose and the urinary lactulose/mannitol (L/M) ratio after a standard oral load were used to assess gastrointestinal permeability. Anti-LPS (IgA, IgM, and IgG) were measured in peripheral blood by Human EndoCAb test kit; TNF-alpha, IL-1beta, IL-6, and IL-10 by Quantikine HS human immunoassays. Sucrose urinary excretion was similar in the three groups, indicating normal gastric permeability. The urinary L/M ratio was significantly higher in ICP than in the other groups [median (interquartile range): 0.018% (0.011-0.023) in ICP, 0.012% (0.009-0.016) in normal pregnancies, and 0.009% (0.008-0.012) in non-pregnant women, P < .01]. No significant differences were found in anti-LPS or cytokines plasma levels except slightly higher levels of IL-6 in ICP patients than in non-pregnant women (P < .05). Four of five women with abnormal urinary L/M ratio during ICP continued to show abnormalities in tests up to 2 years after delivery. In conclusion, an increased intestinal permeability was detected in ICP patients during and after pregnancy. A "leaky gut" may participate in the pathogenesis of ICP by enhancing the absorption of bacterial endotoxin and the enterohepatic circulation of cholestatic metabolites of sex hormones and bile salts.

Bile acid profiles by capillary electrophoresis in intrahepatic cholestasis of pregnancy

ICP (intrahepatic cholestasis of pregnancy) is characterized by pruritus and biochemical cholestasis, including raised SBAs (serum bile acids) and, usually, elevated aminotransferases levels. However, AHP (asymptomatic hypercholanaemia of pregnancy) is defined as the presence of total SBA levels above the cut-off value (11 μM) in healthy pregnant women, thus elevation of total SBAs do not necessarily reflect an ICP condition. The aim of the present study was to describe clinical, obstetric, perinatal and biochemical findings, as well as the SBA profile, in pregnant women studied in the third trimester of pregnancy in order to define characteristic patterns of individual bile acids that enable women with ICP to be distinguished from AHP and healthy pregnancies. Free and conjugated ursodeoxycholic (UDCA), cholic (CA), lithocholic (LCA), deoxycholic (DCA) and chenodeoxycholic (CDCA) acids were evaluated by CE (capillary electrophoresis) in 41 patients (15 of them simultaneously by HPLC), in 30 healthy pregnant women and in 10 non-pregnant women. A highly significant correlation between CE and HPLC for total SBAs (r=0.990) and for individual SBAs was found. Normal pregnant women had higher total SBA levels than non-pregnant women (due to an increase in taurine-conjugated dihydroxy SBAs). Women with ICP had higher levels of total SBAs, the free/conjugated ratio, LCA, CA, CDCA and DCA than normal pregnant women. Newborns from women with ICP had lower birth weight and gestational age. Women with AHP had higher levels of conjugated dihydroxy SBAs than normocholanaemic patients, without any evidence of a clinical difference. In conclusion, the present study has shown a clear difference in SBA profiles between ICP and normal pregnancies (including AHP), involving a shift towards a characteristic hydrophobic composition in women with ICP.

Plasma lipid profiles of women with intrahepatic cholestasis of pregnancy

OBJECTIVE

Intrahepatic cholestasis of pregnancy is associated with dyslipidemia, but the gestational lipid profile in relation to clinical diagnosis of the disease is unknown. The aim of this study was to undertake a detailed analysis of plasma lipids in women presenting with intrahepatic cholestasis of pregnancy and pruritus gravidarum.

METHODS

Plasma lipid concentrations were assessed in nonfasting blood samples from 63 women with intrahepatic cholestasis of pregnancy (n = 54, recruited at the time of diagnosis, and n = 9, who later developed the disease), 43 women with pruritus gravidarum, and 26 healthy pregnant controls during pregnancy and at 4-6 weeks postpartum.

RESULTS

Intrahepatic cholestasis of pregnancy was associated with an abnormal lipid profile. Low-density lipoprotein (LDL) cholesterol, apolipoprotein B-100, and total cholesterol concentrations were significantly raised during pregnancy in women with intrahepatic cholestasis of pregnancy compared with pruritus gravidarum and controls, and LDL-cholesterol was raised before clinical diagnosis. High-density lipoprotein cholesterol was lower in women with intrahepatic cholestasis of pregnancy compared with the pruritus gravidarum group. Ursodeoxycholic acid did not alter plasma lipid concentrations.

CONCLUSION

Intrahepatic cholestasis is associated with dyslipidemia, which may contribute to the pathogenesis of the disease. The elevation of LDL cholesterol and reduction of high-density lipoprotein cholesterol before clinical diagnosis may prove to be a useful biomarker for the early identification of intrahepatic cholestasis of pregnancy and differentiation from pruritus gravidarum.

LEVEL OF EVIDENCE

II-2.

The specific dermatoses of pregnancy revisited and reclassified: Results of a retrospective two-center study on 505 pregnant patients

OBJECTIVES

We sought to evaluate the frequency and clinical characteristics of pruritic dermatoses in pregnancy and to assess a rationalized classification.

METHODS

Data of 505 pregnant patients seen at two university-based dermatologic hospitals (1994-2004) were retrospectively studied.

RESULTS

Diagnoses included eczema in pregnancy (49.7%), polymorphic eruption of pregnancy (PEP) (21.6%), pemphigoid gestationis (PG) (4.2%), intrahepatic cholestasis of pregnancy (ICP) (3%), prurigo of pregnancy (0.8%), pruritic folliculitis of pregnancy (0.2%), and miscellaneous dermatoses (20.6%). Eczema in pregnancy, prurigo of pregnancy, and pruritic folliculitis of pregnancy showed considerable overlap and were summarized as atopic eruption of pregnancy (AEP). While PEP, PG, and ICP presented in late pregnancy, AEP started significantly earlier. Primigravidae and multiple gestations were characteristic for PEP, abdominal involvement for PEP and PG, and a history of affected pregnancies for ICP.

LIMITATIONS

This was a retrospective study.

CONCLUSION

We propose classifying the dermatoses of pregnancy as PG, PEP, AEP, and ICP. Stereotypic immunofluorescence and laboratory findings are diagnostic of PG and ICP, whereas distinct clinical characteristics facilitate discrimination between PEP and AEP.

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 (> or =10 micromol/L) and increased fetal risk. Recently we determined a cutoff level of serum bile acids, > or =40 micromol/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 > or =40 micromol/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.

Efficacy and safety of ursodeoxycholic acid versus cholestyramine in intrahepatic cholestasis of pregnancy

BACKGROUND & AIMS

Treatment of intrahepatic cholestasis of pregnancy with ursodeoxycholic acid appears promising, but data are limited so far. The aim of this randomized study was to evaluate the efficacy and safety of ursodeoxycholic acid in comparison with cholestyramine.

METHODS

Eighty-four symptomatic patients with intrahepatic cholestasis of pregnancy were randomized to receive either ursodeoxycholic acid, 8-10 mg/kg body weight daily (n = 42), or cholestyramine, 8 g daily (n = 42), for 14 days. The primary end point was a reduction of pruritus by more than 50% after 14 days of treatment as evaluated by a pruritus score. Secondary end points were outcome of pregnancy, reduction of serum aminotransferase activities and serum bile acid levels, and drug safety. Intention-to-treat analysis was applied.

RESULTS

Pruritus was more effectively reduced by ursodeoxycholic acid than cholestyramine (66.6% vs 19.0%, respectively; P < .005). Babies were delivered significantly closer to term by patients treated with ursodeoxycholic acid than those treated with cholestyramine (38.7 +/- 1.7 vs 37.4 +/- 1.5 weeks, respectively, P < .05). Serum alanine and aspartate aminotransferase activities were markedly reduced by 78.5% and 73.8%, respectively, after ursodeoxycholic acid, but by only 21.4%, each, after cholestyramine therapy (P < .01 vs ursodeoxycholic acid). Endogenous serum bile acid levels decreased by 59.5% and 19.0%, respectively (P < .02). Ursodeoxycholic acid, but not cholestyramine was free of adverse effects.

CONCLUSIONS

Ursodeoxycholic acid is safe and more effective than cholestyramine in intrahepatic cholestasis of pregnancy.

Cholestasis of pregnancy: a review of the evidence

Intrahepatic cholestasis of pregnancy is a rare disorder, predominately occurring during the third trimester of pregnancy and characterized by pruritus, jaundice, and biochemical disturbances in liver enzymes. While intrahepatic cholestasis of pregnancy poses little maternal risk, there is significant risk to the fetus such as preterm delivery, non-reassuring fetal status, meconium staining, and perinatal mortality. Current evidence proposes susceptibility to derangements in the sulfation of steroid compounds, affecting the metabolism of progesterone and bile acids in the fetal/placental compartment. Treatment with ursodeoxycholic acid is suggested, coupled with close maternal-fetal surveillance and delivery as close to term as possible.

Ursodeoxycholic acid in the treatment of intrahepatic cholestasis of pregnancy. A 12-year experience

OBJECTIVE

To assess the efficacy of ursodeoxycholic acid (UDCA) in patients with intrahepatic cholestasis of pregnancy (ICP) and in the outcome of pregnancy.

METHODS

Retrospective analysis of our 12-year experience treating ICP patients with UDCA. Thirty-two patients with pruritus starting before week 34 of pregnancy and with increased serum bile salts (BS) and alanine aminotransferase (ALT) received UDCA (15 mg/kg/day) for at least 3 weeks before delivery. They were compared with 16 historical controls who did not receive UDCA. All patients were followed up until delivery and in puerperium. Newborns were followed up during 3 months.

RESULTS

UDCA treatment attenuated pruritus (P < 0.05), serum bilirubin and ALT decreased (P < 0.05) and BS declined. Delivery at term (> or = 37 weeks) occurred in 65.7% of UDCA-treated patients compared with only 12.5% in controls (P < 0.01). Infants born to mothers treated with UDCA weighed a mean of 500 g more than the controls (2882+/-582 vs 2385+/-582; P < 0.01). At 3 months, all infants developed normally. Twenty-six children whose mothers received UDCA were re-examined after 1-12 years and they and their mothers were healthy.

CONCLUSIONS

UDCA improved pruritus and biochemical cholestasis, and facilitated deliveries at term in ICP patients, with a higher birthweight compared with historical controls. The drug was well tolerated and no adverse effects were detected in their infants.

Effects of oral and transdermal estradiol administration on levels of sex hormone-binding globulin in postmenopausal women with and without a history of intrahepatic cholestasis of pregnancy

SHBG, the most important transport protein for sex steroids, is produced in the liver under the control of estrogen action. In a randomized, double-blind, prospective crossover study we compared basal levels of serum SHBG and their responses to increasing doses of oral and transdermal estradiol (E2), followed by E2 plus oral progestin (medroxyprogesterone acetate [MPA]), in 40 postmenopausal women with or without a history of intrahepatic cholestasis of pregnancy (ICP), which could affect the synthesis of SHBG. Serum samples collected at baseline, on the last day of each E2 period, and on the last day of the E2 plus MPA combination were assayed for SHBG and E2. Basal levels of SHBG showed no difference between the study groups. Oral but not transdermal E2 increased SHBG concentrations by 67-171% in the control group, but the response was smaller (42-121%) in the ICP group. Addition of MPA decreased SHBG levels by 14-18% in both groups during both treatments. In conclusion, a history of ICP is associated with blunted responses of SHBG to oral estrogen.

Molecular regulation of hepatobiliary transport systems: clinical implications for understanding and treating cholestasis

Hepatobiliary transport systems are responsible for hepatic uptake and excretion of bile salts and other biliary constituents (eg, bilirubin) into bile. Hereditary transport defects can result in progressive familial and benign recurrent intrahepatic cholestasis. Exposure to acquired cholestatic injury (eg, drugs, hormones, proinflammatory cytokines, biliary obstruction or destruction) also results in altered expression and function of hepatic uptake and excretory systems, changes that may maintain and contribute to cholestasis and jaundice. Recruitment of alternative efflux pumps and induction of phase I and II detoxifying enzymes may limit hepatic accumulation of potentially toxic biliary constituents in cholestasis by providing alternative metabolic and escape routes. These molecular changes are mediated by bile salts, proinflammatory cytokines, drugs, and hormones at a transcriptional and posttranscriptional level. Alterations of hepatobiliary transporters and enzymes are not only relevant for a better understanding of the pathophysiology of cholestatic liver diseases, but may also represent important targets for pharmacotherapy. Drugs (eg, ursodeoxycholic acid, rifampicin) used to treat cholestatic liver diseases and pruritus may counteract cholestasis via stimulation of defective transporter expression and function. In addition, therapeutic strategies may be aimed at supporting and stimulating alternative detoxification pathways and elimination routes for bile salts in cholestasis.

Inborn errors of biliary canalicular transport systems

Cholestatic syndromes are inborn or acquired disorders of bile formation. In recent years, several inherited cholestatic syndromes were characterized at the molecular level: progressive familial intrahepatic cholestasis (PFIC) and benign recurrent intrahepatic cholestasis (BRIC). Both PFIC and BRIC were divided phenotypically in distinct subtypes; however, at the genotype level, these clinical entities overlap. PFIC starts in early childhood and progresses toward liver cirrhosis, which often requires liver transplantation within the first decade of life. The diagnosis of PFIC is usually made on the basis of clinical and laboratory findings but needs to be confirmed by genetic and histological analysis. Only recently was it recognized that BRIC, which was estimated as a milder form of PFIC-1, may be caused by more than one gene.

Glutathione S-transferase and liver function in intrahepatic cholestasis of pregnancy and pruritus gravidarum

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease associated with poor maternal and fetal outcome. The diagnosis is based on pruritus with abnormal liver function in the absence of other pathological conditions. However, pruritus in pregnancy is common, and it may be the only presenting feature in ICP. No reliable test currently exists that can discriminate between those women destined to develop ICP and those with the benign condition of pruritus gravidarum (PG). The purpose of this prospective study was to investigate longitudinally the serum concentration of glutathione S-transferase alpha (GSTA, a specific marker of hepatocellular integrity) and to compare this with the temporal profile of conventional liver function markers in women with ICP (n = 63), PG (n = 43), and normal pregnant controls (n = 26). Blood was sampled on at least 3 separate occasions between 16 weeks of gestation and 4 weeks postpartum. Serum concentrations of GSTA increased with gestation in ICP, being significantly higher from 24 (+/-2) weeks compared with controls (400% difference; 95% CI, 240%-734%; P < .001). GSTA was also higher in ICP versus PG (433% difference; 95% CI, 228%-790%; P < .001) throughout the gestational period studied. Significant differences in the ICP compared with control and PG groups were also found for total bile acids, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase and alkaline phosphatase. In conclusion, the measurement of GSTA provides a test of liver dysfunction that distinguishes women with ICP from those with PG. Additionally, on the basis of this study, reference ranges for biochemical markers of liver function require reevaluation in pregnancy.

Do recommended textbooks contain adequate information about bile salt transporters for medical students?

Several studies have recently highlighted a number of limitations in medical textbooks. The aims of this study were to 1) to assess whether available medical textbooks provided students with adequate information about bile salt transporters, 2) compare the level of detail and the amount of information provided in current textbooks on hepatic transport mechanisms with those available in the literature, and 3) compare the amount of information provided in medical textbooks on hepatocyte transport mechanisms with those involving other transporters e.g., those found in the nephron. Seventy medical textbooks from disciplines including physiology, pathology, cell biology, medicine, pediatrics, pharmacology, pathophysiology, and histology published during the past six years were examined. The literature on bile salt transport has been searched mainly from the Internet (MEDLINE and PubMed). Most textbooks failed to provide any information on transporters found in the basolateral and canalicular membranes of hepatocytes. There are also deficiencies in information on bile salt transporters in the terminal ileum. However, up to the end of 2002, 3,610 articles and reviews had been published on hepatobiliary and enterocyte transport of bile salts. During the same period (from 1965), 10,757 articles had been published on renal transport. Thus the contents of textbooks may reflect the overall volume of research knowledge on renal transport. However, despite our current understanding of hepatic and intestinal transport of bile salts and extensive research, particularly over the past 12 years, there are major deficiencies in textbooks in this area. These findings indicate that there is an imbalance in the contents of current textbooks and a lack of information about hepatobiliary physiology, bile salt transporters, bile formation, and mechanisms underlying cholestasis and drug-induced injury. Authors, editors, and publishers of medical textbooks should consider the need to update the information provided on bile salt transporters.

Fifty years with bile acids and steroids in health and disease

Cholesterol and its metabolites, e.g., steroid hormones and bile acids, constitute a class of compounds of great biological importance. Their chemistry, biochemistry, and regulation in the body have been intensely studied for more than two centuries. The author has studied aspects of the biochemistry and clinical chemistry of steroids and bile acids for more than 50 years, and this paper, which is an extended version of the Schroepfer Medal Award lecture, reviews and discusses part of this work. Development and application of analytical methods based on chromatography and mass spectrometry (MS) have been a central part of many projects, aiming at detailed characterization and quantification of metabolic profiles of steroids and bile acids under different conditions. In present terminology, much of the work may be termed steroidomics and cholanoidomics. Topics discussed are bile acids in human bile and feces, bile acid production, bacterial dehydroxylation of bile acids and steroids during the enterohepatic circulation, profiles of steroid sulfates in plasma of humans and other primates, development of neutral and ion-exchanging lipophilic derivatives of Sephadex for sample preparation and group separation of steroid and bile acid conjugates, profiles of steroids and bile acids in human urine under different conditions, hydroxylation of bile acids in liver disease, effects of alcohol-induced redox changes on steroid synthesis and metabolism, alcohol-induced changes of bile acid biosynthesis, compartmentation of bile acid synthesis studied with 3H-labeled ethanol, formation and metabolism of sulfated metabolites of progesterone in human pregnancy, abnormal patterns of these in patients with intrahepatic cholestasis of pregnancy corrected by ursodeoxycholic acid, inherited and acquired defects of bile acid biosynthesis and their treatment, conjugation of bile acids and steroids with N-acetylglucosamine, sulfate-glucuronide double conjugates of hydroxycholesterols, extrahepatic 7alpha-hydroxylation and 3-dehydrogenation of hydroxycholesterols, and extrahepatic formation of C27 bile acids. The final part discusses analysis of free and sulfated steroids in brain tissue by capillary liquid chromatography-electrospray MS and suggests a need for reevaluation of the function of steroid sulfates in rat brain.

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 > or = 10 micromol/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 micromol/L of serum bile acids. Complementary analyses showed that fetal complications did not arise until bile acid levels were > or = 40 micromol/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 > or = 40 micromol/L. No increase in fetal risk was detected in ICP patients with bile acid levels < 40 micromol/L, and we propose that these women be managed expectantly, which would significantly reduce the costs of medical care.

Liver transplantation using an organ donor with HELLP syndrome

BACKGROUND

The shortage of organs for liver transplantation has forced transplant centers to expand the donor pool by using donors traditionally labeled as marginal. One such example is liver transplantation using a donor with HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets), a disorder of late pregnancy that involves the liver as one of the target organs.

METHODS

Two patients who died from complications of HELLP syndrome were evaluated for attempted multi-organ procurement. Donor characteristics, gross and microscopic liver findings, and procurement and transplant outcomes were reviewed.

RESULTS

One of the liver allografts was successfully transplanted; the other was not procured because of poor macroscopic appearance.

CONCLUSION

It is possible to successfully transplant the liver from a donor that succumbs to HELLP syndrome, provided there is adequate recovery of liver function before procurement.

Spontaneous cholecysto- and hepatolithiasis in Mdr2-/- mice: a model for low phospholipid-associated cholelithiasis

Previously, we identified needle-like and filamentous, putatively "anhydrous" cholesterol crystallization in vitro at very low phospholipid concentrations in model and native biles. Our aim now was to address whether spontaneous gallstone formation occurs in Mdr2 (Abcb4) knockout mice that are characterized by phospholipid-deficient bile. Biliary phenotypes and cholesterol crystallization sequences in fresh gallbladder biles and non-fixed liver sections were determined by direct and polarizing light microscopy. The physical chemical nature and composition of crystals and stones were determined by sucrose density centrifugation and before mass and infrared spectroscopy. Gallbladder biles of Mdr2(-/-) mice precipitate needle-like cholesterol crystals at 12 weeks of age on chow. After 15 weeks, more than 50% of Mdr2(-/-) mice develop gallbladder stones, with female mice displaying a markedly higher gallstone-susceptibility. Although gallbladder biles of Mdr2(-/-) mice contain only traces (</= 1.1 mM) of phospholipid and cholesterol, they become supersaturated with cholesterol and plot in the left 2-phase zone of the ternary phase diagram, consistent with "anhydrous" cholesterol crystallization. Furthermore, more than 40% of adult female Mdr2(-/-) mice show intra- and extrahepatic bile duct stones. In conclusion, spontaneous gallstone formation is a new consistent feature of the Mdr2(-/-) phenotype. The Mdr2(-/-) mouse is therefore a model for low phospholipid-associated cholelithiasis recently described in humans with a dysfunctional mutation in the orthologous ABCB4 gene. The mouse model supports the concept that this gene is a monogenic risk factor for cholesterol gallstones and a target for novel therapeutic strategies.

Obstetric cholestasis with elevated gamma glutamyl transpeptidase: incidence, presentation and treatment

BACKGROUND

Obstetric cholestasis (OC) may cause severe pruritus in the mother and lead to fetal distress and stillbirth. The etiology of OC is multifactorial, but includes inherited dysfunction of bile canalicular transporters. One of these, multidrug resistant protein 3 (MDR3), a phospholipid transporter, when dysfunctional is associated with elevated levels of gamma glutamyl transpeptidase (GGT). The aim of the present study was to assess the incidence of OC associated with elevated GGT. We compared the natural history of a cholestatic pregnancy and the efficacy of ursodeoxycholic acid (URSO) in OC patients grouped according to a normal or raised GGT level.

METHODS

Eighty-one patients with OC were analyzed. OC was diagnosed in patients with pruritus and elevated serum bile acids (SBA). Fifty-seven consenting volunteer patients (70%) were treated with URSO.

RESULTS

Elevated GGT at presentation was found in 21 patients (30%) and was associated with significantly higher serum levels of aspartate transaminase (AST), bilirubin (BIL) and SBA. OC presented at approximately the same gestation week in both groups of patients. In patients not treated with URSO, liver function tests (LFT) showed no significant change from the time of diagnosis to delivery. Patients from both groups responded to URSO with significant improvement in their AST and alanine aminotransferase (ALT) levels, but SBA fell significantly only in the normal GGT group.

CONCLUSIONS

An elevated GGT occurs in less than one-third of patients with OC in the UK and, when present, is associated with greater impairment of LFT, but no difference in gestational age at onset. Treatment with URSO appears to be safe and significantly improves LFT in patients with OC, with the exception of SBA in the high GGT group.

ABCB4 gene mutation-associated cholelithiasis in adults

BACKGROUND & AIMS

We recently put forward arguments in favor of ABCB4 gene (adenosine triphosphate-binding cassette, subfamily B, member 4) defects as a risk factor for symptomatic cholelithiasis in adults. In this study, we characterized ABCB4 gene mutations in a series of patients with symptomatic cholelithiasis to determine the genetic basis and the clinical phenotype of ABCB4 gene mutation-associated cholelithiasis.

METHODS

We analyzed the entire ABCB4 gene coding sequences in a first group of 32 patients who had a clinical history compatible with the syndrome previously described, in a second group of 28 patients who presented with a classic gallstone disease that justified a cholecystectomy, and in a third group of 33 patients without a history of cholelithiasis.

RESULTS

We identified both heterozygous and homozygous ABCB4 gene point mutations in 18 of 32 (56%) patients who presented with clinical criteria of the syndrome, whereas no mutation was detected in the 2 other groups of patients (P < 0.001). Three independent clinical features were strongly associated with point mutations: recurrence of symptoms after cholecystectomy (odds ratio, 8.5); intrahepatic hyperechoic foci, intrahepatic sludge, or microlithiasis (odds ratio, 6.1); and age <40 years at the onset of symptoms (odds ratio, 3.0). ABCB4 gene point mutations were detected exclusively in the patients who showed 2 or 3 of these clinical features.

CONCLUSIONS

Our results show that ABCB4 gene mutations represent a major genetic risk factor in a symptomatic and recurring form of cholelithiasis in young adults.

Influence of ethinyloestradiol propanolsulphonate on serum bile acids in healthy volunteers

The present work was done to clarify the relevance of altered serum bile acid (BA) profile in healthy women after the administration of the depot oestrogen ethinyloestradiol propanolsulphonate (EES). In the serum of 20 healthy women before and two times after oral EES application, 11 free and 14 taurine- and glycine-conjugated BA were analysed by HPLC with postcolumn derivatisation and fluorescence detection. EES significantly enhanced the total serum BA concentration and that of taurine-conjugated BAs, more pronounced the secondary BAs taurodeoxycholic, tauroursodeoxycholic and taurolithocholic acid. These secondary BAs are produced in the intestine by bacteria due to 7alpha-dehydroxylation of the primary BAs cholic and chenodeoxycholic acid. Because of unchanged free BAs, also produced by intestinal bacteria due to deconjugation, the results were interpreted as a sign of disturbed transport of BAs into the liver. Inhibition of the liver Na(+)-bile salt co-transporter (Ntcp) in the sinusoidal membrane by ethinyloestradiol, formed from the prodrug EES, may be responsible for the altered BA profile in serum.

Specific dermatoses of pregnancy: an evidence-based systematic review

OBJECTIVE

We conducted an evidence-based systematic analysis of the literature on specific dermatoses of pregnancy.

STUDY DESIGN

The bibliographic databases MEDLINE and EMBASE were screened for studies and reports in all languages about herpes gestationis, pruritic urticarial papules and plaques of pregnancy, pruritic folliculitis of pregnancy, and prurigo of pregnancy from January 1962 to January 2002. As main index terms, including analogs and derivatives, we used the names of specific dermatoses of pregnancy. Intrahepatic cholestasis of pregnancy, not a primary dermatosis, was included herein because this disorder is associated with pregnancy and its secondary skin manifestations must be differentiated from specific dermatoses of pregnancy. Other sources were abstract books of symposia and congresses, theses, textbooks, monographs, reviews, editorials, letters to the editor, free or rapid communications, and the reference lists from all the articles that were retrieved. All articles selected for inclusion in this review were evaluated critically with regard to their impact factor and evidence-based contribution to this field, as measured by their citation index and impact factor of the journal in which they were published. Approximately 39% of articles met the selection criteria.

RESULTS

The clinical features and prognosis of the specific dermatoses of pregnancy have been delineated through a number of retrospective and cohort studies. The molecular biologic and immunogenetic properties of herpes gestationis, pruritic urticarial papules and plaques of pregnancy, and intrahepatic cholestasis of pregnancy have been further clarified. A meta-analysis in this review reveals a higher prevalence of multiple gestation pregnancy (11.7%) among patients with pruritic urticarial papules and plaques of pregnancy. Several investigations have unraveled the fetal complications in intrahepatic cholestasis of pregnancy and herpes gestationis. New treatment modalities in intrahepatic cholestasis of pregnancy (cholestyramine, ursodeoxycholic acid) and herpes gestationis (cyclosporin, intravenous immunoglobulin, and tetracyclines postpartum) have shown promise and warrant further evaluation.

CONCLUSION

During the past few decades, a significant amount of new data has provided new insights into the classification, pathogenesis, treatment, prognosis, and fetal risks that are associated with the specific dermatoses of pregnancy.

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.

Pregnancy and liver disease

Liver disease has an impact on women's health during pregnancy because of the complex interactions between the physiologic changes induced by pregnancy and the pathophysiologic changes of liver disease. In particular, liver diseases that predominantly afflict females, such as primary biliary cirrhosis and autoimmune hepatitis, pose a special problem for conception and management of pregnancy. Pregnancy, moreover, specifically is associated with several potentially life-threatening liver diseases. This article reviews comprehensively the impact of liver diseases on pregnancy and of pregnancy on liver function and liver disease.

Bile acid stress in the mother and baby unit

Intrahepatic cholestasis of pregnancy (ICP) affects about 0.7% of deliveries in Britain. It is regarded as a benign condition for the mother but is associated with increased fetal mortality in late pregnancy and early delivery is advised. Ursodeoxycholic acid (UDCA) treatment is beneficial to the mother and does not appear to harm the fetus. ICP is often regarded as a disease of the maternal liver already made 'cholestatic' by high levels of circulating progesterone. We propose that ICP should be considered as a feto-maternal disease involving complex interactions between maternal and fetal bile acid metabolism across the placenta. During the late stages of gestation, when there is a rise in fetal and maternal bile acid levels, the placenta may fail to render potentially hepatotoxic bile acids water soluble and hence excretable. This might cause a vicious cycle leading to further cholestasis in the maternal liver already challenged by progesterone.

The human bile salt export pump: characterization of substrate specificity and identification of inhibitors

BACKGROUND & AIMS

The bile salt export pump (BSEP) is the major bile salt transporter in the liver canalicular membrane. Our aim was to determine the affinity of the human BSEP for bile salts and identify inhibitors.

METHODS

Human BSEP was expressed in insect cells. Adenosine triphosphatase (ATPase) assays were performed, and bile salt transport studies were undertaken.

RESULTS

The BSEP gene, ABCB11, was cloned and a recombinant baculovirus was generated. Infected insect cells expressed a 140-kilodalton protein that was absent in uninfected and in mock-infected cells. An ATPase assay showed BSEP to have a high basal ATPase activity. Transport assays were used to determine the Michaelis constant for taurocholate as 4.25 micromol/L, with a maximum velocity of 200 pmol x min(-1) x mg(-1) protein. Inhibition constant values for other bile salts were 11 micromol/L for glycocholate, 7 micromol/L for glycochenodeoxycholate, and 28 micromol/L for taurochenodeoxycholate. Cyclosporin A, rifampicin, and glibenclamide were proved to be competitive inhibitors of BSEP taurocholate transport, with inhibition constant values of 9.5 micromol/L, 31 micromol/L, and 27.5 micromol/L, respectively. Progesterone and tamoxifen did not inhibit BSEP.

CONCLUSIONS

The human BSEP is a high-affinity bile salt transporter. The relative affinities for the major bile salts differ from those seen in rodents and reflect the different bile salt pools. BSEP is competitively inhibited by therapeutic drugs. This is a potentially significant mechanism for drug-induced cholestasis.

Treatment of itching associated with intrahepatic cholestasis of pregnancy

OBJECTIVE

To review the drug therapy for the treatment of itching associated with intrahepatic cholestasis of pregnancy (ICP).

DATA SOURCES

A comprehensive literature search was conducted in MEDLINE (1966-July 2002) using the following MeSH terms: pregnancy, itching, intrahepatic cholestasis, cholestyramine, ursodeoxycholic acid, and phenobarbital. Current Contents (1966-July 2002), International Pharmaceutical Abstracts (1970-June 2002), and Cochrane Database were also searched using those terms. Web of Science search was used to search references found in articles.

DATA SYNTHESIS

Eight clinical trials and several observational studies were identified evaluating the safety and efficacy of ursodeoxycholic acid (UDCA) in the treatment of ICP. Although these studies were small and inconsistent, improvement in maternal and fetal morbidity was demonstrated. Observational studies suggest that cholestyramine may be associated with improved maternal morbidity without a documented improvement in fetal outcome. Two observational studies evaluated the efficacy of phenobarbital for ICP treatment. Phenobarbital use was not associated with improved maternal or fetal morbidity/mortality.

CONCLUSIONS

Data from large, well-designed, randomized, controlled trials of treatment of ICP are lacking. Data that are available support the use of UDCA as a first-line agent and cholestyramine as a second-line agent for treatment of ICP. There is little evidence to recommend phenobarbital in the treatment of itching associated with that condition.