Partial External Biliary Diversion Research Articles

Odevixibat: A Novel Bile Salt Inhibitor Treatment for Pruritus in Progressive Familial Intrahepatic Cholestasis.

Chronic pruritus is defined as an itch lasting greater than six weeks. It can manifest from a wide variety of etiologies, as many different substances can act as pruritogens, such as steroids, histamine, progesterone, endogenous opioids, and serotonin. In the setting of cholestatic liver disease, increased bile acids play a major role in chronic pruritus. The itching in cholestatic liver disease is worsened in intensity at night and localized frequently to the palms, soles, knees, and other pressure sites. It can be hard to manage, affecting the quality of sleep and causing irritability, poor attention, and, in some cases, depression. One such disease that results from chronic pruritus is progressive familial intrahepatic cholestasis (PFIC), a group of uncommon hereditary disorders that affects the formation of bile and its outflow from the liver. Previously, the drug ursodeoxycholic acid was used to help manage pruritus or surgical procedures, e.g., partial external biliary diversion or partial internal biliary diversion, to help control complications of the disease. This literature review will discuss three clinical studies covering the effectiveness of odevixibat in treating pruritus in patients with PFIC. Odevixibat (Bylvay) is an oral drug that has been FDA-approved to treat pruritus in patients three months of age and older with PFIC. Odevixibat prevents the reabsorption of bile salts in the intestines, resulting in decreased levels of bile salts via their excretion in stool. Several studies have determined that the drug is well tolerated and provides a nonsurgical, pharmacological treatment alternative for those with PFIC.

Optimal liver transplant procedure in progressive familial intrahepatic cholestasis type 1 treated with biliary diversion or intestinal transplantation: Lessons learned from three cases treated with different approaches.

Progressive familial intrahepatic cholestasis type 1 (PFIC1) is an autosomal recessive cholestatic liver disorder caused by ATP8B1 gene mutations. Although liver transplantation (LT) is indicated for progressive liver disease, postoperative complications, including severe diarrhea and graft steatohepatitis leading to graft loss, have been reported. The first patient had jaundice, pruritus, diarrhea, and growth retardation (weight z-score: -2.5; height z-score: -3.7). She underwent LT with total internal biliary diversion (TIBD) to the colon at 2 years of age. Graft biopsy at the 7-year follow-up examination revealed microvesicular steatosis (60%). Her diarrhea improved, and her growth failure was recovering (weight z-score: -1.0; height z-score: -1.7). The second patient underwent sequential intestine-liver transplantation at 8 years of age due to end-stage liver disease (ESLD) and short bowel syndrome caused by massive bowel resection for internal hernia after partial external biliary diversion (PEBD) at 21 months of age. She developed severe pancreatitis induced by steroid-bolus therapy for rejection after transplantation. She died 1.7 years after intestinal transplantation due to an uncontrollable pancreatic abscess and acute respiratory distress syndrome. The third patient underwent PEBD at 15 months of age and received LT with TEBD at 15 years of age due to ESLD with hepatic encephalopathy. Throughout the perioperative period, she showed no abdominal symptoms, including diarrhea and pancreatitis. Graft biopsy at the 2-year follow-up examination revealed macrovesicular steatosis (60%) with inflammation. The patients showed different outcomes. Effective therapeutic options to mitigate post-LT complications in patients with PFIC1 must be considered individually.

Native liver survival in bile salt export pump deficiency: results of a retrospective cohort study.

Bile salt export pump (ABCB11) deficiency [Progressive familial intrahepatic cholestasis (PFIC2)] is the most common genetic cause of PFIC and is associated with pruritus and progressive liver disease. Surgical biliary diversion or pharmacological [ileal bile acid transporter inhibitor (IBATi)] approaches can be used to block the recirculation of bile acids to the liver. There is a paucity of detailed data on the natural history and, in particular, the longitudinal evolution of bile acid levels to predict treatment response. Cross-sectional data from large international consortia suggested a maximum cutoff value of bile acids after the intervention to predict a successful outcome. This retrospective, single-center, cohort study included all patients with confirmed biallelic pathogenic ABCB11 genotype PFIC2 treated at our institution with ≥2 years follow-up. The outcomes of interventions and predictors of long-term health were analyzed. Forty-eight cases were identified with PFIC2. Eighteen received partial external biliary diversion (PEBD) surgery, and 22 patients underwent liver transplantation. Two patients developed HCC and 2 died. Improved survival with native liver was closely associated with genotype, complete normalization of serum bile acids following PEBD, and alleviation of pruritus. Persistence of mild-to-moderate elevation of bile acids or a secondary rise following normalization was associated with liver disease progression and led to transplantation, suggesting that any prolonged elevation of bile acids worsens the chance of native liver survival. Higher-grade fibrosis at the time of PEBD was not associated with reduced long-term native liver survival. Patients with PFIC2 benefit from PEBD even at a stage of advanced fibrosis. Serum bile acid levels are an early predictor of treatment response and might serve as the gold standard in the evaluation of novel therapies including IBATi.

Evaluation of Clinical Outcomes in Children with Intrahepatic Cholestasis Postpartial External Biliary Diversion: A Single-Center Experience.

Severe pruritus caused by progressive familial intrahepatic cholestasis (PFIC) and Alagille syndrome (AGS) is refractory to medical treatment. Surgical interruption of the enterohepatic circulation is considered the mainstay of alleviating distressing symptoms and delaying cirrhosis. This study aims to evaluate the short-term effect of partial external biliary diversion (PEBD) on pruritus, liver disease progression, patient's growth, and quality of life. This prospective cohort study enrolled children with PFIC and AGS from July 2019 to July 2021, whose guardians consented to the PEBD procedure. A standard surgical approach was performed by a single surgeon. Outcomes were measured subjectively and objectively pre- and post-procedure using the pruritus 5-D itching score, Paediatric Quality of Life Inventory scale (PedsQL), growth parameters, bile acids level, and liver function tests. Patients' follow-up period ranged from 6 to 12 months. Seven patients had PEBD procedure; five with PFIC and two with AGS. A significant improvement was detected in the 5-D itching score (p-value < 0.001), PedsQL (p-value < 0.001), and bile acids level (p-value 0.013). The preexisting growth failure was ameliorated. The downward trend in the bilirubin level was not significant. No influential difference in the other liver function tests occurred. No intra-operative complications encountered. Only one case had a post-operative stoma prolapse which was managed surgically. PEBD procedure could be considered as an effective and safe treatment options for intractable pruritus in patients with PFIC or AGS, providing preserved synthetic liver functions.

Long-Term Outcomes of Patients With Progressive Familial Intrahepatic Cholestasis After Biliary Diversion.

Progressive familial intrahepatic cholestasis is a heterogeneous group of genetic disorders characterized by disrupted bile homeostasis. Patients with this disease typically present with cholestasis and pruritus early in life and often progress to end-stage liver disease. The clinical symptoms that patients with progressive familial intrahepatic cholestasis encounter are usually refractory to medical treatment. Although the effects of biliary diversion surgery on native liver survival are not exactly known, this procedure may provide a positive impact on pruritus and laboratory parameters in these patients. We retrospectively evaluated the clinical and laboratory characteristics of patients with progressive familial intrahepatic cholestasis who underwent partial external biliary diversion between 2002 and 2020 at our center. Diagnosis of progressive familial intrahepatic cholestasis was made by clinical, biochemical, and histopathological characteristics as well as genetic testing. Nine patients were included in the study. Five patients required liver transplant during follow-up, with 4 having liver transplant as a result of endstage liver disease (median interval of 5 years). In 1 patient, partial external biliary diversion was performed 1.5 years after liver transplant for severe diarrhea, metabolic acidosis, and hepatic steatosis. Four patients did not require liver transplant during follow-up (median follow-up time of 7.6 years). Pruritus responded well to partial external biliary diversion in all patients. Among laboratory values evaluated 6 months after biliary diversion, only albumin showed significant improvement. Partial external biliary diversion had favorable results on long-term follow-up. This procedure can provide the relief of pruritus and delay the requirement for liver transplant in patients with progressive familial intrahepatic cholestasis. In our view, partial external biliary diversion should be considered the first-line surgical management for patients with this disease.

Partial External Biliary Diversion for Severe Diarrhea After Liver Transplant in Patients with Progressive Familial Intrahepatic Cholestasis Type 1.

Progressive familial intrahepatic cholestasis is a heterogeneous group of autosomal recessive disorders, and liver transplant is the only curative treatment. A biliary diversion operation for disruption of enterohepatic circulation in patients with progressive familial intrahepatic cholestasis type 1 without cirrhosis is another option. We present a pediatric patient with progressive familial intrahepatic cholestasis type 1 who underwent liver transplant due to end-stage liver disease. After transplant, diarrhea and growth retardation complications resolved after partial external biliary diversion surgery.

Avoiding Liver Transplantation in Progressive Familial Intrahepatic Cholestasis: Role of Partial Biliary Diversion

Progressive familial intra-hepatic cholestasis (PFIC) is a rare cholestatic disorder affecting children often resulting in end stage liver failure. Patients usually present with unremitting pruritus as the most distressing symptoms in addition to jaundice. Its treatment is difficult and varies from medical therapy which is often only symptomatic and provides only brief relief. Non transplant surgical options aim at interrupting the entero-hepatic bile salt circulation and thereby palliating symptoms, delaying disease progression. There are however few long term reports regarding the results of these biliary diversion procedures. We report six cases of PFIC who did not respond to medical therapy but had normal liver and underwent partial biliary diversion, at 5 months, 8 months, 13 months 18 months, 22 months and 2 years of age. Four patients had PFIC type 2, all of whom underwent partial internal biliary diversion (PIBD) and two patients had PFIC type 1 in whom we performed a partial external biliary diversion (PEBD) in one and partial internal biliary diversion in the other. One patient died at 9 months after surgery due to unrelated cause, 3 patients were lost to follow up. Remaining two patients are asymptomatic and doing well without need for Liver transplantation at long term follow up of 10 years. Internal diversion appears to have an advantage in terms of having better control of symptoms and quality of life without a stoma. In our experience, partial biliary internal diversion is a safe and easy procedure with good results in patients without fibrosis.

LONG-TERM OUTCOMES OF PEDIATRIC LIVER TRANSPLANTATION FOR PROGRESSIVE FAMILIAL INTRAHEPATIC CHOLESTASIS

Introduction: Progressive familial intrahepatic cholestasis (PFIC) is a rare group of heterogenous autosomal recessive disorders characterized by defective bile acid secretion or transportation leading to progressive cholestasis. The different types of PFIC are associated with varying genetic defects leading to different phenotypes and extrahepatic manifestations. We report our experience with liver transplantation (LT) in eighteen PFIC patients. Methods: We performed a retrospective review of all children less than 18 years old who underwent LT with a diagnosis of PFIC at our institution. Genetic mutation analysis and explant histopathology were used to confirm all diagnoses. Patient demographics, clinical and laboratory studies, and perioperative data including impact of LT on growth were analyzed. Results: Eighteen children with PFIC underwent LT between November 2005 and October 2018. (Table 1) Subtype analysis based on genetic testing and pathology included two PFIC type 1 (PFIC1), ten PFIC type 2 (PFIC2), two PFIC type 3 (PFIC3), two PFIC type 4 (PFIC4), and two PFIC type 5 (PFIC5). Median age at time of liver transplant was one year of age with the youngest transplant performed on a three-month-old and the oldest transplant performed on a 17-year-old. Two patients with PFIC1 had prior internal cholecystojejunocolostomies for biliary diversion. Two patients, both with PFIC2, had prior partial external biliary diversion procedures. Follow-up from time of transplant ranged from 2 to 15 years, with a median of 8 years. There was improvement in growth in terms of height and weight across all PFIC subtypes. Overall mean height z-score improved from -1.89 to -0.84. Mean weight z-score improved from -1.15 to 0.16. Overall median total bilirubin before transplantation was 7.5 mg/dL with normalization to 0.5 mg/dL posttransplant. There have been no graft failures or deaths in our population. Conclusion: LT is a safe and effective long-term treatment for PFIC of all subtypes. It is associated with good outcomes in terms of growth and control of cholestasis as measured in total bilirubin. There is little morbidity in our population with 100% graft and patient survival even after fifteen years of follow-up.

Surgical diversion of enterohepatic circulation in pediatric cholestasis

Progressive familial intrahepatic cholestasis (PFIC) and Alagille syndrome (AS) are conditions caused by either an autosomal recessive or an autosomal dominant genetic defect, and they are both characterized by cholestasis, jaundice, and severe debilitating pruritus refractory to medical management. Before the advent of liver transplantation, most PFIC patients would die from end-stage liver disease in the first decade of life. Although liver transplantation has led to patients’ survival, disease recurrence (PFIC-2) and severe extra-hepatic manifestations of the disease (PFIC-1) occurred post transplant. In the late 1980s, Whitington described the use of partial external biliary diversion in PFIC and AS patients as a successful way to improve symptoms and decrease circulating bile acid serum concentrations. Since then, other diversion techniques have been described (ileal exclusion and partial internal biliary diversion). These techniques have the benefit of avoiding a stoma, but equivalent results have not been demonstrated (recurrence of cholestasis after ileal exclusion, limited follow up after internal biliary diversion). Overall, studies have showed that biliary diversions in children with cholestasis are safe procedures with low morbidity and mortality, and that they can reduce inflammation and ongoing liver injury, therefore delaying or avoiding the need for liver transplantation in some patients.

Systematic Review and Meta-analysis: Partial External Biliary Diversion in Progressive Familial Intrahepatic Cholestasis.

We assessed available data on impact of partial external biliary diversion (PEBD) surgery on clinical outcomes in patients with progressive familial intrahepatic cholestasis (PFIC). We performed a systematic literature review (PubMed) and meta-analysis to evaluate relationships between liver biochemistry parameters (serum bile acids, bilirubin, and alanine aminotransferase [ALT]) and early response (pruritus improvement) or long-term outcomes (need for liver transplant) in patients with PFIC who underwent PEBD. Searches identified 175 publications before September 2018; 16 met inclusion criteria. Receiver operating characteristic (ROC) analysis examined ability of liver biochemistry parameters to discriminate patients who demonstrated early and long-term response to PEBD from those who did not. Regarding pruritus improvement in 155 included patients in aggregate, 104 (67%) were responders, 14 (9%) had partial response, and 37 (24%) were nonresponders. In ROC analyses of individual patient data, post-PEBD serum concentration of bile acids, in particular, could discriminate responders from nonresponders for pruritus improvement (area under the curve, 0.99; P < 0.0001; n = 42); to a lesser extent, this was also true for bilirubin (0.87; P = 0.003; n = 31), whereas ALT could not discriminate responders from nonresponders for pruritus improvement (0.74; P = 0.06; n = 28). Reductions from pre-PEBD values in serum bile acid concentration (0.89; P = 0.0003; n = 32) and bilirubin (0.98; P = 0.002; n = 18) but not ALT (0.62; P = 0.46; n = 18) significantly discriminated decreased aggregate need for liver transplant. Changes in bile acids seem particularly useful in discriminating early and long-term post-PEBD outcomes and may be potential biomarkers of response to interruption of enterohepatic circulation in patients with PFIC.

Inherited Cholestatic Diseases in the Era of Personalized Medicine.

http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-3-reading-mack a video presentation of this article.

Long-term follow-up in children with progressive familial intrahepatic cholestasis type 2 after partial external biliary diversion with focus on histopathological features.

Progressive familial intrahepatic cholestasis (PFIC) comprises agroup of rare cholestatic liver disorders of childhood that could lead to liver cirrhosis. Nowadays, the partial biliary diversion procedure is still atherapeutic option in non-cirrhotic children with PFIC1 or PFIC2 after an ineffective ursodeoxycholic acid (UDCA) therapy. However, the relevant disadvantage of the partial external biliary diversion (PEBD) is that adolescent patients could not accept apermanent stoma. In some of them, despite of good clinical and biochemical results of this procedure, the ileal exclusion (IE) procedure had to be performed many years after PEBD. Our aims were to find the most characteristic early microscopic features of the disease as well as to compare changes in the liver biopsy specimens at the time of diagnosis and long-time (more than 10 years) after asurgical procedure. We examined retrospectively 8 liver biopsies from 4 PFIC2 patients comparing the results from the first biopsies done at the time of PFIC diagnosis and the second ones, done many years after PEBD. The characteristic lobular rosette formations of hepatocytes were found in all patients at the time of diagnosis. Cholestasis was observed in each patient, but only in two of them, centrally located bile plugs were found. The majority of hepatocytes showed degenerative changes from mild to severe degree. In the follow-up biopsies, cholestasis completely disappeared in 3 patients and decreased significantly in 1 other patient. Based on Batts and Ludwig fibrosis scoring system, the liver fibrosis had resolved in two out of three patients. The formation of lobular rosettes with centrally located bile plugs and degenerative changes of hepatocytes seem to be the most characteristic microscopic features in early liver biopsies in PFIC2 patients. Partial external biliary diversion significantly improved the clinical, anthropological, biochemical as well histological outcome of the patients.

Outcomes of surgical management of familial intrahepatic cholestasis 1 and bile salt export protein deficiencies.

Progressive familial intrahepatic cholestasis (PFIC) with normal circulating gamma‐glutamyl transpeptidase levels can result from mutations in the ATP8B1 gene (encoding familial intrahepatic cholestasis 1 [FIC1] deficiency) or the ABCB11 gene (bile salt export protein [BSEP] deficiency). We investigated the outcomes of partial external biliary diversion, ileal exclusion, and liver transplantation in these two conditions. We conducted a retrospective multicenter study of 42 patients with FIC1 deficiency (FIC1 patients) and 60 patients with BSEP deficiency (BSEP patients) who had undergone one or more surgical procedures (57 diversions, 6 exclusions, and 57 transplants). For surgeries performed prior to transplantation, BSEP patients were divided into two groups, BSEP‐common (bearing common missense mutations D482G or E297G, with likely residual function) and BSEP‐other. We evaluated clinical and biochemical outcomes in these patients. Overall, diversion improved biochemical parameters, pruritus, and growth, with substantial variation in individual response. BSEP‐common or FIC1 patients survived longer after diversion without developing cirrhosis, being listed for or undergoing liver transplantation, or dying, compared to BSEP‐other patients. Transplantation resolved cholestasis in all groups. However, FIC1 patients commonly developed hepatic steatosis, diarrhea, and/or pancreatic disease after transplant accompanied by biochemical abnormalities and often had continued poor growth. In BSEP patients with impaired growth, this generally improved after transplantation. Conclusion: Diversion can improve clinical and biochemical status in FIC1 and BSEP deficiencies, but outcomes differ depending on genetic etiology. For many patients, particularly BSEP‐other, diversion is not a permanent solution and transplantation is required. Although transplantation resolves cholestasis in patients with FIC1 and BSEP deficiencies, the overall outcome remains unsatisfactory in many FIC1 patients; this is mainly due to extrahepatic manifestations. (Hepatology Communications 2018;2:515‐528)

Clinical Variability After Partial External Biliary Diversion in Familial Intrahepatic Cholestasis 1 Deficiency.

Familial intrahepatic cholestasis 1 (FIC1) deficiency is caused by a mutation in the ATP8B1 gene. Partial external biliary diversion (PEBD) is pursued to improve pruritus and arrest disease progression. Our aim is to describe clinical variability after PEBD in FIC1 disease. We performed a single-center, retrospective review of genetically confirmed FIC1 deficient patients who received PEBD. Clinical outcomes after PEBD were cholestasis, pruritus, fat-soluble vitamin supplementation, growth, and markers of disease progression that included splenomegaly and aspartate aminotransferase-to-platelet ratio index. Eight patients with FIC1 disease and PEBD were included. Mean follow-up was 32 months (range 15-65 months). After PEBD, total bilirubin was <2 mg/dL in all patients at 8 months after surgery, but 7 of 8 subsequently experienced a total of 15 recurrent cholestatic events. Subjective assessments of pruritus demonstrated improvement, but itching exacerbation occurred during cholestatic episodes. High-dose fat-soluble vitamin supplementation persisted, with increases needed during cholestatic episodes. Weight z scores improved (-3.4 to -1.65, P < 0.01). Splenomegaly did not worsen or develop and 1 patient developed an aminotransferase-to-platelet ratio index score of >0.7 suggesting development of fibrosis 24 months after PEBD. Clinical variability is evident among genetically defined FIC1 deficient patients after PEBD, even among those with identical mutations. Recurrent, self-limited episodes of cholestasis and pruritus are reminiscent of the benign recurrent intrahepatic cholestasis phenotype. Despite diversion of bile from the intestinal lumen, weight gain improved while fat-soluble vitamin requirements persisted. Significant progression of liver disease was not evident during follow-up.

Influence of Partial External Biliary Diversion on the Lipid Profile in Children With Progressive Familial Intrahepatic Cholestasis.

The concentration of bile acids is highly increased in progressive familial intrahepatic cholestasis (PFIC). Bile acids are the end products of cholesterol metabolism, and aid in the absorption of fat-soluble vitamins and dietary fat. The aim of our study was to investigate lipid metabolism in patients with PFIC with focus on the effect of partial external biliary diversion (PEBD). In 26 patients with PFIC, who underwent PEBD surgery at the median age of 2.2 years (range: 0.4-16.6), we analyzed the concentrations of lipids and apolipoproteins both before and 6 months after PEBD. Patients were split into 2 groups according to the outcome of surgery (either "good" or "poor"), and were analyzed separately. A "good" result following surgery was defined as complete relief from pruritus, and normalization of total bilirubin (<1.0 mg/dL) and bile acid concentration in serum (<12 μmol/L). We found abnormal lipid concentrations at baseline in all 26 patients: cholesterol was increased (>190 mg/dL) in 13 patients, phospholipids were increased (>250 mg/dL) in 5 patients, and triglyceride concentration was increased (>150 mg/dL) in 13 patients. After PEBD, the concentrations of plasma cholesterol, triglycerides, and phospholipids decreased significantly, whereas, ApoA-I and high-density lipoprotein cholesterol concentrations increased and the concentrations of apolipoprotein B, low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol significantly decreased. PEBD had neither an effect on ApoE concentration nor on lecithin-cholesterol acyl transferase activity. In the group with a "poor" outcome report following PEBD, total serum cholesterol concentration decreased significantly, and no effect on the concentrations of triglycerides and phospholipids were observed. Patients with PFIC present with a high risk of lipid disturbances. PEBD has a beneficial effect on lipid profile in the majority of cases.

Outcomes following partial external biliary diversion in patients with progressive familial intrahepatic cholestasis

Background/purposePFIC is a family of bile acid (BA) transport disorders that may result in serious liver disease requiring transplantation. We reviewed our experience with PEBD as a method to improve liver function and avoid transplantation. MethodsAll patients with PFIC were reviewed. Outcomes included changes in serum BA, conversion to ileal bypass (IB), and survival without transplantation. Statistics were obtained using paired t-test and Wilcoxon test. ResultsThirty-five patients with PFIC were identified. Data were available in 24. Twenty-four children (12 males) underwent PEBD: 10 PFIC-1, 13 PFIC-2, and one PFIC-3. BA levels decreased in PFIC-1 patients (1724±3215 to 11±6μmol/L, P=0.03) and in the single PFIC-3 patient (821 to 11.2μmol/L), but not significantly in PFIC-2 patients (193±99 to 141±118μmol/L, P=0.15). Seven patients were converted to IB. There were no significant changes in BA levels following conversion. Five-year transplant-free survival was 100% in PFIC-1 and PFIC-3, but only 38% (5/13) in PFIC-2 (P=0.004). ConclusionPEBD is an effective procedure to reduce total BA levels and improve symptoms in PFIC patients. However, it appears to be less efficacious in the PFIC-2 group. The higher BA levels could contribute to ongoing liver damage, and thus a higher transplant rate in PFIC-2 patients. Level of evidenceLevel IV.

Clinical Course Following Partial External Biliary Diversion for Progressive Familial Intrahepatic Cholestasis 1: A Report of Two Patients

AIM: To better understand the effect of partial external biliary diversion (PEBD) in patients with progressive familial intrahepatic cholestasis 1 (PFIC1). MATERIALS AND METHODS: We analyzed quantitative changes in the concentrations of individual bile acids in serum, urine, and biliary bile, and concomitant changes in symptoms such as pruritus, in 2 patients whose PFIC1 clinically evolved to resemble the course of benign recurrent intrahepatic cholestasis (BRIC) upon treatment with PEBD. RESULTS: Patient 1 showed good therapeutic effect after PEBD including improved liver function test results and decreased total bile acids in serum, as well as decreased pruritus. The cholic acid (CA)/chenodeoxycholic acid (CDCA) ratio in biliary bile also decreased. Patient 2, however, experienced little decrease in pruritus after PEBD, and showed no clear change in the CA/CDCA ratio. Nonetheless, this patient’s course did not rapidly worsen. CONCLUSION: In PFIC1, increased bile secretion and a decreased CA/CDCA ratio in biliary bile may be the most important responses after PEBD. Relief of pruritus is also an important sign of therapeutic effect. Moreover, progression of symptoms in PFIC1 sometimes can be delayed by PEBD, resulting in a relatively mild BRIC-like course, even when the CA/CDCA ratio and pruritus show little change. However, mechanisms underlying clinical benefits remain obscure.

Byler disease: early natural history.

Byler disease, originally described in Amish kindred, results from mutations in ATPase Class I Type 8b Member 1 (ATP8b1). Specific clinical reports of Amish Byler disease were last published 40 years ago. These investigations were directed at the present detailed clinical understanding of the early course of hepatic manifestations of Byler disease. This study analyzed routine clinical practice and outcomes of children with Byler disease (defined by homozygous c.923G>T mutation in ATP8b1), who initially presented to Children's Hospital of Pittsburgh of UPMC between January 2007 and October 2014. Data were analyzed to the earlier of 24 months of age or partial external biliary diversion. Six children presented between 1 and 135 days of life: 2 presented with newborn direct hyperbilirubinemia, 2 had complications of coagulopathy, 1 had failure to thrive and rickets, and 1 sibling was identified by newborn genetic testing. Intensive fat-soluble vitamin supplementation was required to prevent insufficiencies in vitamins D, E, and K. Hyperbilirubinemia was variable both over time and between children. Serum bile acid levels were elevated, whereas γ-glutamyltranspeptidase levels were low normal. Scratching behavior (pruritus) was intractable in 4 of 6 children with onset between 6 and 12 months of age. Features of portal hypertension were not observed. Partial external biliary diversion was used during the second year of life in 4 children. Detailed analysis of Byler disease revealed varied disease presentation and course. Nutritional issues and pruritus dominated the clinical picture in the first 2 years of life.

MYO5B and bile salt export pump contribute to cholestatic liver disorder in microvillous inclusion disease

Microvillous inclusion disease (MVID) is a congenital disorder of the enterocyte related to mutations in the MYO5B gene, leading to intractable diarrhea often necessitating intestinal transplantation (ITx). Among our cohort of 28 MVID patients, 8 developed a cholestatic liver disease akin to progressive familial intrahepatic cholestasis (PFIC). Our aim was to investigate the mechanisms by which MYO5B mutations affect hepatic biliary function and lead to cholestasis in MVID patients. Clinical and biological features and outcome were reviewed. Pretransplant liver biopsies were analyzed by immunostaining and electron microscopy. Cholestasis occurred before (n = 5) or after (n = 3) ITx and was characterized by intermittent jaundice, intractable pruritus, increased serum bile acid (BA) levels, and normal gamma-glutamyl transpeptidase activity. Liver histology showed canalicular cholestasis, mild-to-moderate fibrosis, and ultrastructural abnormalities of bile canaliculi. Portal fibrosis progressed in 5 patients. No mutation in ABCB11/BSEP or ATP8B1/FIC1 genes were identified. Immunohistochemical studies demonstrated abnormal cytoplasmic distribution of MYO5B, RAB11A, and BSEP in hepatocytes. Interruption of enterohepatic BA cycling after partial external biliary diversion or graft removal proved the most effective to ensure long-term remission. MVID patients are at risk of developing a PFIC-like liver disease that may hamper outcome after ITx. Our results suggest that cholestasis in MVID patients results from (1) impairment of the MYO5B/RAB11A apical recycling endosome pathway in hepatocytes, (2) altered targeting of BSEP to the canalicular membrane, and (3) increased ileal BA absorption. Because cholestasis worsens after ITx, indication of a combined liver ITx should be discussed in MVID patients with severe cholestasis. Future studies will need to address more specifically the effect of MYO5B dysfunction in BA homeostasis.

Ileal Exclusion in Children With Progressive Familial Intrahepatic Cholestasis

Children with progressive familial intrahepatic cholestasis (PFIC) rarely benefit from medical treatment and most patients require surgical intervention. Partial external biliary diversion (PEBD) is presently the treatment of choice but for those who cannot benefit from PEBD, an alternative surgical procedure--ileal exclusion (IE)--was introduced. The aim of this study was to analyze our experience with IE in children with PFIC. This procedure was performed in 9 patients (6 girls, 3 boys) at the median age of 11 years (range 8-21). In 4 children, it was the primary operation (group 1), and in 5, IE was performed after PEBD (group 2). All of the patients were screened for ABCB11 and ATP8B1 mutations, and in 3 cases, PFIC type 2 was confirmed. Median follow-up after IE surgery was 8.5 years (range 3-14). In group 1, 1 patient had to be converted to PEBD and the remaining 3 children experienced alleviation in pruritus and decrease in bilirubin and bile acids concentrations 2 and 5 years after IE. After 10 years, only 2 children were still accessible for follow-up. In both, pruritus varied and elevated serum bile acids were observed. Of the 5 patients who underwent IE after PEBD, 1 eventually required liver transplantation, 1 developed varying degree of pruritus, and 3 female patients, operated on because of aesthetic reasons, had excellent outcomes. IE is an alternative rescue option to PEBD and should be offered cautiously, only to patients who cannot benefit from PEBD.