Severe Unconjugated Hyperbilirubinemia Research Articles

Clinical and genetic risk factors associated with neonatal severe hyperbilirubinemia: a case-control study based on the China Neonatal Genomes Project.

Objective: We aimed to investigate the clinical and genetic risk factors associated with neonatal severe unconjugated hyperbilirubinemia. Methods: This was a retrospective, 1:1 matched, case-control study. We included 614 neonates diagnosed with severe unconjugated hyperbilirubinemia (serum total bilirubin level ≥425μmol/L or serum total bilirubin concentration that met exchange transfusion criteria) from the China Neonatal Genomes Project in Children's Hospital of Fudan University. Clinical exome sequencing data were analyzed using a data analysis pipeline of Children's Hospital of Fudan University. The factors associated with severe unconjugated hyperbilirubinemia were assessed using univariable and multivariable logistic regression analyses. Interaction analyses were examined between clinical and genetic risk factors. Results: ABO/Rh incompatibility hemolysis (odds ratio [OR] 3.36, 95% confidence interval [CI] 2.32-4.86), extravascular hemorrhage (OR 2.95, 95% CI 2.24-3.89), weight loss (OR 5.46, 95% CI 2.88-10.36), exclusive breastmilk feeding (OR 3.56, 95% CI 2.71-4.68), and the homozygous mutant of UGT1A1 211G>A (OR 2.35, 95% CI 1.54-3.59) were all identified as factors significantly associated with severe unconjugated hyperbilirubinemia. The presence of UGT1A1 211G>A mildly increased the risk of severe unconjugated hyperbilirubinemia caused by ABO/Rh incompatibility hemolysis (OR 3.98, 95% CI 2.19-7.23), although the effect is not statistically significant. Conclusion: ABO/Rh incompatibility hemolysis, extravascular hemorrhage, weight loss, exclusive breastmilk feeding, and the homozygous mutant of UGT1A1 211G>A were found to be risk factors for severe unconjugated hyperbilirubinemia. Clinical factors remain the most crucial and preventable determinants in managing severe unconjugated hyperbilirubinemia, with a minimal genetic contribution. The establishment of preconception care practices and the reinforcement of screening for the aforementioned risk factors are essential steps for preventing severe unconjugated hyperbilirubinemia.

Gene Therapy in Patients with the Crigler–Najjar Syndrome

BackgroundPatients with the Crigler–Najjar syndrome lack the enzyme uridine diphosphoglucuronate glucuronosyltransferase 1A1 (UGT1A1), the absence of which leads to severe unconjugated hyperbilirubinemia that can cause irreversible neurologic injury and death. Prolonged, daily phototherapy partially controls the jaundice, but the only definitive cure is liver transplantation.MethodsWe report the results of the dose-escalation portion of a phase 1–2 study evaluating the safety and efficacy of a single intravenous infusion of an adeno-associated virus serotype 8 vector encoding UGT1A1 in patients with the Crigler–Najjar syndrome that was being treated with phototherapy. Five patients received a single infusion of the gene construct (GNT0003): two received 2×1012 vector genomes (vg) per kilogram of body weight, and three received 5×1012 vg per kilogram. The primary end points were measures of safety and efficacy; efficacy was defined as a serum bilirubin level of 300 μmol per liter or lower measured at 17 weeks, 1 week after discontinuation of phototherapy.ResultsNo serious adverse events were reported. The most common adverse events were headache and alterations in liver-enzyme levels. Alanine aminotransferase increased to levels above the upper limit of the normal range in four patients, a finding potentially related to an immune response against the infused vector; these patients were treated with a course of glucocorticoids. By week 16, serum bilirubin levels in patients who received the lower dose of GNT0003 exceeded 300 μmol per liter. The patients who received the higher dose had bilirubin levels below 300 μmol per liter in the absence of phototherapy at the end of follow-up (mean [±SD] baseline bilirubin level, 351±56 μmol per liter; mean level at the final follow-up visit [week 78 in two patients and week 80 in the other], 149±33 μmol per liter).ConclusionsNo serious adverse events were reported in patients treated with the gene-therapy vector GNT0003 in this small study. Patients who received the higher dose had a decrease in bilirubin levels and were not receiving phototherapy at least 78 weeks after vector administration. (Funded by Genethon and others; ClinicalTrials.gov number, NCT03466463.)

Increased Total Serum Bilirubin Level Post-Ibuprofen Use Is Inversely Correlated with Neonates' Body Weight.

Backgrounds: Drugs with the ability to displace bilirubin from albumin-binding sites subsequently leading to an increased bilirubin level may cause hyperbilirubinemia in neonates. Ibuprofen is commonly used to treat patent ductus arteriosus (PDA) in neonates, yet the use of ibuprofen has drawn mixed conclusions. We performed a retrospective study to determine how ibuprofen use influences the total serum bilirubin (TSB) level in neonates of differing birth weight (BW). Materials and methods: Neonates (including premature infants) born at Chang Gung Memorial Hospital, Taiwan during January 2004 to July 2020 were entered into this study. We recorded the phototherapy duration, including the initial day and end day, and determined the average influence of one-day phototherapy on TSB level. The highest monitored TSB level post-ibuprofen use minus the one measured prior to ibuprofen use was considered the TSB change following ibuprofen administration in this study, and the above-mentioned influence of daily phototherapy on the TSB level was used to correlate the results. Neonates with any of the following conditions were excluded: those who received ceftriaxone, those with intraventricular hemorrhage, and those infected with TORCH. Results: The average daily influence of phototherapy on the TSB level of neonates was −0.20 (−0.57~0.05) mg/dL, −0.28 (−0.84~0.13) mg/dL, −0.75 (−1.77~0.10) mg/dL, and −1.60 (−2.70~−0.50) mg/dL in neonates with BWs of <1 kg, 1–1.49 kg, 1.5–2.49 kg, and ≥2.5 kg, respectively, indicating that neonates with a BW ≥ 1.5 kg experienced a greater reduction in TSB level following phototherapy as compared with those with a BW < 1.5 kg. The average TSB increase following ibuprofen use in neonates was 3.38 ± 2.77 mg/dL, 2.04 ± 2.53 mg/dL, and 1.34 ± 2.24 mg/dL in neonates with BWs of <1 kg, 1–1.49 kg, and ≥1.5 kg, respectively, i.e., an elevated TSB change with a decreased neonate BW was noted post-ibuprofen use (p = 0.026, one-way analysis of variance (ANOVA)). Conclusions: As ibuprofen use is correlated with an apparent increase in TSB level in neonates with a lower BW, especially in those with a BW < 1 kg, iv acetaminophen can be an appropriate alternative to ibuprofen for ELBW neonates for the treatment of PDA if they are experiencing severe unconjugated hyperbilirubinemia.

Chemoprevention of bilirubin encephalopathy with a nanoceutical agent.

Targeted rapid degradation of bilirubin has the potential to thwart incipient bilirubin encephalopathy. We investigated a novel spinel-structured citrate-functionalized trimanganese tetroxide nanoparticle (C-Mn3O4 NP, the nanodrug) to degrade both systemic and neural bilirubin loads. Severe neonatal unconjugated hyperbilirubinemia (SNH) was induced in neonatal C57BL/6j mice model with phenylhydrazine(PHz) intoxication. Efficiency of the nanodrug on both in vivo bilirubin degradation and amelioration of bilirubin encephalopathy and associated neurobehavioral sequelae were evaluated. Single oral dose (0.25 mg kg-1 bodyweight) of the nanodrug reduced both total serum bilirubin (TSB) and unconjugated bilirubin (UCB) in SNH rodents. Significant (p < 0.0001) UCB and TSB-degradation rates were reported within 4-8 h at 1.84 ± 0.26 and 2.19 ± 0.31 mg dL-1 h-1, respectively. Neural bilirubin load was decreased by 5.6 nmol g-1 (p = 0.0002) along with improved measures of neurobehavior, neuromotor movements, learning, and memory. Histopathological studies confirm that the nanodrug prevented neural cell reduction in Purkinje and substantia nigra regions, eosinophilic neurons, spongiosis, and cell shrinkage in SNH brain parenchyma. Brain oxidative status was maintained in nanodrug-treated SNH cohort. Pharmacokinetic data corroborated the bilirubin degradation rate with plasma nanodrug concentrations. This study demonstrates the in vivo capacity of this novel nanodrug to reduce systemic and neural bilirubin load and reverse bilirubin-induced neurotoxicity. Further compilation of a drug-safety-dossier is warranted to translate this novel therapeutic chemopreventive approach to clinical settings. None of the current pharmacotherapeutics treat severe neonatal hyperbilirubinemia (SNH) to prevent risks of neurotoxicity. In this preclinical study, a newly investigated nano-formulation, citrate-functionalized Mn3O4 nanoparticles (C-Mn3O4 NPs), exhibits bilirubin reduction properties in rodents. Chemopreventive properties of this nano-formulation demonstrate an efficacious, efficient agent that appears to be safe in these early studies. Translation of C-Mn3O4 NPs to prospective preclinical and clinical trials in appropriate in vivo models should be explored as a potential novel pharmacotherapy for SNH.

Gilbert or Crigler\u2013Najjar syndrome? Neonatal severe unconjugated hyperbilirubinemia with P364L UGT1A1 homozygosity

BackgroundSeveral mutations of bilirubin uridine diphosphate-glucuronosyltransferase gene (UGT1A1) have been reported in patients with unconjugated hyperbilirubinemia. Few reports are available about the p.Pro364Leu mutation (P364L, c.1091C > T) in homozygous newborns. We describe the clinical, laboratory and therapeutic approach in two Chinese neonates with severe jaundice, homozygous for the P364L mutation.Case presentationTwo Chinese breastfed female infants presented prolonged unconjugated hyperbilirubinemia at the age of 1 month. Total bilirubin was higher than 15 mg/dl (D < 1). An exhaustive etiological work-up to detect possible causes of hyperbilirubinemia (notably hemolytic ones) was negative.The promoter and coding regions of UGT1A1 were amplified by polymerase chain reaction (PCR) from genomic DNA isolated from leukocytes. Both patients resulted homozygous for a variant site within the coding region of the gene in the 4 exon, c.1091C > T, p.Pro364Leu.In front of the persistently high level of unconjugated bilirubin, phototherapy was performed without persistent results. A treatment with phenobarbital was then begun and bilirubin level progressively decreased, with a complete and persistent normalization. The therapy was stopped.ConclusionUGT1A1 enzyme activity associated with the P364L mutation has been described as 35.6% of the wild-type enzyme activity. Photo-therapy and phenobarbital can be useful in front of persistently high level of unconjugated bilirubin.Our cases presented high bilirubin values, overlapping between Gilbert syndrome (GS) and Crigler-Najjar syndrome type II (CNS), but the complete normalization of bilirubin makes GS more likely. Homozygous P364L variant can be associated with severe neonatal unconjugated hyperbilirubinemia in Chinese infants, but jaundice can completely resolve in a few months, contrary to what happens in Crigler-Najjar syndrome type II.

Liver transplantation in Crigler-Najjar Syndrome Type I: A single center experience

Background and Aim: Crigler-Najjar syndrome is a rare genetic disorder of bilirubin conjugation resulting in severe and persistent unconjugated hyperbilirubinemia within the first week of life. Diagnosis is made clinically or by genetic testing. Treatment includes phototherapy beyond the neonatal period or liver transplantation. Without liver transplantation most of these kids will have neurological sequalae due to bilirubin encephalopathy or may be fatal. Here we report the profile of six cases who underwent liver transplantation for CNS I at our center.

Clinical and Genetic Etiologies of Neonatal Unconjugated Hyperbilirubinemia in the China Neonatal Genomes Project

To investigate the clinical and genetic causes of neonatal unconjugated hyperbilirubinemia. We included 1412 neonates diagnosed with unconjugated hyperbilirubinemia (total serum bilirubin >95 percentile for age), from the China Neonatal Genomes Project between August 2016 and September 2019, in the current study. Clinical data and targeted panel sequencing data on 2742 genes including known unconjugated hyperbilirubinemia genes were analyzed. Among the 1412 neonates with unconjugated hyperbilirubinemia, 37% had severe unconjugated hyperbilirubinemia, with total serum bilirubin levels that met the recommendations for exchange transfusion. Known clinical causes were identified for 68% of patients. The most common clinical cause in the mild unconjugated hyperbilirubinemia group was infection (17%) and in the severe group was combined factors (21%, with infection combined with extravascular hemorrhage the most common). A genetic variant was observed in 55 participants (4%), including 45 patients with variants in genes associated with unconjugated hyperbilirubinemia and 10 patients with variants that were regarded as additional genetic findings. Among the 45 patients identified with unconjugated hyperbilirubinemia-related variants, the genes were mainly associated with enzyme deficiencies, metabolic/biochemical disorders, and red blood cell membrane defects. G6PD and UGT1A1 variants, were detected in 34 of the 45 patients (76%). Known clinical causes, which varied with bilirubin levels, were identified in approximately two-thirds of the patients. Genetic findings were identified in 4% of the patients, including in patients with an identified clinical cause, with G6PD and UGT1A1 being the most common genes in which variants were detected.

The Effects of Bilirubin and Lumirubin on Metabolic and Oxidative Stress Markers

For severe unconjugated hyperbilirubinemia the gold standard treatment is phototherapy with blue-green light, producing more polar photo-oxidation products, believed to be non-toxic. The aim of the present study was to compare the effects of bilirubin (BR) and lumirubin (LR), the major BR photo-oxidation product, on metabolic and oxidative stress markers. The biological activities of these pigments were investigated on several human and murine cell lines, with the focus on mitochondrial respiration, substrate metabolism, reactive oxygen species production, and the overall effects on cell viability. Compared to BR, LR was found to be much less toxic, while still maintaining a similar antioxidant capacity in the serum as well as suppressing activity leading to mitochondrial superoxide production. Nevertheless, due to its lower lipophilicity, LR was less efficient in preventing lipoperoxidation. The cytotoxicity of BR was affected by the cellular glycolytic reserve, most compromised in human hepatoblastoma HepG2 cells. The observed effects were correlated with changes in the production of tricarboxylic acid cycle metabolites. Both BR and LR modulated expression of PPARα downstream effectors involved in lipid and glucose metabolism. Proinflammatory effects of BR, evidenced by increased expression of TNFα upon exposure to bacterial lipopolysaccharide, were observed in murine macrophage-like RAW 264.7 cells. Collectively, these data point to the biological effects of BR and its photo-oxidation products, which might have clinical relevance in phototherapy-treated hyperbilirubinemic neonates and adult patients.

Efficacy of AAV8-hUGT1A1 with Rapamycin in neonatal, suckling, and juvenile rats to model treatment in pediatric CNs patients

A clinical trial using adeno-associated virus serotype 8 (AAV8)-human uridine diphosphate glucuronosyltransferase 1A1 (hUGT1A1) to treat inherited severe unconjugated hyperbilirubinemia (Crigler-Najjar syndrome) is ongoing, but preclinical data suggest that long-term efficacy in children is impaired due to loss of transgene expression upon hepatocyte proliferation in a growing liver. This study aims to determine at what age long-term efficacy can be obtained in the relevant animal model and whether immune modulation allows re-treatment using the same AAV vector. Neonatal, suckling, and juvenile Ugt1a1-deficient rats received a clinically relevant dose of AAV8-hUGT1A1, and serum bilirubin levels and anti-AAV8 neutralizing antibodies (NAbs) in serum were monitored. The possibility of preventing the immune response toward the vector was investigated using a rapamycin-based regimen with daily intraperitoneal (i.p.) injections starting 2 days before and ending 21 days after vector administration. In rats treated at postnatal day 1 (P1) or P14, the correction was (partially) lost after 12 weeks, whereas the correction was stable in rats injected at P28. Combining initial vector administration with the immune-suppressive regimen prevented induction of NAbs in female rats, allowing at least partially effective re-administration. Induction of NAbs upon re-injection could not be prevented, suggesting that this strategy will be ineffective in patients with low levels of preexisting anti-AAV NAbs.

Prediction of the need for phototherapy during hospital stay in preterm infants by transcutaneous bilirubinometry

BackgroundNeonatal hyperbilirubinemia is a common condition that frequently requires treatment with phototherapy and less commonly by exchange transfusion, especially in preterm infants. It is important to identify and monitor infants at risk of severe unconjugated hyperbilirubinemia early in the postnatal period to instigate appropriate management plans. AimsTo evaluate transcutaneous bilirubinometry (TCB) as a screening tool at 24 and 48 h of age to predict the need for phototherapy during hospital stay in preterm infants. Study designA single centre prospective cohort study in a level III perinatal centre. SubjectsPreterm infants (23+0 to 36+6 weeks of gestation) were eligible for enrolment. Outcome measuresPrimary outcome was to assess the predictive value of TCB at 24 and 48 h of age for the need of phototherapy during hospital stay. ResultsA total of 338 preterm infants were enrolled. The majority of infants (98.1%) born below 32 weeks of gestation required phototherapy. For infants born at >31 + 6 weeks of gestation, TCB at 24 h of age ≥81 μmol/l had sensitivity 83%, specificity 56%, positive predictive value (PPV) 54.7% and negative predictive value (NPV) 84%. TCB at 48 h of age ≥145 μmol/l had sensitivity 65%, specificity 62%, PPV 24% and NPV 90%. ConclusionTCB performed poorly at 24 and 48 h of age as a predictor of phototherapy during hospital stay in preterm infants. The negative predictive value of the test at 48 h of age might be helpful for infants born after 31 + 6 weeks of gestation.

UGT1A1 Variants c.864+5G>T and c.996+2_996+5del of a Crigler-Najjar Patient Induce Aberrant Splicing in Minigene Assays.

A large fraction of DNA variants impairs pre-mRNA splicing in human hereditary disorders. Crigler-Najjar syndrome (CNS) is characterized by a severe unconjugated hyperbilirubinemia caused by variants in the UGT1A1 gene. We previously reported one CNS-type II patient with two splice-site variants in trans (c.864+5G>T and c.996+2_996+5del). According to MaxEntScan, both disrupt their corresponding donor sites (c.864+5G>T: 6.99 → 2.28; c.996+2_996+5del: 5.96 → −11.02), so they were selected for subsequent functional tests. Given the unavailability of patient RNA, we constructed an UGT1A1 splicing-reporter minigene with exons 1–4 to characterize the underlying splicing anomaly. The variant c.996+2_996+5del generated two aberrant transcripts, Δ(E2) (exon 2 skipping/64%) and ▼(E2q135) (intron retention of 135-nt/36%), which lead to the loss of 18 conserved amino-acids and the gain of 45 new ones of a critical functional domain, respectively. The c.864+5G>T variant mainly produced the aberrant transcript Δ(E1q141) (141-nt deletion/70.4%) and the full-length isoform (29.6%). Δ(E1q141) would provoke the loss of 47 amino-acids of the N-terminal domain that encodes for substrate specificity. Thus, the three anomalous transcripts are likely to inactivate UGT1A1. Moreover, this patient is also homozygous for the promoter variant A(TA)7TAA that decreases UGT1A1 expression by 70%, so the full-length transcript produced by c.864+5G>T would be even more reduced (<9%), thus supporting the diagnosis of CNS-type II. Therefore, minigenes represent valuable tools for the functional and clinical classifications of genetic variants.

EFFECT OF PHOTOTHERAPY ON SERUM CALCIUM LEVELS IN NEONATAL JAUNDICE IN FULL TERM NEONATES

Introduction: The most prevalent anomalous physical finding during the first week of life is neonatal hyperbilirubinemia (NNH). It is estimated that more than two thirds of newborn babies have acquired clinical jaundice. It was also discovered that in the unconjugated hyperbilirubinemia of most neonates represents a common or exaggerated physiological syndrome. The physical immaturity of infants to handle increased production of bilirubin is referred to as Jaundice. This becomes potentially neurotoxic if severe unconjugated hyperbilirubinemia is left untreated. One of the routine strategies for treating hyperbilirubinemia is known as phototherapy. However it is not a harmless interference. This can produce negative results, such as dehydration, temperature volatility, blood flow redistribution, genotoxicity, rashes on the skin, loose skin, stools, damage to retinas, hypocalcemia and bronze baby syndrome. One of the lesser known but which has a potential adverse effect of phototherapy is hypocalcemia. A total serum calcium concentration of &lt; 7 mg / dl or ionised calcium concentration &lt; 4mg / dl (&lt; 1mol / L) is classified as neonatal hypocalcemia. Hypocalcemia increases the permeability of cells to sodium ions and increases the excitability of cell membranes.&#x0D; Material &amp; Methods: 60 full term neonates were included in present cross sectional study who was admitted to Neonatal Intensive Care Unit (NICU). Full term neonates who completed 37 weeks of gestation with unconjugated hyperbilirubinemia who require phototherapy. Under the normal protocol, traditional phototherapy equipment containing four blue light fluorescent lamps with wavelengths of 410-470 nm was mounted at a distance of 25-35 cm from the skin surface of neonates with entirely covered eyes and genitals. At 15μW / cm2 /nm at the level of the infant's skin, the irradiance during phototherapy was assessed and maintained consistently.&#x0D; Results: Among 60 neonates included in this study there were 27 (45%) male whereas 33 (55%) female neonates. In present study the mean levels of serum calcium before phototherapy was 9.21 with standard deviation of 0.83 while the serum calcium levels after phototherapy were 8.36 with standard deviation of 0.78. There was a statistically significant difference between serum mean calcium levels before and after phototherapy (p=0.001).&#x0D; Conclusion: A major issue is phototherapy induced hypocalcemia. Before beginning and during phototherapy for neonatal jaundice and close monitoring of neonates for signs of hypocalcemia, careful calcium status calculation should be carried out.. After phototherapy, there is a substantial reduction in the amount of serum calcium, but the risk of hypocalcemia in stable full-term neonates is minimal.

Clinical profiles and outcomes of neonates with neonatal hyperbilirubinemia and treated with double volume exchange transfusion: a retrospective study

Background: Double volume exchange transfusion (DVET) for severe unconjugated hyperbilirubinemia has become less common events now days in pediatric practices. But kernicterus is still common in low income country like India. The aim of the study was to determine the clinical profile and outcome in neonates who were treated with DVET.Methods: This was a retrospective study in neonate’s ≥34 weeks of gestation that were treated with DVET for severe neonatal hyperbilirubinemia over a period of four years.Results: In our study, 37 neonates underwent DVET. Male neonates (62.13%) and normal vaginal delivery (NVD) (70.2%) are common. ABO Isoimmunisation was commonest cause (56.75%) of exchange transfusion. The mean TSBR at pre exchange and Post Exchange were 27.39 ± 5.99mg/dl and 15.16 ± 4.00mg/dl (p&lt;0.05). Ten neonates (27%) among 37 neonates required twice DVET.Thrombocytopenia14 (37.83%); Seizure 5(13.5%) and Hypocalcaemia 3(8.1%) were common complication noted among total 17 (45.94%) neonates. BIND occurred in 15 neonates (40.5%) at the time of admission and seven (18.9%) neonates had persistent neurological abnormality at discharge. Neonate with BIND had early onset of jaundice (44.13±15.37 hours vs. 61.22±28.23hrs, p&lt;0.05), with higher pre exchange TSBR value(28.96 ±8.5mg/dl vs. 26.22±3.17mg/dl). Neonates admitted with BIND had higher percentage of persistent encephalopathy (40% vs. 4.5%,p&lt;0.05), abnormal tone (33.3% vs. 4.5%,p&lt;0.05), abnormal feeding (33.3% vs. 4.5%,p&lt;0.05) and abnormal posture (26.6% vs. 0%,p&lt;0.05) at discharge as compared to those without BIND. No death occurred in this study population.Conclusions: Early detection and aggressive therapy with DVET can prevent neonates from brain injury.

A novel UGT1A1 gene mutation causing severe unconjugated hyperbilirubinemia: a case report

BackgroundCrigler-Najjar syndrome (CNs) presents as unconjugated hyperbilirubinemia, as a result of UGT1A1 deficiency, and can be categorized in a severe (type I) and mild (type II) phenotype. CNs type II patients usually benefit from phenobarbital treatment that induces residual UGT1A1 activity.Case presentationHere we present a CNs type II patient that is not responsive to phenobarbital treatment, which can be explained by two heterozygous mutations in the UGT1A1 gene. A 3 nucleotide insertion in the HNF-1α binding site in the proximal promoter previously reported in a Crigler-Najjar patient on one allele and a novel two nucleotide deletion in exon 1, resulting in a frameshift and a premature stop codon.ConclusionIn newly diagnosed CNs patients with unconjugated bilirubin levels consistent with CNs type II but that are unresponsive to phenobarbital treatment, disruption of the HNF-1α binding site in the proximal promoter should be considered as a probable cause. Upon confirming a mutation in the HNF-1α site, phenobarbital treatment should be stopped or at least be reconsidered because of its sedative effects and its teratogenic properties.

Neonatal Jaundice.

Hyperbilirubinemia is a common occurrence in neonates; it may be physiological or pathological. Conjugated hyperbilirubinemia may result from medical or surgical causes, and can result in irreversible liver damage if untreated. The aim of imaging is the timely diagnosis of surgical conditions like biliary atresia and choledochal cysts. Abdominal ultrasound is the first line imaging modality, and Magnetic resonance cholangiopancreatography (MRCP) also has a role, especially in pre-operative assessment of choledochal cysts (CDCs). For biliary atresia, the triangular cord sign and gallbladder abnormalities are the two most useful ultrasound features, with a combined sensitivity of 95%. Liver biopsy has an important role in pre-operative evaluation; however, the gold standard for diagnosis of biliary atresia remains an intra-operative cholangiogram. Choledochal cysts are classified into types according to the number, location, extent and morphology of the areas of cystic dilatation. They are often associated with an abnormal pancreaticobiliary junction, which is best assessed on MRCP. Caroli's disease or type 5 CDC comprises of multiple intrahepatic cysts. CDCs, though benign, require surgery as they may be associated with complications like cholelithiasis, cholangitis and development of malignancy. Severe unconjugated hyperbilirubinemia puts neonates at high risk of developing bilirubin induced brain injury, which may be acute or chronic. Magnetic resonance imaging of the brain is the preferred modality for evaluation, and shows characteristic involvement of the globus pallidi, subthalamic nuclei and cerebellum - in acute cases, these areas show T1 hyperintensity, while chronic cases typically show hyperintensity on T2 weighted images.

Jaundice: Newborn to Age 2 Months.

1. Debra H. Pan, MD* 2. Yolanda Rivas, MD* 1. *Division of Pediatric Gastroenterology and Nutrition, The Children’s Hospital at Montefiore, Bronx, NY * Abbreviations: AAP: : American Academy of Pediatrics ALT: : alanine aminotransferase AST: : aspartate aminotransferase BA: : biliary atresia BUGT: : bilirubin uridine diphosphate-glucuronosyltransferase GALD: : gestational alloimmune liver disease GGT: : γ-glutamyl transpeptidase G6PD: : glucose-6-phosphate dehydrogenase Ig: : immunoglobulin IVIg: : intravenous Ig MCT: : medium-chain triglyceride MR: : magnetic resonance MRCP: : MR cholangiopancreatography PFIC: : progressive familial intrahepatic cholestasis PN: : parenteral nutrition PT: : prothrombin time TORCH: : toxoplasmosis, other (syphilis, varicella-zoster, parvovirus B19), rubella, cytomegalovirus, and herpes simplex Neonatal jaundice is a common clinical sign that indicates hyperbilirubinemia. Clinicians should become familiar with the differential diagnoses of hyperbilirubinemia in newborns and young infants and the importance of early referral of all patients with cholestatic jaundice to a pediatric gastroenterologist or hepatologist. After completing this article, readers should be able to: 1. Recognize jaundice as a sign of hyperbilirubinemia and identify risk factors for neonatal jaundice. 2. Explain bilirubin metabolism. 3. Define hyperbilirubinemia and differentiate between the types of hyperbilirubinemia in newborns and young infants. 4. Explain the broad differential diagnoses of neonatal jaundice. 5. Recognize the importance of screening and postdischarge follow-up to prevent severe unconjugated hyperbilirubinemia. 6. Describe the management of neonatal jaundice, including cholestasis. The term jaundice, derived from the French word jaune , meaning yellow, is a yellowish discoloration of the skin, sclerae, and mucous membranes that is caused by tissue deposition of pigmented bilirubin. Jaundice is also known as icterus, from the ancient Greek word ikteros, signifying jaundice. Jaundice is a common clinical sign in newborns, especially during the first 2 weeks after birth. The first description of neonatal jaundice and bilirubin staining of the newborn brain goes back to the eighteenth century. The finding of jaundice on physical examination is an indicator of hyperbilirubinemia. This differs from carotenemia, which can also manifest as a pale yellow-red skin color and is caused by a high level of carotene in the blood. Older children and adults have a normal total serum bilirubin level less than 1.5 mg/dL (26 μmol/L), with the conjugated fraction accounting for less than 5%. (1) Hyperbilirubinemia is defined as a total serum bilirubin level greater than 1.5 …

Promoterless gene targeting without nucleases rescues lethality of a Crigler-Najjar syndrome mouse model.

Crigler‐Najjar syndrome type I (CNSI) is a rare monogenic disease characterized by severe neonatal unconjugated hyperbilirubinemia with a lifelong risk of neurological damage and death. Liver transplantation is the only curative option, which has several limitations and risks. We applied an in vivo gene targeting approach based on the insertion, without the use of nucleases, of a promoterless therapeutic cDNA into the albumin locus of a mouse model reproducing all major features of CNSI. Neonatal transduction with the donor vector resulted in the complete rescue from neonatal lethality, with a therapeutic reduction in plasma bilirubin lasting for at least 12 months, the latest time point analyzed. Mutant mice, which expressed about 5–6% of WT Ugt1a1 levels, showed normal liver histology and motor‐coordination abilities, suggesting no functional liver or brain abnormalities. These results proved that the promoterless gene therapy is applicable for CNSI, providing therapeutic levels of an intracellular ER membrane‐bound enzyme responsible for a lethal liver metabolic disease.

Effect of unconjugated hyperbilirubinemia on neonatal autonomic functions: evaluation by heart rate variability

Background: Serum bilirubin levels beyond the physiological limits, may lead to alterations in autonomic regulation in a newborn infant. Heart rate variability (HRV), is a noninvasive and quantitative marker of the activity of the autonomic nervous system (ANS). To date, few studies have demonstrated the undesirable effects of severe unconjugated hyperbilirubinemia (UHB) on autonomic functions, and only one study has used HRV as a marker of the autonomic activity. However, the relationship between altered cardiac autonomic functions and UHB by using the HRV derived from 24-hour Holter electrocardiography (ECG) recording has not been investigated previously.Objective: We aimed to assess whether a relationship exists between severe UHB and cardiac autonomic dysfunction by evaluating HRV via 24-hour Holter ECG recording.Methods: This single-center, prospective, case-control study was conducted on 50 full-term newborn infants with severe UHB requiring phototherapy and 50 healthy infants as controls. HRV assessment was performed by using 24-hour Holter ECG recording.Results: There was no significant difference in terms of mean average heart rate, mean maximum heart rate and mean RR duration between the groups. However, mean minimum heart rate was significantly lower in the study group. When 24-hour time and frequency domain parameters were compared, time and frequency domain parameters rMSDD as well as high frequency (HF), which represent parasymphathetic activity, were significantly higher in the study group. Furthermore, low frequency to high frequency (LF/HF) ratio, that serves as an indicator of sympathovagal balance, was significantly lower in the study group.Conclusion: Severe UHB may cause cardiac autonomic dysfunction in favor of parasympathetic predominance in jaundiced neonates.

Biliverdin Reductase inhibitors did not improve severe unconjugated hyperbilirubinemia in vivo

We aimed to identify potent biliverdin reductase (BVRA) inhibitors as a novel concept for the treatment of severe unconjugated hyperbilirubinemia. 1280 FDA-approved compounds were screened in vitro for their ability to inhibit human and rat BVRA activity and 26 compounds were identified as BVRA inhibitors. Montelukast and Disulfiram were selected as potentially clinically applicable drugs and tested to reduce serum unconjugated bilirubin (UCB) levels in the Ugt1a1-deficient rat, a model for chronic unconjugated hyperbilirubinemia. Oral administration of Disulfiram was toxic in the Ugt1a1-deficient rat (weight loss, transaminase elevation). Oral Montelukast administration led to low serum concentrations and did not alter serum UCB levels. Intraperitoneal injections of Montelukast resulted in concentrations up to 110 μmol/L in serum and 400 μmol/L in the liver. Still, serum UCB levels remained unaltered. This first study on biliverdin reductase inhibition as a novel concept for treatment of unconjugated hyperbilirubinemia identified putative in vitro BVRA inhibitors. Montelukast, the clinically most suitable inhibitor, did not result in reduction of serum UCB in the Ugt1a1-deficient rat. The proposed treatment strategy will not result in amelioration of severe unconjugated hyperbilirubinemia in humans without the identification or development of more potent BVRA inhibitors.

The establishment of a high resolution melting analysis based rapid screening system for UGT1A1 gene mutation

Objective To develop a high-resolution melting (HRM) assay for rapidly screening Gilbert syndrome (GS) and Crigler-Najjar syndrome (CNS) associated with UGT1A1 defects. Method Methodology was developed. Then, we applied the established method to analyze 61 clinical samples from neonatal patients with severe unexplained unconjugated hyperbilirubinemia. Neonates with known risk factors for developing hyperbilirubinemia, such as ABO hemolysis, G6PD deficiency, sepsis, hypoxic ischemic encephalopathy were excluded. Five pairs of PCR primers were designed to detect the five common mutations (G211A, C686A, C1091T, C1352T and T1456G) in Asia population. PCR and HRM Assay conditions were optimized. UGT1A1 genotyping in clinical samples was performed by using the established HRM analysis, and all results were subsequently confirmed by direct DNA sequencing. Results The mutants were readily differentiated by using HRM analysis. In this study, 42 neonates were identified with UGT1A1 mutation, and 4 different known variants were detected. Conclusion HRM analysis in this study was economical, convenient, rapid, effective for screening UGT1A1 gene mutations, which can serve as an reliable method for the clinical diagnosis of GS and CNS and the large-scale molecular epidemiological research of UGT1A1 gene-related diseases.(Chin J Lab Med, 2017, 40: 101-104) Key words: Gilbert disease; Crigler-Najjar syndrome; Hyperbilirubinemia, neonatal; Glucuronosyltransferase; Mutation; Polymerase chain reaction; High resolution melting