Transient Neonatal Cholestasis Research Articles

Expanding the phenotypic landscape of Gaucher disease type 3c with a novel entity - Transient neonatal cholestasis

Gaucher disease (GD) is the most frequent lysosomal storage disorder due to biallelic pathogenic variants in GBA gene. Only homozygous D409H variant has been associated with the cardiovascular phenotype which is also known as Gaucher disease type 3c. In this descriptive study, we presented phenotypic heterogeneity and a novel clinical finding among 13 patients with GD type 3c. Patients presented with varying degrees of cardiac valve and/or aortic calcifications (84,6%) and corneal opacities (76,9%) in addition to visceral (100%), hematological (92,3%), neurological (92,3%), and skeletal (30%) manifestations. Also, cervical dystonia (38,4%) and psychiatric disorders (46,1%) were not infrequent entities with respect to neurological involvement in GD type 3c. In this report, we highlight transient neonatal cholestasis (38,4%) as a novel finding in GD type 3c. Neonatal cholestasis is a finding associated with Gaucher type 2, but transient neonatal cholestasis has not been reported in GD patients, so far. The clinical features of GD type 3c are highly heterogeneous, from disease severity or age of onset to disease progression. Also, we concluded that phenotypic spectrum may be associated with age at onset of clinical symptoms. As, patients presenting in infancy or childhood had mainly visceral and hematological involvement and patients presenting in adolescence and adulthood had mainly cardiac, neurological involvement, and psychiatric behavioral disorders. Identifying the heterogeneous clinical course of these patients in this fatal disease, may lead a sufficient understanding of the pathophysiology which will enable targeted therapeutic interventions.

A Retrospective Multicentric Study of 34 Patients with Niemann–Pick Type C Disease and Early Liver Involvement in France

To describe the clinical features and course of liver involvement in a cohort of patients with Niemann-Pick type C disease (NP-C), a severe lysosomal storage disorder. Patients with genetically confirmed NP-C (NPC1, n=31; NPC2, n=3) and liver involvement before age 6months were retrospectively included. Clinical, laboratory test, and imaging data were collected until the last follow-up or death; available liver biopsy specimens were studied using anti-CD68 immunostaining. At initial evaluation (median age, 17days of life), all patients had hepatomegaly, 33 had splenomegaly, and 30 had neonatal cholestasis. Portal hypertension and liver failure developed in 9 and 4 patients, respectively. Liver biopsy studies, performed in 16 patients, revealed significant fibrosis in all 16 and CD68+ storage cells in 15. Serum alpha-fetoprotein concentration measured in 21 patients was elevated in 17. Plasma oxysterol concentrations were increased in the 16 patients tested. Four patients died within 6months of life, including 3 from liver involvement. In patients who survived beyond age 6months (median follow-up, 6.1years), cholestasis regressed in all, and portal hypertension regressed in all but 1; 25 patients developed neurologic involvement, which was fatal in 16 patients. Liver involvement in NP-C consisted of transient neonatal cholestasis with hepatosplenomegaly, was associated with liver fibrosis, and was responsible for death in 9% of patients. The combination of liver anti-CD68 immunostaining, serum alpha-fetoprotein measurement, and studies of plasma biomarkers should facilitate early identification of NP-C.

Presentation of Congenital Portosystemic Shunts in Children.

Background: Congenital portosystemic shunts (CPSS) are rare vascular anomalies resulting in communications between the portal venous system and the systemic venous circulation, affecting an estimated 30,000 to 50,000 live births. CPSS can present at any age as a multi-system disease of variable severity mimicking both common and rare pediatric conditions. Case presentations: Case A: A vascular malformation was identified in the liver of a 10-year-old girl with tall stature, advanced somatic maturation, insulin resistance with hyperinsulinemia, hyperandrogenemia and transient hematuria. Work-up also suggested elevated pulmonary pressures. Case B: A young girl with trisomy 8 mosaicism with a history of neonatal hypoglycemia, transient neonatal cholestasis and tall stature presented newly increased aminotransferase levels at 6 years of age. Case C: A 3-year-old boy with speech delay, tall stature and abdominal pain underwent abdominal ultrasound (US) showing multiple liver nodules, diagnosed as liver hemangiomas by hepatic magnetic resonance imaging (MRI). Management and outcome: After identification of a venous malformation on liver Doppler US, all three patients were referred to a specialized liver center for further work-up within 12 to 18 months from diagnosis. Angio-computed tomography (CT) scan confirmed the presence of either an intrahepatic or extrahepatic CPSS with multiples liver nodules. All three had a hyperintense signal in the globus pallidus on T1 weighted cerebral MRI. Right heart catheterization confirmed pulmonary hypertension in cases A and C. Shunts were closed either using an endovascular or surgical approach. Liver nodules were either surgically removed if there was a risk of malignant degeneration or closely monitored by serial imaging when benign. Conclusion: These cases illustrate most of the common chief complaints and manifestations of CPSS. Liver Doppler US is the key to diagnosis. Considering portosystemic shunts in the diagnostic work-up of a patient with unexplained endocrine, liver, gastro-intestinal, cardiovascular, hematological, renal or neurocognitive disorder is important as prompt referral to a specialized center may significantly impact patient outcome.

Cholangiopathy and Biliary Fibrosis in Cyp2c70-Deficient Mice Are Fully Reversed by Ursodeoxycholic Acid.

Background and AimsBile acids (BAs) aid intestinal fat absorption and exert systemic actions by receptor-mediated signaling. BA receptors have been identified as drug targets for liver diseases. Yet, differences in BA metabolism between humans and mice hamper translation of pre-clinical outcomes. Cyp2c70-ablation in mice prevents synthesis of mouse/rat-specific muricholic acids (MCAs), but potential (patho)physiological consequences of their absence are unknown. We therefore assessed age- and gender-dependent effects of Cyp2c70-deficiency in mice.MethodsThe consequences of Cyp2c70-deficiency were assessed in male and female mice at different ages.ResultsCyp2c70-/- mice were devoid of MCAs and showed high abundances of chenodeoxycholic and lithocholic acids. Cyp2c70-deficiency profoundly impacted microbiome composition. Bile flow and biliary BA secretion were normal in Cyp2c70-/- mice of both sexes. Yet, the pathophysiological consequences of Cyp2c70-deficiency differed considerably between sexes. Three-week old male Cyp2c70-/- mice showed high plasma BAs and transaminases, which spontaneously decreased thereafter to near-normal levels. Only mild ductular reactions were observed in male Cyp2c70-/- mice up to 8 months of age. In female Cyp2c70-/- mice, plasma BAs and transaminases remained substantially elevated with age, gut barrier function was impaired and bridging fibrosis was observed at advanced age. Addition of 0.1% ursodeoxycholic acid to the diet fully normalized hepatic and intestinal functions in female Cyp2c70-/- mice.ConclusionCyp2c70-/- mice show transient neonatal cholestasis and develop cholangiopathic features that progress to bridging fibrosis in females only. These consequences of Cyp2c70-deficiency are restored by treatment with UDCA, indicating a role of BA hydrophobicity in disease development.

ABCB11 deficiency presenting as transient neonatal cholestasis: Correlation with genotypes and BSEP expression.

ABCB11 deficiency presenting in infancy is believed generally to manifest as persistent/progressive cholestasis. We describe a group of patients with biallelic ABCB11 variants whose disorder manifested as transient neonatal cholestasis (TNC). Neonatal intrahepatic cholestasis in 68 children (31 males) with biallelic predictedly pathogenic variants (PPV) in ABCB11 was classified as transient (TNC group, n=23, 11 males), intermittent (benign recurrent intrahepatic cholestasis [BRIC] group, n=3, 1 male) or persistent/ progressive (progressive familial intrahepatic cholestasis [PFIC] group, n=42, 19 males). Clinical, genetic and bile salt export pump (BSEP) expression information was correlated with outcomes. The median onset age of jaundice was 3days (birth to 2months) for the TNC group and 10.5days (birth to 3months) for the PFIC group (P=.034). The median length of follow-up of TNC patients was 44months (12months-168months). At presentation, hepatobiliary-injury biomarker values were similar between the groups (P>.05). TNC patients (17/23) more often than PFIC patients (20/42, P=.041) harboured biallelic non-null variants (predicted not to terminate translation prematurely). TNC patient livers (7/7) more often than PFIC patient livers (5/16, P=.005) expressed immunohistochemically detectable BSEP. Kaplan-Meier analysis showed better prognosis for patients with BSEP expression (P=.009). Too few BRIC patients were available for statistical study. Neonatal cholestasis associated with biallelic PPV in ABCB11 can resolve temporarily or persistently in one third of cases. Resolution is more likely in patients with biallelic non-null PPV or with liver BSEP expression.

Abnormal Bilirubin Metabolism in Patients With Sodium Taurocholate Cotransporting Polypeptide Deficiency.

The aim of the study was to explore the significance of sodium taurocholate cotransporting polypeptide (NTCP) deficiency and its clinical features in Chinese children presenting with isolated persistent hypercholanemia. The exon and adjacent regions of SLC10A1, the gene encoding NTCP, were sequenced in 33 Chinese children presenting with isolated hypercholanemia. Clinical history and medical data were reviewed. Growth milestones were compared with the national standard. The serum direct bilirubin concentration at last follow-up was compared with age- and sex-matched controls. A variant, c.800C>T, p. S267F of SLC10A1 was detected in all subjects; 30 patients were homozygotes and 3 were compound heterozygotes. Nine patients presented with transient neonatal cholestasis, and 1 with a persistent mild conjugated hyperbilirubinemia. The serum direct bilirubin level in NTCP-deficient patients was significantly higher than age- and sex-matched controls even after the neonatal cholestasis stage (2.85 ± 1.50 vs 1.49 ± 0.70 μmol/L, P = 0.00008). No growth delay or other severe long-term clinical consequences were observed. NTCP deficiency is the exclusive or major cause of isolated hypercholanemia in Han Chinese children, with c.800C>T the major contributing genetic variation. The defect may affect bilirubin metabolism and present as transient neonatal cholestasis and/or persistent mild conjugated hyperbilirubinmia, but with no apparent long-term clinical consequences.

Histological demonstration of BSEP/ABCB11 inhibition in transient neonatal cholestasis: a case report

BackgroundIdiopathic or transient neonatal cholestasis (TNC) represents a group of cholestatic disorders with unidentified origin and remains a diagnosis of exclusion. Dysfunction of hepatobiliary transporters mediating excretion of biliary constituents from hepatocytes may play a central role in the pathogenesis of cholestasis. Despite variants of bile salt (BS) export pump (BSEP/ABCB11) have already been described in TNC, the pathogenic role of BSEP dysfunction in TNC remained so far elusive.Case presentationWe report on a newly-identified heterozygous ABCB11 missense variant (c.1345G > A, p.Glu449Lys) which was associated with prolonged cholestasis in a term infant after a complicated neonatal period. Moreover, we show for the first time almost completely abolished BSEP expression on the hepatocellular membrane in TNC.ConclusionThis report demonstrates for the first time a close association between the prolonged cholestasis in infancy and impaired BSEP expression on the hepatocyte canalicular membrane in a heterozygous carrier of newly-identified ABCB11 variant.

Alpha-1 Antitrypsin Deficiency-Mediated Liver Toxicity: Why Do Some Patients Do Poorly? What Do We Know So Far?

Alpha-1 antitrypsin deficiency (AATD) is a rare genetic disease caused by mutations in the SERPINA1 gene and is associated with a decreased level of circulating alpha-1 antitrypsin (AAT). Among all the known mutations in the SERPINA1 gene, homozygous for the Z allele is well-known to result in both lung and liver disease. Unlike the lung injury that occurs in adulthood with the environment (notably, tobacco) as a co-factor, the hepatic damage is more complicated. Despite a common underlying gene mutation, the liver disease associated with AATD presents a considerable variability in the age-of-onset and severity, ranging from transient neonatal cholestasis (in early childhood) to cirrhosis and liver cancer (in childhood and adulthood). Given that all the cofactors- genetics and/or environmental- have not been fully identified, it is still impossible to predict which individuals with AATD may develop severe liver disease. The discovery of these modifiers represents the major challenge for the detection, diagnosis, and development of new therapies to provide alternative options to liver transplantation. The aim of this current review is to provide an updated overview of our knowledge on why some AATD patients associated with liver damage progress poorly.

Evolução laboratorial da colestase multifatorial em pacientes pediátricos

Introdução: No fígado imaturo do recém-nascido (RN) a colestase neonatal pode ocorrer em associação a um ou vários fatores de risco, sem patologia subjacente. Esta condição denomina-se colestase neonatal multifatorial transitória. Prematuridade, restrição de crescimento intra-uterino ou situações que levam a maior estresse oxidativo (isquemia, comprometimento hemodinâmico, infecções, intervenções cirúrgicas, pausa alimentar, alimentação parenteral e fármacos) estão relacionadas com sua gênese. Objetivo: Avaliar a evolução da colestase neonatal multifatorial quanto a sua duração, assim como verificar as alterações médias das enzimas hepáticas, aspartato aminotransferase (AST), alanina aminotransferase (ALT), e canaliculares, gamaglutamiltransferase (GGT), e da bilirrubina direta (BD), comparando ainda a duração da colestase nos pacientes que fizeram uso do ácido ursodesoxicólico (UDCA) com o tempo de evolução dos que não o fizeram, no intuito de caracterizar melhor essa condição clínica e de chamar a atenção do profissional de saúde sobre sua natureza transitória, evitando dessa maneira a solicitação de exames mais específicos, onerosos e desnecessários. Método: Estudo transversal, com 32 pacientes de zero a 90 dias que apresentavam colestase neonatal multifatorial, acompanhados no ambulatório de hepatologia pediátrica do IMIP, no período de agosto de 2016 a agosto de 2017. Os dados foram coletados através de consulta ao prontuário. A análise estatística dos dados foi realizada por meio do software “R” v.3.3.1. Resultados: A maioria dos pacientes era do sexo masculino (59,38%). A idade média de início da colestase foi de 35,5 dias, e a de término de 171,3 dias. A média de duração da colestase foi de 135,8 dias. O valor médio da BD do início e término da colestase foi de 6,05 e 0,29 mg/dL, respectivamente. Com relação às enzimas hepáticas e canaliculares, as médias dos valores de AST, ALT e GGT do início foram 194,7, 123,8 e 387,9 U/L, e de término 69,1, 56 e 121,6 U/L, respectivamente. Apenas 11 pacientes fizeram uso do UDCA. O tempo médio de duração da colestase neste grupo foi de 114,1 dias. Aqueles que não usaram o UDCA, 21 pacientes, apresentaram icterícia colestática por um tempo médio de 147,1 dias. Conclusão: Diante dos resultados obtidos com a análise retrospectiva dos pacientes com diagnóstico de colestase multifatorial, chama a atenção a natureza transitória e benigna desta condição clínica, com duração média da colestase em torno de 136 dias de vida e declínio importante dos níveis das enzimas hepáticas e canaliculares após resolução do quadro

Identification of novel loci for pediatric cholestatic liver disease defined by KIF12, PPM1F, USP53, LSR, and WDR83OS pathogenic variants

PurposeGenetic testing in pediatric cholestasis can be very informative but genetic causes have not been fully characterized. MethodsExome sequencing and positional mapping in seven families with cholestatic liver disease and negative clinical testing for known disease genes. ResultsKIF12, which encodes a microtubule motor protein with a tentative role in cell polarity, was found to harbor three homozygous likely deleterious variants in three families with sclerosing cholangitis. KIF12 expression is dependent on HNF-1β, deficiency which is known to cause bile duct dysmorphogenesis associated with loss of KIF12 expression. In another extended family, we mapped an apparently novel syndrome of sclerosing cholangitis, short stature, hypothyroidism, and abnormal tongue pigmentation in two cousins to a homozygous variant in PPM1F (POPX2), a regulator of kinesin-mediated ciliary transport. In the fifth family, a syndrome of normal gamma glutamyltransferase (GGT) cholestasis and hearing loss was found to segregate with a homozygous truncating variant in USP53, which encodes an interactor with TJP2. In the sixth family, we mapped a novel syndrome of transient neonatal cholestasis, intellectual disability, and short stature to a homozygous variant in LSR, an important regulator of liver development. In the last family of three affected siblings, a novel syndrome of intractable itching, hypercholanemia, short stature, and intellectual disability was mapped to a single locus that contains a homozygous truncating variant in WDR83OS (C19orf56), known to interact with ATP13A2 and BSEP. ConclusionOur results expand the genetic heterogeneity of pediatric cholestatic liver disease and highlight the vulnerability of bile homeostasis to a wide range of molecular perturbations.

Metabolic liver diseases presenting with neonatal cholestasis: at the crossroad between old and new paradigms.

Metabolic liver diseases (MLD) are an important group of disorders presenting with neonatal cholestasis (NC). The spectrum of liver involvement is wide and the presumptive diagnosis is traditionally based on clinical and laboratory findings. Recently, next-generation sequencing (NGS) panels have emerged as an appealing tool to diagnose neonatal/infantile cholestatic disorders. The aim of this study was to identify clinical phenotypes of liver injury and contribute to find a diagnostic methodology that integrates new molecular diagnostic tools. We retrospectively analyzed the clinical and biochemical features of 16 patients with MLD and NC. Patients were categorized into three groups: A-NC with liver failure (N = 8): tyrosinemia type I (n = 2), classic galactosemia (n = 5), mitochondrial DNA depletion syndrome (n = 1); B-NC evolving with chronic liver disease (N = 5): argininemia (n = 2); mitochondrial cytopathy (n = 1); congenital disorders of glycosylation type Ia (n = 1); Zellweger syndrome (n = 1); and C-transient NC (N = 3): Niemann-Pick type C (n = 2), citrullinemia type II(n = 1).Conclusion: MLD presenting with NC can be categorized into three main clinical phenotypes of liver injury. We highlight transient NC as a clue for MLD that must be pursued. New molecular diagnostic tools can play a key role, but application criteria must be established to make them cost-effective. What is Known: • Metabolic liver diseases are an important group of disorders presenting with neonatal cholestasis. • The diagnostic approach is challenging and traditionally based on clinical and laboratory findings. Next-generation sequencing is a recent and rapidly developing tool in pediatric hepatology. What is New: • We provide a liver-targeted characterization of metabolic liver diseases presenting with neonatal cholestasis, categorizing them into three clinical phenotypes that may narrow the diagnostic possibilities. • A clinical decision-making algorithm is proposed, in which the NGS technology is integrated.

P058 Transient early-onset neonatal cholestasis with severe cytolysis in perinatal asphyxia: a case report

P058 Transient early-onset neonatal cholestasis with severe cytolysis in perinatal asphyxia: a case report

Refined Multidisciplinary Protocol-Based Approach to Short Bowel Syndrome Improves Outcomes.

Management of short bowel syndrome (SBS) has significantly evolved recently. We present our single-center, 25-year experience focusing on the implementation of a refined multidisciplinary SBS care protocol. This is a retrospective review of the patients with SBS treated at our tertiary center from 1988 to 2014, with either <25% short bowel remaining or duration of parenteral nutrition (PN) >3 months. Patients with primary intestinal motility disorders were excluded. Clinical characteristics, including intestinal anatomy, markers of cholestasis, and catheter-related infections (CRIs), were analyzed. The implementation of a refined modern uniform management protocol in 2009 divided the cohort into 2 subgroups, whose outcomes are compared. Forty-eight patients with SBS were identified (median gestational age 33 weeks). Of them, 22 were born between 2009 and 2014. The main causes of SBS were necrotizing enterocolitis (46%) and midgut volvulus (23%). Median remaining small bowel length was 36 cm. The overall survival was 23 of 26 (88%) before 2009 and 21 of 22 (95%) thereafter, whereas none were transplanted. Duration of PN shortened from a median of 15 to 6 months (P = 0.0015) in the latter cohort, whereas frequency of autologous intestinal reconstruction surgery (31%) remained unchanged. Frequency of neonatal cholestasis was similar in both groups (75%), but cleared in all after 2009. Before 2009, 2 patients died of progressive cholestatic liver failure. The CRI rates decreased from 1.7 to 0.7 per 1000 catheter-days between 2000-2008 and 2009-2014, respectively (P = 0.0178). Uniform refined multidisciplinary approach decreased the duration of PN and CRI rates with high transplant-free survival and avoidance of liver failure, although the frequency of transient neonatal cholestasis remained unchanged.

A novel GATA6 mutation leading to congenital heart defects and permanent neonatal diabetes: A case report

Permanent neonatal diabetes mellitus is a rare condition mostly due to heterozygous mutations in the KCNJ11, ABCC8 and INS genes. Neonatal diabetes due to pancreatic agenesis is extremely rare. Mutations in PDX1, PTF1A, HNF1B, EIF2AK3, RFX6 and GATA6 genes have been shown to result in pancreatic agenesis or hypoplasia. This report describes a 40-day-old male infant diagnosed with permanent neonatal diabetes associated with atrial septal defect, pulmonary stenosis, patent ductus arteriosus and a novel de novo heterozygous missense mutation (p.N466S) in the GATA6 gene with no evidence of exocrine pancreas insufficiency. In addition to permanent neonatal diabetes, the patient had transient idiopathic neonatal cholestasis and hypoglycaemic episodes unrelated to insulin treatment, features that are rarely described in children with permanent neonatal diabetes.

Association of variants of ABCB11 with transient neonatal cholestasis

The significance of ABCB11 variants have been studied in some cholestatic diseases, but this is not clear in transient neonatal cholestasis (TNC). The aim of the present study was to explore the association between ABCB11 variants and TNC. This was a case-control study. A total of 192 children with TNC referred to a tertiary referral hospital in eastern China were enrolled as subjects, and 196 healthy children were selected as controls. Part of the promoter and exons of the ABCB11 gene were sequenced directly. The single nucleotide polymorphism (SNP) site of V444A was tested using fluorescent quantitative polymerase chain reaction. Potential consequences of variants were predicted using bioinformatics software. The biochemistry indices were compared between the patients with or without possibly pathogenic variants/mutations. Twenty-eight variants, including 14 novel ones, were detected. Four novel, possibly pathogenic mutations (I416I, K436N, R928Q and IVS7+5G>A) were detected in six subjects. The γ-glutamyltransferase level of these six was lower than in the others (P = 0.054). The genotype distribution of the four common SNP sites, V444A, A535A, A865V and A1082A, was not significantly different between TNC patients and controls. Approximately 3% of TNC cases can be attributed to ABCB11 mutations.

Delayed Postnatal Presentation of Biliary Atresia in 2 Premature Neonates

Delayed Postnatal Presentation of Biliary Atresia in 2 Premature Neonates

Transient neonatal cholestasis

Due to immaturity of mechanisms involved in bile formation, the newborn is more susceptible to develop cholestasis. The causes of neonatal cholestasis are: infection, genetic and metabolic diseases, biliary atresia, and unknown or idiopathic etiologies. Most patients in whom no etiology is found are considered to belong to the group of transient neonatal cholestasis by some authors. Transient neonatal cholestasis is characterized by: early-onset cholestasis, absence of a known cause of neonatal cholestasis, normalization of clinical and biochemical parameters during follow-up, and a history of some neonatal injurious event (asphyxia, sepsis, total parenteral nutrition, etc.).

Enfermedad de Niemann-Pick tipo C: desde una colestasis neonatal hacia un deterioro neurológico. Variabilidad fenotípica

Introduction Niemann-Pick type C is a lysosomal storage disorder caused by a defect in intracellular trafficking of cholesterol. It is a rare disease, usually caused by mutations in NPC1 gene, but in some cases by mutations in NPC2 gene. Usually it is present in the paediatric age with a great variability of clinical manifestations. This disease leads to neurological degeneration with various age-related symptoms. Transient neonatal cholestasis, the appearance of splenomegaly and/or hepatomegaly may occur years before the neurological symptoms. Patients and methods We report 6 cases diagnosed in our unit in the last 20 years. We reviewed the clinical manifestations, neuroradiological findings (MRI) and molecular analysis of all of them. Results The disease began before 6 years of age and 5 cases had liver dysfunction and cholestasis in the neonatal period. Ascites was detected in 2 cases in prenatal period. Five cases have or had splenomegaly. Mutations in NPC1 gene were detected in all of them. Conclusions It is important to understand this disease and the identification of early clinical symptoms to make an early diagnosis, leading to appropriate treatment and avoiding unnecessary tests. Moreover, it is important to suitably advise families and provide them with genetic counselling.

Relapsing features of bile salt export pump deficiency after liver transplantation in two patients with progressive familial intrahepatic cholestasis type 2

PFIC2 is caused by mutations in ABCB11 encoding BSEP. In most cases affected children need liver transplantation that is thought to be curative. We report on two patients who developed recurrent normal GGT cholestasis mimicking primary BSEP disease, after liver transplantation. PFIC2 diagnosis was made in infancy in both patients on absence of canalicular BSEP immunodetection and on ABCB11 mutation identification. Liver transplantation was performed at age 9 (patient 1) and 2.8 (patient 2) years without major complications. Cholestasis with normal GGT developed 17 and 4.8years after liver transplantation, in patient 1 and patient 2, respectively, during an immunosuppression reduction period. Liver biopsies showed canalicular cholestasis, giant hepatocytes, and slight lobular fibrosis, without evidence of rejection or biliary complications. An increase in immunosuppression resulted in cholestasis resolution in only one patient. Both patients developed atrial fibrillation, and one melanonychia. The newborn of patient 1 developed transient neonatal normal GGT cholestasis. Immunofluorescence staining of normal human liver sections with patient's sera, collected at the time of cholestasis, and using an anti-human IgG antibody to detect serum antibodies, showed reactivity to a canalicular epitope, likely to be BSEP. Indeed, Western blot analysis showed that patient 2 serum recognized rat Bsep. Allo-immune mediated BSEP dysfunction may occur after liver transplantation in PFIC2 patients leading to a PFIC2 like phenotype. Extrahepatic features and/or offspring transient neonatal cholestasis of possible immune mediated mechanisms, may be associated. Increasing the immunosuppressive regimen might be an effective therapy.

The Spectrum of Liver Diseases Related toABCB4Gene Mutations: Pathophysiology and Clinical Aspects

Class III multidrug resistance P-glycoproteins, Mdr2 in mice and MDR3 in human, are canalicular phospholipid translocators involved in biliary phospholipid (phosphatidylcholine) excretion. The role of an ABCB4 gene defect in liver disease has been initially proven in a subtype of progressive familial intrahepatic cholestasis called PFIC3, a severe pediatric liver disease that may require liver transplantation. Several ABCB4 mutations have been identified in children with PFIC3 and are associated with low level of phospholipids in bile leading to a high biliary cholesterol saturation index. ABCB4 mutations are associated with loss of canalicular MDR3 protein and /or loss of protein function. There is evidence that a biallelic or monoallelic ABCB4 defect causes or predisposes to several human liver diseases (PFIC3, low phospholipid associated cholelithiasis syndrome, intrahepatic cholestasis of pregnancy, drug-induced liver injury, transient neonatal cholestasis, adult biliary fibrosis, or cirrhosis). Most patients with MDR3 deficiency have a favorable outcome with ursodeoxycholic acid (UDCA) therapy, but some PFIC3 patients who do not respond to UDCA treatment still require liver transplantation. The latter should be good candidates for a targeted pharmacologic approach and/or to cell therapy in the future.