Progressive Familial Intrahepatic Cholestasis Type Research Articles

Nutritional assessment in patients with progressive familial intrahepatic cholestasis type 3

Rationale: Progressive familial intrahepatic cholestasis (PFIC) is a group of genetic diseases affecting the hepatocellular transport and bile formation. In PFIC3 there is a defect in the ABCB4 gene, which leads to impaired biliary phospholipid secretion, damaged hepatocytes and bile ducts, and heterogeneous clinical presentation. Growth impairment is often described in children with cholestatic liver diseases. The aim of our study was to assess the nutritional status in patients with PFIC3.

Whole-Genome Sequencing Reveals Large ATP8B1 Deletion/Duplications as Second Mutations Missed by Exome-Based Sequencing

Progressive familial intrahepatic cholestasis type 1 (PFIC1) results from biallelic pathogenic variants in ATP8B1. This study sought second pathogenic variants in ATP8B1 by whole-genome sequencing (WGS) in four unrelated low γ-glutamyl transpeptidase cholestasis patients in whom clinical suspicion of PFIC1 was high and gene-panel or Sanger sequencing had identified only one pathogenic variant in ATP8B1. Sanger sequencing confirmed WGS findings and determined the origin of each variant. Novel nonrecurrent structural variants in three patients (patient 1 to patient 3) were identified in trans: g.55396652_55403080del (6427-bp deletion), g.55335906_55346620dup (10,715-bp duplication), and g.55362063_55364293dup (2231-bp duplication). One synonymous variant in patient 4 was recognized in trans (c.1029G>A, p. Thr343Thr) and demonstrated as deleterious. In conclusion, WGS improves genetic diagnostic yield in PFIC1. These findings expand the gene-variant spectrum associated with familiar intrahepatic cholestasis 1 (FIC1) disease and for the first time report tandem duplication in ATP8B1 associated with cholestasis.

P-82 URSODEOXYCHOLIC ACID AND/OR CIPROFIBRATE FOR TREATING PATIENTS WITH PRESUMPTIVE DIAGNOSIS OF LOW PHOSPHOLIPID CHOLELITHIASIS, A CLINICAL SPECTRUM OF PROGRESSIVE FAMILIAL INTRAHEPATIC CHOLESTASIS TYPE 3

Low Phospholipid-Associated Cholelithiasis (LPAC) is a clinical spectrum of Progressive Familial Intrahepatic Cholestasis type 3 (PFIC3), with mutations in the ABCB4 gene, reduced levels of phosphatidylcholine in bile, formation of cholesterol gallstones, damage of bile ducts epithelium and cholestasis. Ursodeoxycholic acid (UDCA) is effective and fibrates may also be used to activate PPAR - α receptor, inducing bile secretion of phosphatidylcholine. Retrospectively evaluate efficacy and safety of ciprofibrate in LPAC/PFIC3. Diagnosis of PFIC3 was confirmed by detection of mutations of ABCB4 gene. LPAC diagnosis was suggested by 2 out of 5 criteria: biliary symptoms before 40 years; recurrence after cholecystectomy; intrahepatic lithiasis; cholelithiasis in first‐degree relatives; intrahepatic cholestasis of pregnancy or contraceptive‐induced cholestasis. Enzymes, liver function and pruritus were analyzed after 3, 6 and 12 months of UDCA and after ciprofibrate 100mg/day using the Wilcoxon test. 27(93%) patients with clinical diagnosis of LPAC and 2 of PFIC3. 23 (79%) female with mean age at onset of symptoms of 26.7±13.6 years. 23(80%) had family history of biliary disease; 22(76%) cholelithiasis before 40 years; 7(24%) intrahepatic lithiasis. 22/29 (78%) received ciprofibrate after 4.5±4.9 months of UDCA use, in a mean dose of 13.1±2.2mg/kg/day. During UDCA there was a significant decrease in aminotransferases, alkaline phosphatase(AP) and gamma-glutamyltransferase(GGT) levels, without significant improvement in the liver function. After addition of fibrate, pruritus disappeared in all 7 patients, with significant improvement of AP, GGT and albumin in the third month. There was no significant renal dysfunction. Fibrate was discontinued in 8: 1 liver transplantation, 2 irregular use, 5 side effects. 27 patients are still in follow up. Ciprofibrate was beneficial to improve pruritus and laboratory tests in LPAC/PFIC3 after partial response with UDCA. Fibrate therapy was safe and well tolerated.

Two Novel Pathogenic Variants of TJP2 Gene and the Underlying Molecular Mechanisms in Progressive Familial Intrahepatic Cholestasis Type 4 Patients.

Progressive familial intrahepatic cholestasis (PFIC) is an autosomal recessive inherited disease that accounts for 10%–15% childhood cholestasis and could lead to infant disability or death. There are three well-established types of PFIC (1–3), caused by mutations in the ATP8B1, ABCB11, and ABCB4 genes. Biallelic pathogenic variants in the tight junction protein 2 gene (TJP2) were newly reported as a cause for PFIC type 4; however, only a limited number of patients and undisputable variants have been reported for TJP2, and the underlying mechanism for PFIC 4 remains poorly understood. To explore the diagnostic yield of TJP2 analysis in suspected PFIC patients negative for the PFIC1–3 mutation, we designed a multiplex polymerase chain reaction-based next-generation sequencing method to analyze TJP2 gene variants in 267 PFIC patients and identified biallelic rare variants in three patients, including three known pathogenic variants and two novel variants in three patients. By using CRISPR-cas9 technology, we demonstrated that TJP2 c.1202A > G was pathogenic at least partially by increasing the expression and nuclear localization of TJP2 protein. With the minigene assay, we showed that TJP2 c.2668-11A > G was a new pathogenic variant by inducing abnormal splicing of TJP2 gene and translation of prematurely truncated TJP2 protein. Furthermore, knockdown of TJP2 protein by siRNA technology led to inhibition of cell proliferation, induction of apoptosis, dispersed F-actin, and disordered microfilaments in LO2 and HepG2celles. Global gene expression profiling of TJP2 knockdown LO2 cells and HepG2 cells identified the dysregulated genes involved in the regulation of actin cytoskeleton. Microtubule cytoskeleton genes were significantly downregulated in TJP2 knockdown cells. The results of this study demonstrate that TJP2 c.1202A > G and TJP2 c.2668-11A > G are two novel pathogenic variants and the cytoskeleton-related functions and pathways might be potential molecular pathogenesis for PFIC.

Long-term liver transplant outcomes for progressive familial intrahepatic cholestasis type 1: The Pittsburgh experience.

Progressive familial intrahepatic cholestasis type 1 (PFIC1) arises from biallelic variants in the ATP8B1gene that annul FIC1 activity, resulting in progressive liver disease. Liver transplant (LT) is indicated in refractory disease; however, post-LT complications including worsening diarrhea and steatohepatitis progressing to fibrosis with graft loss have been reported. We aim to describe long-term outcomes of PFIC1 LT recipients at our center, focusing on the histological changes of the allografts. We assessed 7 PFIC1 patients post-LT at the Children's Hospital of Pittsburgh (CHP). All pre-transplant, explant, and sequential post-transplant pathology samples were reviewed. Continuous data are presented as the mean±SD. We compared the pre- and post-transplant height and weight z-scores using Wilcoxon signed-rank test. Seven (29% male) patients with PFIC1 received a LT (n=6) or had post-LT care (n=1) at CHP. Six had confirmed or suspected identical genetic. At a mean follow-up of 10.9years, both patient survival and graft survival were 100%. Diarrhea persisted (n=3) or newly developed (n=4) in all patients after LT contributing to ongoing growth failure, with mean z-scores -2.63 (weight) and -2.98 (height) at follow-up. Histologically, allograft steatosis was common but was not accompanied by significant inflammation, ballooning, or fibrosis. We show that extrahepatic disease persists and near-universal allograft steatosis occurs. However, at a mean follow-up period of over 10years, no patients developed steatohepatitis or significant fibrosis, and both patient survival and graft survival are excellent.

Impact of Genotype, Serum Bile Acids, and Surgical Biliary Diversion on Native Liver Survival in FIC1 Deficiency.

Background and AimsMutations in ATPase phospholipid transporting 8B1 (ATP8B1) can lead to familial intrahepatic cholestasis type 1 (FIC1) deficiency, or progressive familial intrahepatic cholestasis type 1. The rarity of FIC1 deficiency has largely prevented a detailed analysis of its natural history, effects of predicted protein truncating mutations (PPTMs), and possible associations of serum bile acid (sBA) concentrations and surgical biliary diversion (SBD) with long‐term outcome. We aimed to provide insights by using the largest genetically defined cohort of patients with FIC1 deficiency to date.Approach and ResultsThis multicenter, combined retrospective and prospective study included 130 patients with compound heterozygous or homozygous predicted pathogenic ATP8B1 variants. Patients were categorized according to the number of PPTMs (i.e., splice site, frameshift due to deletion or insertion, nonsense, duplication), FIC1‐A (n = 67; no PPTMs), FIC1‐B (n = 29; one PPTM), or FIC1‐C (n = 34; two PPTMs). Survival analysis showed an overall native liver survival (NLS) of 44% at age 18 years. NLS was comparable among FIC1‐A, FIC1‐B, and FIC1‐C (% NLS at age 10 years: 67%, 41%, and 59%, respectively; P = 0.12), despite FIC1‐C undergoing SBD less often (% SBD at age 10 years: 65%, 57%, and 45%, respectively; P = 0.03). sBAs at presentation were negatively associated with NLS (NLS at age 10 years, sBAs < 194 µmol/L: 49% vs. sBAs ≥ 194 µmol/L: 15%; P = 0.03). SBD decreased sBAs (230 [125‐282] to 74 [11‐177] μmol/L; P = 0.005). SBD (HR 0.55, 95% CI 0.28‐1.03, P = 0.06) and post‐SBD sBA concentrations < 65 μmol/L (P = 0.05) tended to be associated with improved NLS.ConclusionsLess than half of patients with FIC1 deficiency reach adulthood with native liver. The number of PPTMs did not associate with the natural history or prognosis of FIC1 deficiency. sBA concentrations at initial presentation and after SBD provide limited prognostic information on long‐term NLS.

Concomitant congenital CMV infection and inherited liver diseases

Inherited liver diseases may present in infancy as cholestatic jaundice progressing to severe hepatic dysfunction. Congenital cytomegalovirus (cCMV) infection may initially involve the liver, yet in otherwise healthy hosts rarely leads to long-term hepatic disease. We report a series of three patients, diagnosed with hereditary liver diseases: progressive familial intrahepatic cholestasis (PFIC) type IV, alpha 1 anti-trypsin deficiency (A1ATD) and Alagille syndrome (ALGS), who were also diagnosed with cCMV infection. All patients were treated with valgancilovir for symptomatic cCMV infection (6–12 months), followed by suppressive dosing in the 2 patients with PFIC and A1ATD. Following 15–24 months of follow-up – the patients with PFIC and A1ATD developed severe liver failure, and the third had ongoing cholestatic disease with stable synthetic function. We propose a significant contribution of cCMV infection to the course of the inherited primary disease, possibly leading to further compromise of the liver. We recommend screening patients with inherited liver disease for cCMV, and considering anti-viral treatment with valganciclovir to delay hepatic disease progression.

Cloning of human ABCB11 gene in E. coli required the removal of an intragenic Pribnow-Schaller Box before it’s Insertion into genomic safe harbor AAVS1 site using CRISPR–Cas9

Background: Genomic safe harbors are sites in the genome which are safe for gene insertion such that the inserted gene will function properly, and the disruption of the genomic location doesn’t cause any foreseeable risk to the host. The AAVS1 site is the genetic location which is disrupted upon integration of adeno associated virus (AAV) and is considered a ‘safe-harbor’ in human genome because about one-third of humans are infected with AAV and so far there is no apodictic evidence that AAV is pathogenic or disruption of AAVS1 causes any disease in man. Therefore, we chose to target the AAVS1 site for the insertion of ABCB11, a bile acid transporter which is defective in progressive familial intra hepatic cholestasis type-2 (PFIC-2), a lethal disease of children where cytotoxic bile salts accumulate inside hepatocytes killing them and eventually the patient. Methods: We used the CRISPR Cas9 a genome editing system to insert the ABCB11 gene at AAVS1 site in human cell-lines. Results: We found that human ABCB11 sequence has a “Pribnow- Schaller Box” which allows its expression in bacteria and expression of ABCB11 protein which is toxic to E. coli; the removal of this was required for successful cloning. We inserted ABCB11 at AAVS1 site in HEK 293T using CRISPR-Cas9 tool. We also found that the ABCB11 protein has similarity with E. coli endotoxin (lipid A) transporter MsbA. Conclusions: We inserted ABCB11 at AAVS1 site using CRISPR-Cas9; however, the frequency of homologous recombination was very low for this approach to be successful in vivo.

Pharmacological Premature Termination Codon Readthrough of ABCB11 in Bile Salt Export Pump Deficiency: An In Vitro Study.

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a severe hepatocellular cholestasis due to biallelic mutations in ABCB11 encoding the canalicular bile salt export pump (BSEP). Nonsense mutations are responsible for the most severe phenotypes. The aim was to assess the ability of drugs to induce readthrough of six nonsense mutations (p.Y354X, p.R415X, p.R470X, p.R1057X, p.R1090X, and p.E1302X) identified in patients with PFIC2. The ability of G418, gentamicin, and PTC124 to induce readthrough was studied using a dual gene reporter system in NIH3T3 cells. The ability of gentamicin to induce readthrough and to lead to the expression of a full-length protein was studied in human embryonic kidney 293 (HEK293), HepG2, and Can 10 cells using immunodetection assays. The function of the gentamicin-induced full-length protein was studied by measuring the [3 H]-taurocholate transcellular transport in stable Madin-Darby canine kidney clones co-expressing Na+-taurocholate co-transporting polypeptide (Ntcp). Combinations of gentamicin and chaperone drugs (ursodeoxycholic acid, 4-phenylbutyrate [4-PB]) were investigated. In NIH3T3, aminoglycosides significantly increased the readthrough level of all mutations studied, while PTC124 only slightly increased the readthrough of p.E1302X. Gentamicin induced a readthrough of p.R415X, p.R470X, p.R1057X, and p.R1090X in HEK293 cells. The resulting full-length proteins localized within the cytoplasm, except for BsepR1090X , which was also detected at the plasma membrane of human embryonic kidney HEK293 and at the canalicular membrane of Can 10 and HepG2 cells. Additional treatment with 4-PB and ursodeoxycholic acid significantly increased the canalicular proportion of full-length BsepR1090X protein in Can 10 cells. In Madin-Darby canine kidney clones, gentamicin induced a 40% increase of the BsepR1090X [3 H]-taurocholate transport, which was further increased with additional 4-PB treatment. This study constitutes a proof of concept for readthrough therapy in selected patients with PFIC2 with nonsense mutations.

Effect of CFTR correctors on the traffic and the function of intracellularly retained ABCB4 variants.

ABCB4 is expressed at the canalicular membrane of hepatocytes. This ATP-binding cassette (ABC) transporter is responsible for the secretion of phosphatidylcholine into bile canaliculi. Missense genetic variations of ABCB4 are correlated with several rare cholestatic liver diseases, the most severe being progressive familial intrahepatic cholestasis type 3 (PFIC3). In a repurposing strategy to correct intracellularly retained ABCB4 variants, we tested 16 compounds previously validated as cystic fibrosis transmembrane conductance regulator (CFTR) correctors. The maturation, intracellular localization and activity of intracellularly retained ABCB4 variants were analyzed in cell models after treatment with CFTR correctors. In addition, in silico molecular docking calculations were performed to test the potential interaction of CFTR correctors with ABCB4. We observed that the correctors C10, C13, and C17, as well as the combinations of C3+C18 and C4+C18, allowed the rescue of maturation and canalicular localization of four distinct traffic-defective ABCB4 variants. However, such treatments did not permit a rescue of the phosphatidylcholine secretion activity of these defective variants and were also inhibitory of the activity of wild type ABCB4. In silico molecular docking analyses suggest that these CFTR correctors might directly interact with transmembrane domains and/or ATP-binding sites of the transporter. Our results illustrate the uncoupling between the traffic and the activity of ABCB4 because the same molecules can rescue the traffic of defective variants while they inhibit the secretion activity of the transporter. We expect that this study will help to design new pharmacological tools with potential clinical interest.

Progressive familial intrahepatic cholestasis type 3: Report of four clinical cases, novel ABCB4 variants and long-term follow-up

Introduction and objectivesProgressive familial intrahepatic cholestasis type 3 (PFIC-3) is a rare autosomal recessive cholestatic liver disorder caused by mutations in the ABCB4 gene. The aim of this study was to present the phenotypic and genotypic spectrum of 4 Polish PFIC-3 patients diagnosed in a one-referral centre. Materials and methodsThe study included 4 patients with cholestasis and pathogenic variants in the ABCB4 gene identified by next-generation sequencing (NGS) of a targeted-gene panel or whole exome sequencing (WES). Clinical, laboratory, histological, and molecular data were collected. ResultsFour patients (three males) were identified. The age at first noted clinical signs and symptoms was 6, 2.5, 14, and 2 years respectively; the mean age was 6 years. Those signs and symptoms include pruritus (2 out of 4 patients) and hepatomegaly with splenomegaly (4 out of 4 patients). The age at the time of referral to our centre was 9, 3, 15, and 2.5 years respectively, while the mean age was 7 years. Chronic cholestatic liver disease of unknown aetiology was established in all of them. The NGS analysis was performed in all patients at the last follow-up visit. Three novel variants including c.902T>A, p.Met301Lys, c.3279+1G>A, p.?, and c.3524T>A, p.Leu1175His were identified. The time from the first consultation to the final diagnosis was 14, 9, 3, and 1 year respectively; the mean was 6.8 years. A detailed follow-up was presented. ConclusionsThe clinical phenotype of PFIC-3 could be variable. The clinical and biochemical diagnosis of PFIC-3 is difficult, thus the NGS study is very useful in making a proper diagnosis.

Reduced spontaneous itch in mouse models of cholestasis

Pruritus is one of the most distressing symptoms in cholestatic patients. Plasma autotaxin (ATX) activity correlates with the severity of pruritus in cholestatic patients, but the pathophysiology is unclear. To study pruritus in mice, we measured scratch activity in cholestatic Atp8b1 mutant mice, a model for Progressive Familial Intrahepatic Cholestasis type 1, and wild type mice (WT) with alpha-naphthylisothiocyanate (ANIT)-induced cholestasis. To induce cholestasis, Atp8b1 mutant mice received a diet containing 0.1% cholic acid (CA) and WT mice were treated with ANIT. In these mice ATX was also overexpressed by transduction with AAV-ATX. Scratch activity was measured using an unbiased, electronic assay. Marked cholestasis was accomplished in both Atp8b1 mutant mice on a CA-supplemented diet and in ANIT-treatment in WT mice, but scratch activity was decreased rather than increased while plasma ATX activity was increased. Plasma ATX activity was further increased up to fivefold with AAV-ATX, but this did not induce scratch activity. In contrast to several reports two cholestatic mouse models did not display increased scratch activity as a measure of itch perception. Increasing plasma ATX activity by overexpression also did not lead to increased scratch activity in mice. This questions whether mice are suitable to study cholestatic itch.

A215 MDR3 DEFICIENCY MIMICKING WILSON DISEASE

Abstract Background The chronic phenotype of ALF includes a broad differential diagnosis. Class III multi-drug resistance P-glycoprotein 3 (MDR3) deficiency, also referred to as progressive familial intrahepatic cholestasis type 3, is an autosomal recessive genetic disorder. It is caused by a defect on the ABCB4 gene located on chromosome 7, which encodes MDR3. MDR3 is responsible for transporting phosphatidylcholine across the canalicular membrane, thereby allowing it to be incorporated into bile micelles. MDR3 deficiency results in increased levels of free bile acids and detergent bile. Progressive cholangiopathy ensues from this detergent bile and indirectly leads to cholestasis and liver failure in severe cases. Significantly increased urinary and hepatic copper (Cu), which are hallmarks of Wilson disease, have also been reported in patients with acute hepatitis and cholestasis including patients with MDR3 deficiency Aims We report a case of a girl who presented with a chronic phenotype of PALF, who had multiple features of Wilson disease and so was treated as such until genetic analysis confirmed MDR3 deficiency Methods Results A 6 year old girl presented to the ED with a 1mth history of epistaxis and a 1wk history of abdominal pain and distension, facial edema, pallor and fever. Her family history was significant for parental consanguinity and maternal itch during pregnancy. On examination she had clubbing, scleral icterus and a distended abdomen with hepatosplenomegaly. Her bloodwork showed bicytopenia (HGB 53 &amp; Plts 63) along with liver dysfunction (INR 2.9, albumin 25, conjugated bilirubin 9) and raised liver enzymes (transaminases &amp; GGT &amp;gt;10xULN). Her total serum bile acids were raised at 134. An US showed hepatosplenomegaly with multiple hyperechoic nodules and perisplenic varices. She was extensively worked up for malignancy, autoimmune and metabolic disease. Serum ceruloplasmin was reduced, ophthalmology examination showed no KF rings and her 24hr urinary Cu was 10xULN. Liver Cu quantification was markedly raised at 40xULN. Liver biopsy showed cirrhosis with fibrosis related minimal non-specific portal and septal inflammation. Additionally, complete loss of canalicular staining on immunohistochemistry for MDR3 protein was noted, suggestive of MDR3 deficiency. Based on the Cu levels, a provisional diagnosis of Wilson disease was made and Cu chelation therapy was commenced pending genetic testing. A cholestatic gene panel subsequently showed homozygous pathogenic variant for the ABCB4 gene. Trientine was stopped and she was commenced on ursodeoxycholic acid. Though biochemically she remains largely unchanged, she is clinically stable whilst awaiting a liver transplant Conclusions This case highlights the diagnostic difficulties associated with Cu test result interpretation in patients with chronic cholestatic liver disease and urges a thorough consideration of alternative diagnoses of PALF Funding Agencies None

Morphology of transplanted liver in recurrent progressive familial intrahepatic cholestasis type 2

Progressive familial intrahepatic cholestasis type 2 (PFIC-2), formerly known as Byler’s syndrome, is an autosomal recessive disorder. In infancy or early childhood, this disease leads to end-stage hepatic disease, in which liver transplantation is the only radical treatment. In general, liver transplantation outcomes are good, but in the long term, PFIC-2 may reoccur. We present a case where a girl, aged 28 months, who suffered from cirrhosis resulting from PFIC-2, underwent a related transplantation of the left lateral sector of the liver (her grandmother as the donor). Punch biopsy was performed 8 years after the liver transplant due to graft dysfunction. Histopathology revealed a recurrent PFIC-2. F4. Increased liver failure was the reason for retransplantation of the left lobe of the liver also from a related donor (mother). Pathological pictures in the biopsy specimen and in the liver removed during retransplantation were identical, which once again confirmed PFIC-2 recurrence.

The Bile Salt Export Pump: Molecular Structure, Study Models and Small-Molecule Drugs for the Treatment of Inherited BSEP Deficiencies.

The bile salt export pump (BSEP/ABCB11) is responsible for the transport of bile salts from hepatocytes into bile canaliculi. Malfunction of this transporter results in progressive familial intrahepatic cholestasis type 2 (PFIC2), benign recurrent intrahepatic cholestasis type 2 (BRIC2) and intrahepatic cholestasis of pregnancy (ICP). Over the past few years, several small molecular weight compounds have been identified, which hold the potential to treat these genetic diseases (chaperones and potentiators). As the treatment response is mutation-specific, genetic analysis of the patients and their families is required. Furthermore, some of the mutations are refractory to therapy, with the only remaining treatment option being liver transplantation. In this review, we will focus on the molecular structure of ABCB11, reported mutations involved in cholestasis and current treatment options for inherited BSEP deficiencies.

Burden of illness of progressive familial intrahepatic cholestasis in the US, UK, France, and Germany: study rationale and protocol of the PICTURE study

ABSTRACT Background: Progressive familial intrahepatic cholestasis (PFIC) is an ultra-rare disease with a considerable burden on pediatric patients and their caregivers, impacting quality of life (QoL). The mortality rates highlight a significant need for efficacious treatments. Real-world data on associated costs and QoL are needed to gauge the potential impact of new pharmacological treatments. Methods: Clinical and socio-economic burden of PFIC on patients/caregivers, health systems, and society will be assessed. Patient/caregiver- and physician-level retrospective cross-sectional data will be collected from the US, UK, France, and Germany, for PFIC types 1, 2, 3. A representative sample of physicians will provide clinical and resource utilization information using an electronic Case Report Form (eCRF). Patient/caregiver surveys will collect socio-economic and QoL data, enabling assessment of PFIC impact on QoL. Mean costs (direct medical/non-medical, indirect) will be calculated. The study materials were reviewed by medical professionals and patient representatives and received ethical approval from the University of Chester. Discussion: The study aims to reveal the unmet medical need, disease burden, resource utilization, and costs of PFIC, to raise awareness with policymakers and healthcare professionals, and provide support for the patient/caregiver community. As novel PFIC therapies recently emerged, this study will yield quantifiable data for health technology assessments.

Clinical characteristics and gene variants of patients with infantile intrahepatic cholestasis

Objective To explore the clinical characteristics and genetic findings of patients with infantile intrahepatic cholestasis. Methods The clinical data were collected in children who were admitted to the Department of Gastroenterology in Children's Hospital, Capital Institute of Pediatrics from June 2017 to June 2019 and were suspected of inherited metabolic diseases. Next generation sequencing based on target gene panel was used for gene analysis in these children. Sanger sequencing technology was used to verify the genes of the members in this family. Results Forty patients were enrolled. Pathogenic gene variants were identified in 13 patients (32%), including SLC25A13 gene variation in 3 patients who were diagnosed with citrin deficiency, JAG1 gene variation in 3 patients who were diagnosed with Alagille syndrome, ABCB11 gene variation in 3 patients who were diagnosed with progressive familial intrahepatic cholestasis type 2, HSD3B7 gene variation in 1 patient who was diagnosed with congenital bile acid synthesis defect type 1, AKR1D1 gene variation in 1 patient who was diagnosed with congenital bile acid synthesis defect type 1, NPC1 gene variation in 1 patient who was diagnosed with Niemann-Pick disease, and CFTR gene variation in 1 patient who was diagnosed with cystic fibrosis. Conclusions The etiology of infantile intrahepatic cholestasis is complex. Next generation sequencing is helpful in the diagnosis of infantile intrahepatic cholestasis.

Синдром холестаза у детей раннего возраста

This article aims to give an up to date review of existing literature on the early manifestations of pathology accompanied by intrahepatic cholestasis in infants. Cholestasis is usually diagnosed in infants with some congenital disorders or some infectious diseases. Its early diagnosis will improve the prognosis for the rest of patient's life. The severity of clinical manifestations of congenital disorders is determined by the type of disorder, as well as by anatomical and physiological characteristics of the liver and biliary tract of infants. There are two types of cholestasis of newborns and infants associated with congenital liver diseases: intrahepatic and extrahepatic. Intrahepatic cholestasis is caused by impaired synthesis or excretion of bile acids observed in patients with progressive familial intrahepatic cholestasis (PFIC) types 1, 2, and 3, benign recurrent intrahepatic cholestasis, and Alagille syndrome. In this article, we discuss the approaches to differential diagnosis of cholestatic diseases at their onset in infants, when it is crucial to determine the management strategy and prevent severe complications, such as cirrhosis, portal hypertension, and liver failure. Key words: intrahepatic cholestasis, hyperbilirubinemia, infants, bile ducts, bile acids, liver

Progressive familial CD10 deficient ductopenic disorder; Hitherto an unnamed entity! - A case report

Inherited liver disorders are group of genetic diseases that cause early liver involvement many of them progressing to early cirrhosis. Of the familial cholestatic disorders most widely studied are progressive familial intrahepatic cholestatic disorders. These disorders are caused by defects in enzymes involved with the formation and excretion of bile constituents. They are, however, not associated with ductopenia. We herein report the first case of a familial cholestatic disorder in three female siblings resident of Lahore, Pakistan presenting as chronic cholestasis all progressing to cirrhosis before 10 years of age. The first two female siblings underwent liver transplants for chronic cholestasis. The third sibling underwent liver biopsy for the evaluation of cholestasis and later liver transplant for same. There are no other associated cardiac or skeletal anomalies in any of the sisters. The findings of biopsy and explant tissue were similar in all three sibling sisters. There are features of advanced fibrosis, significant ductopenia, bile ductular reaction at the porto-parenchymal interface, cholestasis, increased copper stores on rhodanine stain no loss of bile salt export pump, and multi-drug resistant 3 protein (MDR3), and the absence of CD10 from canaliculi. The findings raised differentials for progressive familial intrahepatic cholestasis (PFIC) type 3, Alagille syndrome, and variant of familial cholestatic disorder. PFIC 3 causes cholestasis, but the presence of MDR3 stain, ductopenia, and deficient CD10 are not seen in PFIC 3. Familial ductopenic disorders have been identified in the adult population called as idiopathic adulthood ductopenia and had autosomal dominant pattern of inheritance. The argument against Alagille syndrome is the absence of any other syndromic features of Alagille and autosomal recessive mode of inheritance. These findings led us to conclude if there is a need to redefine a new entity of progressive familial CD10 deficient ductopenic disorder. The findings though limited by genetic studies give way for further research on the subject.

Gene Therapy for Progressive Familial Intrahepatic Cholestasis: Current Progress and Future Prospects.

Progressive Familial Intrahepatic Cholestasis (PFIC) are inherited severe liver disorders presenting early in life, with high serum bile salt and bilirubin levels. Six types have been reported, two of these are caused by deficiency of an ABC transporter; ABCB11 (bile salt export pump) in type 2; ABCB4 (phosphatidylcholine floppase) in type 3. In addition, ABCB11 function is affected in 3 other types of PFIC. A lack of effective treatment makes a liver transplantation necessary in most patients. In view of long-term adverse effects, for instance due to life-long immune suppression needed to prevent organ rejection, gene therapy could be a preferable approach, as supported by proof of concept in animal models for PFIC3. This review discusses the feasibility of gene therapy as an alternative for liver transplantation for all forms of PFIC based on their pathological mechanism. Conclusion: Using presently available gene therapy vectors, major hurdles need to be overcome to make gene therapy for all types of PFIC a reality.