Interpreting conjugated bilirubin levels in newborns

The effects of gestational age on neonatal cholestasis: A retrospective cohort study

BACKGROUND

Reference guidelines for neonatal conjugated hyperbilirubinemia (cholestasis) management use a uniform approach regardless of gestational age (GA). We hypothesize that the clinical pattern of neonatal cholestasis is tightly related to GA. The aim of this study was to describe the effects of GA on neonatal cholestasis.

METHODS

A retrospective 4-year cohort study in a 70-bed neonatal care unit. Neonates with conjugated bilirubin≥34.2μmol/L (2 mg/dL) were identified. The incidence, clinical characteristics, etiology, treatment, and prognosis were compared between infants <32 and≥32 weeks GA.

RESULTS

Overall incidence of cholestasis was 4% (125/3402). It was >5 times higher and the mean duration was >1.5 times longer in neonates <32 weeks GA (10% versus 1.8%, p <0.01 and 49 versus 31 days, p <0.01, respectively). The onset of cholestasis was later in neonates <32 weeks (22 versus 10 days of life, p <0.001). This later onset of cholestasis was associated with parenteral nutrition, whereas the earlier onset was associated with other causes. Treatment using fish oil lipids was more frequently administrated to infants <32 weeks GA, whereas Ursodeoxycholic acid was administrated more frequently in≥32 weeks GA. Cholestasis resolved during hospitalization in 73% of <32 versus 38% in≥32 weeks GA infants (p <0.01).

CONCLUSIONS

The incidence, clinical presentation, etiology, treatment, and clinical evolution of neonatal cholestasis were all significantly affected by GA. Our results support the use of a GA-oriented approach for the management of neonatal cholestasis.

Dysmorphic Gallbladder Found on Prenatal Ultrasound as a Hint for Biliary Atresia

Biliary atresia (BA) is a rare but devastating cholangiopathy. We report a case series of dysmorphic gallbladders detected during prenatal ultrasound, which were confirmed as BA after birth. We present the prenatal ultrasound findings as well as integral follow-up, with an aim to raise awareness regarding the association between BA and dysmorphic gallbladder. Although this dysmorphic gallbladder is a strong hint for BA, it is also important to search for other related sonographic features, such as the presence of microcysts at the hepatic hilum, dilated right hepatic artery, and seroperitoneum, which may provide more evidence for the diagnosis of BA.

A simplified HPLC-based method for measuring unconjugated bilirubin, bilirubin-monoglucuronide, bilirubin-diglucuronide, and delta-bilirubin in plasma with increased conjugated bilirubin

Prolonged icterus is an important and common problem in neonatology and accurate determination of the different bilirubin species, including differentiation between delta-bilirubin and mono- and di-conjugated bilirubin, is useful for diagnostic purposes. However, most bilirubin measurements routinely performed in the clinical laboratory are hampered by the lack of separation of the four bilirubin fractions (unconjugated bilirubin, mono-conjugated bilirubin, di-conjugated bilirubin, and delta-bilirubin). Herein, we propose a high-performance liquid chromatography-based method, independent of commercially available standards or reliable molar absorption coefficients, for the determination of bilirubin fractions in blood samples from icteric patients. The method is a robust and reliable candidate for a semi-automatized setup for measuring the various bilirubin fractions in a specialized laboratory handling samples from clinics with expertise in biliary disease.

Fractionated Bilirubin Among 252,892 Utah Newborns With and Without Biliary Atresia: A 15-year Historical Birth Cohort Study

OBJECTIVES

To determine whether neonatal conjugated or direct bilirubin levels were elevated in infants with biliary atresia, and to estimate the number of newborns that would have positive screens in the nursery necessitating repeat testing following discharge.

STUDY DESIGN

We used administrative data from a large integrated healthcare network in Utah to identify newborns who had a fractionated bilirubin recorded during birth admission from 2005 through 2019. Elevated conjugated bilirubin was defined as greater than 0.2 mg/dL and direct bilirubin was defined as greater than 0.5 mg/dL (>97.5^th percentile for the assays). We performed simulations to estimate the anticipated number of false positive screens.

RESULTS

There were 32 cases of biliary atresia and 468,161 live births during the study period (1/14,700). 252,892 newborns had fractionated bilirubin assessed including 26 of those subsequently confirmed to have biliary atresia. Conjugated or direct bilirubin was elevated in all 26 infants with biliary atresia and an additional 3,246 (1.3%) newborns without biliary atresia. Simulated data suggest nine to 21 per 1,000 screened newborns will have an elevated conjugated or direct bilirubin using laboratory-based thresholds for a positive screen. Screening characteristics improved with higher thresholds without increasing false negative tests.

CONCLUSIONS

This study validates the previous findings that conjugated or direct bilirubin are elevated in the newborn period in patients with biliary atresia. A higher threshold for conjugated bilirubin improved screening performance. Future studies are warranted to determine the optimal screening test for biliary atresia and to assess the effectiveness and cost-effectiveness of implementing such a program.

Management of severe hyperbilirubinemia in the cholestatic neonate: a review and an approach

A review of the literature demonstrates that severe total hyperbilirubinemia (total serum bilirubin ≥ 20 mg/dL [340 µmol/L]) in some cholestatic term (≥37 weeks) and late-preterm (≥34^0/7-36^6/7 weeks) gestation neonates poses a risk for bilirubin-induced brain damage. When the direct bilirubin fraction is <50% of the total serum bilirubin this risk is associated with the total serum bilirubin alone and treatment decisions should be based on the total serum bilirubin. On the other hand, there are limited data on the risk of bilirubin-induced brain damage in the neonate with severe total hyperbilirubinemia and a direct bilirubin fraction that is equal to or exceeds 50% of the total serum bilirubin. When this rare combination occurs, efforts to keep the indirect bilirubin fraction from reaching severe levels might, nevertheless, be prudent.

Ventilation and respiratory outcome in extremely preterm infants: trends in the new millennium

Ventilation and respiratory care have substantially changed over the last decades in extremely premature neonates but the impact on respiratory health remains largely unclear. To determine changes in respiratory care and disease frequency in extremely premature infants, a retrospective single-centre cohort study of extremely preterm infants was performed. All infants born alive between 24 + 0 and 27 + 6 weeks of gestation in 2000-2001 (Epoch 1), 2009-2010 (Epoch 2), and 2018-2019 (Epoch 3) were included. The primary outcome of this study was the incidence of bronchopulmonary dysplasia (BPD, diagnosed according to three different criteria) or death. Secondary outcomes included the usage of different ventilation modes, changes in pharmacotherapy, and the incidence of significant extra-pulmonary morbidities. A total of 184 neonates were included of whom 151 survived until 36 weeks of corrected GA (cGA). Oxygen or positive pressure dependence increased over time (26.1%, 41.7%, and 56.1% respectively), with higher adjusted odds in Epoch 3 for the composite outcome "BPD or death" (adjusted odds ratio: 2.55 [95%CI 1.19-5.61]). Severity-based definitions showed increasing trends in survivors only. Time spent on invasive mechanical ventilation was similar throughout the years, but the use of non-invasive ventilation significantly increased in Epoch 3 (32.0 [95%CI 25.0-37.0] vs 27.0 [95%CI 26.0-32.0] vs 53.0 [95%CI 46.0-58.0] days). Moreover, mortality-adjusted rates of severe IVH, NEC, or intestinal perforation and multiple sepsis tended to decrease.   Conclusion: In spite of significant clinical advancements and adherence to novel treatment guidelines in our neonatal intensive care unit, the incidence of BPD increased over time. What is Known: • Rates of BPD are stable or increase in population-based studies. • Extremely preterm infants are particularly susceptible to developing BPD. What is New: • Despite increased use of evidence-based corticosteroid administration and early initiation of caffeine, the incidence of BPD has not decreased over the past decade.  • Increased usage of non-invasive ventilation is associated with an increase of BPD incidence.

Etiology and outcome of neonatal cholestasis: an experience in a tertiary center of Bangladesh

Background

Neonatal cholestasis (NC) is a major cause of morbidity and mortality in young infants. This study examines the etiology of NC and its outcome during 2 years of follow-up at a tertiary referral center in Bangladesh.

Results

Out of 80 cholestatic infants, 60% had intrahepatic cholestasis with a mean age of onset of 12.4±2.8 days and a mean age of admission of 82.4±29.0 days. The remaining 40% were extrahepatic with a mean age of onset of 6.7±2.3 days and a mean age of admission of 94.6±50.4 days. Biliary atresia (BA), idiopathic neonatal hepatitis (INH), and TORCH (Toxoplasma, rubella, cytomegalovirus, and herpes simplex) infection except rubella were the most common causes. After receiving treatment, 46.2% of the cases improved, 23.8% deteriorated with morbidity, and 30% died. The majority of the children with INH, TORCH, choledochal cyst, hypothyroidism, galactosemia, and urinary tract infection (UTI) with sepsis were improved. Significant mortality was found in BA (56.6%), intrahepatic bile duct paucity (PIBD) (100%), and progressive familial intrahepatic cholestasis (PFIC) (100%) whereas the rest of BA (43.4%) live with persistent morbidity. Significant clinical improvement was observed in 37 (46.2%) cases of cholestasis evidenced by decreasing jaundice, change of color of urine from dark to normal color, change of stool color from pale to yellow, and gradual decrease in liver size from hepatomegaly state. In addition, decreasing median total bilirubin, direct bilirubin, alanine transaminase, gamma-glutamyl transferase, and alkaline phosphatase showed biochemical improvement at 2 years follow-up. The age of admission, etiology, and presence of ascites are the predictors of outcomes.

Conclusion

BA was the most common cause of extrahepatic while INH and TORCH infection were the most common cause of intrahepatic cholestasis. Majority of children with intrahepatic cholestasis improved but deteriorated with BA and genetic causes. Prompt referral and early diagnosis as well as the etiology of NC were the main determinants of the favorable outcome.

Newborn Screening for Biliary Atresia: a Review of Current Methods

PURPOSE OF REVIEW

Biliary atresia is a serious neonatal liver disease due to obstructed bile ducts that has better outcomes when detected and treated in the first 30-45 days of life. This review examines different methods to screen newborns for biliary atresia as well as discusses observations from ongoing screening programs implemented in parts of the United States.

RECENT FINDINGS

Screening strategies for biliary atresia include detecting persistent jaundice, examining stool color, testing fractionated bilirubin levels, or measuring bile acid levels from dried blood spot cards. The stool color card program is the most widely used screening strategy worldwide. An alternative approach under investigation in the United States measures fractionated bilirubin levels, which are abnormal in newborns with biliary atresia. Fractionated bilirubin screening programs require laboratories to derive reference ranges, nurseries to implement universal testing, and healthcare systems to develop infrastructure that identifies and acts upon abnormal results. Biliary atresia meets the disease-specific criteria for newborn screening. Current studies focus on developing a strategy which also meets all test-specific criteria. Such a strategy, if implemented uniformly, has the potential to accelerate treatment and reduce biliary atresia's large liver transplant burden.

Congenital Adrenal Hyperplasia: Diagnostic Pitfalls in Prolonged Neonatal Jaundice

Congenital Adrenal Hyperplasia (CAH) is a genetic disorder that leads to cortisol deficiency. However, prolonged neonatal jaundice is a rare presentation of CAH. The pathophysiology of hyperbilirubinemia in CAH is still ill-defined. Plausible causes are related to the synthesis of bile, maturity of the liver and adrenal function. This case reported a neonate who presented with severe prolonged jaundice that lasted for more than a month. A short Synacthen test confirmed diagnosis of CAH. He was started on steroid replacement. He had regular follow-up under paediatric endocrinologist and primary care physician for long-term monitoring and overall health care. This case demonstrates the importance of recognizing the clinical and biochemical features of CAH for early detection and referral. Long-term follow-up and monitoring is necessary due to the risk of complications and side effects of medications. This is the first case of CAH presented with persistent hyperbilirubinemia to be reported from Malaysia. The case describes the difficult workup that has been encountered in the patient's care and management.

Diagnostic Yield of Newborn Screening for Biliary Atresia Using Direct or Conjugated Bilirubin Measurements

IMPORTANCE

Treating biliary atresia in newborns earlier can delay or prevent the need for liver transplant; however, treatment typically occurs later because biliary atresia is difficult to detect during its early stages.

OBJECTIVE

To determine the diagnostic yield of newborn screening for biliary atresia with direct or conjugated bilirubin measurements and to evaluate the association of screening implementation with clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional screening study of 124 385 infants born at 14 Texas hospitals between January 2015 and June 2018; and a pre-post study of 43 infants who underwent the Kasai portoenterostomy as treatment for biliary atresia at the region's largest pediatric hepatology center before (January 2008-June 2011) or after (January 2015-June 2018) screening implementation. Final follow-up occurred on July 15, 2019.

EXPOSURES

Two-stage screening with direct or conjugated bilirubin measurements. In stage 1, all newborns were tested within the first 60 hours of life, with a positive screening result defined as bilirubin levels exceeding derived 95th percentile reference intervals. In stage 2, infants who had a positive screening result in stage 1 were retested at or before the 2-week well-child visit, with a positive screening result defined as bilirubin levels greater than the stage 1 result or greater than 1 mg/dL.

MAIN OUTCOMES AND MEASURES

The primary outcomes of the screening study were sensitivity, specificity, positive predictive value, and negative predictive value based on infants testing positive in both stages. The reference standard was biliary atresia diagnosed at the region's pediatric hepatology centers. The primary outcome of the pre-post study was the age infants underwent the Kasai portoenterostomy for treatment of biliary atresia.

RESULTS

Of 124 385 newborns in the screening study, 49.2% were female, 87.6% were of term gestational age, 70.0% were white, and 48.1% were Hispanic. Screening identified the 7 known infants with biliary atresia with a sensitivity of 100% (95% CI, 56.1%-100.0%), a specificity of 99.9% (95% CI, 99.9%-99.9%), a positive predictive value of 5.9% (95% CI, 2.6%-12.2%), and a negative predictive value of 100.0% (95% CI, 100.0%-100.0%). In the pre-post study, 24 infants were treated before screening implementation and 19 infants were treated after screening implementation (including 6 of 7 from the screening study, 7 from screening at nonstudy hospitals, and 6 from referrals because of clinical symptoms). The age infants underwent the Kasai portoenterostomy was significantly younger after screening was implemented (mean age, 56 days [SD, 19 days] before screening implementation vs 36 days [SD, 22 days] after screening implementation; between-group difference, 19 days [95% CI, 7-32 days]; P = .004).

CONCLUSIONS AND RELEVANCE

Newborn screening with direct or conjugated bilirubin measurements detected all known infants with biliary atresia in the study population, although the 95% CI around the sensitivity estimate was wide and the study design did not ensure complete ascertainment of false-negative results. Research is needed in larger populations to obtain more precise estimates of diagnostic yield and to better understand the clinical outcomes and cost-effectiveness of this screening approach.

Prevalence and Prognostic Value of Abnormal Liver Test Results in Critically Ill Children and the Impact of Delaying Parenteral Nutrition

OBJECTIVES

In the Early versus Late Parenteral Nutrition in the Pediatric ICU randomized controlled trial, delaying parenteral nutrition to beyond day 7 (late parenteral nutrition) was clinically superior to supplemental parenteral nutrition initiated within 24 hours (early parenteral nutrition), but resulted in a higher rise in bilirubin. We aimed to document prevalence and prognostic value of abnormal liver tests in the PICU and the impact hereon of withholding early parenteral nutrition.

DESIGN

Preplanned secondary analysis of the Early versus Late Parenteral Nutrition in the Pediatric ICU randomized controlled trial. Total bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, alkaline phosphatase plasma concentrations were measured systematically in PICU. Liver test analyses were adjusted for baseline characteristics including severity of illness.

SETTING

Three PICUs in Belgium, the Netherlands, and Canada.

PATIENTS

As neonatal jaundice was considered a confounder, only the 1,231 of the 1,440 Early versus Late Parenteral Nutrition in the Pediatric ICU-patients 28 days to 17 years old were included.

INTERVENTIONS

Late parenteral nutrition as compared with early parenteral nutrition.

MEASUREMENTS AND MAIN RESULTS

During the first seven PICU days, the prevalence of cholestasis (> 2 mg/dL [34.2 μmol/L] bilirubin) ranged between 3.8% and 4.9% and of hypoxic hepatitis (≥ 20-fold upper limit of normality for alanine aminotransferase and aspartate aminotransferase) between 0.8% and 2.2%, both unaffected by the use of parenteral nutrition. Throughout the first week in PICU plasma bilirubin concentrations were higher in late parenteral nutrition patients (p < 0.05), but became comparable to early parenteral nutrition patients as soon as parenteral nutrition was started on day 8. Plasma concentrations of gamma-glutamyl transpeptidase, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase were unaffected by parenteral nutrition. High day 1 plasma concentrations of gamma-glutamyl transpeptidase, alanine aminotransferase, and aspartate aminotransferase (p ≤ 0.01), but not alkaline phosphatase, were independent risk factors for PICU mortality. Day 1 plasma bilirubin concentrations displayed a U-shaped association with PICU mortality, with higher mortality associated with bilirubin less than 0.20 mg/dL and greater than 0.76 mg/dL (< 3.42 μmol/L and > 13 μmol/L) (p ≤ 0.01).

CONCLUSIONS

Overt cholestasis and hypoxic hepatitis were rare and unrelated to the nutritional strategy. However, withholding parenteral nutrition up to 1 week in PICU increased plasma bilirubin. A mild elevation of bilirubin on the first PICU day was associated with lower risk of death and may reflect a stress response, rather than true cholestasis.

Detection of Cytomegalovirus in Liver Tissue by Polymerase Chain Reaction in Infants With Neonatal Cholestasis

AIM

Cytomegalovirus (CMV) is associated with neonatal cholestasis (NC). Diagnosis of CMV infection is most often based on either positive blood CMV IgM or CMV blood polymerase chain reaction (PCR). Isolation of CMV in liver tissues in patients with NC has rarely been reported. This study was undertaken to see if CMV is present in liver tissues of patients with NC and evaluate the correlation between positive CMV PCR in liver tissue with the serology and blood PCR.

METHODS

This study was conducted in 31 infants with NC from June 2015 to December 2016. All patients underwent blood CMV IgM, blood CMV PCR and liver CMV PCR. Prevalence of CMV in NC based on positive liver CMV PCR was calculated. Sensitivity and specificity of the serologic markers and blood CMV PCR to identify CMV infection in the liver was determined.

RESULTS

CMV IgM was positive in 13 (42%) patients, CMV IgG was positive in 26 (84%) patients and blood CMV PCR was positive in 23 (74%) patients. Liver CMV PCR was positive in 16 (52%) patients. Fifteen (48%) patients had biliary atresia (BA), 10 (32%) patients had neonatal hepatitis, 5 (16%) had paucity of bile ducts and 1 (3%) had ascending cholangitis. Of the 16 patients with positive liver CMV PCR, 8 (50%) had BA, 4 (25%) had neonatal hepatitis, 3 (19%) had paucity of bile ducts and 1 (6%) had ascending cholangitis. Sensitivity of blood CMV IgM in relation to liver CMV PCR was 69% and specificity was 61%. Sensitivity of blood CMV PCR was 61% and specificity was 71% when compared with liver CMV PCR.

CONCLUSION

CMV is present in the liver tissues of more than half the patients with NC. Serology or blood CMV PCR is apparently not an accurate marker of CMV in the liver tissue. Also, CMV infection in children seems to be associated equally with BA or non-BA neonatal hepatitis.

Conjugated Hyperbilirubinemia in the Neonate and Young Infant

Cholestatic jaundice in the first few weeks of life may herald potentially life-threatening pathology. It is therefore incumbent upon the pediatric practitioner to have a high index of suspicion for severe disease when investigating jaundice in a young infant. This article outlines the epidemiology, pathophysiology, differential diagnosis, and diagnostic workup for both the most common and the most severe causes of cholestasis in the neonatal period.

Direct bilirubin levels observed in prolonged neonatal jaundice: a retrospective cohort study

OBJECTIVE

Prolonged neonatal jaundice is common and usually benign; however, assessment of bilirubin fractions is recommended to determine the need for further assessment for congenital liver disease, particularly biliary atresia. The direct (conjugated) bilirubin thresholds currently used are variable and poorly evidenced. Hence, we aimed to delineate direct bilirubin levels in disease-free neonates with prolonged jaundice.

METHODS

We performed a retrospective cohort analysis of split bilirubin levels, and subsequent follow-up, for all neonates initially assessed in our prolonged neonatal jaundice clinic over 2 years. We plotted centile charts for total, direct and direct-total bilirubin ratio levels against age at sampling. The association was assessed using linear regression analysis.

RESULTS

Data were collected for 420 neonates (501 blood samples) across an age range of 10-70 days. No significant liver disease was found. For each day of older age, total bilirubin fell by 3.72 µmol/L (95% CI 2.46 to 5.00) and direct bilirubin fell by 0.39 µmol/L (0.18 to 0.59). The ratio between the two did not change significantly (-0.0006 to +0.0034). The 95th centile for direct bilirubin was stable at ~25 µmol/L. Direct-total bilirubin ratio was very variable with some 95th centiles >30%.

CONCLUSIONS

In a clinically relevant population of disease-free neonates with prolonged jaundice both the total and the direct bilirubin decreased with age. The absolute direct bilirubin is more useful clinically than the direct-total bilirubin ratio. Our results support National Institute for Health and Care Excellence guidance that conjugated bilirubin >25 µmol/L, or even more stringent criteria, constitutes an appropriate threshold for further investigation for neonatal liver disease.

Management options for cholestatic liver disease in children

Due to a peculiar age-dependent increased susceptibility, neonatal cholestasis affects the liver of approximately 1 in every 2500 term infants. A high index of suspicion is the key to an early diagnosis, and to implement timely, often life-saving treatments. Even when specific treatment is not available or curative, prompt medical management and optimization of nutrition are of paramount importance to survival and avoidance of complications. Areas covered: The present article will prominently focus on a series of newer diagnostic and therapeutic options of cholestasis in neonates and infants blended with consolidated established paradigms. The overview of strategies for the management reported here is based on a systematic literature search published in English using accessible databases (PubMed, MEDLINE) with the keywords biliary atresia, choleretics and neonatal cholestasis. References lists from retrieved articles were also reviewed. Expert commentary: A large number of uncommon and rare hepatobiliary disorders may present with cholestasis during the neonatal and infantile period. Potentially life-saving disease-specific pharmacological and surgical therapeutic approaches are currently available. Advances in hepatobiliary transport mechanisms have started clarifying fundamental aspects of inherited and acquired cholestasis, laying the foundation for the development of possibly more effective specific therapies.

Conjugated hyperbilirubinemia presenting in first fourteen days in term neonates

AIM

To describe the etiology and characteristics of early-onset conjugated hyperbilirubinemia (ECHB) presenting within 14 d of life in term neonates.

METHODS

Retrospective review was performed of term infants up to 28-d-old who presented with conjugated hyperbilirubinemia (CHB) at a tertiary center over a 5-year period from January 2010 to December 2014. CHB is defined as conjugated bilirubin (CB) fraction greater than 15% of total bilirubin and CB greater or equal to 25 μmol/L. ECHB is defined as CHB detected within 14 d of life. “Late-onset” CHB (LCHB) is detected at 15-28 d of life and served as the comparison group.

RESULTS

Total of 117 patients were recruited: 65 had ECHB, 52 had LCHB. Neonates with ECHB were more likely to be clinically unwell (80.0% vs 42.3%, P < 0.001) and associated with non-hepatic causes (73.8% vs 44.2%, P = 0.001) compared to LCHB. Multifactorial liver injury (75.0%) and sepsis (17.3%) were the most common causes of ECHB in clinically unwell infants, majority (87.5%) had resolution of CHB with no progression to chronic liver disease. Inborn errors of metabolism were rare (5.8%) but associated with high mortality (100%) in our series. In the subgroup of clinically well infants (n = 13) with ECHB, biliary atresia (BA) was the most common diagnosis (61.5%), all presented initially with normal stools and decline in total bilirubin but with persistent CHB.

CONCLUSION

Secondary hepatic injury is the most common reason for ECHB. BA presents with ECHB in well infants without classical symptoms of pale stools and deep jaundice.

Utility of measuring direct bilirubin at first 72 h of age in neonates admitted to the neonatal intensive care unit

OBJECTIVE

To assess the utility of measuring direct bilirubin (DB) during the first 72 h of life in infants admitted to the neonatal intensive care unit (NICU).

STUDY DESIGN

Infants born between May 2006 and June 2013, and admitted to the NICU were included. Abnormal DB was defined as: DB level⩾1 mg dl^-1 with a corresponding TB of ⩽5 mg dl^-1 or DB level >20% of the corresponding TB>5 mg dl^-1.

RESULTS

The DB levels were measured in 3715 infants during the first 72 h of life. Sixty-three infants (1.7%) had abnormal DB. In a number of infants with potentially treatable diseases (biliary atresia and choledochal cyst), the only abnormal finding was a mildly elevated DB (1 to 2 mg dl^-1) during the first 3 days of life. In 22 infants (35%), the cause for high DB was unknown (16%) or not investigated (19%).

CONCLUSIONS

Routine measurement of DB in neonates admitted to NICU may be helpful in identifying potentially treatable causes of cholestasis.

Newborn Direct or Conjugated Bilirubin Measurements As a Potential Screen for Biliary Atresia

OBJECTIVES

Although screening for biliary atresia (BA) is associated with improved outcomes, no screening program currently exists in the United States. In this study, we explore the possibility of a screening strategy based on newborn direct or conjugated bilirubin (DB or CB) measurements. Our objective is to estimate testing's sensitivity and specificity for BA.

METHODS

Two groups were examined retrospectively. For sensitivity calculations, a BA group consisting of infants born between January 2011 and December 2014, diagnosed with BA, and cared for at a pediatric gastroenterology referral center was examined. For specificity calculations, a non-BA group that comprised of infants born between June 2009 and August 2011 in a hospital with a policy of checking newborn bilirubin concentrations was studied.

RESULTS

All 35 infants with newborn DB or CB measurements in the BA group had elevated concentrations, translating to a sensitivity of 100% (95% CI 87.7-100). In the non-BA group, 8936 of 9102 infants had DB concentrations within the laboratory's reference interval, translating to a specificity of 98.2% (95% CI 97.9-98.4). Three methods-calculating direct:total bilirubin ratios, using 99% reference intervals, and repeat testing-changed specificity to different degrees.

CONCLUSIONS

Newborn DB or CB measurements may have a high sensitivity and specificity for BA. Specificity can be further improved by using 99% reference intervals and/or repeat testing. Our findings can serve as the foundation for larger prospective studies, to determine whether newborn DB or CB measurements can be an effective screening strategy for BA.

Cholestasis beyond the Neonatal and Infancy Periods

Cholestasis results from impairment in the excretion of bile, which may be due to mechanical obstruction of bile flow or impairment of excretion of bile components into the bile canaliculus. When present, cholestasis warrants prompt diagnosis and treatment. The differential diagnosis of cholestasis beyond the neonatal period is broad and includes congenital and acquired etiologies. It is imperative that the clinician differentiates between intrahepatic and extrahepatic origin of cholestasis. Treatment may be supportive or curative and depends on the etiology. Recent literature shows that optimal nutritional and medical support also plays an integral role in the management of pediatric patients with chronic cholestasis. This review will provide a broad overview of the pathophysiology, diagnostic approach, and management of cholestasis beyond the neonatal and infancy periods.

Italian guidelines for the management and treatment of neonatal cholestasis

Hyperbilirubinemia is a frequent condition affecting newborns during the first two weeks of life and when it lasts more than 14 days it is defined as prolonged jaundice. This condition requires differential diagnosis between the usually benign unconjugated hyperbilirubinemia and the pathological conjugated hyperbilirubinemia, that is mainly due to neonatal cholestasis. It is important that the diagnosis of neonatal cholestasis be well-timed to optimize its management, prevent worsening of the patient’s outcome, and to avoid premature, painful, expensive, and useless tests. Unfortunately, this does not always occur and, therefore, the Task Force on Hyperbilirubinemia of the Italian Society of Neonatology presents these shared Italian guidelines for the management and treatment of neonatal cholestasis whose overall aim is to provide a useful tool for its assessment for neonatologists and family pediatricians.

A screening algorithm for the efficient exclusion of biliary atresia in infants with cholestatic jaundice

BACKGROUND

Neonates with cholestasis may undergo many tests before biliary atresia (BA) or an alternative diagnosis is reached, and delayed intervention may worsen outcomes. An optimal diagnostic approach to reduce risk, cost, and delay has yet to be defined. The purpose of this study was to develop an algorithm that rapidly and accurately excludes BA for infants with cholestatic jaundice.

METHODS

A single-center retrospective comparison of diagnostic workup was made between cholestatic infants with BA, and those without BA who underwent hepatobiliary iminodiacetic acid (HIDA) scan during admission. Patients were born between 2000 and 2010 and those older than 100days at assessment were excluded. Sensitivity and specificity analysis of predictive variables was performed and an algorithm constructed.

RESULTS

There were 45 BA and 167 non-BA patients. Some variables were 100% sensitive for the exclusion of BA: conjugated bilirubin <2.5mg/dL, gamma-glutamyl transpeptidase <150U/L, excretion on HIDA, or a normal percutaneous cholangiogram. Clinical variables and ultrasound were less useful as screening tests owing to low specificity and sensitivity, respectively. Liver biopsy was 98% sensitive and 84% specific in the diagnosis of BA. An algorithm was constructed that rules out BA with a negative laparotomy rate of 3-22%.

CONCLUSION

We propose a screening algorithm for infants with conjugated hyperbilirubinemia that permits efficient exclusion of BA with minimal invasive testing and with a low risk of negative laparotomy. This algorithm now requires prospective evaluation to determine its diagnostic accuracy and its ability to reduce hospital costs, patient morbidity, and time to Kasai portoenterostomy in patients with BA.

Development of an equation to correct for hemolysis in direct bilirubin measurements

BACKGROUND

Direct bilirubin is measured for the investigation of pediatric and adult jaundice. Package inserts suggest that hemolysis decreases direct bilirubin measurements, but no published studies have adequately described the extent of interference.

METHODS

The influence of hemolysis on direct bilirubin quantification (Beckman AU680) was evaluated by titrating increasing amounts of hemoglobin into specimens with variable starting concentrations of direct bilirubin. An equation was derived to predict the nominal interference-free concentration of direct bilirubin as a function of measured concentration and hemolysis-index.

RESULTS

Hemolysis decreased the direct bilirubin concentration reported by the AU680. The extent of interference is a function of both the interference-free concentration of direct bilirubin and the degree of hemolysis.

CONCLUSIONS

The concentration of direct bilirubin in hemolyzed specimens can be predicted.

International incidence and outcomes of biliary atresia

OBJECTIVES

International trends in incidence and outcomes of biliary atresia (BA) are controversial and a wide range of estimates have been reported worldwide. We reviewed the population-based literature to assess international variation of BA incidence and outcomes, and to assess the evidence for seasonal variation in incidence, centralization of Kasai hepatoportoenterostomy, and newborn screening.

METHODS

We conducted a systematic review (registration number CRD42011001441) of observational or interventional research within MEDLINE, EMBASE, and the Cochrane Database, which reported incidence, prevalence, or outcomes of infants with BA. Population-based studies, defined by inclusion of an entire population or representative sample, were included. Outcomes included overall survival, native liver survival (NLS), and time to Kasai hepatoportoenterostomy. Single- or multicenter studies were excluded unless those centers captured all potential patients within a jurisdiction. Two independent data extractors reviewed the abstracts and articles.

RESULTS

A total of 40 studies were included following review of 3128 references. A wide range of incidence was reported internationally. Ten-year overall survival ranged from 66.7% to 89%. NLS ranged from 20.3% to 75.8% at 1 to 3 years and 24% to 52.8% at 10 years. Earlier age at Kasai was a predictor of improved NLS. Seasonality was reported in 11 studies, and 3 reported an increased incidence during the months of August to March. The evidence for centralization of Kasai to high-volume centers is promising but does not account for all case-mix, provider, or health system factors involved in volume-outcome relations. Stool color card screening resulted in earlier Kasai and improved NLS in Taiwan.

CONCLUSIONS

Large, international studies could help fill the gaps in knowledge identified by this review.

Neonatal Cholestasis

Cholestatic jaundice is a common presenting feature of neonatal hepatobiliary and metabolic dysfunction. Any infant who remains jaundiced beyond age 2 to 3 weeks should have the serum bilirubin level fractionated into a conjugated (direct) and unconjugated (indirect) portion. Conjugated hyperbilirubinemia is never physiologic or normal. The differential diagnosis of cholestasis is extensive, and a step-wise approach based on the initial history and physical examination is useful to rapidly identify the underlying etiology. Early recognition of neonatal cholestasis is essential to ensure timely treatment and optimal prognosis. Even when specific treatment is not available, infants who have cholestasis benefit from early medical management and optimization of nutrition. Future studies are necessary to determine the most reliable and cost-effective method of universal screening for neonatal cholestasis.

Neonatal cholestasis: opportunities to increase early detection

OBJECTIVE

To describe primary care management of early and prolonged jaundice in otherwise-healthy term infants to identify opportunities to increase early diagnosis of cholestasis.

METHODS

Community-based pediatricians in St Louis, Missouri completed a mailed, anonymous, 29-item survey to assess practice demographics, timing of routine newborn office visits, and the management of early and prolonged neonatal jaundice.

RESULTS

A total of 108 of 230 (47%) of eligible physicians responded (mean years in practice, 15.3, SD, 9.4). More respondents were very familiar with national guidelines for management of early (49%) than prolonged (16%) neonatal jaundice. Eighty-six percent reported all newborns were checked with transcutaneous bilirubin before hospital discharge. For transcutaneous bilirubin results at 48 hours of 7, 10, 12 and 15 mg/dL, 1%, 26%, 70%, and 74% of respondents, respectively, would order a fractionated bilirubin. Although the first routine visit usually occurred in the first week after discharge, 25% of physicians reported the 2nd visit was routinely scheduled after 4 weeks of age. Ninety-four percent reported they would obtain a fractionated bilirubin for infants jaundiced beyond 4 weeks of age. If cholestasis was identified at 6 weeks of age, 32% would obtain additional testing without referral to a subspecialist.

CONCLUSIONS

Management of early and prolonged neonatal jaundice is variable. Current practices appear to miss opportunities for early diagnosis of cholestasis and referral that are unlikely to be addressed without redesigning systems of care.

Conjugated hyperbilirubinemia in children

A variety of anatomic, infectious, autoimmune, and metabolic diseases can lead to conjugated hyperbilirubinemia, both in the newborn period and later in childhood. The pediatric practitioner is most likely to encounter conjugated hyperbilirubinemia in the neonatal period.It is crucial to maintain a high degree of suspicion for cholestasis in the persistently jaundiced newborn. The goal is recognition of conjugated hyperbilirubinemia between 2 and 4 weeks after birth, allowing for the prompt identification and management of infants who have biliary atresia, which remains the most common cause of neonatal cholestasis.

Early inflammatory markers for prediction of cholestasis in very-low-birth-weight infants

BACKGROUND

Neonatal cholestasis is associated with increased mortality and other adverse outcomes. There are no tools for prediction of infants at risk for cholestasis.

OBJECTIVE

To determine if cholestasis in very-low-birth-weight (VLBW) infants is associated with alterations in cytokines or C-reactive protein (CRP) and, if so, whether inflammatory markers predict which infants will develop cholestasis.

METHODS

VLBW infants expected to be on parenteral nutrition for >7 days were enrolled in this prospective cohort study. Infants with direct bilirubin ≥1.0 mg/dl were considered to have a high risk for cholestasis and were compared to infants who never developed direct bilirubin ≥1.0 mg/dl. Standard descriptive statistics were used to compare biomarkers over time. Multivariable models were used to estimate associations between early inflammatory markers and cholestasis.

RESULTS

Of 63 infants enrolled, 29 were at risk for cholestasis. CRP was highly correlated with direct bilirubin. Infants in the high-risk group had significantly higher IL-1β, IL-6, IL-8, and IL-10 at 2, 4, and 6 weeks and CRP at 2 and 6 weeks. In logistic models, CRP (OR = 4.97, p = 0.02) or IL-1β (OR = 1.11, p = 0.008) at 2 weeks of age was predictive of cholestasis. In linear mixed-effects models, CRP (p < 0.001) or IL-6 (p = 0.02) and IL-8 (p < 0.001) were predictive of cholestasis.

CONCLUSION

Elevated CRP and cytokines are associated with cholestasis in VLBW infants. These inflammatory markers are candidates for further research into the pathogenesis, prediction, and prevention of cholestasis.

Patients with biliary atresia have elevated direct/conjugated bilirubin levels shortly after birth

OBJECTIVES

Healthy infants are thought to acquire biliary atresia (BA) in the first weeks of life. Because those diagnosed earlier have better outcomes, we were interested in determining the earliest time BA could be detected. We started by examining the immediate postnatal period, hypothesizing that newborns would not yet have acquired disease and still have normal direct/conjugated bilirubin (DB/CB) levels.

PATIENTS AND METHODS

Newborn DB/CB levels were obtained retrospectively from birth hospitals. Subjects with BA were born between 2007 and 2010 and cared for at Texas Children's Hospital. Those with BA splenic malformation syndrome or born prematurely were excluded. Control subjects were term newborns who later never developed neonatal liver disease.

RESULTS

Of the 61 subjects with BA, 56% had newborn DB/CB levels measured. All DB/CB levels exceeded laboratory norms and rose over time. At 24 to 48 hours of life, subjects with BA had mean DB levels significantly higher than those of controls (1.4 ± 0.43 vs. 0.19 ± 0.075 mg/dL, P < .0001), even while their mean total bilirubin (TB) levels remained below phototherapy limits. Finally, despite the elevated DB/CB levels, the majority of patients (79%) had normal DB:TB ratios ≤ 0.2.

CONCLUSIONS

Patients with BA have elevated DB/CB levels shortly after birth. To detect affected infants earlier and improve outcomes, the results suggest two possibilities: (1) screen all newborns for elevated DB/CB levels, rather than just those who appear jaundiced; and then (2) follow all newborns with elevated DB/CB levels, rather than just those with DB:TB ratios >0.2.