Benign recurrent intrahepatic cholestasis: a long-term follow-up study of two patients

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.

Animal models to study bile acid metabolism

The use of animal models, particularly genetically modified mice, continues to play a critical role in studying the relationship between bile acid metabolism and human liver disease. Over the past 20 years, these studies have been instrumental in elucidating the major pathways responsible for bile acid biosynthesis and enterohepatic cycling, and the molecular mechanisms regulating those pathways. This work also revealed bile acid differences between species, particularly in the composition, physicochemical properties, and signaling potential of the bile acid pool. These species differences may limit the ability to translate findings regarding bile acid-related disease processes from mice to humans. In this review, we focus primarily on mouse models and also briefly discuss dietary or surgical models commonly used to study the basic mechanisms underlying bile acid metabolism. Important phenotypic species differences in bile acid metabolism between mice and humans are highlighted.

Successful treatment with colestimide for a bout of cholestasis in a Japanese patient with benign recurrent intrahepatic cholestasis caused by ATP8B1 mutation

Benign recurrent intrahepatic cholestasis (BRIC) is an autosomal recessive disorder characterized by bouts of cholestasis that resolve spontaneously without leaving considerable liver damage. Most of BRIC patients have mutations in ATP8B1 gene coding FIC1 protein. It has been suggested that an imbalance between the gut absorption of bile acids and the liver excretion possibly causes the development of cholestasis. We encountered a Japanese woman patient with familial intrahepatic cholestasis type 1 (FIC1) deficiency manifesting BRIC, in whom a rapid and gross elevation of serum total bile acid (TBA) level preceded that of serum total bilirubin level. Interestingly, the early administration of colestimide prevented the development of hyperbilirubinemia along with the additional elevation of serum TBA level. This case suggests that FIC1 deficiency causes an imbalance between the gut absorption of bile acids and the liver excretion leading to cholestasis, and raised the possibility that colestimide may be used as an optional treatment for BRIC.

Depletion of high-density lipoprotein and appearance of triglyceride-rich low-density lipoprotein in a Japanese patient with FIC1 deficiency manifesting benign recurrent intrahepatic cholestasis

OBJECTIVE

Lipoprotein metabolism in FIC1 deficiency due to ATP8B1 mutations has never been studied sufficiently. This study was performed to investigate the detailed lipoprotein metabolism in benign recurrent intrahepatic cholestasis (BRIC) caused by FIC1 deficiency.

PATIENTS AND METHODS

Lipoprotein profile and major lipoprotein regulators such as lecithin:cholesterol acyltransferase (LCAT), hepatic triglyceride lipase (HTGL), lipoprotein lipase, and cholesteryl ester transfer protein in a Japanese patient with BRIC were serially examined during a bout of cholestasis. Liver expression of farnesoid X receptor (FXR), which suppresses high-density lipoprotein (HDL) generation, was also examined.

RESULTS

Hypercholesterolemia and lipoprotein X accumulation were never observed throughout this study. When the cholestasis was severe, triglyceride-rich low-density lipoprotein (LDL) accounted for most of the plasma lipoproteins whereas HDL was hardly detectable. Concurrently, activities of all regulators were decreased, together with decreases of the serum parameter for liver protein synthesis. In particular, suppressions of LCAT and HTGL activities were severe and greatly contributed to the appearance of triglyceride-rich LDL. As the cholestasis improved, this LDL gradually transformed into normal LDL with the recoveries of LCAT and HTGL activities. The activities of all regulators for the last 1 to 2 months were normal but HDL remained depleted. His liver showed low FXR expression compared with control livers.

CONCLUSIONS

The present study showed an appearance of triglyceride-rich LDL due to suppressions of LCAT and HTGL activities and a depletion of HDL that is not able to be explained by lipoprotein regulators or FXR in our patient.

Benign recurrent intrahepatic cholestasis

Benign recurrent intrahepatic cholestasis (BRIC) is a rare cause of cholestasis in children. The disease may start in infancy or early childhood. Jaundice persists or recurs throughout life but does not lead to chronic liver disease or cirrhosis. Treatment is mostly symptomatic. The condition has not been reported in Indian children. We report an interesting case of BRIC in a 9-year-old boy who had recurrent episodes of jaundice since when he was 1 yr old.

Progressive familial intrahepatic cholestasis: genetic disorders of biliary transporters

Progressive familial intrahepatic cholestasis types 1, 2 and 3 are childhood diseases of the liver. Benign recurrent intrahepatic cholestasis is predominantly an adult form with similar clinical symptoms that spontaneously resolve. These genetic disorders have significantly helped to unravel the basic mechanisms of the canalicular bile transport processes. Progressive familial intrahepatic cholestasis type 1 involves a gene also linked to benign recurrent intrahepatic cholestasis. The gene codes for an aminophospholipid translocase protein that maintains the integrity of the membrane. How a mutation in this protein causes cholestasis is unknown but is thought to involve the enterohepatic recirculation of bile acids. Progressive familial intrahepatic cholestasis types 2 and 3 involve the canalicular bile salt export pump and a phospholipid translocase, respectively, both of which are fundamental to bile secretion. This review covers the clinical manifestations, genetics, treatment and mechanism of each disease.

Benign recurrent intrahepatic cholestasis progressing to progressive familial intrahepatic cholestasis: low GGT cholestasis is a clinical continuum

Benign recurrent intrahepatic cholestasis (BRIC) is an autosomal recessive liver disease, characterised by intermittent attacks of cholestasis, which can start at any age and last for several weeks to months. Characteristically serum GGT activity is low and normal liver structure is preserved. Progressive familial intrahepatic cholestasis (PFIC) is another liver disease, characterised by severe cholestasis, starting almost invariably before 6 months of age. All patients progress to cirrhosis, liver failure and death, unless a liver transplantation is performed. We now identified four patients who presented in childhood with recurrent attacks of cholestasis, while in the course of the disease the cholestasis gradually became permanent. Although liver biopsies performed in the early stages of the disease showed normal liver architecture, late stage biopsies revealed evident fibrosis with porto-portal septa formation. In conclusion, the disease of these patients started with the clinical and histopathological characteristics of BRIC but progressed to PFIC.

FIC1, the protein affected in two forms of hereditary cholestasis, is localized in the cholangiocyte and the canalicular membrane of the hepatocyte

BACKGROUND/AIMS

FIC1 (familial intrahepatic cholestasis 1) is affected in two clinically distinct forms of hereditary cholestasis, namely progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis. Here we examined the subcellular localization of this protein within the liver.

METHODS

Antibodies raised against different epitopes of human FIC1 were used for immunoblot analysis and immunohistochemical detection of FICI.

RESULTS

Immunoblot analysis of intestine and liver tissue extracts from human, rat and mouse origin indicated that the antibodies raised against FIC1 specifically detected FIC1 as a 140-kDa protein. In the liver homogenate of a PFIC1 patient, FIC1 could not be detected. Analysis of isolated rat liver membrane vesicles indicated that this protein is predominantly present in the canalicular membrane fraction. Immunohistochemical detection of the protein in liver sections confirmed that FIC1 was present in the canalicular membrane, whereas no staining was observed in the PFIC1 patients liver. Double label immunofluorescence of murine liver revealed that FIC1 colocalized with cytokeratin 7 in cholangiocytes.

CONCLUSIONS

The localization of FIC1 in the canalicular membrane and cholangiocytes suggests that it may directly or indirectly play a role in bile formation since mutations in FICI are associated with severe symptoms of cholestasis.

[Benign recurrent intrahepatic cholestasis: a seven-year follow-up report]

Benign recurrent intrahepatic cholestasis is a rare autosomal recessive disorder characterized by repeated episodes of intense pruritus and jaundice. Patients are completely asymptomatic for months to years between symptomatic periods. We report a case of a patient with a 7-year history of benign recurrent intrahepatic cholestasis. During the follow-up period the patient has suffered three attacks of cholestasis, confirmed by biochemical tests and histological exam. Liver enzymes were normal between the cholestasis episodes. Despite multiple attacks of cholestasis, no permanent liver damage has occurred. Although the diagnosis of benign recurrent intrahepatic cholestasis is rare, it should be included in the evaluation of a patient with cholestasis. The patients should be reassured of the benign course of this disorder.

Benign recurrent intrahepatic cholestasis in a Saudi child

We report a case of benign recurrent intrahepatic cholestasis (BRIC) in an 11-year-old Saudi girl who developed three episodes of pruritus and jaundice at the ages of 4, 8, and 9 years. These episodes were almost stereotypic and lasted 5-8 weeks. Although she had elevated liver enzymes and serum bile acids in her blood during the attacks, they returned to normal between attacks. Thorough investigation excluded other causes of liver disease and her recurrent attacks were shortened by cholestyramine therapy. A diagnosis of BRIC should be kept in mind in patients with cholestasis.

Other hereditary diseases and the liver

In this chapter, an abbreviated account is presented on the subject of hereditary diseases and the liver. However, it is incomplete because Alagille syndrome, storage disorders, alpha-1-antitrypsin deficiency and Wilson disease are not included as they appear in other chapters of this volume. Biliary atresia is omitted because all available evidence does not support any significant genetic association. Molecular biological techniques have enabled linkage of several liver cholestatic disorders to chromosomal loci, and further characterization of the canalicular bile salt transporter (cBST) will advance our understanding of pathogenetic mechanisms involved in benign and progressive cholestatic syndromes. Disorders that have been treated as separate entities may have common 'roots', exemplified by the concept of the ductal plate malformation in fibropolycystic disease. Whereas the majority of disorders referred to in this chapter present early in life, there are several that are associated with liver failure in the neonatal period, which makes early recognition particularly important. Liver transplantation offers a cure for many hereditary disorders affecting the liver but it is not applicable to all.

A gene encoding a P-type ATPase mutated in two forms of hereditary cholestasis

Cholestasis, or impaired bile flow, is an important but poorly understood manifestation of liver disease. Two clinically distinct forms of inherited cholestasis, benign recurrent intrahepatic cholestasis (BRIC) and progressive familial intrahepatic cholestasis type 1 (PFIC1), were previously mapped to 18q21. Haplotype analysis narrowed the candidate region for both diseases to the same interval of less than 1 cM, in which we identified a gene mutated in BRIC and PFIC1 patients. This gene (called FIC1) is the first identified human member of a recently described subfamily of P-type ATPases; ATP-dependent aminophospholipid transport is the previously described function of members of this subfamily. FIC1 is expressed in several epithelial tissues and, surprisingly, more strongly in small intestine than in liver. Its protein product is likely to play an essential role in enterohepatic circulation of bile acids; further characterization of FIC1 will facilitate understanding of normal bile formation and cholestasis.

Autosomal-recessive inheritance of benign recurrent intrahepatic cholestasis

Benign recurrent intrahepatic cholestasis (BRIC) is a rare disorder characterized by recurrent episodes of cholestasis without permanent liver damage. Familial and sporadic cases have been described. Based on existing evidence, both autosomal-recessive and autosomal-dominant inheritance have been considered. We describe a large Dutch pedigree with 4 patients, strongly suggesting autosomal-recessive inheritance.

The adverse influence of pregnancy upon sulphation: a clue to the pathogenesis of intrahepatic cholestasis of pregnancy?

Sulphation of oestrogens and monohydroxy bile acids is important in attenuating their cholestatic potential. Thus, impairment of sulphation could lead to retention of cholestatic compounds and precipitate intrahepatic cholestasis in susceptible individuals. We tested the hypothesis that such a mechanism may be involved in the pathogenesis of intrahepatic cholestasis of pregnancy. In vivo and in vitro assessment of sulphation capacity was performed in patients with cholestasis of pregnancy, compared with control females on and off the oestrogen-containing oral contraceptive pill and control individuals during normal pregnancy and post partum, to assess the influence of high oestrogen states upon this metabolic pathway. During in vivo studies utilising paracetamol as a metabolic probe, the proportion of paracetamol sulphate and sulphate: glucuronide ratio were decreased in those with elevated oestrogens, whether the rise in oestrogens was endogenous, in pregnancy (paracetamol sulphate p < 0.05; paracetamol sulphate:glucuronide ratio p < 0.01), or exogenous, with the contraceptive pill (paracetamol sulphate p = 0.2; paracetamol sulphate:glucuronide ratio p < 0.001). In vitro, platelet sulphotransferase activity was measured, utilising phenol as substrate. Sulphotransferase activity decreased during pregnancy compared with repeat measurements post partum (p < 0.005) and compared with non-pregnant individuals (p < 0.05). In conclusion, we have shown that elevated oestrogens are associated with significant impairment in sulphation capacity. An imbalance of sulphation with glucuronidation provoked by high circulating oestrogen levels may be contributory in the pathogenesis of cholestasis of pregnancy.

Therapy with ursodeoxycholic acid in cholestatic liver disease

Ursodeoxycholic acid (UDCA) has beneficial effects on symptoms, liver biochemistry and, possibly, liver histology in primary biliary cirrhosis and other cholestatic liver diseases. UDCA may exert these beneficial effects by a direct hepatoprotective effect, by influencing the enterohepatic circulation of endogenous bile salts, by enhancing bile flow through a cholehepatic shunt mechanism or by immune modulation. In the present article, established and potential indications for UDCA are reviewed.

Benign recurrent intrahepatic cholestasis: altered bile acid metabolism

Altered bile acid metabolism has been claimed to play a role in the etiology of benign recurrent intrahepatic cholestasis (BRIC). Therefore, we studied bile acid metabolism in detail in 10 patients with this syndrome. Pool sizes of both primary bile acids were estimated simultaneously, using deuterated cholic acid and chenodeoxycholic acid. The pool sizes of cholic acid and chenodeoxycholic acid, expressed in micromoles per kilogram body weight, were significantly contracted in BRIC patients during a cholestasis-free period: 8.0 +/- 4.2 and 11.7 +/- 4.7, respectively, versus 24.1 +/- 11.7 and 22.9 +/- 7.8 in controls. Fractional turnover rates (per day) for cholic acid and chenodeoxycholic acid were increased: 0.70 +/- 0.29 and 0.58 +/- 0.27, respectively, versus 0.29 +/- 0.12 and 0.23 +/- 0.10 in controls. Bile acid pool composition expressed as percentages in BRIC patients was cholic acid 34 +/- 17, chenodeoxycholic acid 38 +/- 9, deoxycholic acid 27 +/- 18, and lithocholic acid 1 +/- 1, with a glycine to taurine conjugation ratio of 6.7 +/- 4.9. Corresponding values for 32 controls were cholic acid 57 +/- 13, chenodeoxycholic acid 29 +/- 9, deoxycholic acid 14 +/- 9, and lithocholic acid less than 1, with a glycine to taurine conjugation ratio of 2.4 +/- 1.3. Fecal bile acid loss, in micromoles per kilogram body weight per day, was 11.2 +/- 9.0 in BRIC patients compared with 2.8 +/- 1.4 in controls. The serum 7 alpha-hydroxycholesterol level (nanomoles per liter) was significantly increased in BRIC patients: 326 +/- 179 versus 171 +/- 90 in controls. These results suggest that in BRIC patients spillover of bile acids into the colon occurs, which leads to increased fecal bile acid loss and a reduced bile acid pool size. Increased serum 7 alpha-hydroxycholesterol is probably indicative of an accelerated bile acid synthesis rate due to increased activity of cholesterol 7 alpha-hydroxylase, the enzyme catalyzing the first step in the major pathway of bile acid synthesis. The results of our study suggest that in BRIC patients a contracted bile acid pool increases the susceptibility of the liver for cholestatic agents.