Xenobiotic Nuclear Receptor Signaling Determines Molecular Pathogenesis of Progressive Familial Intrahepatic Cholestasis.

Progressive familial intrahepatic cholestasis (PFIC) is a genetically heterogeneous disorder of bile flow disruption due to abnormal canalicular transport or impaired bile acid (BA) metabolism, causing excess BA accumulation and liver failure. We previously reported an intrahepatic cholestasis mouse model based on loss of function of both farnesoid X receptor (FXR; NR1H4) and a small heterodimer partner (SHP; NR0B2) [double knockout (DKO)], which has strong similarities to human PFIC5. We compared the pathogenesis of DKO livers with that of another intrahepatic cholestasis model, Bsep-/-, which represents human PFIC2. Both models exhibit severe hepatomegaly and hepatic BA accumulation, but DKO showed greater circulating BA and liver injury, and Bsep-/- had milder phenotypes. Molecular profiling of BAs uncovered specific enrichment of cholic acid (CA)-derived BAs in DKO livers but chenodeoxycholate-derived BAs in Bsep-/- livers. Transcriptomic and proteomic analysis revealed specific activation of CA synthesis and alternative basolateral BA transport in DKO but increased chenodeoxycholic acid synthesis and canalicular transport in Bsep-/-. The constitutive androstane receptor (CAR)/pregnane X receptor (PXR)-CYP2B/CYP2C axis is activated in DKO livers but not in other cholestasis models. Loss of this axis in Fxr:Shp:Car:Pxr quadruple knockouts blocked Cyp2b/Cyp2c gene induction, impaired bilirubin conjugation/elimination, and increased liver injury. Differential CYP2B expression in DKO and Bsep-/- was recapitulated in human PFIC5 and PFIC2 livers. In conclusion, loss of FXR/SHP results in distinct molecular pathogenesis and CAR/PXR activation, which promotes Cyp2b/Cyp2c gene transcription and bilirubin clearance. CAR/PXR activation was not observed in Bsep-/- mice or PFIC2 patients. These findings provide a deeper understanding of the heterogeneity of intrahepatic cholestasis.

Expression and significance of dendritic cells and Th17/Treg in serum and placental tissues of patients with intrahepatic cholestasis of pregnancy.

PURPOSE: Dendritic cells (DCs) are involved in immune system, which can also regulate the differentiation of T helper 17 (Th17) and regulatory T cells (Treg). DCs and Th17/Treg participate in preeclampsia and recurrent spontaneous abortion (RSA), but there is still lack of research in intrahepatic cholestasis of pregnancy (ICP). The aim was to evaluate the expression and significance of CD83+DCs, CD1a+DCs, interleukin-17 (IL-17) and IL-35 in serum and placental tissues of patients with ICP. METHODS: Thirty cases of mild ICP, 25 cases of severe ICP were selected, and 30 cases of normal pregnant women were selected as control group. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry (IHC) were used to detect the expression of CD83+DCs, CD1a+DCs, IL-17 and IL-35 in serum and placenta tissues, respectively. RESULTS: There were more CD83+DCs, IL-17 expressed in placenta from women with ICP than in normal pregnancies, while the number of decidual CD1a+DCs, IL-35 was significantly lower in ICP than in normal pregnant women. The comparison within three groups had statistical difference (p < .05). Serum CD83+DCs and CD1a+DCs levels had no significance. IL-17 was higher in ICP, while IL-35 was lower. CONCLUSIONS: DCs are involved in damaging the maternal-fetal immune tolerance by changing the phenotype and mature state, which may affect the differentiation of Th17/Treg to cause ICP.

Cholangitis Lenta: A Clinicopathologic Study of 28 Cases.

Cholangitis lenta, also known as ductular cholestasis, cholangiolar cholestasis, or subacute nonsuppurative cholangitis, is an uncommon type of cholangitis characterized by ductular reaction with inspissated bile in dilated ductules. The literature on this unique entity has been limited to only a few studies based on a very limited number of cases, which importantly suggest an association with sepsis and/or intra-abdominal infection. The clinical, laboratory, and histologic features of 28 cases of cholangitis lenta are herein investigated. Twenty-five (89.3%) patients were liver transplant recipients. Most notably, the majority of patients showed clinical signs and symptoms of sepsis, and positive microbiology cultures were demonstrated in 24 (85.7%) patients. Significantly, 15 (53.6%) patients died during their hospitalization, ranging from 2 days to 5 months after the initial liver biopsy that showed histologic features of cholangitis lenta. Among the 13 discharged patients, including 2 who received retransplantation, 4 (14.3%) subsequently died of pneumonia, graft dysfunction, or fungal infection within 7 months to 9.3 years. Only 9 (32.1%) patients were alive at the last follow-up, with the follow-up time ranging from 3.8 to 10.4 years. Our data show that the finding of cholangitis lenta on liver biopsy is thus frequently associated with sepsis and with a high mortality rate. Therefore, accurate diagnosis of this condition on liver biopsy is imperative as it is an indication that the patient may have a potentially life threatening condition that requires immediate medical attention and management.

Diagnostic considerations for cholestatic liver disease.

Cholestatic liver disease results from insufficient bile synthesis, secretion and/or flow through the biliary tract. Common presenting features include fatigue, pruritus, and cholestatic liver enzyme abnormalities wherein elevations of serum alkaline phosphatase and gamma-glutamyltransferases levels exceed those of alanine and aspartate aminotransferases. With prolonged cholestasis, fat soluble vitamin deficiencies, fibrosis, cirrhosis, and, on occasion, carcinoma of the biliary tract or liver can occur. Once mechanical obstruction to bile flow has been ruled out, the majority of causes can be classified as immune-mediated, infectious, or miscellaneous. Because specific therapeutic options are increasing for many causes of cholestasis, an accurate diagnosis is an important first step towards treatment. Thus, this review focuses on the diagnostic features of non-mechanical causes of cholestasis.

Dermatoses of pregnancy: Nomenclature, misnomers, and myths.

The most recent reclassification of dermatoses of pregnancy includes polymorphic eruption of pregnancy, atopic eruption of pregnancy, and pemphigoid gestationis; intrahepatic cholestasis of pregnancy, strictly not a dermatosis, was included in specific dermatoses of pregnancy for working purposes. Another dermatosis, pustular psoriasis of pregnancy, could be included for similar reasons. The nomenclature of these pregnancy-specific eruptions has been revised several times, generating potential confusion among practitioners. Clouding the picture further are misnomers that have been used to describe dermatoses of pregnancy. In addition, several cutaneous conditions that are associated with, but not specific to, pregnancy, have been misunderstood, which has resulted in certain myths among patients and physicians. In this contribution, we describe how the nomenclature of each dermatosis of pregnancy has evolved to fit the current classification scheme. We then identify several misnomers that have generated confusion within the scheme. Finally, we debunk several myths that have developed around cutaneous conditions outside of this scheme, in both mother and newborn.

The Hepatitis Aggressiveness Score (HAS): a novel classification system for post-liver transplantation recurrent hepatitis C.

Several histopathologic features have been described in cases of fibrosing cholestatic hepatitis C (FCH-C). We investigated whether FCH-associated features can be utilized as the basis of a novel grading system for the entire population of post-liver transplantation (LT) recurrent hepatitis C virus (HCV) infection. Liver biopsies obtained at a median (interquartile range) of 12.3 (10.4-13.8) months post-LT from 170 patients with recurrent HCV were included. Biopsies were assessed for the following FCH features: (1) ductular reaction, (2) cholestasis, (3) hepatocyte ballooning, and (4) periportal sinusoidal fibrosis. A Hepatitis Aggressiveness Score (HAS) was assigned on the basis of the number of FCH features as follows: 0 features=HAS 1; 1 to 2 features=HAS 2; and 3 to 4 features=HAS 3. We analyzed the performance of this novel system in predicting clinicopathologic outcomes compared with conventional grading systems after a median (interquartile range) follow-up of 24 (13-45.5) months. The HAS classification was highly predictive of fibrosis progression (P<0.001) and was the best predictor of graft loss in a multivariable analysis model, which included all conventional hepatitis grading systems (adjusted hazard ratio=5.5, confidence interval 2.9-10.7, P<0.001 for HAS 3 vs. HAS 1 and 2, compared with adjusted hazard ratio=1.0, confidence interval 0.5-1.9, P=0.94 for the presence of moderate to severe necroinflammation by at least 1 conventional grading system). Presence of at least 3 of 4 FCH features (HAS 3 group) characterized a subset of patients with distinctly worse prognosis and severe cholestatic disease (ie, FCH-C). We propose a novel approach to the histologic grading of post-LT recurrent HCV based exclusively on FCH features. This system allows accurate identification of FCH-C cases and stratification of all recurrent HCV patients into distinct prognostic categories.

Recent developments in the specific dermatoses of pregnancy.

During pregnancy, the mother undergoes changes to sustain and enable normal growth and development of the fetus. Common physiological changes include linea nigra, fibroepithelial polyps, striae, spider angioma, palmar erythema and pruritis gravidarum. However, there are some changes that are purely pathological, and these are termed the pregnancy-specific dermatoses (PSDs). The PSDs occur during pregnancy or in the immediate postpartum period. They do not include the various benign conditions or pre-existing dermatoses and tumours that may present or worsen with pregnancy. They do include a number of distinct and identifiable conditions: atopic eruption of pregnancy (AEP), polymorphic eruption of pregnancy (PEP), intrahepatic cholestasis of pregnancy (ICP) and pemphigoid gestationis (PG). These are a heterogeneous group of skin conditions characterized by pruritis and inflammatory changes. In addition, pruritis gravidarum is sometimes considered pathophysiological and thus part of this group, rather than a physiological process. Each of these conditions has a distinct, but not fully understood, pathogenesis. The mechanisms leading to PSD may be a reflection on the hormonal and immunological changes associated with pregnancy. AEP and PEP are benign conditions, and although they can cause distress to the mother, they are otherwise minor. However, ICP and PG are more serious conditions, and both carry the potential for serious risks to both the mother and the fetus. Thus, the pathophysiology of these latter two conditions is considered in more detail in the following article.

Progressive familial intrahepatic cholestasis (PFIC) type 1, 2, and 3: a review of the liver pathology findings.

Progressive familial intrahepatic cholestatic diseases encompass a group of autosomal recessive hereditary diseases, which usually present in infancy or childhood, with cholestasis of hepatocellular origin. The currently preferred nomenclature for the three PFIC disorders that have been characterized to date is FIC1 deficiency, BSEP deficiency, and MDR3 deficiency, relating to mutations in the specific genes involved in bile acid formation and transport. Since the first description of these diseases, extensive clinical, biochemical, and molecular studies have increased our understanding of the features specific to each one of them. This review focuses mainly on the liver histology, summarizing their characteristic pathologic features, the correlation to specific genotypes, and complications arising with disease progression.

Familial cholestasis: progressive familial intrahepatic cholestasis, benign recurrent intrahepatic cholestasis and intrahepatic cholestasis of pregnancy.

Progressive familial intrahepatic cholestasis (PFIC) type 1, 2 and 3 are due to mutations in ATP8B1, ABCB11 and ABCB4, respectively. Each of these genes encodes a hepatocanalicular transporter, which is essential for the proper formation of bile. Mutations in ABCB4 can result in progressive cholestatic disease, while mutations in ATP8B1 and ABCB11 can result both in episodic cholestasis, referred to as benign recurrent intrahepatic cholestasis (BRIC) type 1 and 2, as well as in progressive cholestatic disease. This suggests a clinical continuum and these diseases are therefore preferably referred to as ATP8B1 deficiency and ABCB11 deficiency. Similarly PFIC type 3 is designated as ABCB4 deficiency. Heterozygous mutations in each of these transporters can also be associated with intrahepatic cholestasis of pregnancy. This review summarizes the pathophysiology, clinical features and current as well as future therapeutic options for progressive familial- and benign recurrent intrahepatic cholestasis as well as intrahepatic cholestasis of pregnancy.

Nutrición enteral en hepatopatías crónicas en niños y adolescentes / Enteral nutrition in chronic liver disease in children and adolescents

La desnutrición que se observa en enfermedades hepáticas crónicas en niños se asocia a un aumento de requerimientos por gasto calórico elevado. La historia clínica incluye un recordatorio de alimentación, evaluación clínica, antropometría. Los niños con colestasis deben recibir una dieta hipercalórica. Es fundamental garantizar el aporte calórico calculado completo y la alimentación enteral. Se debe garantizar un crecimiento adecuado en un niño en lista de espera para trasplante. Los niños con enfermedades metabólicas requieren el uso de fórmulas comerciales especiales.

Malnutrition seen in chronic liver disease in children is associated with increased requirements for high caloric expenditure. The medical history includes a reminder of food, clinical evaluation, anthropometry. Children with cholestasis should receive a high calorie diet. It is essential to ensure complete and estimated calorie enteral feeding. It must ensure adequate growth in a child on the waiting list for transplantation. Children with metabolic diseases require the use of special comercial formulations.

DHPLC screening for mutations in progressive familial intrahepatic cholestasis patients.

Progressive familial intrahepatic cholestasis (PFIC) is a group of rare heterogeneous autosomal recessive disorders characterized by metabolic defects in biliary proteins involved in the formation and transfer of bile acids in the liver. The genotype-phenotype correlation is not always clear. Mutations in the ATP8B1, BSEP and MDR3 genes have been associated with PFIC1, PFIC2 and PFIC3, respectively. This study sought to characterize the molecular genetic basis for PFIC subtypes in Israel. It was conducted on 14 children with PFIC and their families; 10 with a PFIC1 or PFIC2 phenotype and 4 with a PFIC3 phenotype. Using denaturing high-performance liquid chromatography (DHPLC), five different mutations were identified in four affected families: three novel mutations in BSEP (G19R-g181c, S226L-c803t and G877R-g2755a), one novel mutation in MDR3 (IVS14+6 t/c) and one heterozygous mutation in ATP8B1 (R600W, in a family with the PFIC1/PFIC2 phenotype). The cause of PFIC was identified in 20% of the families tested. These findings indicate the probable involvement of additional genes in PFIC and the need for further studies to determine whether the abnormality lies on the RNA or protein level. A better understanding of the phenotype-genotype correlation in PFIC will lead to improved diagnoses and treatments.

Colestasis genéticas / Genetic cholestasis

Los avances en genética molecular han cambiado nuestro abordaje de los pacientes con colestasis intrahepática. La identificación de mutaciones enciertos genes nos permite hoy arribar al diagnóstico genético de varias formas de colestasis, agrupadas previamente como colestasis intrahepáticafamiliar progresiva. Las tres formas descriptas:tipos 1, 2 y 3, son el resultado de mutaciones en los genes ATP8B1, ABCB11 y ABCB4. Hallazgosclínicos, bioquímicos e histológicos nos orientan en el diagnóstico. El tratamiento tiene como objetivosaliviar los síntomas y mejorar la calidadde vida. Los errores congénitos en la síntesis de ácidos biliares representan un subgupo de las colestasis familiares. El tratamiento de reemplazo con ácido ursodesoxicólico y ácido cólico evitanla progresión de la lesión hepática.

Colestasis genéticas / Genetic cholestasis

Los avances en genética molecular han cambiado nuestro abordaje de los pacientes con colestasis intrahepática. La identificación de mutaciones enciertos genes nos permite hoy arribar al diagnóstico genético de varias formas de colestasis, agrupadas previamente como colestasis intrahepáticafamiliar progresiva. Las tres formas descriptas:tipos 1, 2 y 3, son el resultado de mutaciones en los genes ATP8B1, ABCB11 y ABCB4. Hallazgosclínicos, bioquímicos e histológicos nos orientan en el diagnóstico. El tratamiento tiene como objetivosaliviar los síntomas y mejorar la calidadde vida. Los errores congénitos en la síntesis de ácidos biliares representan un subgupo de las colestasis familiares. El tratamiento de reemplazo con ácido ursodesoxicólico y ácido cólico evitanla progresión de la lesión hepática.(AU)

Benign recurrent intrahepatic cholestasis type 2 is caused by mutations in ABCB11.

BACKGROUND & AIMS: Progressive familial intrahepatic cholestasis (PFIC) and benign recurrent intrahepatic cholestasis (BRIC) are hereditary liver disorders; PFIC is characterized by severe progressive liver disease whereas BRIC patients have intermittent attacks of cholestasis without permanent liver damage. Mutations in ATP8B1 are present in PFIC type 1 and in a subset of BRIC patients. We hypothesized that a genetically distinct form of BRIC is associated with mutations in ABCB11. This gene encodes the bile salt export pump (BSEP) and is mutated in PFIC type 2. METHODS: Patients from 20 families were included; all had a normal ATP8B1 sequence. Sequencing of all 27 coding exons including the splice junctions of ABCB11 revealed 8 distinct mutations in 11 patients from 8 different families: one homozygous missense mutation (E297G) previously described in PFIC2 patients, 6 novel missense mutations, and one putative splice site mutation. RESULTS: In 12 families, no mutations in ATB8B1 or ABCB11 were detected. Pancreatitis is a known extrahepatic symptom in BRIC caused by ATP8B1 mutations, but was not present in BRIC patients with mutations in ABCB11. In contrast, cholelithiasis was observed in 7 of 11 BRIC patients with mutations in ABCB11, but has not been described in ATP8B1-affected BRIC patients. CONCLUSIONS: Mutations in ABCB11 are associated with BRIC, and consistent with the genetic classification of PFIC into 2 subtypes, we propose that this disorder be named BRIC type 2.

[Grading of intrahepatic cholestasis of pregnancy].

OBJECTIVE: This study was to evaluate the grading of intrahepatic cholestasis of pregnancy (ICP). METHODS: All 278 ICP cases were collected in the First Affiliated Hospital of Chongqing Medical University between Jan 1999 and May 2003. They were graded into mild ICP and severe ICP based on liver function test. Outcome of pregnancy and perinatal mortality were assessed. RESULTS: One hundred and ninety two cases were diagnosed as mild ICP while 86 cases were as severe ICP. There was significant difference in the average time of expectant therapy (10.3 +/- 4.8 vs 19.1 +/- 6.4 days) and gestational weeks (35.8 +/- 1.6 vs 37.7 +/- 1.9) between severe ICP and mild ICP groups (P < 0.01 and P < 0.001). The incidences of meconium passage, newborn asphyxia and admissions to neonatal intensive care unit in severe ICP were significantly higher than that in mild ICP. These were 38.4% vs 9.4%, 12.8% vs 4.2%, and 30.2% vs 9.4%, respectively. The difference of perinatal mortality between the patients with ICP diagnosed by using and not using the grading system (0.7% - 1.2% vs 3.9% - 6.0%) was statistically significant (P < 0.01). CONCLUSION: Grading of ICP based on liver function test may improve perinatal prognosis.

Disorders of bile formation and biliary transport.

A wide range of cholestatic liver diseases result from various primary defects in bile formation. Clinical features include jaundice, pruritus, failure to thrive, fat malabsorption, cholelithiasis, and variably progressive cirrhosis. Accurate diagnosis of these disorders is essential for determination of prognosis and selection of the most appropriate therapies. Severe genetic defects in canalicular bile acid and phospholipid excretion lead to progressive liver disease that often requires liver transplantation. Defects in bile acid biosynthesis and aminophospholipid transport may be responsive to medical or non-transplant surgical approaches.