Crigler-Najjar Research Articles

Therapeutic Options for Crigler–Najjar Syndrome: A Scoping Review

Crigler–Najjar Syndrome (CNS) is a rare genetic disorder caused by mutations in the UGT1A1 gene, leading to impaired bilirubin conjugation and severe unconjugated hyperbilirubinemia. CNS presents in the following forms: CNS type 1 (CNS1), the more severe form with the complete absence of UGT1A1 activity, and CNS type 2 (CNS2), with partial enzyme activity. This narrative review aims to provide a detailed overview of CNS, highlighting its clinical significance and the need for new, more effective treatments. By summarizing current knowledge and discussing future treatments, this article seeks to encourage further research and advancements that can improve outcomes for CNS patients. The literature analysis showed that CNS1 requires aggressive management, including phototherapy and plasmapheresis, but liver transplantation (LT) remains the only definitive cure. The timing of LT is critical, as it must be performed before the onset of irreversible brain damage (kernicterus), making early intervention essential. However, LT poses risks such as graft rejection and lifelong immunosuppression. CNS2 is milder, with patients responding well to phenobarbital and having a lower risk of kernicterus. Recent advancements in gene therapy and autologous hepatocyte transplantation offer promising alternatives to LT. Gene therapy using adeno-associated virus (AAV) vectors has shown potential in preclinical studies, though challenges remain in pediatric applications due to liver growth and pre-existing immunity. Autologous hepatocyte transplantation avoids the risk of rejection but requires further research. These emerging therapies provide hope for more effective and less invasive treatment options, aiming to improve the quality of life for CNS patients and reduce reliance on lifelong interventions.

Analysis of UGT1A1 genotype-phenotype correlation in Chinese patients with gilbert and crigler-Najjar II syndrome

The spectrum of UDP-glucuronosyltransferase (UGT1A1) variants, which are associated with Gilbert syndrome (GS) and Crigler-Najjar syndrome (CNS-II), has been reported in Chinese and western countries. However, the genotype-phenotype correlation of the individual UGT1A1 variants in GS and CNS-II remains to be clarified. To explore the UGT1A1 variant pattern and genotype-phenotype correlations, we enrolled 310 Chinese patients, including 232 patients with GS and 78 with CNS-II. Peripheral blood samples were collected for screening variants in the gene UGT1A1 by a polymerase chain reaction and Sanger sequencing. The correlation between different UGT1A1 variants and clinical phenotypes was analyzed. A total of 21 UGT1A1 variants were identified, including nine novel variants, and constituted 42 UGT1A1 genotypes in the GS and CNS-II patients. The most common UGT1A1 variants were A (TA)7TAA, p.G71R, p.Y486D, p.P364L, and p.P229Q, which were different from western countries. The p.Y486D variant had higher minor allele frequency in CNS-II than in GS whereas the A (TA)7TAA variant had higher minor allele frequency in GS than in CNS-II. The serum total bilirubin and triglyceride had significant differences among 14 recurrent genotypes of UGT1A1, in which the serum total bilirubin in patients with compound p.Y486D (homozygous)/p.G71R variant was significantly higher compared with homozygous A (TA)7TAA, homozygous p.G71R, compound heterozygous A (TA)7TAA/p.G71R and A (TA)7TAA/p.P364L, and combined heterozygous A (TA)7TAA/p.G71R/p.P229Q, while the serum triglyceride in patients with combined A (TA)7TAA (homozygous)/p.P229Q variant was significantly higher compared with compound heterozygous A (TA)7TAA/p.G71R, single heterozygous A (TA)7TAA, single heterozygous p.G71R, and homozygous A (TA)7TAA. The spectrum of UGT1A1 genotypes in Chinese patients was distinct from western countries. There were differential levels of serum total bilirubin and triglyceride in patients with recurrent genotypes of UGT1A1.

Circulating lncRNAs HOTTIP and HOTAIR as Potential Biomarkers in Crigler-Najjar Syndrome: A Preliminary Report from Shiraz Liver Transplant Research Center

Crigler-Najjar syndrome (CNS) is a rare autosomal recessive disorder characterized by impaired bilirubin metabolism, leading to neurotoxic unconjugated bilirubin accumulation. Liver transplantation remains the only effective treatment, highlighting the need for novel diagnostic and therapeutic approaches. Long non-coding RNAs (lncRNAs) have emerged as potential biomarkers in various diseases, including cancer. This study aimed to evaluate the expression of lncRNAs HOTTIP and HOTAIR in CNS patients and healthy controls, exploring their potential as non-invasive diagnostic tools. Serum samples from CNS patients (n = 6) and healthy controls (n = 26) were analyzed using quantitative real-time polymerase chain reaction. While both lncRNAs showed decreased expression in CNS patients compared to controls, the differences were not statistically significant. However, receiver operating characteristic curve analysis revealed promising diagnostic performances for both lncRNAs. Correlations between lncRNA expression and clinical parameters were explored, revealing potential associations with disease progression. Overall, this study provides preliminary insights into the role of lncRNAs HOTTIP and HOTAIR in CNS and underscores the need for further research to validate their utility as biomarkers and therapeutic targets in this rare disorder.

Gene therapy of Crigler-Najjar syndrome: a first in the field of hepatology!

Gene therapy of Crigler-Najjar syndrome: a first in the field of hepatology!

Behavioral and neurocognitive phenotypes in Crigler-Najjar syndrome in Tunisia

IntroductionCrigler-Najjar 1 (CN1) due to exon 3 mutations of the UGT1A1 gene is a not rare genetic disease in Tunisia with a founder effect. CN1 syndrome is very severe, and most of CN1 Tunisian patients die soon after birth, within a maximum of one year, due to kernicterus. Liver transplantation, which is the only available therapeutic method for CN1, remains unreachable.ObjectivesThe aim of this study was to report behavioral and neurocognitive phenotypes in CN1 patients who survived to school enrollment.Methods We have selected all patients evaluated from 2004 to 2010, both clinically and molecularly, for a deficiency of bilirubin-UGT enzyme activity leading to a pathological elevation of unconjugated bilirubin with a suspicion of CN1 syndrome. Direct sequencing of targeted PCR amplification products was performed for molecular analysis of UGT1A1. Behavioral and mental features of patients were studied through our genetic counselling.Results We identified 15 patients with the homozygous c.1070 A>G Tunisian mutation. Their age at diagnosis ranged from one week to 9 months for 13 patients. Six of them died within a month of molecular investigation. Only two boys were of school age, i.e. 6 and 9 years. The first had been hospitalized at 3 months year-old for a prolonged jaundice treated with phenobarbital and phototherapy. His psychomotor and neurological development was normal, with school attendance at the age of six. The second patient presented with an unexplored jaundice at the age of 3 days, which was later complicated by seizures and treated with phenobarbital. Despite neurological and motor sequelae associated to language impairments with slurred speech, he attended school at the age of six.ConclusionsThe neurological and behavioral profile of CN1 patients depends on familial and medical management. Quick diagnosis, close follow up and early liver transplantation can improve prognosis.Disclosure of InterestNone Declared

UGT1A1 gene mutation spectrum with indirect hyperbilirubinemia in children

Objective: To explore the relevancy between the uridine diphosphate-glucuronylgly-cosyltransferase 1A1 (UGT1A1) gene mutation and the phenotype of indirect hyperbilirubinemia in children. Methods: Sixteen cases with indirect hyperbilirubinemia who visited the Department of Gastroenterology, Children's Hospital of Nanjing Medical University from July 2013 to November 2019 were retrospectively analyzed and were divided into Gilbert syndrome (GS), Crigler-Najjar syndrome type II (CNS-II), and indirect hyperbilirubinemia groups unexplained by UGT1A1 gene mutations. The differences in gene mutation site information and general clinical data were compared. The association between gene mutation spectrum and bilirubin level was explored by t-test analysis. Results: Ten of the sixteen cases with indirect hyperbilirubinemia had GS, three had CNS-II, and three had indirect hyperbilirubinemia unexplained by UGT1A1 gene mutations. A total of six mutation types were detected, of which c.211G > A accounted for 37.5% (6/16), c.1456T > G accounted for 62.5% (10/16), and TATA accounted for 37.5% (6/16), respectively. Compared with the GS group, the CNS group had early disease onset incidence, high serum total bilirubin (t = 5.539, P < 0.05), and indirect bilirubin (t = 5.312, P < 0.05). However, there was no significant difference in direct bilirubin levels (t = 1.223, P > 0.05) and age of onset (t = 0.3611, P > 0.05) between the two groups. There was no significant correlation between the number of UGT1A1 gene mutations and serum bilirubin levels. Children with c.1456T > G homozygous mutations had the highest serum bilirubin levels. Conclusion: The common pathogenic variants of the UGT1A1 gene sequence are c.1456T > G, c.211G > A, and TATA, indicating that these site mutations are related to the occurrence of indirect hyperbilirubinemia and have important guiding significance for the etiological analysis of indirect hyperbilirubinemia in children.

Development of a minimal PBPK-QSP modeling platform for LNP-mRNA based therapeutics to study tissue disposition and protein expression dynamics

Physiologically based pharmacokinetic models have gained significant recognition as effective mathematical models that enable deeper mechanistic investigation of drug delivery and tissue disposition. Here we describe the development of a platform PBPK-quantitative systems pharmacology (QSP) model to study tissue delivery of lipid nanoparticle (LNP) based mRNA therapeutics. The model is calibrated to published data in the context of Crigler-Najjar syndrome. Sensitivity analyses were performed to explore factors that influence protein expression and pharmacodynamic response following LNP-mRNA liver disposition. The most sensitive determinants of protein exposures were mRNA stability, translation, and cellular uptake rate, while the liver influx rate of lipid nanoparticle did not appreciably impact protein expression. Indeed, protein expression level may be tuned by modulation of mRNA degradation rate. However, simulations predicted that when the intrinsic half-life of the translated protein falls below a certain threshold, lowering mRNA degradation rate may not rescue protein exposure, a design feature that should be considered in optimal design of mRNA therapeutics. Additionally, interplay of LNP degradation rate and mRNA escape rate from endosomes was found to be crucial in modulation of protein expression. Simulations predicted that at a given LNP degradation rate, protein exposure varied linearly with mRNA escape rate. We further extended the model by incorporating LNP recycling to identify conditions necessary for observing a second peak in mRNA pharmacokinetics (PK). Simulations predict that with a fast recycling and slow tissue re-uptake rates, a robust second peak is observed in the plasma mRNA concentration curve. The amplitude and timing of the second peak could be tuned with recycling and re-uptake rates. Modeling results indicate that within the context of non-secreted mRNA mediated enzyme replacement therapy, recycling may depress or improve protein exposure depending on the re-uptake rate of the recycled LNP. The model is subsequently used to generate virtual animal cohorts to investigate optimal dosing and schedule of the compound. Virtual instances of the model were then employed to identify design principles that potentially reduce dosing frequency while maintaining efficacy. This study demonstrates the potential applications of coupled PBPK-QSP model for LNP based mRNA therapeutics as a translational platform.

Health-related quality of life and cognitive function in children with Crigler–Najjar syndrome type 1

ABSTRACT Background The aim of the study was to assess the health-related quality of life (HRQOL) and cognitive function in patients with Crigler–Najjar syndrome (CNS) type I and its impact on their lives. Methods Twenty-one patients diagnosed with CNS type I aged 1 month to 18 years in the Paediatric Hepatology Unit of Cairo University Children’s Hospital were enrolled in this cross-sectional observational study. The patients’ health-related quality of life (HRQOL) was assessed using the World Health Organization Quality Of Life BREF questionnaire (WHOQOL-BREF) and the Short Form 36 Health Survey Questionnaire (SF-36). Cognitive function was assessed using the Stanford–Binet Intelligence Scale: Fifth Edition (SB5). Results All patients had a history of admission to a neonatal intensive care unit, 17 were managed by phototherapy only and 5 also underwent exchange transfusion. According to the WHOQOL questionnaire, 11 cases (52.4%) had a low QOL score, and 7 of 13 patients had an average score for their total IQ test. Cases with poor compliance to phototherapy had statistically significantly lower QOL scores (p=0.001), while, according to the SF36 survey, cases who received exchange transfusion had statistically significantly higher cognitive function (p=0.03). There was a positive correlation between the neurological effect as a complication of the disease and poor physical QOL. Conclusion Paediatric patients with CNS have significantly lower HRQOL, especially physically, psychologically and environmentally. It is recommended that assessment of HRQOL should be a routine part of follow-up in CNS patients. Patients whose HRQOL is affected receive regular psychiatric counselling, social support and rehabilitation. Abbreviations: CNS: Crigler–Najjar syndrome; HRQOL: health-related quality of life; IQ: intelligence quotient; NICU: neonatal intensive care unit; QOL: quality of life; SB5: Stanford–Binet intelligence scale: 5th edition; SF–36: Short Form 36 Health Survey Questionnaire; UDGT: uridine diphosphate glucuronosyl transferase; UGT1A1: uridine 5’–diphosphate glucuronosyltransferase; WHOQOL–BREF: World Health Organization Quality of Life Brief Version.

Living Donor Liver Transplantation in Patients with Crigler-Najjar Syndrome Type 1: Report of Three Cases

Living Donor Liver Transplantation in Patients with Crigler-Najjar Syndrome Type 1: Report of Three Cases

Liver-directed gene therapy for inherited metabolic diseases.

Gene therapy clinical trials are rapidly expanding for inherited metabolic liver diseases whilst two gene therapy products have now been approved for liver based monogenic disorders. Liver-directed gene therapy has recently become an option for treatment of haemophilias and is likely to become one of the favoured therapeutic strategies for inherited metabolic liver diseases in the near future. In this review, we present the different gene therapy vectors and strategies for liver-targeting, including gene editing. We highlight the current development of viral and nonviral gene therapy for a number of inherited metabolic liver diseases including urea cycle defects, organic acidaemias, Crigler-Najjar disease, Wilson disease, glycogen storage disease Type Ia, phenylketonuria and maple syrup urine disease. We describe the main limitations and open questions for further gene therapy development: immunogenicity, inflammatory response, genotoxicity, gene therapy administration in a fibrotic liver. The follow-up of a constantly growing number of gene therapy treated patients allows better understanding of its benefits and limitations and provides strategies to design safer and more efficacious treatments. Undoubtedly, liver-targeting gene therapy offers a promising avenue for innovative therapies with an unprecedented potential to address the unmet needs of patients suffering from inherited metabolic diseases.

Auxiliary partial orthotopic liver transplantation (APOLT) for Crigler-Najjar syndrome: a retrospective analysis

Auxiliary partial orthotopic liver transplantation (APOLT) for Crigler-Najjar syndrome: a retrospective analysis

Atrial Septal Defect Device Closure in Patients with Metabolic or Genetic Diseases

Background: The coexistence of a metabolic or genetic disease can complicate the course of an atrial septal defect device closure. Methods: The database of our hospital was searched for patients who had undergone atrial septal defect (ASD) device closure and had concurrent metabolic and genetic diseases. Out of 188 such patients, 11 were identified. Results: This cohort study included 11 patients with type 1 diabetes mellitus, insulin resistance, mitochondrial diseases, rickets, Seckel syndrome, Alagille syndrome, cystic fibrosis, Down syndrome, and Crigler-Najjar syndrome type II. The patients were followed for a median of 4 years. Two patients experienced thromboembolic events. One procedure failed as the device was embolized. Large devices with a waist circumference greater than 1.5 times the body weight were used in 3 patients. One patient died 19 days after the procedure due to multi-organ failure, which was not related to device closure. Conclusions: In patients with metabolic or genetic diseases, this procedure may be complicated by factors such as small patient size, hypercoagulation, organ failure (cardiac, renal, or hepatic), vascular abnormalities, and issues with anesthesia or transesophageal echocardiography. It is recommended that careful attention be given to the specific challenges associated with each disease. The utilization of large devices can be considered safe, particularly in patients beyond 4 years of age.

CRISPR-Cas9-mediated somatic correction of a one-base deletion in the Ugt1a gene ameliorates hyperbilirubinemia in Crigler-Najjar syndrome mice

CRISPR-Cas9-mediated somatic correction of a one-base deletion in the Ugt1a gene ameliorates hyperbilirubinemia in Crigler-Najjar syndrome mice

Synthetic augmentation of bilirubin metabolism in human pluripotent stem cell-derived liver organoids

UGT1A1 (UDP glucuronosyltransferase family 1 member A1)is the primary enzyme required for bilirubin conjugation, which is essential for preventing hyperbilirubinemia. Animal models lack key human organic aniontransporting polypeptides with distinct epigenetic control over bilirubin metabolism, necessitating a human model to interrogate the regulatory mechanism behind UGT1A1 function. Here, we use induced pluripotent stem cells to develop human liver organoids that can emulate conjugation failure phenotype. Bilirubin conjugation assays, chromatin immunoprecipitation, and transcriptome analysis elucidated the role of glucocorticoid antagonism in UGT1A1 activation. This antagonism prevents the binding of transcriptional repressor MECP2 at the expense of NRF2 with associated off-target effects. Therefore, we introduced functional GULO (L-gulonolactone oxidase) in human organoids to augment intracellular ascorbate for NRF2 reactivation. This engineered organoid conjugated more bilirubin and protected against hyperbilirubinemia when transplanted in immunosuppressed Crigler-Najjar syndrome rat model. Collectively, we demonstrate that our organoid system serves as a manipulatable model for interrogating hyperbilirubinemia and potential therapeutic development.

Coexistence of mutations of Gilbert’s syndrome and Crigler-Najjar syndrome in an infant with unconjugated hyperbilirubinemia—a case report

BackgroundJaundice in the newborn period is a very common entity; rare inherited causes are often forgotten. Persistent unconjugated hyperbilirubinemia in the intermediate levels with non-hemolytic features must prompt the necessity for evaluating for genetic defects in bilirubin metabolism.Case presentationThree-and-a-half-month-old first-born girl of consanguineous marriage presented with jaundice from day 5 of life. Dark yellow color urine or pale stools were not present. Antenatal and birth history was normal. She had mild pallor and icterus and no hepatosplenomegaly. Total serum bilirubin was 8.2 mg/dl, and direct was 0.4 mg/dl. Workup for hemolytic anemia, thyroid function test, and sonography of abdomen was normal. Syrup phenobarbitone was started, and bilirubin levels after dropped to 2 mg/dl. Crigler-Najjar type II syndrome (CN II) or Gilbert’s syndrome (GS) was suspected. Next-generation sequencing for UGT1A1 gene mutation showed homozygous missense mutation consistent with CN II and 7 TA repeats in the promoter region consistent with GS. Bilirubin levels gradually fell after starting oral phenobarbitone syrup, and at 5 years of age, a trial of withholding phenobarbitone was given, and bilirubin levels remained lower, and she is asked to follow-up with bilirubin levels every 15 days to assess the need for reintroducing the therapy. Parents are planning for a second pregnancy, and a preconception genetic counseling has been done.ConclusionGenetic confirmation of coexistence of mutations causing GS and CN II have an implication on long-term neurological complications of unconjugated hyperbilirubinemia in stress or crisis situations. Prenatal diagnostic testing must be advised for detecting homozygous UGT1A1 mutations to diagnose CN II and Gilbert mutations for each of the future pregnancies. Considering the side effects of long-term phenobarbitone therapy, the decision can be taken on case-to-case basis of stopping the therapy while monitoring TSB levels.

FREQUENCY OF COMMON CAUSES OF SEVERE HYPERBILIRUBINEMIA IN NEONATES LEADING TO EXCHANGE TRANSFUSION

Neonatal often have hyperbilirubinemia, which may become severe if left untreated. Severe hyperbilirubinemia in neonates that necessitates exchange transfusions may lead to "kernicterus," which has a high risk of morbidity. This descriptive cross-sectional research examined the medical records of sixty newborns who had exchange transfusions at HMC Peshawar between March 2021 and March 2022 and weighed more than two kilos. There were 22 (36%) females and 38 (64%) males in the group. With 37.2% of cases, ABO incompatibility was the most common reason for exchange transfusions. Other causes, such as cephalohematoma and Crigler-Najjar syndrome, were followed by unidentified causes (26.5%), Rh incompatibility without immune hydrops (15.2%), sepsis (08.3%), and urinary tract infections (05.2%). Exclusive breastfeeding and vaginal deliveries were associated variables. It was discovered that the average serum bilirubin level was 28.5 mg/dl (SD = 09.02). The objective of our study was to identify and quantify the most frequent reasons babies needing exchange transfusions have severe hyperbilirubinemia. This study was conducted in the Department of Peaderitcs HMC Peshawar between March 2021 and March 2022. The causes of severe hyperbilirubinemia in neonates needing an exchange transfusion were investigated in this research using a descriptive cross-sectional methodology. Medical records from HMC Peshawar served as the primary source of information. In all, 60 infants weighing over two kilograms received exchange transfusions within the allotted period. The primary emphasis of the data extraction method was on variables such as serum bilirubin levels, linked diseases, gender, and the cause of hyperbilirubinemia. The causes included ABO incompatibility, Rh incompatibility without immune hydrops, sepsis, urinary tract infection, and cephalohematoma. Further information was also gathered on the kind of feeding and the mode of delivery. Frequencies, percentages, averages, and standard deviations were computed using statistical techniques, mostly descriptive statistics. The results were then examined about the study's objectives. Twenty-two (36%) and 38 (64%) of the sixty neonates studied for this research were female. ABO incompatibility was shown to be the most common cause of severe hyperbilirubinemia necessitating exchange transfusion, explaining 22 (37.2%) instances. In decreasing order of frequency, the other reasons were: sepsis, 5 (8.3%); urinary tract infection, 3 (5.2%); unidentified causes, 16 (26.5%); Rh incompatibility without immune hydrops, 9 (15.2%); and other causes such as cephalohematoma and Crigler-Najjar syndrome, 2 (3.3%). One interesting finding was that newborns born vaginally and those nursed exclusively were more likely to need an exchange transfusion. The average blood bilirubin level throughout the group was 28.5 mg/dl, with a standard deviation 9.02. This research emphasizes the need to watch for ABO incompatibility in neonates, particularly those delivered vaginally, as it is significantly linked to the requirement for exchange transfusions. The most common reason for exchange transfusions for hyperbilirubinemia was found to be ABO incompatibility. Adolescents who were nursed exclusively, male, and born vaginally were more likely to need an exchange transfusion. Neonatal with ABO incompatibility would need close observation after discharge, particularly if they were vaginally born.

A Case Report and Literature Review of Primary Central Nervous System Lymphoma in a Patient with Crigler–Najjar Syndrome: How We Managed

AbstractPrimary central nervous system lymphoma (PCNSL) is a rare form of CNS tumor that can be managed with curative intent using high-dose chemotherapeutic drugs. High-dose methotrexate is an essential drug for the management of PCNSL. We present a case of a 26-year-old man with a known comorbidity of Crigler–Najjar syndrome type II and a baseline bilirubin of 13.5 mg/dL, presented with somnolence and ataxia. In view of hyperbilirubinemia, the optimal treatment for CNS lymphoma, the De Angelis protocol, was modified for this patient. The patient tolerated the chemotherapy well with manageable fluctuations in bilirubin levels, followed by consolidation with whole-brain radiotherapy. He remains asymptomatic 6 months after the onset of the symptoms with the disease in complete remission. We highlight here this unusual case of PCNSL where high-dose methotrexate was used with close observation of liver function in view of hyperbilirubinemia in a known case of Crigler–Najjar syndrome.

Free Bilirubin Induces Neuro-Inflammation in an Induced Pluripotent Stem Cell-Derived Cortical Organoid Model of Crigler-Najjar Syndrome.

Bilirubin-induced neurological damage (BIND), which might progress to kernicterus, occurs as a consequence of defects in the bilirubin conjugation machinery, thus enabling albumin-unbound free bilirubin (BF) to cross the blood-brain barrier and accumulate within. A defect in the UGT1A1 enzyme-encoding gene, which is directly responsible for bilirubin conjugation, can cause Crigler-Najjar syndrome (CNS) and Gilbert's syndrome. We used human-induced pluripotent stem cell (hiPSC)-derived 3D brain organoids to model BIND in vitro and unveil the molecular basis of the detrimental effects of BF in the developing human brain. Healthy and patient-derived iPSCs were differentiated into day-20 brain organoids, and then stimulated with 200 nM BF. Analyses at 24 and 72 h post-treatment point to BF-induced neuro-inflammation in both cell lines. Transcriptome, associated KEGG, and Gene Ontology analyses unveiled the activation of distinct inflammatory pathways, such as cytokine-cytokine receptor interaction, MAPK signaling, and NFκB activation. Furthermore, the mRNA expression and secretome analysis confirmed an upregulation of pro-inflammatory cytokines such as IL-6 and IL-8 upon BF stimulation. This novel study has provided insights into how a human iPSC-derived 3D brain organoid model can serve as a prospective platform for studying the etiology of BIND kernicterus.

Auxiliary partial orthotopic liver transplantation (APOLT) for Crigler-Najjar syndrome: A retrospective analysis

BackgroundCrigler-Najjar syndrome is an ultra-rare hereditary disorder characterized by severe jaundice and risk of neurological complications. Current treatments, such as phototherapy, have limitations, and liver transplantation is often necessary. Auxiliary partial orthotopic liver transplantation (APOLT) is a potential treatment option. Still, its safety and efficacy in Pakistani patients with Crigler-Najjar syndrome Type I (CNS-I) have not been well established. MethodsThis retrospective study reviewed the outcomes of five pediatric patients with CNS-I who underwent APOLT at a tertiary care center in Pakistan. Patient demographics, surgical details, postoperative course, complications, and follow-up data were analyzed. The primary endpoint was the feasibility and safety of APOLT, while secondary endpoints included improvement in serum bilirubin levels, neurological symptoms, and survival rates. ResultsAmong five patients diagnosed with CNS-I, APOLT was performed without intraoperative complications. During the median follow-up period of 6 months, there were no cases of relaparotomy, graft rejection, biliary complications, or portal venous thrombosis. One patient developed a portal venous stricture, but his symptoms were controlled with conservative measures. Postoperative liver function tests showed a significant improvement, with an average reduction of 90% in serum bilirubin levels. There was some improvement in neurological symptoms, and the overall patient and graft survival rate was 100%. ConclusionThis study suggests that APOLT is a feasible and safe treatment option in patients with CNS-I. It improves liver function, bilirubin levels, and neurological symptoms. Further research with larger sample sizes is warranted to confirm these findings and evaluate the long-term outcomes of APOLT in this patient population.

Mild Crigler-Najjar Syndrome with Progressive Liver Disease-A Multicenter Retrospective Cohort Study.

Crigler-Najjar Syndrome (CNS) with residual activity of UDP-glucuronosyltransferase 1A1 (UGT1A1) and no need for daily phototherapy is called mild Crigler-Najjar Syndrome. Most of these patients need medical treatment for enzyme induction (phenobarbital) to lower blood levels of unconjugated bilirubin (UCB). Apart from this, no long-term problems have been described so far. The phenotype of patients with the homozygous pathogenic variant c.115C>G p.(His39Asp) in UGT1A1 is described as variable. Clinical observations of our patients led to the assumption that patients with variant c.115C>G have a mild CNS phenotype while having a high risk of developing progressive liver disease. For mild CNS disease, progressive liver disease has not been described so far. Therefore, we conducted a retrospective multicenter analysis of 14 patients with this particular variant, aiming for better characterization of this variant. We could confirm that patients with variant c.115C>G have a high risk of progressive liver disease (seven of fourteen), which increases with age despite having a very mild CNS phenotype. Earlier predictors and causes for an unfavorable disease course are not detectable, but close follow-up could identify patients with progressive liver disease at the beginning. In conclusion, these patients need close and specialized follow-up. Our study questions whether fibrosis in the CNS is really driven by high amounts of UCB or phototherapy.