Progressive Familial Intrahepatic Cholestasis in Korea: A Clinicopathological Study of Five Patients

BACKGROUND: Progressive familial intrahepatic cholestasis (PFIC) is a heterogeneous group of autosomal recessive liver diseases that present as neonatal cholestasis. Little is known of this disease in Korea. METHODS: The records of five patients histologically diagnosed with PFIC, one with PFIC1 and four with PFIC2, by liver biopsy or transplant were reviewed, and ATP8B1 and ABCB11 mutation status was analyzed by direct DNA sequencing. Clinicopathological characteristics were correlated with genetic mutations. RESULTS: The first symptom in all patients was jaundice. Histologically, lobular cholestasis with bile plugs was the main finding in all patients, whereas diffuse or periportal cholestasis was identified only in patients with PFIC2. Giant cells and ballooning of hepatocytes were observed in three and three patients with PFIC2, respectively, but not in the patient with PFIC1. Immunostaining showed total loss of bile salt export pump in two patients with PFIC2 and focal loss in two. Lobular and portal based fibrosis were more advanced in PFIC2 than in PFIC1. ATP8B1 and ABCB11 mutations were identified in one PFIC1 and two PFIC2 patients, respectively. One PFIC1 and three PFIC2 patients underwent liver transplantation (LT). At age 7 months, one PFIC2 patient was diagnosed with concurrent hepatocellular carcinoma and infantile hemangioma in an explanted liver. The patient with PFIC1 developed steatohepatitis after LT. One patient showed recurrence of PFIC2 after 10 years and underwent LT. CONCLUSIONS: PFIC is not rare in patients with neonatal cholestasis of unknown origin. Proper clinicopathologic correlation and genetic testing can enable early detection and management.

Benign Recurrent Intrahepatic Cholestasis Type 2 in Siblings with Novel ABCB11 Mutations / 대한소아소화기영양학회지

Benign recurrent intrahepatic cholestasis (BRIC), a rare cause of cholestasis, is characterized by recurrent episodes of cholestasis without permanent liver damage. BRIC type 2 (BRIC2) is an autosomal recessive disorder caused by ABCB11 mutations. A 6-year-old girl had recurrent episodes of jaundice. At two months of age, jaundice and hepatosplenomegaly developed. Liver function tests showed cholestatic hepatitis. A liver biopsy revealed diffuse giant cell transformation, bile duct paucity, intracytoplasmic cholestasis, and periportal fibrosis. An ABCB11 gene study revealed novel compound heterozygous mutations, including c.2075+3A>G in IVS17 and p.R1221K. Liver function test results were normal at 12 months of age. At six years of age, steatorrhea, jaundice, and pruritus developed. Liver function tests improved following administration of phenylbutyrate and rifampicin. Her younger brother developed jaundice at two months of age and his genetic tests revealed the same mutations as his sister. This is the first report of BRIC2 confirmed by ABCB11 mutations in Korean siblings.

Study on mechanism of Dahuanglingxian Capsule for intervening gallstone formation by regulating ABCB11 and ABCC2 / 重庆医学

Objective To explore the mechanism of Dahuanglinxian Capsule for intervening gallstone formation by regulating the expression levels of ABCB11 and ABCC2 mRNA and protein.Methods Forty male C57BL/6 mice were divided into the normal group(group N),model group (group M),ursodeoxycholic acid group (group U) and Dahuanglinxian Capsule treatment group (group D),10 cases in each group.The group N was fed with normal diet,while the group M,U and D were fed with lithogenic fodder for 8 weeks.Meanwhile the group U and D were given the medication intervention,once daily,for continuous 8 weeks of gavage.After successful modeling,mRNA and protein expression levels of ABCB11 and ABCC2 were detected by RT-PCR and immunohistochemistry.Results Compared with the other three groups,the expressions of ABCB11 and ABCC2 mRNA gene and protein in M group were significantly reduced(P＜0.01);while,there was no statistical difference in the expressions of ABCB11 and ABCC2 mRNA and protein between the group D and N(P＞0.05).Conclusion Dahuanglinxian Capsule can prevent the gallstone formation by regulating the expression of ABCB11 and ABCC2 mRNA and protein.

Relationship between phenotype and genotype of ABCB11 deficiency in siblings and literature review / 中华儿科杂志

Objective@#To explore the relationship between genotype and phenotype of ABCB11 deficiency.@*Methods@#Clinical data of two siblings with ABCB11 deficiency were retrospectively analyzed. Related literature from PubMed, CNKI and Wangfang databases was reviewed to date (up to August 2017) with 'ABCB11 gene’ or 'bile salt export pump’, 'cholestasis’ and 'child’ as key words.@*Results@#The patients were siblings. Both of them presented as jaundice, pruritus and hepatosplenomegaly since 3 days after birth. Significant laboratory findings on admission of the older sister included high total bilirubin, 170 µmol/L;conjugated bilirubin, 115.8 µmol/L;alanine aminotransferase, 168 U/L;total bile acid 186.3 µmol/L and normal gamma-glutamyl transpeptidase. While routine laboratory data of the younger brother were as follows: total bilirubin, 148.8 µmol/L;conjugated bilirubin, 96.3 µmol/L;alanine aminotransferase, 232.8 U/L;total bile acid 226 µmol/L, and normal gamma-glutamyl transpeptidase.Both received ursodeoxycholic acid and fat-soluble vitamins. Liver pathology of the younger brother showed giant hepatocytes with ballooning degeneration, focal necrosis and intrahepatic cholestasis. Both the patients harbor the same compound heterozygous mutations in ABCB11 gene, c.145C>T (p.Q49X) and c.1510G>A (p.E504K). The sister is 9 years old now, with normal liver function. Jaundice faded around 3 months after birth, pruritus relieved at age 5, and medications was stopped since then. The brother progressed to liver failure after an operation on perianal abscess when he was 8-month-old, and received living-related liver transplantation when he was 9 month and 20 days old (from his mother). Now he is 1 year and 5 months old, with normal liver function. Both are under our follow-up. Literature review revealed 18 ABCB11 deficiency patients from 7 families who had apparent different prognoses, within each family the siblings had the same ABCB11 gene mutation. Seven cases relieved after ursodeoxycholic acid therapy and/or partial external biliary diversion, 5 received orthotopic liver transplantation, 2 developed hepatocellular carcinoma and 4 cases died in childhood.@*Conclusions@#The clinical manifestations of ABCB11 deficiency may vary greatly in patients carrying the same genotype, even in siblings. Patients should be managed in individualized maner.

A Rare BSEP Mutation Associated with a Mild Form of Progressive Familial Intrahepatic Cholestasis Type 2

ABSTRACT Progressive Familial Intrahepatic Cholestasis type 2 (PFIC2) is a rare cholestatic disorder diagnosed in infancy or childhood that can lead to severe hepatic fibrosis and liver failure. Mutations in the ABCB11 gene result in a deficiency of the bile salt export protein (BSEP) and accumulation of bile inside the hepatocytes. Hepatocellular carcinoma is another condition associated with severe forms of deletion mutations in the ABCB11 gene. Treatment options including ursodeoxycholic acid biliary diversion have mixed outcomes and some patients require liver transplantation. Here, we describe two siblings with an extremely mild form of PFIC2 inherited from heterozygous parents. The elder sibling had acute liver failure at the age of six months and both siblings had pruritus, cholestasis, coagulopathy and fat-soluble-vitamin deficiencies in infancy but have been asymptomatic past infancy. Genetic testing of the siblings revealed that each were compound heterozygotes for two missense mutations of the ABCB11 gene: p.C68Y and p.R832H. Medical treatment typical for PFIC2 has not been necessary for either patient. This is the first report of these variants following a mild course in two affected patients.(AU)

Correlation of variations of ABCB11 gene and primary intrahepatic stone / 中华消化外科杂志

Objective To investigate the correlation of variations of ABCB11 gene and primary intrahepatic stone (PIS).Methods The retrospective case-control study was conducted.The clinical data of 319 patients with PIS and 344 healthy controls who were admitted to the Southwest Hospital of the Third Military Medical University between December 2012 and December 2015 were collected.Three hundred and ninteen patients with PIS and 344 healthy controls were respectively allocated into the PIS and control groups.Twenty-seven exons in ABCB11 gene were detected via polymerase chain reaction (PCR) and DNA sanger sequencing.Observation indicators included:(1) variations and genotype frequency distribution of ABCB11 gene in the 2 groups;(2) correlation analysis between variations of ABCB11 gene and clinical data of patients with PIS:preoperative indicators of liver function test,recurrent episodes of cholangitis,preoperative obstructive jaundice,type and recurrence of stones.Comparison between groups in variations and genotype frequency distribution of ABCB11 gene was analyzed by the Logistic regression.The Kruskal-Wallis H test was performed to explore the correlation between genotype of ABCB11 gene and clinical test results of patients with PIS.Correlation between genotype of ABCB11 gene and clinicopathological data of patients with PIS was analyzed by the chi-square test.Results (1) Variations and genotype frequency distribution of ABCB11 gene in the 2 groups:whole-exome sequencing results showed that synonymous mutations of rs3815675,rs2287616 and rs497692 and missense mutations of rs2287617,rs2287622 and rs118109635 in the PIS group were respectively detected in exon 4,9,24 and 9,13,21.CT genotype frequency of rs118109635 was 4.70％(15/319) in the PIS group and 1.45％ (5/344) in the control group,respectively,with a statistically significant difference [OR=3.49,95％ confidence interval (CI):1.17-10.40,P＜0.05].GG and AG+GG genotype frequency of rs497692 were 46.08％ (147/319),87.46％ (279/319) in the PIS group and 37.79％ (130/344),79.36％ (273/344) in the control group,respectively,with a statistically significant difference (OR=1.73,1.65,95％ CI:1.05-2.83,1.04-2.61,P＜0.05).(2) Correlation analysis between variations of ABCB11 gene and clinical data of patients with PIS:levels of glutamyl-transpeptidase (GGT),alkaline phosphatase (ALP) and direct bilirubin (DBil) in the PIS group were 167 U/L (range,7-1 968 U/L),166 U/L (range,36-1 527 U/L),4 μmol/L(range,1-272 μmol/L) in the CC genotype of rs118109635 and 433 U/L(range,17-864 U/L),232 U/L (range,85-613 U/L),6 μmol/L(range,2-173 μmol/L) in the CT genotype of rs118109635,respectively,with a statistically significant difference (H=6.025,5.879,8.056,P＜0.05).Globulin level of PIS group was respectively 32 g/L (range,20-40 g/L),34 g/L(range,17-50 g/L) and 33 g/L(range,14-49 g/L) in the AA,AG and GG genotype of rs497692,respectively,with a statistically significant difference (H=12.119,P＜0.05).Of 81 patients with recurrence of PIS,GG and GA genotypes of rs2287617 were detected in 78 and 3 patients,respectively,with a statistically significant difference (x2=5.367,P＜0.05);TT,TC and CC genotypes of rs2287622 were detected in 12,39 and 30 patients,respectively,with a statistically significant difference (x2=6.153,P＜0.05).Of 127 patients with obstructive jaundice,116 and 11 patients had CC and CT genotypes of rs118109635,respectively,with a statistically significant difference (x2=7.381,P＜0.05);11,43 and 73 patients had AA,AG and GG genotypes of rs497692,respectively,with a statistically significant difference (x2 =11.364,P＜0.05).Conclusion There is a correlation between rs118109635 and rs497692 of ABCB11 gene and PIS,meanwhile,the above variation loci are associated with obstruction of biliary tract and cholestasis.

Early Diagnosis of ABCB11 Spectrum Liver Disorders by Next Generation Sequencing / 대한소아소화기영양학회지

PURPOSE: The goal of this study was the early diagnosis of ABCB11 spectrum liver disorders, especially those focused on benign recurrent intrahepatic cholestasis and progressive familial intrahepatic cholestasis. METHODS: Fifty patients presenting neonatal cholestasis were evaluated to identify underlying etiologies. Genetic analysis was performed on patients suspected to have syndromic diseases or ABCB11 spectrum liver disorders. Two families with proven ABCB11 spectrum liver disorders were subjected to genetic analyses to confirm the diagnosis and were provided genetic counseling. Whole exome sequencing and Sanger sequencing were performed on the patients and the family members. RESULTS: Idiopathic or viral hepatitis was diagnosed in 34%, metabolic disease in 20%, total parenteral nutrition induced cholestasis in 16%, extrahepatic biliary atresia in 14%, genetic disease in 10%, neonatal lupus in 2%, congenital syphilis in 2%, and choledochal cyst in 2% of the patients. The patient with progressive familial intrahepatic cholestasis had novel heterozygous mutations of ABCB11 c.11C>G (p.Ser4*) and c.1543A>G (p.Asn515Asp). The patient with benign recurrent intrahepatic cholestasis had homozygous mutations of ABCB11 c.1331T>C (p.Val444Ala) and heterozygous, c.3084A>G (p.Ala1028Ala). Genetic confirmation of ABCB11 spectrum liver disorder led to early liver transplantation in the progressive familial intrahepatic cholestasis patient. In addition, the atypically severe benign recurrent intrahepatic cholestasis patient was able to avoid unnecessary liver transplantation after genetic analysis. CONCLUSION: ABCB11 spectrum liver disorders can be clinically indistinguishable as they share similar characteristics related to acute episodes. A comprehensive genetic analysis will facilitate optimal diagnosis and treatment.

Bile acids and sphingosine-1-phosphate receptor 2 in hepatic lipid metabolism

The liver is the central organ involved in lipid metabolism. Dyslipidemia and its related disorders, including non-alcoholic fatty liver disease (NAFLD), obesity and other metabolic diseases, are of increasing public health concern due to their increasing prevalence in the population. Besides their well-characterized functions in cholesterol homoeostasis and nutrient absorption, bile acids are also important metabolic regulators and function as signaling hormones by activating specific nuclear receptors, G-protein coupled receptors, and multiple signaling pathways. Recent studies identified a new signaling pathway by which conjugated bile acids (CBA) activate the extracellular regulated protein kinases (ERK1/2) and protein kinase B (AKT) signaling pathway via sphingosine-1-phosphate receptor 2 (S1PR2). CBA-induced activation of S1PR2 is a key regulator of sphingosine kinase 2 (SphK2) and hepatic gene expression. This review focuses on recent findings related to the role of bile acids/S1PR2-mediated signaling pathways in regulating hepatic lipid metabolism.

A novel ABCB11 mutation in an Iranian girl with progressive familial intrahepatic cholestasis.

Progressive familial intrahepatic cholestasis is an autosomal recessive liver disorder caused by (biallelic) mutations in the ATP8B1 of ABCB11 gene. A nine‑year‑old girl with cholestasis was referred for genetic counseling. She had a family history of cholestasis in two previous expired siblings. Genetic analysis of the ABCB11 gene led to the identification of a novel homozygous mutation in exon 25. The mutation 3593‑ A > G lead to a missense mutation at the amino acid level (His1198Arg). This mutation caused PFIC2 due to abnormal function in the bile salt export pump protein (BSEP).

Genetic diagnosis of progressive familial intrahepatic cholestasis type 2 / 临床儿科杂志

Objectives To investigate the clinical features of progressive familial intrahepatic cholestasis type 2 (PFIC2) and to illustrate the importance of genetic diagnosis. Methods The mutations in 27 exons of ABCB11 encoding bile salt export pump (BSEP) were identiifed using polymerase chain reaction (PCR) and direct DNA sequencing in 6 children with suspected PFIC2. The pathogenicity of the newly identiifed mutations were predicted by SIFT, PolyPhen-2, SNPs&GO software. The clini-cal features and laboratory examinations were reviewed. Results Four disease-causing mutations, p.R928*, p.E554K, p.R575Q and p.Y337H were identiifed, and the last three mutations were novel. These three kinds of novel mutations can cause the disease. Two children with genetic diagnosis had such manifestations as onset within a month after birth, jaundice, hepatosplenomegaly, upset, increased levels of total bilirubin and direct bilirubin, GGT<100 U/L and high levels of total bile acid. Conclusions Genetic diagnosis is a potent tool for clinical diagnosis of PFIC2.

Significance of V444A polymorphism of ABCB11 gene in neonatal cholestasis / 中华实用儿科临床杂志

Objective To explore the association between one common variant in ABCB11-1331T ＞ C (V444A) and neonatal cholestasis.Methods One hundred and ninety-two children with neonatal cholestasis were enrolled as case group,and 196 healthy children were selected as healthy control group.The SNP site of V444A was tested by fluorescent quantitative PCR.Fisher's exact test was performed to detect the differences in allele and genotype distribution between the 2 groups.Wilcoxon rank-sum test was used to test the differences of total bilirubin,total bile acid,γ-glutamyl transpeptidase levels among the patients with different genotypes.Results TT,TC and CC genotypic distribution of V444A were not significantly different between patients and controls (P =0.530).The T allele in the case group accounted for 29.9％,in the healthy control group accounted for 26.3％,there was no significant difference between the 2 groups(OR =1.12,P =0.264).Total bilirubin,total bile acid,γ-glutamyl transpeptidase levels in patients with different genotypes of V444A were also not statistically different (all P ＞ 0.05).Conclusion Only V444A variant may have no impacts on neonatal cholestasis.

ABCB11 Gene Variation and Cholestatic Diseases / 实用儿科临床杂志

ABCB11 gene encodes bile salt export pump (BSEP).It is almost exclusively expressed in the canalicular microvilli of liver.It is the principal conveyor of bile acids from hepatocyte cytoplasm into bile canaliculus.It is clearly that BSEP defects can induce progressive familial intrahepatic cholestasis type 2 and benign recurrent intrahepatic cholestasis type 2.ABCB11 gene variation are also responsible for intrahepatic cholestasis of pregnancy,drug-induced cholestasis,primary sclerosis cholangitis and primary bile cirrhosis.This paper reviewed the association of ABCB11 gene variation and these diseases.