A case report of a novel 22 bp duplication within exon 1 of the UGT1A1 in a Sudanese infant with Crigler-Najjar syndrome type I.

BACKGROUND: Crigler Najjar type 1 is a rare autosomal recessive condition caused by the absence of UDPGT enzyme due to mutations in the UGT1A1 gene. This enzyme is responsible for elimination of unconjugated bilirubin from the body by glucuronidation. Affected individuals are at risk for kernicterus and require lifelong phototherapy. Liver transplant is the only definitive treatment. CASE PRESENTATION: Here we report a case of a 6 month old Sudanese female infant with CN1 whose molecular analysis revealed a novel homozygous 22 base pair duplication (c.55_76dup) in the coding exon 1 of the UGT1A1 gene. This 22 bp duplication causes a frame shift leading to a premature stop codon. She underwent a successful liver transplant at 7 months of age and is doing well at 1 year follow-up. CONCLUSION: This study shows that molecular diagnosis helps in precise diagnosis of CN1 and in prognosis, prompt medical intervention and appropriate therapy. This particular 22 bp duplication within the coding region of UGT1A1 can be a founder mutation in the Sudanese population.

Ultrasound-guided in Utero Transplantation of Placental Stem Cells into the Liver of Crigler-Najjar Syndrome Model Rat.

BACKGROUND: Advances in prenatal screening and early diagnosis of genetic disease will potentially allow for preemptive treatment of anticipated postnatal disease by in utero cell transplantation (IUCT). This strategy carries potential benefits over postnatal treatment, which might allow for improved engraftment and function of the transplanted cells. Congenital metabolic disorders may be an ideal target for this type of therapy, as in most cases, they require replacement of a single deficient hepatic enzyme, and multiple small-animal models exist for preclinical testing. METHODS: The Gunn rat, a Crigler-Najjar syndrome model animal lacking UDP-glucuronosyltransferase (UGT1A1), was used as recipient. Human amniotic epithelial cells (hAECs), which possess hepatic differentiation potential, were transplanted into the midgestation fetal Gunn rat liver via ultrasound-guided IUCT. The impact of IUCT on live birth and postnatal survival was evaluated. Human cell engraftment was immunohistochemically analyzed on postnatal day 21. RESULTS: Ultrasound-guided IUCT was conducted in rat fetuses on embryonic day 16. Following IUCT, the antihuman mitochondria-positive cells were detected in the liver of recipient rats at postnatal day 21. CONCLUSIONS: Here, we have introduced ultrasound-guided IUCT of hAEC using a small-animal model of a congenital metabolic disorder without immunosuppression. The immunological advantage of IUCT was demonstrated with xenogeneic IUCT. This procedure is suitable to conduct preclinical studies for exploring the feasibility and efficacy of ultrasound-guided transuterine cell injection using rodent disease models.

A Novel Pathogenic UGT1A1 Variant in a Sudanese Child with Type 1 Crigler-Najjar Syndrome.

Uridine diphosphate glucuronosyltransferases (UGTs) are key enzymes responsible for the body's ability to process a variety of endogenous and exogenous compounds. Significant gains in understanding UGT function have come from the analysis of variants seen in patients. We cared for a Sudanese child who showed clinical features of type 1 Crigler-Najjar syndrome (CN-1), namely severe unconjugated hyperbilirubinemia leading to liver transplantation. CN-1 is an autosomal recessive disorder caused by damaging mutations in the gene for UGT1A1, the hepatic enzyme responsible for bilirubin conjugation in humans. Clinical genetic testing was unable to identify a known pathogenic UGT1A1 mutation in this child. Instead, a novel homozygous variant resulting in an in-frame deletion, p.Val275del, was noted. Sanger sequencing demonstrated that this variant segregated with the disease phenotype in this family. We further performed functional testing using recombinantly expressed UGT1A1 with and without the patient variant, demonstrating that p.Val275del results in a complete lack of glucuronidation activity, a hallmark of CN-1. Sequence analysis of this region shows a high degree of conservation across all known catalytically active human UGTs, further suggesting that it plays a key role in the enzymatic function of UGTs. Finally, we note that the patient's ethnicity likely played a role in his variant being previously undescribed and advocate for greater diversity and inclusion in genomic medicine.

Rigler Sign in a Child With Posttransplant Lymphoproliferative Disease: A Sign That Should Not Be Missed.

Rigler sign is a double wall sign suggesting pneumoperitoneum and intestinal perforation, and it needs emergency surgical treatment. Early diagnosis of intestinal perforation by clinical symptoms, presence of Rigler sign in abdominal radiography, and then early surgical treatment can reduce mortality. Here, we report a patient with Crigler-Najjar syndrome who underwent liver transplant and then developed posttransplant lymphoproliferative disease and received chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab. She was referred to the emergency department due to abdominal distension with positive Rigler sign in abdominal radiography; intraoperative findings revealed intestinal perforation. Pediatricians and surgeons should be aware of Rigler sign so that it is diagnosed early and emergency surgical treatment can be performed.

Liver Fibrosis Associated With Crigler-Najjar Syndrome in a Compound Heterozygote: A Case Report.

Crigler-Najjar syndrome is a hereditary unconjugated hyperbilirubinemia. Two forms of the disease are recognized. Type I is more severe and results in kernicterus if left untreated, and Type II is less severe and responds to phenobarbital. While Crigler-Najjar syndrome is thought by many to have normal liver histology, few reports of the liver pathology exist. Herein, we present a 19-year-old patient with Crigler-Najjar who underwent liver transplantation. The liver showed marked canalicular cholestasis with portal and variable, delicate, bridging fibrosis. Correlation of the patient's genetic test results and clinical phenotype is presented.

Gunn Rats as a Surrogate Model for Evaluation of Hepatocyte Transplantation-Based Therapies of Crigler-Najjar Syndrome Type 1.

Liver transplantation has been established as a curative therapy for acute and chronic liver failure, as well as liver-based inherited metabolic diseases. Because of the complexity of organ transplantation and the worldwide shortage of donor organs, hepatocyte transplantation is being developed as a bridging therapy until donor organs become available, or for amelioration of inherited liver-based diseases. The Gunn rat is a molecular and metabolic model of Crigler-Najjar syndrome type 1, which is characterized by lifelong unconjugated hyperbilirubinemia due to the lack of uridinediphosphoglucuronate glucuronosyltransferase-1 (UGT1A1)-mediated bilirubin glucuronidation. Gunn rats are convenient for evaluating the effect of hepatocyte transplantation or gene therapy, because the extent of UGT1A1 replacement can be assessed by serial determination of serum bilirubin levels, and excretion of bilirubin glucuronides in bile provide definitive evidence of the function of the transplanted hepatocytes or the effect of gene therapy. The core techniques involved in hepatocyte transplantation in Gunn rats are discussed in this chapter.

De Novo Donor-Specific HLA Antibody Formation in Two Patients With Crigler-Najjar Syndrome Type I Following Human Hepatocyte Transplantation With Partial Hepatectomy Preconditioning.

Clinical hepatocyte transplantation is hampered by low engraftment rates and gradual loss of function resulting in incomplete correction of the underlying disease. Preconditioning with partial hepatectomy improves engraftment in animal studies. Our aim was to study safety and efficacy of partial hepatectomy preconditioning in clinical hepatocyte transplantation. Two patients with Crigler-Najjar syndrome type I underwent liver resection followed by hepatocyte transplantation. A transient increase of hepatocyte growth factor was seen, suggesting that this procedure provides a regenerative stimulus. Serum bilirubin was decreased by 50%, and presence of bilirubin glucuronides in bile confirmed graft function in both cases; however, graft function was lost due to discontinuation of immunosuppressive therapy in one patient. In the other patient, serum bilirubin gradually increased to pretransplant concentrations after ≈600 days. In both cases, loss of graft function was temporally associated with emergence of human leukocyte antigen donor-specific antibodies (DSAs). In conclusion, partial hepatectomy in combination with hepatocyte transplantation was safe and induced a robust release of hepatocyte growth factor, but its efficacy on hepatocyte engraftment needs to be evaluated with additional studies. To our knowledge, this study provides the first description of de novo DSAs after hepatocyte transplantation associated with graft loss.

[Crigler-Najjar's syndrome is a rare cause of perinatal hyperbilirubinaemia]. / Crigler-Najjars syndrom er en sjælden årsag til perinatal hyperbilirubinæmi.

A seven-day-old, mature girl was hospitalized with serum unconjugated bilirubin 420 micromol/l. She was treated with phototherapy, which continued at home until the age of 14 years. Serum total bilirubin was then 250-300 micromol/l and she received a liver transplantation. At the age of 22 years she had no signs of chronic bilirubin encephalopathy. There was no activity of bilirubin UDP-glucuronosyl transferase in the liver, and a mutation was found in one of the coding exons in the gene. The girl suffered from Crigler-Najjar's syndrome type 1. In Denmark the incidence was about 2.7 × 10-6 in the period 1977-2010. The prevalence was about 0.5 × 10-6.

Liver transplantation in Crigler-Najjar syndrome type I disease.

BACKGROUND: Crigler-Najjar syndrome type I (CNS I) is a very rare autosomal recessive inherited disease that liver transplantation can properly deal with. METHODS: We present one case of an 18-month-old child with CNS I diagnosed by clinical findings and genetic detecting. LTx was performed 5 days after kernicterus broke out and neurological symptoms were successfully reversed. RESULT: Magnetic resonance imaging and magnetic resonance spectroscopy showed encouraging results that brain pathology had a trend to return to normal in 1-year follow-up, combined with electroencephalogram and motor development estimate studies. CONCLUSIONS: Liver transplantation can cure CNS I with reversible neurological symptoms to some extent in time. Magnetic resonance spectroscopy may be a future option of predicting brain conditions and selecting suitable patients with CNS I for transplantation.

Orthodontic treatment of a child with Crigler-Najjar syndrome type I using tacrolimus following liver transplantation.

The present study reports the orthodontic treatment of a child with Crigler-Najjar syndrome type I following a liver transplant and administration of tacrolimus (1 mg/day). Tacrolimus (FK506) is fundamental to immunosuppression following transplantation. The child exhibited Class II division 1 malocclusion. The treatment option was to use a Herbst appliance for seven months and a fixed appliance (straight wire) for 12 months.

Functional characterization of hepatocytes for cell transplantation: customized cell preparation for each receptor.

The first indication of hepatocyte transplantation is inborn liver-based metabolic disorders. Among these, urea cycle disorders leading to the impairment to detoxify ammonia and Crigler-Najjar Syndrome type I, a deficiency in the hepatic UDP-glucuronosyltransferase 1A1 present the highest incidence. Metabolically qualified human hepatocytes are required for clinical infusion. We proposed fast and sensitive procedures to determine their suitability for transplantation. For this purpose, viability, attachment efficiency, and metabolic functionality (ureogenic capability, cytochrome P450, and phase II activities) are assayed prior to clinical cell infusion to determine the quality of hepatocytes. Moreover, the evaluation of urea synthesis from ammonia and UDP-glucuronosyltransferase 1A1 activity, a newly developed assay using beta-estradiol as substrate, allows the possibility of customizing cell preparation for receptors with urea cycle disorders or Crigler-Najjar Syndrome type I. Sources of human liver and factors derived from the procurement of the liver sample (warm and cold ischemia) have also been investigated. The results show that grafts with a cold ischemia time exceeding 15 h and steatosis should not be accepted for hepatocyte transplantation. Finally, livers from non-heart-beating donors are apparently a potential suitable source of hepatocytes, which could enlarge the liver donor pool.

Living related liver transplantation in Crigler-Najjar syndrome type 1.

Four children underwent living related liver transplantation because of Crigler-Najjar syndrome type 1. Three were infants aged 2, 8(1/2), and 15 months, and weighed 5, 8, and 10 kg, respectively. Pretransplantation unconjugated bilirubin concentration was 22 to 30 mg/dL despite 12 to 14 hours of phototherapy daily. Patient 1, the 2-month-old infant, with unconjugated bilirubin concentration of 30 mg/dL, had a high-pitched cry, suggestive of bilirubin encephalopathy; results of neurologic examination were normal. Plasmapheresis and urgent liver transplantation were performed. Patient 4, a 13-year-old girl, had learning difficulties at school and attended a special class. Three patients received left lateral liver segments, and 1 patient received a left lobe. Biliary reconstruction was completed with duct-to-duct anastomosis. Bile leakage developed at the anastomosis in 2 patients, which was treated successfully with cholangioplasty. In all patients, the unconjugated bilirubin concentration normalized by day 1 posttransplantation, and no phototherapy was necessary. After transplantation, the 2-month-old infant with suspected encephalopathy exhibited hypotonia, spasticity of the lower extremities, and lack of head control. He died after vomitus aspiration during sleep at 10 months posttransplantation. The other 3 patients are alive with normal neurodevelopmental milestones. Irreversible brain damage may occur early in the course of Crigler-Najjar syndrome type 1. Urgent treatment including plasmapheresis, exchange transfusion, phototherapy, and liver transplantation may not reverse brain damage. Young infants must be evaluated carefully for subtle signs and symptoms of bilirubin encephalopathy. Liver transplantation is curative if performed before development of neurologic dysfunction.

Treatment of Crigler-Najjar Syndrome type 1 by hepatic progenitor cell transplantation: a simple procedure for management of hyperbilirubinemia.

Crigler-Najjar Syndrome (CNS) is characterized by mild, chronic unconjugated hyperbilirubinemia resulting from an autosomal-recessive inherited deficiency of hepatic uridine/diphosphoglucuronate-glucuronosyl transferase 1Al since birth. Herein we have reported a confirmed case of CNS type 1 in a 2-year-old girl with an unconjugated hyperbilirubinemia (>30 mg/dL) treated by hepatic progenitor cell infusion through the hepatic artery. No procedure-related complications were encountered. No kernicterus was observed. The total bilirubin started falling at 10 days after cell infusion. Two months after cell infusion the bilirubin fell from 29.0 to 16 mg/dL, with the conjugated bilirubin increasing approximately fivefold, the unconjugated bilirubin decreasing nearly twofold, and the SGPT also decreasing from 210 U/L to 64 U/L. This study demonstrated the efficacy of hepatic progenitor cells to manage hyperbilirubinemia in these patients. As the procedure is simple and the patient has tolerated the cell therapy, infusion can be repeated as required to manage hyperbilirubinemia, which often causes lethal kernicterus. This study was developed to assess the safety, feasibility, and efficacy of hepatic progenitor cell transplantation in a child with CNS type 1.

Liver cell transplantation for Crigler-Najjar syndrome type I: update and perspectives.

Liver cell transplantation is an attractive technique to treat liver-based inborn errors of metabolism. The feasibility and efficacy of the procedure has been demonstrated, leading to medium term partial metabolic control of various diseases. Crigler-Najjar is the paradigm of such diseases in that the host liver is lacking one function with an otherwise normal parenchyma. The patient is at permanent risk for irreversible brain damage. The goal of liver cell transplantation is to reduce serum bilirubin levels within safe limits and to alleviate phototherapy requirements to improve quality of life. Preliminary data on Gunn rats, the rodent model of the disease, were encouraging and have led to successful clinical trials. Herein we report on two additional patients and describe the current limits of the technique in terms of durability of the response as compared to alternative therapeutic procedures. We discuss the future developments of the technique and new emerging perspectives.

Cell-mediated rejection results in allograft loss after liver cell transplantation.

Liver cell transplantation in humans has been impeded by invariable loss of the graft. It is unclear whether graft loss is due to an immune response against donor hepatocytes. Transplantation with ABO-matched liver cells was performed in a patient with Crigler-Najjar type 1. After successful engraftment, there was a gradual loss of graft function. Solid-phase enzyme immunoassay testing and cell-complement cytotoxicity assays detecting preformed antibodies directed toward class I and/or class II human leukocyte antigen (HLA) molecules were negative. In contrast, a striking host alloresponse to either the HLA-B39 or C7 antigen was found, suggesting that a vigorous response to a defined mismatched HLA antigen contributed to graft loss in our patient. This study provides evidence that a T-cell-mediated immune mechanism could be responsible for human liver cell transplant graft loss. This finding warrants confirmation in future liver cell transplants in humans.

Percutaneous transhepatic venous angioplasty and stenting in a 9-month-old patient with hepatic vein obstruction after partial liver transplantation.

Hepatic venous outflow obstruction is a rare but serious complication after liver transplantation. We report ultrasound-guided percutaneous transhepatic stent placement in a 9-month-old infant with a left lateral split liver transplantation with near-complete hepatic vein obstruction.

Clinical utility of electrophysiological evaluation in Crigler-Najjar syndrome.

We evaluated the neurological and neurophysiological features in ten patients with genetically characterized Crigler-Najjar (CN) syndrome: four with typical type I CN had undergone orthotopic liver transplantation (OLT); six had type II CN, and three of them developed severe hyperbilirubinemia with a limited response to phenobarbital leading to an intermediate phenotype I/II. Clinical neurological and multimodal electrophysiological evaluations [electroencephalogram (EEG), visual (VEPs), motor (MEPs) and brainstem auditory (BAEPs) evoked potentials] were performed. Neurological examinations showed mild hand tremor in four patients (one pre-OLT and one post-OLT type I, two type I/II). EEG revealed high voltage paroxysmal discharges in four patients (three type I/II, and one type I with a marked improvement after OLT). VEPs showed P100 wave increased latency in five patients (three type I, and two type I/II considered for OLT evaluation). MEPs showed prolonged central motor conduction time in five patients (two type I; one type I/II; two type II). Only EEG and VEPs findings showed a correlation with high bilirubin levels. BAEPs were normal. In conclusion, VEPs and EEG contribute to identify and monitor bilirubin neurotoxic effects, and may play a decisional role in some cases of severe hyperbilirubinemia without overt neurologic damage.

Overcoming the portal steal phenomenon in auxiliary partial orthotopic liver transplantation by modulation of the venous outflow of the native liver.

The main drawback of auxiliary partial orthotopic liver transplantation (APOLT) is the competition of the portal flow between the graft and the native liver, leading to graft failure. In two patients with Crigler-Najjar syndrome type I, the intrahepatic resistance of the native liver was increased by occluding the recipients middle hepatic vein during parenchymal transection, leading the portal flow towards the graft. This new surgical technique could encourage centers to recommence APOLT.

Permanent access to the portal system for cellular transplantation using an implantable port device.

A novel application of the implantable Port-a-Cath (PAC) system is described in the context of cellular transplantation. A silicone catheter was inserted in a collateral branch of the portal vein and connected to a port device positioned subcutaneously on the left thoracic cage. This permanent vascular access allowed iterative intraportal infusions of allogenic hepatocytes without the need of repeated transhepatic catheterization of the portal vein. Using this technique, repeated infusions of cryopreserved and / or fresh hepatocytes were successfully carried out in 3 children with inborn errors of liver metabolism, with the aim of progressively providing a sufficient mass of transplanted liver cells to stabilize the metabolic condition of the patients. We suggest that this technique might also be valuable in pancreatic islet cell transplantation.