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.

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.

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.

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.

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.

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.

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.

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.

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.

Orthotopic liver transplantation for Crigler-Najjar type I disease in six children.

Hyperbilirubinemia in Crigler-Najjar disease type I (CN) can be partially controlled by daily phototherapy, but these children remain at permanent risk of developing brain damage due to kernicterus. Because liver transplantation is the only available curative treatment for liver-based inborn errors of metabolism, orthotopic liver transplantation (OLT) was performed in six patients with CN. Mean age at surgery was 52.5 months (range 27 to 100). Despite a mean daily phototherapy of 12.4 +/- 0.8 hr, mean bilirubin of the 6 patients was 388 microM/L (range 175 to 703) before OLT; one of them was also being treated with tin-protoporphyrin. All 6 had elevated AST/ALT, ranging from 1.4 to 6 times upper normal values. Complications occurred in three patients after OLT, including miliary tuberculosis in one, graft rejection and retransplantation in one, and hepatic artery thrombosis in one. All patients survive with normal serum bilirubin level (follow up 6 to 116 months). Four have normal enzymes on post-OLT follow-up (30 to 95 months), follow a normal education program, and have a normal social life. One recently transplanted patient has progressively normalizing liver function tests 6 months after OLT. One patient transplanted at 8 y.o. (now 116 months post-OLT) has moderate neurological delay due to pretransplant kernicterus, and posttransplant chronic persistent hepatitis. Our series shows that OLT cures hyperbilirubinemia in CN patients, with an excellent survival prospect. The procedure should be decided upon before neurological sequelae occur, since these persist after transplantation.

Successful liver transplantation of two brothers with crigler-najjar syndrome type 1 using a single cadaveric organ.

Crigler-Najjar type 1 disease (CNS1) is the result of a genetic defect, leading to complete functional loss of an enzyme which glucuronidates bilirubin. As a consequence, unconjugated bilirubin accumulates and may cause kernicterus, the most serious complication in adolescents. Phototherapy effectively adjusts bilirubin levels less than critical concentrations over many years but become less effective in elder children. Therefore, liver transplantation must be performed as definite therapy in these patients to avoid irreversible neurological deficits. Two brothers with CNS1, one without neurological deficits and one with moderate brain injury underwent orthotopic split liver transplantation from the same donor. The intra- and postoperative course of both patients was uneventful. Bilirubin levels normalized after transplantation in both recipients. Furthermore, mental and physical development considerably improved upon transplantation in the brother with neurological dysfunction. Therefore, orthotopic liver transplantation in CNS1 patients should be performed early enough to avoid irreversible brain damage, i.e., as a prophylactic procedure.

In situ splitting of the liver in the heart-beating cadaveric organ donor for transplantation in two recipients.

SLT presents an interesting concept to alleviate the organ shortage for children with end-stage liver disease. The procedure has, however, not gained wide acceptance. This is not only related to the complexity of the procedure, but also to the poorer results and the complications reported on the right side graft. We report on a first case in which we applied a new concept for splitting. The liver was split in situ in the heart-beating cadaveric donor with the aim of reducing the problems with the right side graft. This procedure makes splitting of the liver possible without submitting the recipient of the right side to increased risk. Therefore, in situ splitting of the liver has the potential of making splitting of liver grafts the rule rather than the exception, thus increasing the organ pool for small children presently carrying a high risk of dying on the waiting list.

Correction of congenital indirect hyperbilirubinemia by small intestinal transplantation.

INTRODUCTION: Crigler-Najjar syndrome, type I, is a disease characterized by complete absence of hepatic bilirubin glucuronidation. The congenital indirect hyperbilirubinemia is due to an autosomal recessive deficiency of the enzyme, uridine diphosphate glucuronosyl transferase (UDPGT). The inbred homozygous Gunn rat is also deficient in UDPGT, exhibits unconjugated hyperbilirubinemia, and is an excellent animal model of the Crigler-Najjar syndrome. This study was performed to test the ability of transplanted intestine from normal Wistar rat donors to correct the deficiency in hepatic bilirubin conjugation. MATERIALS AND METHODS: In phase 1, Gunn rats underwent 40-cm heterotopic small-bowel transplants from either Wistar (experimental) or Gunn (control) rats. In phase 2, 15- to 20-cm Wistar-to-Gunn jejunal transplants were placed either heterotopically or orthotopically (in intestinal continuity). All rats were treated with cyclosporin A (CsA), 5 mg/kg per day. Serum bilirubin levels were determined spectrophotometrically at weekly intervals posttransplantation. In phase 2, UDPGT activity was quantitated at 0, 2, 4, and 8 weeks using known quantities of bilirubin as substrate. RESULTS: Total bilirubin levels decreased significantly in the 40-cm heterotopic transplant recipient rats. From the initial values of 7.12 +/- 0.59 mg/dL, levels reached the nadir of 4.23 +/- 0.27 mg/dL. A parallel drop in serum levels of indirect bilirubin was noted (5.04 +/- 0.54 mg/dL to 2.74 +/- 0.23 mg/dL). After 6 weeks, bilirubin levels began to rise toward pretransplant values. In contrast, there was no significant change in bilirubin levels in the control Gunn-to-Gunn rats. Fifteen- to 20-cm heterotopic Wistar-to-Gunn transplants caused a qualitatively similar drop in total and indirect bilirubin levels. Orthotopic (in continuity) Wistar-to-Gunn transplants lowered serum bilirubin levels more rapidly, and the effect was sustained throughout the 8-week study period. By 1 week posttransplantation, total bilirubin levels dropped from 5.11 +/- 0.48 mg/dL to 2.41 +/- 0.16 mg/dL (P < 0.05); data at 8 weeks averaged 1.84 +/- 0.35 mg/dL. Respective data for indirect bilirubin levels were 4.81 +/- 0.45 mg/dL, 2.26 +/- 0.18 mg/dL, and 1.35 +/- 0.39 mg/dL. Wistar rat UDPGT activity in intestine and liver averaged 0.61 +/- 0.05 and 1.88 +/- 0.06 mg bilirubin conjugated/mg tissue per hour, respectively. Enzyme activity in the transplanted intestine persisted throughout the course of the study. CONCLUSION: Transplants of small intestine with known UDPGT activity partially corrected the deficiency in Gunn rats and allayed the hyperbilirubinemia. Since the small intestine is known to contain small but significant amounts of a large number of predominantly hepatic enzymes, bowel transplantation may be an appropriate treatment for this and other similar genetic enzyme deficiencies.

Removal of protein-bound and unbound unconjugated bilirubin by perfusion of plasma through an anion-exchange resin in a case of Crigler-Najjar syndrome type I.

BACKGROUND: Patients with Crigler-Najjar syndrome, type I (CNS-I) have an inherited absence of hepatocellular bilirubin uridine diphosphate-glucuronosyltransferase activity, which results in severe unconjugated hyperbilirubinaemia, often causing kernicterus and death in infancy or childhood. METHODS: Our patient is a 19-year-old Japanese man with CNS-I diagnosed by the complete absence of the hepatocellular enzyme in a liver biopsy and genotyping. The efficacies of the removal of protein-bound (PBB) and unbound (UB) unconjugated bilirubin by phototherapy, plasma perfusion and liver transplantation were compared in the patient. RESULTS: At the age of 5 years, phototherapy treatment reduced the patient's PBB by 21% and UB by 34%, and 98% of the bilirubin produced daily was removed. At the age of 16 years, plasma perfusion combined with nightly phototherapy completely removed the daily production of bilirubin; however, by 24 h post-treatment, the PBB and UB were again increased. Apparently, these treatments were effective in reducing PBB and UB, but the effect was only temporary. Following liver transplantation, PBB and UB decreased to normal concentrations. CONCLUSIONS: Liver transplantation as a potential cure should be performed at a younger age, particularly in confirmed CNS-I cases for which reliable effects of phototherapy cannot be guaranteed.

[Allogenic liver transplantation: a form of "gene therapy" in metabolic diseases. Munich results and a review]. / Die allogene Lebertransplantation--eine Form der "Gentherapie" bei metabolischen Erkrankungen. Münchener Ergebnisse und Ubersicht.

INTRODUCTION: Liver transplantation is the method of choice for metabolic diseases and end-stage liver failure. METHODS: At the Klinikum Grosshadern we have performed liver transplantation for inborn errors of metabolism in 24 patients (5.3% of all transplantations, 16 adults, age 39 +/- 13 years; 8 children, age 9 +/- 3 years); 19 patients received a transplant for end-stage liver disease, and in 5 cases because of fulminant hepatic failure. RESULTS: Twenty-four patients received 27 transplants. In 3 cases, a split-liver transplantation was performed; one patient received a combined lung-liver graft. The 5-year survival rate for children is 100% and for adults 68%. CONCLUSIONS: Liver transplantation for inborn errors of metabolism not only replaces the diseased organ, but also leads to complete reversal of the metabolic defect.

Intensive care course after orthotopic liver transplantation in children.

Eight children 1 to 13 years old, were submitted to OLT. Six patients had normal liver function and complete rehabilitation 4 to 17 months after OLT. Two patients died during their ICU course respectively on day 15 and 34 after operation. The ICU management of the surviving patients is compared to the two fatal cases. At the time of admission in the ICU, there was no difference between the two groups, except for age. All patients were physiologically stable and needed essentially continuous monitoring and nursing care. All were rapidly weaned off artificial ventilation. During the first week after operation, surviving patients demonstrate improvement of liver function test, absence of infection, normal renal function and short ICU stay. They all suffered from systemic hypertension easily controlled by drugs. The two fatal cases were less than 15 months old and did not show improvement of their liver function. They suffered from severe infection, renal failure and protracted systemic hypertension and needed prolonged invasive monitoring and therapy.

Orthotopic liver segment transplantation.

This paper describes a method of liver transplantation in which only one segment from a donor organ is used to replace one part of the recipient's own liver. The patient was a nine-year-old boy with Crigler-Najjar, a rare inborn error of metabolism, in which the enzyme needed to conjugate bile is absent. The technique of orthotopic liver segment replacement is described, and the possibilities of using this procedure to help patients with some other inherited metabolic disorders is discussed. When this paper was written, the procedure has been performed only once before, on an adult in the USA.