Hepatobiliary complications of oral contraceptives

The effect of hormonal contraceptive therapy on clinical laboratory parameters: a literature review

Hormonal contraceptives (HC) are widely used among women in reproductive ages. In this review, the effects of HCs on 91 routine chemistry tests, metabolic tests, and tests for liver function, hemostatic system, renal function, hormones, vitamins and minerals were evaluated. Test parameters were differently affected by the dosage, duration, composition of HCs and route of administration. Most studies concerned the effects of combined oral contraceptives (COC) on the metabolic, hemostatic and (sex) steroids test results. Although the majority of the effects were minor, a major increase was seen in angiotensinogen levels (90-375 %) and the concentrations of the binding proteins (SHBG [∼200 %], CBG [∼100 %], TBG [∼90 %], VDBP [∼30 %], and IGFBPs [∼40 %]). Also, there were significant changes in levels of their bound molecules (testosterone, T3, T4, cortisol, vitamin D, IGF1 and GH). Data about the effects of all kinds of HCs on all test results are limited and sometimes inconclusive due to the large variety in HC, administration routes and dosages. Still, it can be concluded that HC use in women mainly stimulates the liver production of binding proteins. All biochemical test results of women using HC should be assessed carefully and unexpected test results should be further evaluated for both methodological and pre-analytical reasons. As HCs change over time, future studies are needed to learn more about the effects of other types, routes and combinations of HCs on clinical chemistry tests.

Mitoquinol mesylate (MITOQ) attenuates diethyl nitrosamine-induced hepatocellular carcinoma through modulation of mitochondrial antioxidant defense systems

Diethyl nitrosamine (DEN) induced cirrhosis-hepatocellular carcinoma (HCC) model associates cancer progression with oxidative stress and mitochondrial dysfunction. This study investigated the effects of mitoquinol mesylate (MitoQ), a mitochondrial-targeted antioxidant on DEN-induced oxidative damage in HCC Wistar rats. Fifty male Wistar rats were randomly divided into five groups. Healthy control, DEN, and MitoQ groups were orally administered exactly 10 mg/kg of distilled water, DEN, and MitoQ, respectively for 16 weeks. Animals in the MitoQ + DEN group were pre-treated with MitoQ for a week followed by co-administration of 10 mg/kg each of MitoQ and DEN. DEN + MitoQ group received DEN for 8 weeks, then co-administration of 10 mg/kg each of DEN and MitoQ till the end of 16th week. Survival index, tumour incidence, hematological profile, liver function indices, lipid profile, mitochondrial membrane composition, mitochondrial respiratory enzymes, and antioxidant defense status in both mitochondrial and post-mitochondrial fractions plus expression of antioxidant genes were assessed. In MitoQ + DEN and DEN + MitoQ groups, 80% survival occurred while tumour incidence decreased by 60% and 40% respectively, compared to the DEN-only treated group. Similarly, MitoQ-administered groups showed a significant (p < 0.05) decrease in the activities of liver function enzymes while hemoglobin concentration, red blood cell count, and packed cell volume were significantly elevated compared to the DEN-only treated group. Administration of MitoQ to the DEN-intoxicated groups successfully enhanced the activities of mitochondrial F1F0-ATPase and succinate dehydrogenase; and up-regulated the expression and activities of SOD2, CAT, and GPx1. Macroscopic and microscopic features indicated a reversal of DEN-induced hepatocellular degeneration in the MitoQ + DEN and DEN + MitoQ groups. These data revealed that MitoQ intervention attenuated DEN-induced oxidative stress through modulation of mitochondrial antioxidant defense systems and alleviated the burden of HCC as a chemotherapeutic agent.

Norethisterone‐induced cholestasis: A case report

Case presentation

This case report concerns a 49‐year‐old woman who developed cholestasis (build‐up of bile in the liver) two months and a half after initiating norethisterone, progestin‐only pills, which resolved after the withdrawal of these pills.

Triggers of benign recurrent intrahepatic cholestasis and its pathophysiology: a review of literature

Benign recurrent intrahepatic cholestasis (BRIC) is a rare genetic disorder that is characterized by episodes of cholestasis followed by complete resolution. The episodic nature of BRIC raises concerns about its possible trigger factors. Indeed, case reports of this orphan disease have associated BRIC to some triggers. In the absence of any reviews, we reviewed BRIC trigger factors and its pathophysiology. The study consisted of a systematic search for case reports using PubMed. Articles describing a clear case of BRIC associated with a trigger were included resulting in 22 articles that describe 35 patients. Infection was responsible for 54.3% of triggered episodes, followed by hormonal, drugs, and miscellaneous causes reporting as 30%, 10%, and 5.7% respectively. Females predominated with 62.9%. The longest episode ranged between 3 months to 2 years with a mean of 32.37 weeks. The mean age of the first episode was 14.28 ranging between 3 months to 48 years. Winter and autumn were the major seasons during which episodes happened. Hence, BRIC is potentially triggered by infection, which is most commonly a viral infection, hormonal disturbances as seen in oral contraceptive pills and pregnancy state, and less commonly by certain drugs and other causes. The appearance of cholestasis during the first two trimesters of pregnancy compared to intrahepatic cholestasis of pregnancy could help to differentiate between the two conditions. The possible mechanism of BRIC induction implicates a role of BSEP and ATP8B1. While estrogen, drugs, and cytokines are known to affect BSEP, less is known about their action on ATP8B1.

Contraceptive vaginal ring-induced cholestasis in a patient with a history of intrahepatic cholestasis of pregnancy

INTRODUCTION

Intrahepatic cholestasis of pregnancy (ICP) is a heterogeneous group of liver disorders with a high recurrence rate. Patients with a history of ICP are at risk of developing contraceptive-induced cholestasis, especially if they harbour a biliary transporter mutation. We report the first case of drug-induced cholestasis associated with a contraceptive vaginal ring (CVR) in a patient with a prior history of ICP.

PRESENTATION

Our patient was a women with a history of multiple pregnancies and spontaneous abortions and early and severe ICP. Two to four weeks after initiation of CVR, she developed signs and symptoms of cholestasis, which resolved after discontinuation of the CVR. A thorough investigation to exclude other plausible causes of cholestasis was performed, including a liver biopsy. Genetic testing revealed pathogenic mutations in both the ABCB11 and ABCB4 genes.

DISCUSSION

Although a history of ICP used to be an absolute contraindication for oral contraceptive pills (OCP), recent studies suggest a lower risk of cholestasis associated with low-dose oestrogen pills (20-35 mcg compared to the original 50 mcg). No previous case report could confirm the theoretical risk associated with the use of a CVR, which delivers a very low estrogen dose (15 mcg). The two biliary transporter mutations identified in our case could potentially explain the patient's susceptibility to the cholestatic effect of oestrogen.

CONCLUSION

This case illustrates that CVR can trigger drug-induced cholestasis in a susceptible patient. While such cases should not discourage the trial of low-dose hormonal contraception in women with prior ICP, an appropriate follow-up is necessary to ensure early detection and treatment of drug-induced cholestasis.

Liver Biochemical Abnormalities in Adolescent Patients with Turner Syndrome

OBJECTIVE

Elevated liver function tests (LFTs) are common in adult Turner syndrome (TS) patients. Data regarding children and adolescents are lacking. To investigate the prevalence of abnormal LFTs in children and adolescents with TS during several years of observation; to evaluate the potential impact of increased body mass index (BMI) and sex hormone replacement therapy (HRT) on LFTs.

METHODS

The analysis included 100 girls with TS, aged 4-16 years, all of whom were receiving recombinant human growth hormone therapy. A longitudinal study was conducted which included 81 patients.

RESULTS

Mean BMI-standard deviation (SD) score of the subjects was 0.63 (SD: 1.53). Forty-four were being treated with HRT. Elevated LFTs were found in 34% of the patients overall (32% not receiving HRT vs 36% on HRT). The relative risk of increased LFTs was not higher in obese vs normal weight [odds ratio (OR): 0.2; 95% confidence interval (CI): 0.1-0.36, p=0.38 vs OR: 0.16; 95% CI: 0.08-0.3, p=0.1]. HRT did not increase the risk of abnormal LFTs activity (OR: 0.8; 95% CI: 0.5-1.2, p=0.37 vs OR: 0.7; 95% CI: 0.4-1.1, p=0.27). During the follow-up period (mean±SD=4.31±0.82 years), no patient developed overt liver disease. There was no significant increase nor decrease of abnormal LFT frequency in the subsequent years of follow up.

CONCLUSION

Constantly elevated LFTs in TS are common in children and adolescents with TS. However the causes and clinical significance remain unclear. This study suggests that obesity and HRT do not increase the risk of elevated LFTs.

Drug-induced cholestasis

Cholestatic drug-induced liver injury (DILI) can be a diagnostic challenge due to a large differential diagnosis, variability in clinical presentation, and lack of serologic biomarkers associated with this condition. The clinical presentation of drug-induced cholestasis includes bland cholestasis, cholestatic hepatitis, secondary sclerosing cholangitis, and vanishing bile duct syndrome. The associate mortality of cholestatic DILI can be as high as 10%, and thus prompt recognition and removal of the offending agent is of critical importance. Several risk factors have been identified for drug-induced cholestasis, including older age, genetic determinants, and properties of certain medications. Antibiotics, particularly amoxicillin/clavulanate, remain the predominant cause of cholestatic DILI, although a variety of other medications associated with this condition have been identified. In this review, we summarize the presentation, clinical approach, risk factors, implicated medications, and management of drug-induced cholestatic liver injury. (Hepatology Communications 2017;1:726-735).

Oral Contraceptives Use and Liver Cancer Risk: A Dose-Response Meta-Analysis of Observational Studies

Studies about the association between oral contraceptives use and liver cancer risk have generated controversial results. Therefore, a meta-analysis of cohort and case-control studies was performed to quantitatively summarize the existing evidence.Eligible studies were identified by a computer search of PubMed and Embase databases and handed-search of reference lists, without any limitations. Study-specific risk estimates (RRs) with 95% confidence intervals (CIs) were combined with random-effects model.A total of 17 articles were included in this meta-analysis. Overall, there was no statistically significant association between oral contraceptives use and liver cancer risk (RR: 1.23, 95% CI: 0.93-1.63). In a dose-analysis of meta-analysis, a linear relationship between oral contraceptives use and liver cancer risk (P for linearity = 0.391) was found, although this correlation was not statistically significant.Oral contraceptives use was not positively associated with the risk of liver cancer.

Drug-induced cholestasis

Cholestasis caused by drugs is an important differential diagnosis in patients presenting with a biochemical cholestatic pattern. The extent of serologic tests and radiological imaging depends on the clinical context. The underlying condition of the patient and detailed information on drug use, results of rechallenge, and the documented hepatotoxicity of the drug are important to establish a diagnosis of drug-induced liver injury (DILI). Most cases of cholestatic DILI are mild, but in rare cases, ductopenia and cholestatic cirrhosis can develop. Approximately 10% of patients with cholestatic jaundice caused by drugs develop liver failure.

Liver involvement in Turner syndrome

Liver test abnormalities are frequent in adult patients with Turner syndrome, corresponding to various pathophysiological mechanisms. Steatosis, steatofibrosis and steatohepatitis are the most frequently reported lesions, caused by metabolic disorders, which are commonly related to overweight. Marked architectural changes, including nodular regenerative hyperplasia, multiple focal nodular hyperplasia and cirrhosis, found in some patients, are associated with a risk of severe liver-related complications. Architectural changes are often observed and are associated with vascular disorders caused by congenitally abnormal vessels. Finally, small bile duct alterations resembling sclerosing cholangitis occur in several patients. Oestrogen replacement therapy does not cause liver toxicity in patients with Turner syndrome and is not contraindicated in case of elevated liver enzymes. Moreover, in recent studies, oestrogen therapy was reported to improve liver function tests. Because of the wide spectrum of potential liver injuries that may occur in Turner syndrome patients, a regular screening of liver enzymes is recommended for early detection and treatment.

A case of prolonged cholestatic hepatitis induced by azithromycin in a young woman

Azithromycin, a semisynthetic macrolides, is frequently prescribed for the treatment of middle ear and upper respiratory tract infections, bronchitis, and community-acquired pneumonia. This antibiotic is usually well tolerated, and a rapid resolving cholestatic hepatitis has been described up to now only in six patients all, except one, over 65 years of age. We here report the case of a prolonged cholestatic hepatitis after administration of azithromycin in a young woman with no history of liver disease.

Genetic variations of bile salt transporters as predisposing factors for drug-induced cholestasis, intrahepatic cholestasis of pregnancy and therapeutic response of viral hepatitis

INTRODUCTION

Drug-induced cholestasis, intrahepatic cholestasis of pregnancy and viral hepatitis are acquired forms of liver disease. Cholestasis is a pathophysiologic state with impaired bile formation and subsequent accumulation of bile salts in hepatocytes. The bile salt export pump (BSEP) (ABCB11) is the key export system for bile salts from hepatocytes.

AREAS COVERED

This article provides an introduction into the physiology of bile formation followed by a summary of the current knowledge on the key bile salt transporters, namely, the sodium-taurocholate co-transporting polypeptide NTCP, the organic anion transporting polypeptides (OATPs), BSEP and the multi-drug resistance protein 3. The pathophysiologic consequences of altered functions of these transporters, with an emphasis on molecular and genetic aspects, are then discussed.

EXPERT OPINION

Knowledge of the role of hepatocellullar transporters, especially BSEP, in acquired cholestasis is continuously increasing. A common variant of BSEP (p.V444A) is now a well-established susceptibility factor for acquired cholestasis and recent evidence suggests that the same variant also influences the therapeutic response and disease progression of viral hepatitis C. Studies in large independent cohorts are now needed to confirm the relevance of p.V444A. Genome-wide association studies should lead to the identification of additional genetic factors underlying cholestatic liver disease.

The role of the sodium-taurocholate cotransporting polypeptide (NTCP) and of the bile salt export pump (BSEP) in physiology and pathophysiology of bile formation

Bile formation is an important function of the liver. Bile salts are a major constituent of bile and are secreted by hepatocytes into bile and delivered into the small intestine, where they assist in fat digestion. In the small intestine, bile salts are almost quantitatively reclaimed and transported back via the portal circulation to the liver. In the liver, hepatocytes take up bile salts and secrete them again into bile for ongoing enterohepatic circulation. Uptake of bile salts into hepatocytes occurs largely in a sodium-dependent manner by the sodium taurocholate cotransporting polypeptide NTCP. The transport properties of NTCP have been extensively characterized. It is an electrogenic member of the solute carrier family of transporters (SLC10A1) and transports predominantly bile salts and sulfated compounds, but is also able to mediate transport of additional substrates, such as thyroid hormones, drugs and toxins. It is highly regulated under physiologic and pathophysiologic conditions. Regulation of NTCP copes with changes of bile salt load to hepatocytes and prevents entry of cytotoxic bile salts during liver disease. Canalicular export of bile salts is mediated by the ATP-binding cassette transporter bile salt export pump BSEP (ABCB11). BSEP constitutes the rate limiting step of hepatocellular bile salt transport and drives enterohepatic circulation of bile salts. It is extensively regulated to keep intracellular bile salt levels low under normal and pathophysiologic situations. Mutations in the BSEP gene lead to severe progressive familial intrahepatic cholestasis. The substrates of BSEP are practically restricted to bile salts and their metabolites. It is, however, subject to inhibition by endogenous metabolites or by drugs. A sustained inhibition will lead to acquired cholestasis, which can end in liver injury.

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.

Contraception in women with medical problems

Women with medical disease have a higher incidence of maternal mortality compared with healthy women, with cardiac disease now being the most common cause of maternal death in the UK. A handful of medical conditions exist where pregnancy is not recommended due to mortality rates approaching 50%. It is imperative that such women have the most reliable methods of contraception available. Contraceptive agents may themselves affect medical disease, or may interact with medications used by such women. There may be a range of contraceptive agents suitable for each medical condition. The contraceptive selected should be tailored to suit the individual. The following points should be considered when deciding on the most appropriate contraceptive agent: efficacy, thrombotic risk (oestrogen containing contraceptives), arterial risks (oestrogen containing contraceptives), infective risk (e.g. insertion of intrauterine device [IUD]), vagal stimulation (e.g. insertion of IUD, ESSURE(®)), bleeding risks with patients on anticoagulants, interaction with concomitant drugs, effects of anaesthesia and ease of use. This review aims to cover the different contraceptive agents available and the best ones to use for certain medical illnesses.

Molecular bases of the fetal liver-placenta-maternal liver excretory pathway for cholephilic compounds

Potentially toxic endogenous compounds, such as bile acids (BAs) and biliary pigments, as well as many xenobiotics, such as drugs and food components, are biotransformed and eliminated by the hepatobiliary system with the collaboration of the kidney. However, the situation is very different during pregnancy because the fetal liver produces biliary compounds despite the fact that this organ, owing to its immaturity, is not able to eliminate them into bile. Moreover, the excretory ability of the fetal kidneys is also very limited. Thus, during the intra-uterine life, the major route to eliminate fetal BAs and biliary pigments is their transfer to the mother across the placenta. The maternal liver and, to a lesser extent, the maternal kidney, are then in charge of their biotransformation and elimination into faeces and urine respectively. This review describes current knowledge of the machinery responsible for the detoxification and excretion of cholephilic compounds through the pathway formed by the fetal liver-placenta-maternal liver trio.

Oral contraception and the risk of hepatocellular carcinoma

BACKGROUNDS/AIMS

We performed a meta-analysis of observational epidemiological studies to examine the association between oral contraceptives (OC) and hepatocellular carcinoma (HCC).

METHODS

Two independent researchers conducted PubMed searches followed by systematic abstraction of studies that compared OC use between patients with HCC and a group of controls. Pooling of ORs was conducted using a random effects model. Heterogeneity and publication bias among studies were examined.

RESULTS

Twelve case-control studies that included 739 cases and 5223 controls met the inclusion and exclusion criteria. The pooled estimate of ORs (age- and sex-matched only) from all 12 studies was 1.57 (95% CI=0.96-2.54, p=0.07) with a heterogeneity of I(2)=39.9. Exclusion of one large multi-national European study decreased the heterogeneity to I(2)=16.9 and increased the pooled OR to 1.70 (95% CI=1.12-2.59, p=0.01). Eight studies reported adjusted ORs (in addition to age and sex); the pooled estimate was 1.45 (95% CI=0.93-2.27, p=0.11) with a heterogeneity of I(2)=20.4. Only few studies identified or adjusted for other HCC risk factors. Six studies showed a significant 2- to 20-fold increase in HCC risk with longer durations of OC use; however, the reporting was too inconsistent to allow meta-analysis.

CONCLUSIONS

The evidence is inconclusive to establish a relation between oral contraceptives and the risk of hepatocellular carcinoma. Future studies should focus on the duration, intermittency, and recency of OC use.

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).

Hepatobiliary transporters and drug-induced cholestasis

Drug-induced liver injury is an important clinical problem with significant morbidity and mortality. Whereas for most hepatocellular forms of drug-induced hepatic injury the underlying pathophysiological mechanism is poorly understood, there is increasing evidence that cholestatic forms of drug-induced liver damage result from a drug- or metabolite-mediated inhibition of hepatobiliary transporter systems. In addition to their key role in determining hepatic drug exposure and clearance, the coordinated action of these transport systems is essential for bile formation and the biliary secretion of cholephilic compounds and xenobiotics. Any drug-mediated functional disturbance of these processes can lead to an intracellular accumulation of potentially harmful bile constituents and result in the development of cholestatic liver cell damage. In addition to direct drug-mediated inhibition of hepatocellular transport, function of these transporters can be altered by pre-existing hepatic disease and genetic factors, which contribute to the development of drug-induced cholestasis in susceptible individuals. This review summarizes current knowledge about the function of hepatobiliary uptake and efflux systems and discusses factors that might predispose to drug-induced cholestasis.

Hepatocanalicular transport defects: pathophysiologic mechanisms of rare diseases

The apical membrane of the hepatocyte fulfils a unique function in the formation of primary bile. For all important biliary constituents a primary active transporter is present that extrudes or translocates its substrate toward the canalicular lumen. Most of these transporters are ATP-binding cassette (ABC) transporters. Two types of transporters can be recognized: those having endogenous metabolites as substrates (which could be referred to as "physiologic" transporters) and those involved in the elimination of drugs, toxins, and waste products. It should be emphasized that this distinction cannot be strictly made as some endogenous metabolites can be regarded as toxins as well. The importance of the canalicular transporters has been recognized by the pathologic consequence of their genetic defects. For each of the physiologic transporter genes an inherited disease has now been identified and most of these diseases have a quite serious clinical phenotype. Strikingly, complete defects in drug transporter function have not been recognized (yet) or only cause a mild phenotype. In this review we only briefly discuss the inherited defects in transporter function, and we focus on the pathophysiologic concepts that these diseases have generated.

Hepatocellular transporters and cholestasis

The secretion of bile is the result of active hepatocellular transport processes, most of which occur across the canalicular membrane of liver cells. Disturbance of the function and/or expression of these transporters leads to the intracellular accumulation of toxic bile acids, thereby promoting cholestatic liver cell injury. Genetically determined alterations of hepatobiliary transporter function are increasingly recognized as important risk factors for an individual's susceptibility to develop cholestasis. It has become evident that, besides the established pathogenic role of mutations in canalicular transporter genes in progressive and benign forms of familial intrahepatic cholestasis, genetics may also play an important role in acquired cholestatic syndromes, such as intrahepatic cholestasis of pregnancy or drug-induced cholestasis. This overview summarizes the physiologic function and regulation of human hepatobiliary transport systems and discusses the impact of their genetic variations for the pathophysiology of different cholestatic syndromes.

Hemochromatosis (HFE) gene mutations and hepatitis C virus infection as risk factors for porphyria cutanea tarda in Hungarian patients

AIM

It is not clear whether the mutations in hemochromatosis (HFE) gene and hepatitis C virus (HCV) infection act independently in the pathogenesis of porphyria cutanea tarda (PCT). The prevalence of both risk factors varies greatly in different parts of the world. PCT patients from Hungary were evaluated to assess both factors.

METHODS

The prevalence of C282Y and H63D mutations in the HFE gene was determined in 50 PCT patients and compared with the reported control frequencies. Furthermore, the presence of HCV infection was determined and related to the patients' HFE gene status.

RESULTS

The C282Y mutation was found in 8/50 cases (three homozygotes and five heterozygotes), with an 11% allele frequency (vs. 3.8% control) (P<0.05). Seventeen patients were heterozygous, one was homozygous for the H63D mutation, allele frequency 19%, which did not differ significantly from the reported control prevalence of 12.3%. Twenty-two patients (44%) were HCV-RNA positive; six out of them were heterozygous for H63D mutation, one only for the C282Y mutation and one was compound heterozygous for both mutations.

CONCLUSION

HCV infection and HFE C282Y mutation may probably be independent predisposing factors for development of PCT in Hungarian patients.

Vascular involvement of the liver in Turner's syndrome

Unexplained liver test abnormalities are frequent in patients with Turner's syndrome. This cohort study was performed to clarify the histopathologic features, causes, and long-term outcome of liver involvement in these patients. Thirty patients with persistently abnormal liver test results were followed-up for 8.8 +/- 5.2 years. Liver specimens were available in 27 patients. Marked architectural changes were present in 10 patients, including nodular regenerative hyperplasia in six, multiple focal nodular hyperplasia in two, and cirrhosis in two patients. These changes frequently were associated with obliterative portal venopathy lesions and with aortic malformations. There was mild to moderate portal fibrosis in 15 of the 17 other patients, inflammatory infiltrates in nine patients, and nonalcoholic fatty liver disease in 11 patients. Bile duct alterations resembling small duct sclerosing cholangitis were observed in 21 patients (with or without architectural changes). There was no viral, alcoholic, autoimmune, or drug-induced liver damage. Portal hypertension was observed in four patients with marked architectural changes, including three in whom refractory ascites or recurrent variceal bleeding developed, one of whom underwent transplantation. None of the patients without marked architectural changes experienced progressive or decompensated liver disease. There was no evidence of liver toxicity from estrogen replacement therapy. In conclusion, the main causes of liver involvement in Turner's syndrome are vascular disorders, probably of a congenital origin, and nonalcoholic fatty liver disease. In patients with vascular disorders, severe liver disease requiring liver transplantation may develop. Estrogen therapy does not appear to be pathogenically implicated.

Drug-induced cholestasis

Drug-induced cholestasis is a common entity, seen with numerous classes of pharmacological agents. A high index of suspicion is required for the correct diagnosis. Different clinical syndromes may be recognized, with variable degrees of hepatitis in association with cholestasis. The most important aspect of treatment is prompt discontinuation of the offending drug. Several agents have been used for symptomatic relieve of the pruritus associated with cholestasis, including cholestyramine, ursodeoxycholic acid, and opiate antagonists, with limited results. Prognosis is usually good, with few cases of prolonged cholestasis leading to vanishing bile duct syndrome. Liver failure may rarely occur if diagnosis goes unrecognized and the inciting drug is not withdrawn.

Drug-induced cholestasis

Drugs may cause several overlapping syndromes of cholestasis, the pathophysiological syndrome resulting from impaired bile flow. These reactions comprise approximately 17% of all hepatic adverse drug reactions (ADRs) and they may be severe. Causes of 'pure' (bland) cholestasis include oestrogens and anabolic steroids; rarer associations are with antimicrobials and NSAIDs. 'Cholestatic hepatitis' is a common drug reaction in which liver injury and inflammation cause significant elevation of serum alanine aminotransferase (ALT) as well as cholestasis. Chlorpromazine and ketoconazole are classic examples, but it is now exemplified by amoxycillin-clavulanate and other oxy-penicillins. Chronic cholestasis results from small bile duct injury leading to the vanishing bile duct syndrome (VBDS), a disorder mimicking primary biliary cirrhosis, or from injury to larger bile ducts causing secondary sclerosing cholangitis. Whilst there is increasing evidence of a genetic predisposition to cholestatic drug reactions, there are currently no pretreatment tests to predict drug safety. Prevention of severe reactions therefore relies on early detection of liver injury and prompt drug withdrawal. Symptomatic management includes relief of pruritus and correction of fat-soluble vitamin deficiency. In small cohort studies, ursodeoxycholic acid (UDCA) arrested progressive cholestasis in two-thirds of cases, but evidence for use of corticosteroids is anecdotal. This review considers diagnosis, pathogenesis, prevention and management of drug-induced cholestasis, with particular reference to frequently- and newly-described causes.

Pharmacogenetics of hepatocellular transporters

One of the main functions of the liver is the production of bile and the biliary secretion of endogenous and exogenous substances, including drugs and drug metabolites. Bile formation is a complex sequence of cellular events, which involves uptake of bile constituents and xenobiotics on the basolateral (sinusoidal) plasma membrane of hepatocytes and secretion of cholephilic compounds across the apical (canalicular) membrane. These uptake and efflux processes are maintained by distinct transport systems expressed at the two polar surface domains of liver cells. Any functional disturbance of these canalicular transport systems can lead to cholestatic liver disease, which is associated with intracellular accumulation of toxic bile constituents and consecutive cholestatic liver cell damage. Interaction of drugs with hepatobiliary transport systems is increasingly recognized as cause of acquired cholestatic syndromes. Thereby, genetically determined alterations of hepatobiliary transporter functions are important risk factors for an individual's susceptibility to develop cholestasis. Especially, mutations in canalicular transporter genes can cause certain forms of hereditary cholestatic liver disease, including progressive familial intrahepatic cholestasis or intrahepatic cholestasis of pregnancy. In addition, systematic genetic screenings have discovered numerous single nucleotide polymorphisms in hepatobiliary transporter genes that lead to amino acid exchanges in the encoded proteins. However, the functional consequences and the clinical relevance of most of these polymorphisms remain to be defined. This overview summarizes the physiological function of human hepatobiliary transport systems and discusses the impact of their genetic variations for the pathophysiology of cholestatic syndromes and the pharmacogenetics of drug-induced cholestasis.

Understanding and controlling hepatobiliary function

Over the past decade, enormous progress has been made in identifying the mechanisms that underlie hepatobiliary excretion. A set of transport proteins mediates the canalicular transport of most important bile constituents. With the discovery of these transporter genes, the mechanism of bile formation could be partly elucidated and genetic defects caused by mutations in these genes identified. This progress is crucial not only for paediatric and adult hepatology, but also for pharmacology, because the characterization of these transport systems provides tools for the prediction of the pharmacokinetics of drugs. Indeed, there is a growing interest on the part of the pharmaceutical industry for research into transport systems in general and hepatobiliary secretion in particular. For all of these transporter genes, knockout mice have been bred that allow one to assess the in vivo function of each of these transporters with regard to their role in physiology and drug elimination.

Kava--the unfolding story: report on a work-in-progress

This paper, originated as a submission (now updated) to the U.K. Medicines Control Agency and Committee of Safety of Medicines (CSM) on January 11, 2002, in response to a report circulated by the German Federal Institute for Drugs and Medical Products (German initials are BfArM), a compilation of which is summarized in Appendix 2. This agency issued notification in late November 2001 of some thirty adverse events associated with the use of concentrated standardized preparations of kava (Piper methysticum, Forst. f.) reported from Germany and Switzerland. An analysis of the summary of the BfArM case reports (see Appendix 2) shows that these contain duplications among the cases cited. The original submission that was sent to the CSM January 2002 has been updated to the version published here. This new version was completed in April 2002. As a result of the alert from BfArM, the evaluation of kava's safety is now occurring on a worldwide basis and, being that this a matter of considerable importance to the public, the health care community, and regulatory authorities as well as to kava farmers throughout Polynesia, it is it important to depict this progress report. As such, this updated report does not provide final answers. The material released by the BfArM is lacking in detail; however, it is hoped that this report will shed light on the kava controversy. It is anticipated that there will be further updates shortly. This report, prepared on behalf of the Traditional Medicines Evaluation Committee, a subcommittee of the European Herbal Practitioners Association, argues that many of the adverse events cited by the BfArM should not be attributed to kava. In addition, the report states that the properties of concentrated standardized kava extracts - as opposed to preparations that closely approximate those created for traditional use - contribute to causing adverse events. This report proposes a number of simple measures that will ensure that safe kava preparations may continue to be available in the United Kingdom.

Genetic defects in hepatobiliary transport

Bile formation, the exocrine function of the liver, represents a process that is unique to the hepatocyte as a polarized epithelial cell. The generation of bile flow is an osmotic process and largely depends on solute secretion by primary active transporters in the apical membrane of the hepatocyte. In recent years an impressive progress has been made in the discovery of these proteins, most of which belong to the family of ABC transporters. The number of identified ABC transporter genes has been exponentially increasing and the mammalian subfamily now counts at least 52. This development has been of crucial importance for the elucidation of the mechanism of bile formation, and it is therefore not surprising that the development in this field has run in parallel with the discovery of the ABC genes. With the identification of these transporter genes, the background of a number of inherited diseases, which are caused by mutations in these solute pumps, has now been elucidated. We now know that at least six primary active transporters are involved in canalicular secretion of biliary components (MDR1, MDR3, BSEP, MRP2, BCRP and FIC1). Four of these transporter genes are associated with inherited diseases. In this minireview we will shortly describe our present understanding of bile formation and the associated inherited defects.

Hormone replacement therapy may improve hepatic function in women with Turner's syndrome

OBJECTIVE

Women with Turner's syndrome (TS) have recently been shown to be at an increased risk of developing chronic liver disease. There has been some concern that oestrogen replacement therapy may exacerbate hepatic dysfunction. The aim of this study was to assess hepatic function in women with TS and to determine the effect of oral oestradiol valerate on liver enzymes.

DESIGN AND PATIENTS

A retrospective review of liver enzymes of 80 women with TS, followed by a prospective study looking at serum liver enzyme concentrations in 20 women with TS following 3 months on and off hormone replacement therapy (HRT) (oestradiol valerate, 2 mg/levonorgestril 75 microg).

MEASUREMENTS

Liver enzymes (gamma glutamyl transferase, aspartate transaminase and alkaline phosphatase), albumin and bilirubin were measured on and off HRT. Viral hepatitis serology and liver autoantibodies were tested in patients with abnormal liver function.

RESULTS

Thirty-five out of 80 women (44%) had elevated serum liver enzyme concentrations. Two women (2.5%) had a mildly raised serum bilirubin, but protein synthesis was normal in all subjects. HRT resulted in a significant fall in all liver enzymes (P < 0.05) but did not affect serum protein concentrations

CONCLUSIONS

Women with Turner's syndrome often have elevated liver enzymes. Oestrogen/progestagen therapy using oestradiol valerate improves liver function in this group of patients. The mechanisms behind this are unclear.

Risk of obstetric cholestasis in sisters of index patients

The aim of the present study was to evaluate the rate of intrahepatic cholestasis of pregnancy in first-degree relatives of index patients. Index patients (n=65) with singleton pregnancies complicated by intrahepatic cholestasis were identified among the women (n=11 984) who gave birth at Kuopio University Hospital in 1994-1998. The pregnancy histories of relatives of 56 index patients were reviewed and the rate of cholestasis in first-degree relatives was compared with that in the general obstetric population. Obstetric cholestasis was experienced by 9% of the parous sisters and 11% of the mothers of the index patients. The risk per delivery was 6% in the first-degree relatives. The rate in the general obstetric population was 0.54%. The odds ratios and 95% confidence intervals were 12.6 (5.6-28.1) for the sisters and 12.2 (6.2-24.2) for the mothers. Obstetric cholestasis clusters within some families and is under strong genetic influence, although the precise genetic pattern remains obscure. The sisters of index patients are at an increased risk of the disorder and may benefit from close obstetric care.

Transdermal estrogen replacement therapy in postmenopausal women previously treated for porphyria cutanea tarda

Oral contraceptives and postmenopausal estrogen replacement therapy are recognized as risk factors for the development of porphyria cutanea tarda (PCT) in women. The recommended clinical practice is to withhold estrogen therapy in women who have had phlebotomy therapy for PCT and are clinically and biochemically normal. We tested the safety and efficacy of transdermal estrogen replacement therapy in 7 women previously treated for PCT and compared them with 19 non-porphyric control subjects treated with transdermal or oral estrogens. Gonadotrophic hormone levels, estrogen levels, liver function studies, body iron stores, urine porphyrin excretion, and cytochrome P4501A2 (CYP1A2) activity were monitored for 1 year. Four of the women previously treated for PCT completed the study. None had evidence of a porphyric relapse. CYP1A2 activity, measured by three different methods, did not differ between study subjects receiving estrogens, patients with active PCT, and non-porphyric control subjects, nor did CYP1A2 activity change during the study period. Gonadotrophic hormone levels fell and estrogen levels rose in all women receiving estrogens. The administration of estrogens by the transdermal route appeared to be safe in the small number of subjects we studied and should be considered for women previously treated for PCT.

Possible role of endogenous retinoid (Vitamin A) toxicity in the pathophysiology of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of unknown etiology commonly affecting women. It is characterized by progressive destruction of the small intrahepatic bile ducts and portal inflammation, leading to fibrosis and cirrhosis. The major signs and symptoms of PBC, which include pruritus, lethargy, the sicca syndrome, and osteoporosis, closely resemble the manifestations of hypervitaminosis A. Based on a review of the literature and other observations connecting PBC with retinoid metabolism (vitamin A and its derivatives), the hypothesis is proposed that exposure to excess endogenous retinoids contributes to the pathogenesis of PBC and may be to the cause of some of the signs and symptoms associated with the disease.

Hemochromatosis genes and other factors contributing to the pathogenesis of porphyria cutanea tarda

Inherited and acquired factors have been implicated in the pathogenesis of porphyria cutanea tarda (PCT), a disorder characterized by a photosensitive dermatosis and hepatic siderosis. This study, comprising 108 patients with PCT, was intended to define the role of hemochromatosis gene (HFE) mutations in the expression of PCT and to determine the contribution of acquired factors including alcohol, hepatitis C virus (HCV), and estrogen. The 2 known HFEmutations, cysteine 282 tyrosine (Cys282Tyr) and histidine 63 asparagine (His63Asp), were detected by polymerase chain reaction, and anti-HCV immunoglobulin G was detected serologically. Liver biopsies were graded for iron content, inflammation, and fibrosis. Estimates of alcohol and estrogen use were based on a questionnaire. Of the PCT patients tested, 19% were homozygous for the Cys282Tyr mutation; controls were equal to 0.5%. The compound heterozygous genotype was detected in 7% of the PCT patients; controls were less than 1%. The transferrin saturation, serum ferritin, and liver iron burden of all PCT patients were higher than those of nonporphyric controls. The highest values were found in PCT patients homozygous for the Cys282Tyr mutation. Of the patients studied, 59% were HCV positive (compared with 1.8% of the population), and 46% consumed more than 70 g of alcohol daily. Of the female patients, 63% were ingesting estrogens. Hepatic damage was most marked in patients with the Cys282Tyr/Cys282Tyr genotype who had HCV and drank heavily. Homozygosity for the Cys282Tyrmutation and HCV are the greatest risk factors for expression of PCT, and in most patients, more than 1 risk factor was identified. It was common for patients with HCV to consume alcohol. Patients with PCT should be screened for HFE mutations and for HCV.

Transplantation of fetal liver tissue suspension into the spleens of adult syngenic rats: effects of beta-naphthoflavone, phenobarbital and dexamethasone on cytochrome P450 isoforms expression and on glycogen storage

In the present study, the effect of beta-naphthoflavone (BNF), phenobarbital (PB) and dexamethasone (DEX) on the expression of three cytochrome P450 (P450) isoforms, 1A1, 2B1 and 3A2, and on glycogen storage was investigated in intrasplenic liver cell explants in comparison to adult liver. Fetal liver tissue suspensions were transplanted into the spleens of adult male syngenic Fisher inbred rats. Four months after surgery, transplant recipients and age matched controls were orally treated with BNF (1 x 50 mg/kg body weight (b.wt.)), PB (1 x 50 mg/kg b.wt.), DEX (for 3 days 4 mg/kg b.wt. per day), or the respective solvents (dimethylsulfoxide or 0.9% NaCl). The animals were sacrificed 24 (BNF, DEX) or 48 (PB) hours after the last treatment. The livers of both solvent treated transplant recipients and control rats displayed only in few liver lobules a slight P450 1A1, but in all lobules a strong P450 2B1 and 3A2 expression, which was all mainly located in the hepatocytes around the central veins (zone III, according to Rappaport). After BNF administration a P450 1A1 expression was induced in the hepatocytes of the peripheral regions of the liver lobules (zone I, according to Rappaport), whereas the staining of the hepatocytes around the central veins disappeared. Also the staining for P450 2B1 in the hepatocytes of zone III became slightly more pronounced. Following PB treatment the P450 1A1 expression in the hepatocytes of the central regions (zone III), as seen in few lobules after solvent treatment only, was reduced, whereas the staining for P450 2B1 and 3A2 was more pronounced in the hepatocytes of the intermedial and central regions of the liver lobules (zone II and III). DEX treatment diminished P450 1A1 and 2B1 expression within the livers of both transplant recipients and control rats. In contrast, the staining for P450 3A2 was enhanced in all regions of the liver lobules. Transplantation of fetal liver tissue suspensions into the spleens did not influence the inducibility of P450 isoforms expression within the respective livers of the animals. Spleens of control rats displayed no P450 isoforms expression without as well as with induction. In the explant containing spleens, however, similar to normal liver, the transplanted hepatocytes displayed nearly no P450 1A1, but a strong P450 2B1 and 3A2 expression. After BNF treatment a staining for P450 1A1 was induced and also the P450 2B1 expression was slightly more pronounced. PB treatment caused an increase in the staining for P450 2B1 and 3A2 and DEX administration for P450 3A2 within the transplanted hepatocytes. Additionally, after DEX treatment some bile ducts of the explants displayed a slight staining for P450 1A1, 2B1 and 3A2. All hepatocytes within the livers of both solvent treated transplant recipients and control rats displayed a slightly PAS-positive cytoplasma and, in most cases, homogeneously distributed, fine-grained, strongly PAS-stained granules indicating glycogen storage. No regional variance in the glycogen content of the hepatocytes was seen within the liver lobules, but there was a marked difference between the individual hepatocytes of the same lobular region in the extent of glycogen accumulation. The hepatocytes within the explants displayed the same type of glycogen storage as did the adult liver cells. BNF treatment did not display any effect on the glycogen accumulation in livers and intrasplenic liver cell explants. After PB administration, only in livers, but not in the transplants, the glycogen content in the hepatocytes around the central veins was slightly reduced. DEX treatment lead to an excessive storage of fat within the hepatocytes of both livers and spleens. Thus, the glycogen was displaced, leading to a "spoke-wheel" like pattern of glycogen storage. Additionally, within the hepatocytes of both livers and liver cell explants a higher amount of glycogen seemed to be stored and the granules appeared to be more coarse-grained. (ABSTRACT

Contraception in the patient with liver disease

Selection of a method of contraception in patients with liver disease can be complicated. Tubal ligation should be considered in the setting of chronic liver disease for those patients who have completed families. Multiple reversible methods of contraception are currently available but may affect hepatic disease. Estrogen-containing contraceptive methods are contraindicated in patients with acute liver disease. Progestin contraceptives appear to be safe and multiple delivery systems are available. With rare exception, barrier methods and the intrauterine device may be offered as alternative methods.