Forgoing Exchange Transfusion in Neonatal Hyperbilirubinemia: A Single-Center Retrospective Cohort Study

INTRODUCTION

Unconjugated hyperbilirubinemia is part of the everyday life of the neonatal period as it reflects the adaptation of the metabolism of bilirubin. The neonatal hyperbilirubinemia usually resolves spontaneously, but it can also be the cause of an acute or chronic encephalopathy known as kernicterus. Regardless of the cause, the goal of therapy is to prevent this neurotoxicity while not causing undue harm. Phototherapy and, if it is unsuccessful, exchange transfusion (ECT) remain the primary treatment modalities used to keep the maximal total serum bilirubin (TSB) below pathologic levels.

MATERIALS AND METHODS

This is a descriptive retrospective cohort study of 69 live neonates hospitalized in the Department of Neonatology and Neonatal Resuscitation of Mohammed VI University Hospital with unconjugated hyperbilirubinemia requiring ECT and treated with intensive phototherapy instead, spanning five years from March 2016 to March 2021. We aim to demonstrate the effectiveness of phototherapy in achieving prolonged reduction of bilirubin levels and the prevention of neurological complications and to compare our results with those in the literature.

RESULTS

The use of intensive phototherapy in the treatment of neonatal unconjugated hyperbilirubinemia is very effective in lowering total serum bilirubin when its level is in the range of exchange transfusion, and it has succeeded in preventing the neurological complications of severe hyperbilirubinemia.

CONCLUSION

Through this study, it can be seen that phototherapy is an efficacious, simpler, and less hazardous alternative to exchange transfusion in achieving a sustained reduction of bilirubin levels and preventing neurological complications.

Demystifying non-invasive approaches for screening jaundice in low resource settings: a review

All national and international pediatric guidelines universally prescribe meticulous bilirubin screening for neonates as a critical measure to mitigate the incidence of acute bilirubin encephalopathy (ABE) and Kernicterus. The prevailing gold standard for jaundice detection in neonates necessitates invasive blood collection, followed by subsequent biochemical testing. While the invasive procedure provides dependable bilirubin measurements and continues to be the sole gold standard diagnostic method for assessing bilirubin concentration. There exists a pressing need to innovate non-invasive screening tools that alleviate the sampling stress endured by newborns, mitigate iatrogenic anemia, and expedite the turnaround time for obtaining results. The exploration of non-invasive modalities for bilirubin measurements is gaining momentum, driven by the overarching goal of minimizing the number of pricks inflicted upon neonates, thereby rendering screening a swift, efficient, comfortable, and dependable process. This comprehensive review article delves extensively into the array of non-invasive approaches and digital solutions that have been proposed, implemented, and utilized for neonatal bilirubin screening, with a particular emphasis on their application in low-resource settings. Within this context, the review sheds light on the existing methodologies and their practical applications, with a specific focus on transcutaneous bilirubin meters. Moreover, it underscores the prevailing open challenges in this domain and outlines potential directions for future research endeavors. Notably, the review underscores the imperative need for robust educational programs targeted at both families and healthcare personnel to expedite the process of seeking timely care for neonatal jaundice. Additionally, it underscores the necessity for the development of enhanced screening and diagnostic tools that can offer greater accuracy in clinical practice.

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.

Effects of Repetitive Transcranial Magnetic Stimulation on Pallidum GABAergic Neurons and Motor Function in Rat Models of Kernicterus

Kernicterus is a serious complication of hyperbilirubinemia, caused by neuronal injury due to excessive unconjugated bilirubin (UCB) in specific brain areas. This injury induced by this accumulation in the globus pallidus can induce severe motor dysfunction. Repetitive transcranial magnetic stimulation (rTMS) has shown neuroprotective effects in various neurological diseases. This study aimed to investigate the effects of rTMS on pallidal nerve damage and motor dysfunction in a rat model of kernicterus. Rats were divided into a sham group (n = 16), a model group (bilirubin with sham rTMS; n = 16) and an rTMS group (bilirubin with rTMS; n = 16). High-frequency rTMS (10 Hz) was applied starting from 24 h postmodeling for 7 days. The rotarod test, western blotting and immunohistochemical staining were performed to measure motor function and protein expression levels. The rTMS mitigated the negative effects of UCB on the general health of kernicterus-model rats and improved their growth and development. Furthermore, the rTMS alleviated UCB-induced motor dysfunction and increased the expression of GABAergic neuronal marker GAD67 in the globus pallidus. Notably, it also inhibited apoptosis-related protein caspase-3 activation. In conclusion, rTMS could alleviate motor dysfunction by inhibiting apoptosis and increasing globus pallidus GAD67 in kernicterus rat models, indicating that it may be a promising treatment for kernicterus.

Bilirubin-Induced Transcriptomic Imprinting in Neonatal Hyperbilirubinemia

Recent findings indicated aberrant epigenetic control of the central nervous system (CNS) development in hyperbilirubinemic Gunn rats as an additional cause of cerebellar hypoplasia, the landmark of bilirubin neurotoxicity in rodents. Because the symptoms in severely hyperbilirubinemic human neonates suggest other regions as privileged targets of bilirubin neurotoxicity, we expanded the study of the potential impact of bilirubin on the control of postnatal brain development to regions correlating with human symptoms. Histology, transcriptomic, gene correlation, and behavioral studies were performed. The histology revealed widespread perturbation 9 days after birth, restoring in adulthood. At the genetic level, regional differences were noticed. Bilirubin affected synaptogenesis, repair, differentiation, energy, extracellular matrix development, etc., with transient alterations in the hippocampus (memory, learning, and cognition) and inferior colliculi (auditory functions) but permanent changes in the parietal cortex. Behavioral tests confirmed the presence of a permanent motor disability. The data correlate well both with the clinic description of neonatal bilirubin-induced neurotoxicity, as well as with the neurologic syndromes reported in adults that suffered neonatal hyperbilirubinemia. The results pave the way for better deciphering the neurotoxic features of bilirubin and evaluating deeply the efficacy of new therapeutic approaches against the acute and long-lasting sequels of bilirubin neurotoxicity.

Management challenges in the treatment of severe hyperbilirubinemia in low- and middle-income countries: Encouraging advancements, remaining gaps, and future opportunities

Neonatal jaundice (NJ) is common in newborn infants. Severe NJ (SNJ) has potentially negative neurological sequelae that are largely preventable in high resource settings if timely diagnosis and treatment are provided. Advancements in NJ care in low- and middle-income countries (LMIC) have been made over recent years, especially with respect to an emphasis on parental education about the disease and technological advancements for improved diagnosis and treatment. Challenges remain, however, due to lack of routine screening for SNJ risk factors, fragmented medical infrastructure, and lack of culturally appropriate and regionally specific treatment guidelines. This article highlights both encouraging advancements in NJ care as well as remaining gaps. Opportunities are identified for future work in eliminating the gaps in NJ care and preventing death and disability related to SNJ around the globe.

Evidence Suggests a Decrease in the Incidence of Kernicterus in California

We identified children diagnosed with kernicterus in the California Department of Developmental Services and estimated an incidence of 0.42 per 100 000 births from 1988 to 2014, significantly decreasing to 0.04 per 100 000 births after 2009. We also examined national infant kernicterus mortality from 1979 to 2016 using CDC data. It did not decrease significantly.

Total bilirubin assay differences may cause inconsistent treatment decisions in neonatal hyperbilirubinaemia

OBJECTIVES

To assess interlaboratory variability of total serum bilirubin (TSB) results in newborns. Initiated following a clinical incident in which a neonate was transferred to a tertiary hospital for treatment of severe hyperbilirubinemia but on arrival was reclassified into a lower risk category due to a 20% difference in TSB between laboratories.

METHODS

Fresh residual plasma samples from hospital-born infants were pooled to obtain 11 samples across a range of total bilirubin concentrations. Aliquots were light-protected and measured on 7 commercial platforms at 4 accredited medical laboratories. Data from The Royal College of Pathologists of Australasia Quality Assurance Programs' (RCPAQAP) Neonatal Bilirubin program was analysed.

RESULTS

Twenty-four to 30% difference in results for individual samples, largely due to calibration differences between assays. When interpreted according to guidelines, results from different platforms would have led to different clinical interventions in some cases. RCPAQAP results showed significant within-method bias but were not shown to be commutable with patient samples.

CONCLUSIONS

There are clinically significant method-dependent differences in TSB results from neonatal samples, consistent with our clinical incident. The differences are largely due to lack of standardisation of calibrator values. This has implications for healthcare resource use and possibly for the neurodevelopment of infants. Intervention is needed at a number of levels, including clinical reporting of incidents arising from discordant results, commitment by manufacturers to ensure metrological traceability of methods with sufficiently low uncertainty in the final measurements, and availability of commutable quality assurance material to monitor assay performance, especially at the clinical decision points for neonatal jaundice.

Trends in hospitalizations of newborns with hyperbilirubinemia and kernicterus in United States: an epidemiological study

BACKGROUND

Hyperbilirubinemia is one of the most common diagnosis in newborn nurseries in United States. Universal pre-discharge bilirubin screening decreased the incidence of extreme hyperbilirubinemia and risk of kernicterus.

OBJECTIVES

We sought to assess temporal population trends of hyperbilirubinemia, kernicterus and usage of phototherapy, intravenous immunoglobulin (IVIG), and exchange transfusion.

DESIGN/METHODS

Data from Healthcare Cost and Utilization Project (HCUP)-the Kids' Inpatient Database (KID) obtained for years 1997-2012. All neonatal discharges with ICD-9 codes for neonatal jaundice (774.2, 774.6), kernicterus (773.4, 774.7) and procedure codes for phototherapy (99.83), IVIG infusion (99.14), exchange transfusion (99.01) were extracted. We compared the trends of diagnosis of hyperbilirubinemia, kernicterus, use of phototherapy, IVIG, and exchange transfusion.

RESULTS

During the study period, the proportion of infants diagnosed with hyperbilirubinemia increased by 65% (9.4% vs. 15.5%; p<.001) in term infants and 34.5% (33.5% vs. 45%; p<.001) in preterm infants, respectively. Rate of kernicterus discharges significantly reduced from 7 to 1.9 per 100,000 newborns. Overall, the number of exchange transfusions has decreased by 67% during study period while phototherapy and IVIG use increased by 83% and 170%, respectively.

CONCLUSIONS

In last two decades, there was a significant decrease in neonatal discharges with a history of exchange transfusion or with a diagnosis of kernicterus. However, there was a significant increase in number of neonates discharged home with a history of phototherapy during birth hospitalization and decreased number of exchange transfusions were observed during the study period. Incremental implementation of universal predischarge bilirubin screening and treatments based on 2004 AAP recommended risk-based strategies might have contributed to timely interventions in infants with significant hyperbilirubinemia.

Glucose-6-Phosphate Dehydrogenase Deficiency and the Benefits of Early Screening

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzymopathy worldwide, is an insufficient amount of the G6PD enzyme, which is vital to the protection of the erythrocyte. Deficient enzyme levels lead to oxidative damage, hemolysis, and resultant severe hyperbilirubinemia. If not promptly recognized and treated, G6PD deficiency can potentially lead to bilirubin-induced neurologic dysfunction, acute bilirubin encephalopathy, and kernicterus. Glucose-6-phosphate dehydrogenase deficiency is one of the three most common causes for pathologic hyperbilirubinemia. A change in migration patterns and intercultural marriages have created an increased incidence of G6PD deficiency in the United States. Currently, there is no universally mandated metabolic screening or clinical risk assessment tool for G6PD deficiency in the United States. Mandatory universal screening for G6PD deficiency, which includes surveillance and hospital-based risk assessment tools, can identify the at-risk infant and foster early identification, diagnosis, and treatment to eliminate neurotoxicity.

The application of magnetic resonance imaging and diffusion-weighted imaging in the diagnosis of hypoxic-ischemic encephalopathy and kernicterus in premature infants

BACKGROUND

To explore the application of magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in the diagnosis of hypoxic-ischemic encephalopathy and kernicterus in premature infants.

METHODS

Fifty-eight premature infants with hypoxic-ischemic encephalopathy and fifty-eight premature infants with kernicterus who were examined and treated in our hospital between January 2018 and January 2021 were assigned to the observation group or the control group. All patients were examined by MRI imaging and DWI imaging, and the examination results were compared between the two groups.

RESULTS

No significant differences were found in sensitivity, specificity, positive predictive value, or negative predictive value between the observation group and the control group (P>0.05). MRI could clearly visualize the signal changes of patients, whereas DWI did not show any signal changes. There was no significant difference between MRI and DWI in the diagnosis of hypoxic-ischemic encephalopathy in premature infants. Further, there was no significant difference in the diagnostic performance of MRI between the observation group and the control group (P>0.05). However, the diagnostic performance of DWI in the control group was better than that in the observation group, and the difference was statistically significant (P<0.05).

CONCLUSIONS

MRI and DWI imaging have high detection rates for the diagnosis of hypoxic-ischemic encephalopathy and kernicterus in premature infants. These imaging methods can benefit the treatment of premature infants and have important clinical application value.

In memoriam: Henry Szczȩsny Schutta, MD (1928-2020)

Polish-American neurologist and neurologic historian Henry Szczȩsny Schutta, MB BS, MD (1928-2020), was born in the Free City of Gdańsk. After surviving the trauma and devastation wrought on his family and his native country during World War II, Schutta met the love of his life in war-torn Bonn, Germany. Schutta completed premedical studies in Bonn, then medical school in Sydney, Australia, and neurology residency at the National Hospital, Queen Square, London. He then joined the faculty at the University of Pennsylvania (1962-1973), where he became a recognized authority on electron microscopy of the nervous system and muscle, particularly concerning bilirubin encephalopathy, brain swelling, and papilledema. He was subsequently appointed as the inaugural chair of neurology at Downstate Medical Center in Brooklyn (1973-1980) and then chair of neurology at the University of Wisconsin (1980-1995). His academic career spanned four countries on three continents, and included substantive contributions to basic research, clinical care, administration, and teaching. He was most proud of his contributions to education and mentoring. He pushed his trainees to excel, and modeled for them the traits of caring, compassion, dedication, diligence, reasonableness, and fidelity-leavened with wit, charm, and a penchant for humorous historical anecdotes. Many of Schutta's witticisms on rounds ("Schutta-isms") have been retold by subsequent generations of trainees. This biography provides first-person accounts of Schutta's struggles and successes based on his own autobiography, a formal oral history for the American Academy of Neurology Oral History Project, and supporting accounts of his family, trainees, and colleagues.

Economic evaluation of point of care universal newborn screening for glucose-6-Phosphate dehydrogenase deficiency in United States

BACKGROUND AND OBJECTIVES

Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency is frequent inherited enzymopathy that poses potentially preventable risk for extreme hyperbilirubinemia (EHB) which can, rarely, lead to acute bilirubin encephalopathy, childhood kernicterus and death. We aimed to estimate quality adjusted life years (QALY) lost due to G6PD deficiency associated with EHB and economic costs to best estimate value of universal pre-discharge screening.

METHODS

We did a cost utility analysis for US birth cohort utilizing pre-discharge screening decision tree model to estimate population burden and EHB outcomes, based on literature search and expert opinions. Employing human capital approach, we measured health benefits in terms of QALYs and economic losses. QALYs and costs were discounted at 3%; one-way sensitivity analysis was used for decision variables.

RESULTS

We determined for USA live births of 3.86 million in 2017, 1464 cases of EHB were estimated to be due to G6PD deficiency (CI 95%; range: 1270-1656) and contributed 2 deaths (CI 95%; range 1.3-3.2) and 14 (CI 95%; range: 9.1-21.5) cases of kernicterus. Over lifetime horizon, the model predicted undiscounted and discounted gains of 165 (102-252) life years; 241 (183-433) QALYs and 16 (9.9-24.5) life years; 89 (67.9-160.5) QALYs, respectively. Assuming 50% effectiveness, benefit cost ratios ranged from 0.19 to 3.42 for diverse operational settings. The cost to prevent a single case of kernicterus was $2.7 to 6.8 million per annum with cost per QALY gained at $35,946 to $89,159.

CONCLUSION

At incremental cost-effective threshold of $100,000/life year, pre-discharge screening would be expected to prove cost effective in preventing EHB related morbidities and mortality attributed to G6PD deficiency.

Nationwide survey of late-onset hemolysis in very low birthweight infants

BACKGROUND

In Japan, some cases of late-onset acute hemolysis in very low birthweight (VLBW) infants have been reported. These cases had common features but the cause of hemolysis was unknown. The incidence and prognosis of this disease are also unknown. However, there are only few reports of such hemolytic episodes in countries other than Japan. Thus, this study aimed to examine the incidence and clinical course of late-onset acute hemolysis and to establish it as a new disease concept.

METHODS

A nationwide prospective survey was conducted from 2011 to 2015 as a rare disease surveillance project of the Japan Society for Neonatal Health and Development.

RESULTS

Twenty-four cases were confirmed. The median (range) gestational age, birthweight, and onset of hemolytic episodes were 26 weeks and 2 days (23 weeks and 4 days-31 weeks and 2 days), 898 g (627-1,416 g), and 19 days after birth (9-33 days), respectively. Phototherapy, blood transfusion, and exchange transfusion were required in 22 (96%), 24 (100%), and 7 (29%) cases, respectively. During the observation period, no recurrence of the hemolytic episode occurred. All patients survived; however, one case developed kernicterus and suffered severe neurological sequelae.

CONCLUSIONS

In this study, at least 1 out of 1,259 VLBW infants developed hemolysis at 9-33 days after birth in Japan. Owing to the risk of kernicterus, this disease should be recognized as among the important pathological conditions of VLBW infants, suggesting the need to manage jaundice and anemia until 5 weeks after birth.

Curcumin Prevents Cerebellar Hypoplasia and Restores the Behavior in Hyperbilirubinemic Gunn Rat by a Pleiotropic Effect on the Molecular Effectors of Brain Damage

Bilirubin toxicity to the central nervous system (CNS) is responsible for severe and permanent neurologic damage, resulting in hearing loss, cognitive, and movement impairment. Timely and effective management of severe neonatal hyperbilirubinemia by phototherapy or exchange transfusion is crucial for avoiding permanent neurological consequences, but these therapies are not always possible, particularly in low-income countries. To explore alternative options, we investigated a pharmaceutical approach focused on protecting the CNS from pigment toxicity, independently from serum bilirubin level. To this goal, we tested the ability of curcumin, a nutraceutical already used with relevant results in animal models as well as in clinics in other diseases, in the Gunn rat, the spontaneous model of neonatal hyperbilirubinemia. Curcumin treatment fully abolished the landmark cerebellar hypoplasia of Gunn rat, restoring the histological features, and reverting the behavioral abnormalities present in the hyperbilirubinemic rat. The protection was mediated by a multi-target action on the main bilirubin-induced pathological mechanism ongoing CNS damage (inflammation, redox imbalance, and glutamate neurotoxicity). If confirmed by independent studies, the result suggests the potential of curcumin as an alternative/complementary approach to bilirubin-induced brain damage in the clinical scenario.

Zinc Supplementation in Preterm Neonates with Jaundice: Is it Beneficial?

BACKGROUND

Neonatal jaundice is a common neonatal disease that has adverse effects on neonates, especially preterm neonates, when indirect bilirubin level is adequately high to pass the blood-brain barrier, causing bilirubin encephalopathy or kernicterus.

AIM

This study aimed to investigate the value of zinc (Zn) supplementation in preterm neonates with jaundice and whether it will be beneficial.

PATIENTS AND METHODS

A prospective randomized clinical trial, with the identification number TCTR20200504007, was conducted at Tanta University Hospital from July 2016 to March 2018 on 200 preterm neonates with jaundice. The studied neonates were divided into two groups: group 1, which received Zn and phototherapy, and group 2, which received phototherapy only and did not receive Zn. In group 1, 100 preterm neonates with jaundice received Zn as 0.6 mL (cm3) of zinc origin/kg/day orally through the oro-nasogastric tube divided into two doses (every 12 h), which was equal to 1.2 mg elemental zinc/kg/day orally for 10 days.

RESULTS

There was no significant difference in serum bilirubin level between the two groups on the 2nd, 4th, and 6th days of admission, while the serum bilirubin level was significantly decreased in group 1 compared with that in group 2 only on the 8th, 9th, and 10th days of admission. The p-- values were 0.045*, 0.027*, and 0.004*, respectively.

CONCLUSION

Zn administration to preterm neonates with jaundice was found to be beneficial in decreasing serum bilirubin level.

RECOMMENDATION

Zn supplementation should be provided to preterm neonates with jaundice.

Low-dose lipopolysaccharide exposure can increase in vivo bilirubin production rates in newborn mice

AIM

Neonatal haemolysis increases bilirubin production rates, which can then lead to severe hyperbilirubinaemia and bilirubin neurotoxicity. During haemolysis, haem is degraded by haem oxygenase (HO), which can be induced under stress conditions. It is known that neonatal sepsis is a risk factor for haemolysis and severe hyperbilirubinaemia. Here, we evaluated whether an exposure to lipopolysaccharide (LPS) to induce sepsis can upregulate HO-1, further increasing in vivo bilirubin production rates in mouse pups under haem loads.

METHODS

Three-day-old pups were given LPS (1250 μg/kg) or saline (controls). Liver HO enzyme activity, HO-1 mRNA and HO-1 protein were measured post-LPS exposure. We then assessed the effects of LPS treatment on in vivo bilirubin production rates after haem loading.

RESULTS

Liver HO activity significantly increased (142%) over controls 24 hours after treatment with LPS (1250 μg/kg) without mortality. Liver HO-1 mRNA was significantly upregulated 2.47-fold at 24 hours post-LPS administration, while liver HO-1 protein increased 1.29-fold 24 hours post-LPS treatment. After haem loading, pups exposed to LPS had significantly higher bilirubin production rates (1.30-fold) compared with age-matched, saline-treated controls.

CONCLUSION

Low-dose LPS treatment can upregulate liver HO-1 expression and may underlie the severe hyperbilirubinaemia seen in septic infants, particularly when undergoing haemolysis.

Maternal Instruction About Jaundice and the Incidence of Acute Bilirubin Encephalopathy in Nigeria

OBJECTIVE

To evaluate whether teaching mothers about neonatal jaundice will decrease the incidence of acute bilirubin encephalopathy among infants admitted for jaundice.

STUDY DESIGN

This was a multicenter, before-after and cross-sectional study. Baseline incidences of encephalopathy were obtained at 4 collaborating medical centers between January 2014 and May 2015 (Phase 1). Structured jaundice instruction was then offered (May to November 2015; Phase 2) in antenatal clinics and postpartum. Descriptive statistics and logistic regression models compared 3 groups: 843 Phase 1 controls, 338 Phase 2 infants whose mothers received both antenatal and postnatal instruction (group A), and 215 Phase 2 infants whose mothers received no instruction (group B) either because the program was not offered to them or by choice.

RESULTS

Acute bilirubin encephalopathy occurred in 147 of 843 (17%) Phase 1 and 85 of 659 (13%) Phase 2 admissions, which included 63 of 215 (29%) group B and 5 of 338 (1.5%) group A infants. OR for having acute bilirubin encephalopathy, comparing group A and group B infants adjusted for confounding risk factors, was 0.12 (95% CI 0.03-0.60). Delayed care-seeking (defined as an admission total bilirubin ≥18 mg/dL at age ≥48 hours) was the strongest single predictor of acute bilirubin encephalopathy (OR 11.4; 6.6-19.5). Instruction decreased delay from 49% to 17%. Other major risk factors were home births (OR 2.67; 1.69-4.22) and hemolytic disease (hematocrit ≤35% plus bilirubin ≥20 mg/dL) (OR 3.03; 1.77-5.18). The greater rate of acute bilirubin encephalopathy with home vs hospital birth disappeared if mothers received jaundice instruction.

CONCLUSIONS

Providing information about jaundice to mothers was associated with a reduction in the incidence of bilirubin encephalopathy per hospital admission.

Making Locally Fabricated Phototherapy Devices Work Better

BACKGROUND

The efficiency of a phototherapy (PT) device is a function of the irradiance delivered by the device at the surface of the skin. Because cost limits the ability of health care facilities in low- and middle-income countries to procure commercial PT devices, efforts have gone into local fabrication of devices for use in health care facilities in Nigeria. Evaluation of such fabricated devices is yet to be conducted.

OBJECTIVE

To identify and document essential features of locally fabricated phototherapy (FPT) devices in use in Nigeria.

MATERIALS AND METHODS

A cross sectional survey of locally FPT devices available in health facilities providing newborn health care services was conducted as part of evaluating neonatal jaundice management services in Kaduna State. Each FPT was characterized with respect to mobility/portability, adjustability, lamp type, number and color of lamps used. The irradiance of each device was measured using Model 22 Olympic BiliMeter™ at the facility's traditional PT distance and also at a distance at which optimum irradiance is delivered by the device.

RESULTS

A total of 54 PT devices were in use. Thirty-two (59.3%) of these devices were locally fabricated while others were obtained from commercial sources. Of the fabricated devices 22/32 (68.8%) were non-adjustable while the remaining 10 devices were adjustable but with limited adjustability. Only 5/32 (15.6%) of the FPT devices used special blue fluorescent lamps. The majority, 68.8% (22/32) of the FPT devices used ordinary low-intensity blue lamps while the remaining 5/32 (15.6%) devices used white light fluorescent lamps. None of the devices used light emitting diodes as a PT light source. Only three fabricated devices offered irradiance (9.4, 13.6 and 33 µW/cm2/nm) at the facilities' traditional distances for PT.

CONCLUSIONS

FPT devices in use in Kaduna, functioned sub-optimally because of technically inadequate designs. The devices will need to be designed to especially enable adjustability to vary distance between device and patient's skin and the use of lamps which offer high irradiance.

Extreme neonatal hyperbilirubinaemia in refugee and migrant populations: retrospective cohort

OBJECTIVE

To describe neonatal survival and long-term neurological outcome in neonatal hyperbilirubinaemia (NH) with extreme serum bilirubin (SBR) values.

DESIGN

Retrospective chart review, a one-off neurodevelopmental evaluation.

SETTING

Special care baby unit in a refugee camp and clinics for migrant populations at the Thailand-Myanmar border with phototherapy facilities but limited access to exchange transfusion (ET).

PATIENTS

Neonates ≥28 weeks of gestational age with extreme SBR values and/or acute neurological symptoms, neurodevelopment evaluation conducted at 23-97 months of age.

MAIN OUTCOME MEASURES

Neonatal mortality rate, prevalence of acute bilirubin encephalopathy (ABE) signs, prevalence of delayed development scores based on the Griffiths Mental Development Scale (GMDS).

RESULTS

From 2009 to 2014, 1946 neonates were diagnosed with jaundice; 129 (6.6%) had extreme SBR values during NH (extreme NH). In this group, the median peak SBR was 430 (IQR 371-487) µmol/L and the prevalence of ABE was 28.2%. Extreme NH-related mortality was 10.9% (14/129). Median percentile GMDS general score of 37 survivors of extreme NH was poor: 11 (2-42). 'Performance', 'practical reasoning' and 'hearing and language' domains were most affected. Four (10.8%) extreme NH survivors had normal development scores (≥50th centile). Two (5.4%) developed the most severe form of kernicterus spectrum disorders.

CONCLUSION

In this limited-resource setting, poor neonatal survival and neurodevelopmental outcomes, after extreme NH, were high. Early identification and adequate treatment of NH where ET is not readily available are key to minimising the risk of extreme SBR values or neurological symptoms.

Neonatal jaundice: aetiology, diagnosis and treatment

A significant proportion of term and preterm infants develop neonatal jaundice. Jaundice in an otherwise healthy term infant is the most common reason for readmission to hospital. Jaundice is caused by an increase in serum bilirubin levels, largely as a result of breakdown of red blood cells. Bilirubin is conveyed in the blood as 'unconjugated' bilirubin, largely bound to albumin. The liver converts bilirubin into a conjugated form which is excreted in the bile. Very high levels of unconjugated bilirubin are neurotoxic. Phototherapy is a simple and effective way to reduce the bilirubin level. Most term babies have 'physiological' jaundice which responds to a short period of phototherapy, and requires no other treatment. A few babies have rapidly rising bilirubin levels which place them at risk of kernicterus. Current management of jaundice in the UK is guided by the NICE guideline. Any infant with high serum bilirubin or a rapidly rising bilirubin level needs to be treated urgently to avoid neurotoxicity. High levels of conjugated bilirubin in a term baby can indicate biliary atresia, and babies with persisting jaundice must have their level of conjugated bilirubin measured. Preterm infants on long-term parenteral nutrition may develop conjugated jaundice which generally improves with the introduction of enteral feed and weaning of intravenous nutrition.

Clinicopathological Spectrum of Bilirubin Encephalopathy/Kernicterus

Bilirubin encephalopathy/kernicterus is relatively rare, but continues to occur despite universal newborn screening. What is more interesting is the spectrum of clinical and even neuropathological findings that have been reported in the literature to be associated with bilirubin encephalopathy and kernicterus. In this review, the authors discuss the array of clinicopathological findings reported in the context of bilirubin encephalopathy and kernicterus, as well as the types of diagnostic testing used in patients suspected of having bilirubin encephalopathy or kernicterus. The authors aim to raise the awareness of these features among both pediatric neurologists and neuropathologists.

Turkish Neonatal Society guideline to the approach, follow-up, and treatment of neonatal jaundice

Jaundice is one of the most common problems in the newborn. It is generally accepted as a physiologic condition; most cases are benign and transient. However, in a small portion of jaundiced newborn infants, serum bilirubin concentrations increase to a level at which irreversible brain damage can occur. The timely diagnosis and management of severe hyperbilirubinemia is essential to prevent acute bilirubin encephalopathy and kernicterus. Kernicterus still occurs although it is almost always preventable. The focus of this guideline is to reduce the incidence of severe hyperbilirubinemia and bilirubin encephalopathy. Therefore, a system-based approach using the recommendations of this guideline should be implemented in all birthing facilities and continued in ambulatory care of the newborn infants.

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.

[Bronze baby syndrome, an unpredictable complication of phototherapy: A case report]

The bronze baby syndrome is an infrequent dyschromia resulting from phototherapy in newborn babies with neonatal jaundice. Even though the common phenotype has been described in patients with direct neonatal hyperbilirubinemia secondary to cholestasis, several cases of patients with indirect neonatal hyperbilirubinemia who have managed to reverse it have been reported, as well as patients with isolated hyperbilirubinemia.Currently, the physiopathology of this condition is still a subject of controversy and, therefore, there is a lack of clear conducts for its correct diagnosis and treatment.Generally, this syndrome has been considered as a mild condition that is resolved with the suspension of phototherapy. Its duration is usually not greater than the neonatal period, and it has no long-term sequelae. However, its occurrence is considered an absolute contraindication for the continuation of phototherapy. In case of persistence, the recommendation is to decrease bilirrubin levels and proceed with exchange transfusion; this procedure, however, represents risks for the newborn, so our recommendation is to suspend phototherapy and reinitiate it if the direct bilirrubin value decreases, andcholestasis compromise has been discarded. Serial evaluations of acute encephalopathy caused by bilirrubin are absolutely recommended.The objective of this paper was to describe the case of a newborn with ABO incompatibility who developed the bronze baby syndrome. This patient responded satisfactorily to the suspension and resumption of phototherapy without exchange transfusion.

Prevalence of Hypoalbuminemia and Elevated Bilirubin/Albumin Ratios in a Large Cohort of Infants in the Neonatal Intensive Care Unit

OBJECTIVE

To provide descriptive data on serum albumin levels and the bilirubin to albumin (B/A) ratio in neonates admitted to the neonatal intensive care unit, assess the effect of gestational and chronological age on serum albumin and the B/A ratio, and evaluate the association between extreme values and mortality.

STUDY DESIGN

Using a retrospective cohort design, we queried the Pediatrix clinical data warehouse for all infants born between 23 and 41 weeks of gestation from 1997 to 2014 who had a report of both a serum albumin and total serum bilirubin (TSB) level on the same day between birth and 14 days of life.

RESULTS

There were 382 190 paired albumin and bilirubin levels across 164 401 neonates (15% of the 1 072 682 infants in the clinical data warehouse). Both gestational age and postnatal age were independent factors that influenced the values for serum albumin, TSB, and B/A ratio (ANOVA; P < .0001). TSB and B/A ratios values above birth weight-specific thresholds for exchange transfusions were uncommon (<6% of infants). Hypoalbuminemia (<2.5 mg/dL) was common (29% of infants). Neonates with serum albumin levels <2.5 g/dL or with B/A ratio levels exceeding exchange thresholds were at higher risk of death compared with infants who did not exceed these levels. This association was independent of other risk factors (estimated gestational age, birth weight, sex, and the presence of a major anomaly).

CONCLUSION

Both gestational age and postnatal age influence TSB, albumin, and B/A ratios; hypoalbuminemia and extreme B/A ratios are associated with an increased risk of death.

Kernicterus in a boy with ornithine transcarbamylase deficiency: A case report

Ornithine transcarbamylase deficiency (OTCD) is an X-linked urea cycle defect associated with severe and usually fatal hyperammonemia. This study describes a patient with early onset lethal OTCD due to a known pathogenic variant (c.298+1G>A), as well as the novel autopsy finding of kernicterus with relatively low blood concentration of unconjugated bilirubin (UCB) (11.55 mg/dL). The patient was a full-term male with a family history of two previous male siblings who died as newborns after acute neurologic deterioration. The patient's symptoms began at 24 h of life with lethargy that rapidly progressed to coma upon admission to the neonatal intensive care unit. Although hyperammonemia and hyperbilirubinemia were documented, hemofiltration could not be performed. OTCD diagnosis was biochemically established. Despite nutritional intervention and treatment for hyperammonemia, the patient died on the sixth day of life. At autopsy, external brain examination revealed a marked yellow pigmentation typical of kernicterus that included gray matter, particularly the thalamus and basal ganglia; dentate nuclei of the cerebellum and brain stem gray matter were also affected. Microscopic findings were consistent with the classical description of tissue damage in OTCD, including the presence of Alzheimer type II astrocytes in basal ganglia, necrosis, neuronal loss with spongiform degeneration and macrophage infiltration surrounded by astroglia. This condition may be an important comorbidity in newborns with hyperammonemia.

Fluid supplementation for neonatal unconjugated hyperbilirubinaemia

BACKGROUND

Neonatal hyperbilirubinaemia is a common problem which carries a risk of neurotoxicity. Certain infants who have hyperbilirubinaemia develop bilirubin encephalopathy and kernicterus which may lead to long-term disability. Phototherapy is currently the mainstay of treatment for neonatal hyperbilirubinaemia. Among the adjunctive measures to compliment the effects of phototherapy, fluid supplementation has been proposed to reduce serum bilirubin levels. The mechanism of action proposed includes direct dilutional effects of intravenous (IV) fluids, or enhancement of peristalsis to reduce enterohepatic circulation by oral fluid supplementation.

OBJECTIVES

To assess the risks and benefits of fluid supplementation compared to standard fluid management in term and preterm newborn infants with unconjugated hyperbilirubinaemia who require phototherapy.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 5), MEDLINE via PubMed (1966 to 7 June 2017), Embase (1980 to 7 June 2017), and CINAHL (1982 to 7 June 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised controlled trials that compared fluid supplementation against no fluid supplementation, or one form of fluid supplementation against another.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group using the Covidence platform. Two review authors independently assessed the eligibility and risk of bias of the retrieved records. We expressed our results using mean difference (MD), risk difference (RD), and risk ratio (RR) with 95% confidence intervals (CIs).

MAIN RESULTS

Out of 1449 articles screened, seven studies were included. Three articles were awaiting classification, among them, two completed trials identified from the trial registry appeared to be unpublished so far.There were two major comparisons: IV fluid supplementation versus no fluid supplementation (six studies) and IV fluid supplementation versus oral fluid supplementation (one study). A total of 494 term, healthy newborn infants with unconjugated hyperbilirubinaemia were evaluated. All studies were at high risk of bias for blinding of care personnel, five studies had unclear risk of bias for blinding of outcome assessors, and most studies had unclear risk of bias in allocation concealment. There was low- to moderate-quality evidence for all major outcomes.In the comparison between IV fluid supplementation and no supplementation, no infant in either group developed bilirubin encephalopathy in the one study that reported this outcome. Serum bilirubin was lower at four hours postintervention for infants who received IV fluid supplementation (MD -34.00 μmol/L (-1.99 mg/dL), 95% CI -52.29 (3.06) to -15.71 (0.92); participants = 67, study = 1) (low quality of evidence, downgraded one level for indirectness and one level for suspected publication bias). Beyond eight hours postintervention, serum bilirubin was similar between the two groups. Duration of phototherapy was significantly shorter for fluid-supplemented infants, but the estimate was affected by heterogeneity which was not clearly explained (MD -10.70 hours, 95% CI -15.55 to -5.85; participants = 218; studies = 3; I² = 67%). Fluid-supplemented infants were less likely to require exchange transfusion (RR 0.39, 95% CI 0.21 to 0.71; RD -0.01, 95% CI -0.04 to 0.02; participants = 462; studies = 6; I² = 72%) (low quality of evidence, downgraded one level due to inconsistency, and another level due to suspected publication bias), and the estimate was similarly affected by unexplained heterogeneity. The frequencies of breastfeeding were similar between the fluid-supplemented and non-supplemented infants in days one to three based on one study (estimate on day three: MD 0.90 feeds, 95% CI -0.40 to 2.20; participants = 60) (moderate quality of evidence, downgraded one level for imprecision).One study contributed to all outcome data in the comparison of IV versus oral fluid supplementation. In this comparison, no infant in either group developed abnormal neurological signs. Serum bilirubin, as well as the rate of change of serum bilirubin, were similar between the two groups at four hours after phototherapy (serum bilirubin: MD 11.00 μmol/L (0.64 mg/dL), 95% CI -21.58 (-1.26) to 43.58 (2.55); rate of change of serum bilirubin: MD 0.80 μmol/L/hour (0.05 mg/dL/hour), 95% CI -2.55 (-0.15) to 4.15 (0.24); participants = 54 in both outcomes) (moderate quality of evidence for both outcomes, downgraded one level for indirectness). The number of infants who required exchange transfusion was similar between the two groups (RR 1.60, 95% CI 0.60 to 4.27; RD 0.11, 95% CI -0.12 to 0.34; participants = 54). No infant in either group developed adverse effects including vomiting or abdominal distension.

AUTHORS' CONCLUSIONS

There is no evidence that IV fluid supplementation affects important clinical outcomes such as bilirubin encephalopathy, kernicterus, or cerebral palsy in healthy, term newborn infants with unconjugated hyperbilirubinaemia requiring phototherapy. In this review, no infant developed these bilirubin-associated clinical complications. Low- to moderate-quality evidence shows that there are differences in total serum bilirubin levels between fluid-supplemented and control groups at some time points but not at others, the clinical significance of which is uncertain. There is no evidence of a difference between the effectiveness of IV and oral fluid supplementations in reducing serum bilirubin. Similarly, no infant developed adverse events or complications from fluid supplementation such as vomiting or abdominal distension. This suggests a need for future research to focus on different population groups with possibly higher baseline risks of bilirubin-related neurological complications, such as preterm or low birthweight infants, infants with haemolytic hyperbilirubinaemia, as well as infants with dehydration for comparison of different fluid supplementation regimen.

The use of therapeutic plasma exchange to reduce serum bilirubin in a dog with kernicterus

OBJECTIVE

To describe the use of a manual method of therapeutic plasma exchange to reduce total serum bilirubin, manage kernicterus, and halt progression of neurological dysfunction in a dog with immune-mediated hemolytic anemia (IMHA).

CASE SUMMARY

A 5-year-old male neutered Lhasa Apso diagnosed with IMHA developed acute onset neurologic signs consistent with kernicterus. Manual therapeutic plasma exchange was performed in an attempt to reduce total serum bilirubin. The initial exchange was performed at a lower plasma exchange volume due to the dog's critical status and the dog's clinical signs progressed. More aggressive plasma exchange was performed that resulted in a reduction in total serum bilirubin and no further progression of neurologic signs. The dog was euthanized due to suspicion of permanent neurologic changes and need for further blood transfusions. Histopathology postmortem confirmed a diagnosis of kernicterus.

NEW OR UNIQUE INFORMATION PROVIDED

Kernicterus secondary to hyperbilirubinemia is well described in people, but has rarely been reported in dogs. Therapeutic plasma exchange has been used for decades in people to rapidly decrease serum bilirubin when hyperbilirubinemia progresses to neurologic signs, but to the authors' knowledge this has not been described in a dog.

Prediction of 3- to 5-Month Outcomes from Signs of Acute Bilirubin Toxicity in Newborn Infants

OBJECTIVE

To evaluate the ability of the bilirubin-induced neurologic dysfunction (BIND) score to predict residual neurologic and auditory disability and to document the relationship of BIND score to total serum bilirubin (TSB) concentration.

STUDY DESIGN

The BIND score (assessing mental status, muscle tone, and cry patterns) was obtained serially at 6- to 8-hour intervals in 220 near-term and full-term infants with severe hyperbilirubinemia. Neurologic and/or auditory outcomes at 3-5 months of age were correlated with the highest calculated BIND score. The BIND score was also correlated with TSB.

RESULTS

Follow-up neurologic and auditory examinations were performed for 145/202 (72%) surviving infants. All infants with severe acute bilirubin encephalopathy (BIND scores 7-9) either died or suffered residual neurologic and auditory impairment. Of 24 cases with moderate encephalopathy (BIND 4-6), 15 (62.5%) resolved following aggressive intervention and were normal at follow-up. Three of 73 infants with mild encephalopathy (BIND scores 1-3) but severe jaundice (TSB ranging 33.5-38 mg/dL; 573-650 µmol/L) had residual neurologic and/or auditory impairment. A BIND score ≥4 had a specificity of 87.3% and a sensitivity of 97.4% for predicting poor neurologic outcomes (receiver operating characteristic analysis). BIND scores trended higher with severe hyperbilirubinemia (r² = 0.54, P < .005), but 5/39 (13%) infants with TSB ≥36.5 mg/dL (624 µmol/L) had BIND scores ≤3, and normal outcomes at 3-5 months.

CONCLUSIONS

The BIND score can be used to evaluate the severity of acute bilirubin encephalopathy and predict residual neurologic and hearing dysfunction.

Intestinal NCoR1, a regulator of epithelial cell maturation, controls neonatal hyperbilirubinemia

Severe neonatal hyperbilirubinemia (SNH) and the onset of bilirubin encephalopathy and kernicterus result in part from delayed expression of UDP-glucuronosyltransferase 1A1 (UGT1A1) and the inability to metabolize bilirubin. Although there is a good understanding of the early events after birth that lead to the rapid increase in serum bilirubin, the events that control delayed expression of UGT1A1 during development remain a mystery. Humanized UGT1 (hUGT1) mice develop SNH spontaneously, which is linked to repression of both liver and intestinal UGT1A1. In this study, we report that deletion of intestinal nuclear receptor corepressor 1 (NCoR1) completely diminishes hyperbilirubinemia in hUGT1 neonates because of intestinal UGT1A1 gene derepression. Transcriptomic studies and immunohistochemistry analysis demonstrate that NCoR1 plays a major role in repressing developmental maturation of the intestines. Derepression is marked by accelerated metabolic and oxidative phosphorylation, drug metabolism, fatty acid metabolism, and intestinal maturation, events that are controlled predominantly by H3K27 acetylation. The control of NCoR1 function and derepression is linked to IKKβ function, as validated in hUGT1 mice with targeted deletion of intestinal IKKβ. Physiological events during neonatal development that target activation of an IKKβ/NCoR1 loop in intestinal epithelial cells lead to derepression of genes involved in intestinal maturation and bilirubin detoxification. These findings provide a mechanism of NCoR1 in intestinal homeostasis during development and provide a key link to those events that control developmental repression of UGT1A1 and hyperbilirubinemia.

Maternal Empowerment - An Underutilized Strategy to Prevent Kernicterus?

BACKGROUND

Kernicterus is a common cause of death and morbidity in many Low- Middle-income Countries (LMICs) and still occurs in affluent nations. In either case, the immediate cause is delayed treatment of severe hyperbilirubinemia. In the West, a provider driven "systems approach" has been widely adopted to identify babies at risk prior to discharge from birthing centers with follow up monitoring based on the serum bilirubin level at time of discharge. The situation is more complicated in regions of the world where kernicterus is endemic, especially in LMICs where Glucose-6-phosphate Dehydrogenase Deficiency (G6PDd) is common and the system of jaundice management is often fragmented.

OBJECTIVE

To examine reasons for errors in jaundice management leading to kernicterus and the potential beneficial role of enlisting more parental participation in management decisions.

METHOD

We searched world literature related to pitfalls in jaundice management including deficiencies in providers' and parents' knowledge and behavior. Perspectives from mothers of children with kernicterus supplemented the literature review.

RESULT

System failures contributing to kernicterus in affluent countries include a lack of follow up planning, bad advice by providers, and a delay in care seeking by parents. In many LMICs, the majority of births occur at home with unskilled attendants. Traditional practices potentiate hemolysis in G6PDd babies. The danger of severe jaundice is frequently underestimated both by parents and care providers, and cultural and economic barriers as well as ineffective therapies delay care seeking. The failure to provide parents information about identifying severe jaundice and knowledge about the risks and treatment of hyperbilirubinemia has contributed to delayed treatment in both affluent and low-middle-income countries. A recent non-randomized clinical trial, supports teaching all parents skills to monitor jaundice, signs of early neurotoxicity, the importance of breast feeding, avoidance of ineffective or dangerous practices, and when/where to seek help.

CONCLUSION

Empowering parents allow them to participate more fully in care decisions and to confront obstacles to care when provider services fail.

Update on Predicting Severe Hyperbilirubinemia and Bilirubin Neurotoxicity Risks in Neonates

Extreme hyperbilirubinemia and kernicterus, though rare, continue to occur despite the adoption of universal screening. Unless they are known to have glucose-6-phosphate dehydrogenase deficiency, infants who currently develop kernicterus in high resource countries are often otherwise healthy newborns discharged from the well-baby nursery. In this review, we highlight risk factors that increase the risk of a newborn ≥35 weeks gestational age developing severe hyperbilirubinemia, as well as the risk factors that increase the hyperbilirubinemic infant's risk of kernicterus.

Monitoring the Response of Hyperbilirubinemia in the Mouse Brain by In Vivo Bioluminescence Imaging

Increased levels of unconjugated bilirubin are neurotoxic, but the mechanism leading to neurological damage has not been completely elucidated. Innovative strategies of investigation are needed to more precisely define this pathological process. By longitudinal in vivo bioluminescence imaging, we noninvasively visualized the brain response to hyperbilirubinemia in the MITO-Luc mouse, in which light emission is restricted to the regions of active cell proliferation. We assessed that acute hyperbilirubinemia promotes bioluminescence in the brain region, indicating an increment in the cell proliferation rate. Immunohistochemical detection in brain sections of cells positive for both luciferase and the microglial marker allograft inflammatory factor 1 suggests proliferation of microglial cells. In addition, we demonstrated that brain induction of bioluminescence was altered by pharmacological displacement of bilirubin from its albumin binding sites and by modulation of the blood-brain barrier permeability, all pivotal factors in the development of bilirubin-induced neurologic dysfunction. We also determined that treatment with minocycline, an antibiotic with anti-inflammatory and neuroprotective properties, or administration of bevacizumab, an anti-vascular endothelial growth factor antibody, blunts bilirubin-induced bioluminescence. Overall the study supports the use of the MITO-Luc mouse as a valuable tool for the rapid response monitoring of drugs aiming at preventing acute bilirubin-induced neurological dysfunction.

Bilirubin-Induced Neurological Dysfunction: A Clinico-Radiological-Neurophysiological Correlation in 30 Consecutive Children

The clinical expression of bilirubin-induced neurological dysfunction varies according to severity and location of the disease. Definitions have been proposed to describe different bilirubin-induced neurological dysfunction subtypes. Our objective was to describe the severity and clinico-radiological-neurophysiological correlation in 30 consecutive children with bilirubin-induced neurological dysfunction seen over a period of 5 years. Thirty children exposed to acute neonatal bilirubin encephalopathy were included in the study. The mean peak total serum bilirubin level was 625 μmol/L (range 480-900 μmol/L). Acoustic brainstem responses were abnormal in 73% (n = 22). Pallidal hyperintensity was observed on magnetic resonance imaging in 20 children. Peak total serum bilirubin levels correlated with motor severity (P = .03). Children with severe motor impairment were likely to manifest severe auditory neuropathy (P < .01). We found that in a resource-constrained setting, classical kernicterus was the most common bilirubin-induced neurological dysfunction subtype, and the majority of children had abnormal acoustic brainstem responses and magnetic resonance imaging.

A Hypothesis for Using Pathway Genetic Load Analysis for Understanding Complex Outcomes in Bilirubin Encephalopathy

Genetic-based susceptibility to bilirubin neurotoxicity and chronic bilirubin encephalopathy (kernicterus) is still poorly understood. Neonatal jaundice affects 60–80% of newborns, and considerable effort goes into preventing this relatively benign condition from escalating into the development of kernicterus making the incidence of this potentially devastating condition very rare in more developed countries. The current understanding of the genetic background of kernicterus is largely comprised of mutations related to alterations of bilirubin production, elimination, or both. Less is known about mutations that may predispose or protect against CNS bilirubin neurotoxicity. The lack of a monogenetic source for this risk of bilirubin neurotoxicity suggests that disease progression is dependent upon an overall decrease in the functionality of one or more essential genetically controlled metabolic pathways. In other words, a “load” is placed on key pathways in the form of multiple genetic variants that combine to create a vulnerable phenotype. The idea of epistatic interactions creating a pathway genetic load (PGL) that affects the response to a specific insult has been previously reported as a PGL score. We hypothesize that the PGL score can be used to investigate whether increased susceptibility to bilirubin-induced CNS damage in neonates is due to a mutational load being placed on key genetic pathways important to the central nervous system's response to bilirubin neurotoxicity. We propose a modification of the PGL score method that replaces the use of a canonical pathway with custom gene lists organized into three tiers with descending levels of evidence combined with the utilization of single nucleotide polymorphism (SNP) causality prediction methods. The PGL score has the potential to explain the genetic background of complex bilirubin induced neurological disorders (BIND) such as kernicterus and could be the key to understanding ranges of outcome severity in complex diseases. We anticipate that this method could be useful for improving the care of jaundiced newborns through its use as an at-risk screen. Importantly, this method would also be useful in uncovering basic knowledge about this and other polygenetic diseases whose genetic source is difficult to discern through traditional means such as a genome-wide association study.

Magnetic Resonance Imaging Abnormalities in Advanced Acute Bilirubin Encephalopathy Highlight Dentato-Thalamo-Cortical Pathways

A distinct pattern of acute restricted diffusion on magnetic resonance imaging localized to key regions within the dentato-thalamo-cortical pathway was observed early in a term newborn during advanced stages of acute bilirubin encephalopathy. These findings demonstrate that vulnerability to bilirubin toxicity extends across specific neuroanatomic tracts.

Infants at risk of significant hyperbilirubinemia in poorly-resourced countries: evidence from a scoping review

BACKGROUND

Neonatal hyperbilirubinemia is frequently associated with disproportionately high rates of bilirubin-induced mortality and long-term morbidities in low- and middle-income countries (LMICs). This scoping review aimed to identify possible etiological/risk factors for clinically significant hyperbilirubinemia in LMICs so as to guide intervention and future research priorities.

DATA SOURCES

We systematically searched PubMed, Scopus, Excerpt Medica Database, Cumulative Index to Nursing and Allied Health Literature, WHO Library Database, African Index Medicus, African Journals Online, Latin American and Caribbean Health Sciences Literature, and Indian Medical Journals for reports published between January 1990 and August 2014 in LMICs with per capita income of ≤ US$ 6000. We included studies on the etiology of neonatal hyperbilirubinemia or hyperbilirubinemia as significant morbidity for relevant maternal, perinatal and neonatal disorders without restriction on study design.

RESULTS

A total of 131 studies were identified in 23 LMICs from different regions of the world. The factors most frequently associated with neonatal hyperbilirubinemia (in approximately 10% of all studies) were ABO and Rhesus incompatibilities, diabetes mellitus, glucose-6-phosphate dehydrogenase deficiency, prematurity/low birth weight, infection, birth trauma, and drug-induced labor. The role of exclusive breast-feeding and genetic factors was sparsely explored.

CONCLUSIONS

Several maternal, perinatal and neonatal factors are associated with neonatal hyperbilirubinemia in LMICs. Improved research efforts and strategies to address these factors are warranted to curtail the disease burden in these countries.

The Blockade of NF-κB Activation by a Specific Inhibitory Peptide Has a Strong Neuroprotective Role in a Sprague-Dawley Rat Kernicterus Model

Kernicterus, the permanent nerve damage occurring as a result of bilirubin precipitation, still occurs worldwide and may lead to death or permanent neurological impairments. However, the underlying mechanisms remain unclear, and effective therapeutic strategies are lacking. The present study aims to investigate the activation of NF-κB and to identify the effect of NF-κB inhibition on the newborn rat kernicterus model. The NF-κB essential modifier-binding domain peptide (NBD), coupled with the HIV trans-activator of transcription peptide (TAT) was used to inhibit NF-κB. NF-κB was significantly activated in the cerebrum at 1 and 3 h (p < 0.05) after the model was established, as measured by EMSA. NF-κB activation was inhibited by intraperitoneal administration of TAT-NBD. The general conditions of the TAT-NBD-treated rats were improved; meanwhile, these rats performed much better on the neurological evaluation, the rotarod test, and the Morris water maze test (p < 0.05) than the vehicle-treated rats at 28 days. Furthermore, the morphology of the nerve cells was better preserved in the TAT-NBD group, and these cells displayed less neurodegeneration and astrocytosis. Simultaneously, apoptosis in the brain was attenuated, and the levels of the TNF-α and IL-1β proteins were decreased (p < 0.01). These results suggested that NF-κB was activated, and inhibition of NF-κB activation by TAT-NBD not only attenuated the acute neurotoxicity, apoptosis, and inflammation, but also improved the long term neurobehavioral impairments in the kernicterus model rats in vivo. Thus, inhibiting NF-κB activation might be a potential therapeutic approach for kernicterus.

Bilirubin Encephalopathy in a Domestic Shorthair Cat With Increased Osmotic Fragility and Cholangiohepatitis

A 7-month-old female domestic shorthair cat was diagnosed with chronic regenerative hemolytic anemia characterized by increased osmotic fragility of unknown etiology. At 13 months of age, the cat was evaluated for acute collapse. The cat was icteric with severe hyperbilirubinemia but no hematocrit changes. Severe obtundation and lateral recumbency progressed to tetraparesis and loss of proprioception in all 4 limbs, and a cerebellar or brainstem lesion was suspected. Postmortem examination revealed suppurative cholangiohepatitis and acute neuronal necrosis in the nuclei of the brainstem and cerebellum, consistent with bilirubin encephalopathy. This is the first known occurrence of cholangiohepatitis and bilirubin encephalopathy in an adult cat with chronic hemolytic anemia. Although rare, bilirubin encephalopathy should be considered a possible sequela to hyperbilirubinemia in adult patients. It remains unknown whether increased osmotic fragility was related to the cholangiohepatopathy.

Current incidence of clinical kernicterus in preterm infants in Japan

Clinical kernicterus in preterm infants has recently been reported in Japan, diagnosed on the basis of clinical findings during the neonatal and infancy periods. We investigated the incidence of clinical kernicterus in preterm infants <30 weeks gestational age (GA) based on a nationwide survey conducted in 233 certified educational facilities for neonatologists. The numbers of infants admitted and infants who died within 14 days after birth during 2011, and the number of infants who subsequently developed clinical kernicterus, were recorded. A total of 2720 infants were analyzed, representing 59% (2720/4623) of all preterm live births <30 weeks GA in Japan in 2011. Of these, 159 (5.8%) died within 14 days after birth, similar to the national rate. Five infants developed clinical kernicterus in infancy (5/2720, 0.18%). The current incidence of clinical kernicterus in Japan is therefore estimated at 1.8 per 1000 live births <30 weeks GA.

Serum bilirubin and bilirubin/albumin ratio as predictors of bilirubin encephalopathy

BACKGROUND AND OBJECTIVE

Bilirubin/albumin ratio (B/A) may provide a better estimate of free bilirubin than total serum bilirubin (TSB), thus improving identification of newborns at risk for bilirubin encephalopathy. The objective of the study was to identify thresholds and compare specificities of TSB and B/A in detecting patients with acute and posttreatment auditory and neurologic impairment.

METHODS

A total of 193 term/near-term infants, admitted for severe jaundice to Cairo University Children's Hospital, were evaluated for neurologic status and auditory impairment (automated auditory brainstem response), both at admission and posttreatment by investigators blinded to laboratory results. The relationships of TSB and B/A to advancing stages of neurotoxicity were compared by using receiver operating characteristic curves.

RESULTS

TSB and B/A ranged from 17 to 61 mg/dL and 5.4 to 21.0 mg/g, respectively; 58 (30%) of 193 subjects developed acute bilirubin encephalopathy, leading to kernicterus in 35 infants (13 lethal). Auditory impairment was identified in 86 (49%) of 173 infants at admission and in 22 of 128 at follow-up. In the absence of clinical risk factors, no residual neurologic or hearing impairment occurred unless TSB exceeded 31 mg/dl. However, transient auditory impairment occurred at lower TSB and B/A (22.9 mg/dL and 5.7 mg/g, respectively). Intervention values of TSB and B/A set at high sensitivity to detect different stages of neurotoxicity had nearly the same specificity.

CONCLUSIONS

Both TSB and B/A are strong predictors of neurotoxicity, but B/A does not improve prediction over TSB alone. Threshold values detecting all affected patients (100% sensitivity) increase with advancing severity of neurotoxicity.

Apnea in acute bilirubin encephalopathy

Central apnea, defined as cessation of breathing for ≥20s, is frequent in premature infants born at <34 weeks׳ gestation but uncommon among healthy late preterm (34(0/7)-36(6/7) weeks׳ gestation) and term (≥37 weeks׳ gestation) infants, where it is usually a clinical manifestation of a neurological or metabolic problem. There is growing evidence that marked unconjugated hyperbilirubinemia is associated with central apnea in neonates. This article explores the reported association between acute bilirubin encephalopathy and symptomatic apneic events in newborns and the possible mechanisms involved in the pathogenesis of this phenomenon. The prevalence of symptomatic apneic events in reports of acute bilirubin encephalopathy suggests this clinical finding should be considered a sign of bilirubin neurotoxicity.

Incidence, etiology, and outcomes of hazardous hyperbilirubinemia in newborns

BACKGROUND AND OBJECTIVES

Total serum bilirubin (TSB) levels ≥ 30 mg/dL are rare but potentially hazardous. A better understanding of their incidence, causes, and outcomes could help inform preventive efforts.

METHODS

We identified infants born ≥ 35 weeks' gestational age from 1995-2011 in Kaiser Permanente Northern California (n = 525409) and examined the medical records of infants with a TSB ≥ 30 mg/dL to determine etiology and the occurrence of acute bilirubin encephalopathy. We reviewed inpatient and outpatient encounters through 2013 for evidence of sensorineural hearing loss (SNHL) or cerebral palsy (CP).

RESULTS

We identified 47 infants with TSB ≥ 30 mg/dL (8.6 per 100000 births). In 44 infants (94%), the hyperbilirubinemia occurred after the initial birth hospitalization. The etiology was not identified in 33 (70%). Glucose-6-phosphate dehydrogenase (G6PD) activity was measured in only 25 (53%) of whom 10 (40%) were deficient. Four children had acute bilirubin encephalopathy of whom 2 developed both CP and SNHL, and 1 developed isolated SNHL. These 3 infants all had G6PD deficiency and TSB >40 mg/dL. One additional 35-week infant with TSB 38.2 mg/dL had SNHL.

CONCLUSIONS

Hazardous (≥ 30 mg/dL) hyperbilirubinemia is a rare event. No etiology could be identified from the clinical record in most cases. G6PD deficiency was the leading cause of hazardous hyperbilirubinemia when an etiology was identified, but many were not tested. Chronic, bilirubin-induced neurotoxicity was uncommon and occurred only in the setting of additional risk factors and TSB values well over (>15 mg/dL) the American Academy of Pediatrics exchange transfusion thresholds.

Extreme neonatal hyperbilirubinemia and a specific genotype: a population-based case-control study

OBJECTIVES

Extreme hyperbilirubinemia (plasma bilirubin ≥ 24.5 mg/dL) is an important risk factor for severe bilirubin encephalopathy. Several risk factors for hyperbilirubinemia are known, but in a large number of patients, a causal factor is never established. UGT1A1 is the rate-limiting enzyme in bilirubin's metabolism. The genotype of Gilbert syndrome, the UGT1A1*28 allele, causes markedly reduced activity of this enzyme, but its association with neonatal hyperbilirubinemia is uncertain and its relationship with extreme hyperbilirubinemia has not been studied. We examined whether the UGT1A1*28 allele is associated with extreme hyperbilirubinemia.

METHODS

The UGT1A1*28 allele was assessed in a case-control study of 231 white infants who had extreme hyperbilirubinemia in Denmark from 2000 to 2007 and 432 white controls. Cases were identified in the Danish Extreme Hyperbilirubinemia Database that covers the entire population. Genotypes were obtained through the Danish Neonatal Screening Biobank. Subgroup analysis was done for AB0 incompatible cases.

RESULTS

No association was found between the UGT1A1*28 allele and extreme hyperbilirubinemia. With the common genotype as reference, the odds ratio of extreme hyperbilirubinemia was 0.87 (range, 0.68-1.13) for UGT1A1*28 heterozygotes and 0.77 (range, 0.46-1.27) for homozygotes. Also, no association was found for AB0 incompatible cases.

CONCLUSIONS

The UGT1A1*28 allele was not associated with risk for extreme hyperbilirubinemia in this study.

New autopsy findings in different brain regions of a preterm neonate with kernicterus: neurovascular alterations and up-regulation of efflux transporters

BACKGROUND

Kernicterus is an irreversible brain damage caused by bilirubin deposition in selective brain regions. Sick and preterm infants with hyperbilirubinemia are particularly susceptible to the condition.

METHODS

We studied autopsied brain tissue from a premature female infant with kernicterus with a bilirubin:albumin molar ratio of 1.0, hypoxia, acidosis, and seizures. The patient, previously described as having cerebellar axon/myelin loss and angiogenic sprouting, was assessed for histopathological features in brain regions less investigated, such as hippocampus and corpus striatum. Results were compared with age-matched controls.

RESULTS

Increased blood vessel density with poorly defined lumen structures was observed in the mesencephalon, pons, and medulla oblongata, and, more predominantly, in the corpus striatum and hippocampus. These two regions exhibited increased expression of vascular endothelial growth factor, paralleled by vascular endothelial growth factor receptor-2, and albumin extravasation into the brain parenchyma. No similar findings were observed in the nonjaundiced babies with hypoxia that served as controls (one preterm with sepsis and a term infant with pneumonia). We found increased cellular expression of multidrug resistance-associated protein 1 and P-glycoprotein in the hippocampus, known as defensive mechanisms against bilirubin-induced cytotoxicity. Increased density of blood vessels and microvascular permeability, together with parenchymal albumin, may have contributed to increasing the brain content and retention of bilirubin, a condition implicated in kernicterus disease.

CONCLUSIONS

This novel finding in a premature baby with kernicterus and associated risk factors deserves to be investigated in similar patients to better understand the less-well described effects of bilirubin-induced neurological sequelae in preterm infants.