Cholestatic syndromes of infancy

Clinical characteristics of neonatal cholestasis in a tertiary hospital and the development of a novel prediction model for mortality

Background

Few studies have described the aetiologies of neonatal cholestasis, and the overall neonatal cholestasis-related mortality (NCM) rate is unclear. We investigated the aetiology and outcome of neonatal cholestasis in a tertiary hospital and developed an NCM prediction model for these patients.

Methods

Patients aged <100 days with serum direct bilirubin (DB) levels of >1.0 mg/dL were retrospectively screened. Diagnostic and laboratory data during the 8-week follow-up period after enrolment between 2005 and 2020 were extracted digitally, and medical charts were reviewed manually by clinicians. Logistic regression was used to derive a prediction model for the 1-year mortality outcome of neonatal cholestasis, and performance evaluation and external validation were conducted for the NCM prediction model.

Findings

We enrolled 4028 neonates with DB of >1.0 mg/dL at least once. Prematurity and birth injury (35.4%), complex heart anomalies (18.6%), liver diseases (11.4%), and gastrointestinal anomalies (9.2%) were the most common aetiologies; 398 (9.9%) patients died before one year of age. The peak value of DB was positively correlated to the 1-year mortality rate. In the multivariate analysis, simple laboratory indices, including platelet, prothrombin time, aspartate aminotransferase, albumin, direct bilirubin, creatinine, and C-reactive protein, were independent predictors of 1-year mortality outcome of complete-case subjects. Using these laboratory indices, a logistic regression-based NCM prediction model was constructed. It showed acceptable performances on discrimination (area under the curve, 0.916), calibration (slope, 1.04) and Brier scoring (0.072). The external validation of the sample (n = 920) from two other centres also revealed similar performance profiles of the NCM model.

Interpretation

Various aetiologies of neonatal cholestasis were identified in a tertiary hospital, resulting in unfavourable outcomes of a large proportion. The NCM prediction model may have the potential to help clinicians to be aware of high-risk neonatal cholestasis.

Diagnostic value of anti-smooth muscle antibodies and liver enzymes in differentiation of extrahepatic biliary atresia and idiopathic neonatal hepatitis

BACKGROUND

We aimed to evaluate the diagnostic value of anti-smooth muscle antibodies (ASMA) and two liver markers (gamma-glutamyl transpeptidase [GGT] and alkaline phosphatase [ALP]) for differentiating between patients with extrahepatic biliary atresia (EHBA) and idiopathic neonatal hepatitis (INH).

MATERIALS AND METHODS

During April 2010-2011, all infants at 2 weeks of age who were diagnosed with cholestasis and admitted to Children's Hospital of Tabriz were enrolled. Based on the results of physical examination, laboratory, imaging and pathological studies, neonates were divided into two groups (EHBA and INH). Receiver operating characteristics analysis was used to define sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy for ASMA, GGT and ALP.

RESULTS

Thirty neonates with cholestasis (18 with EHBA and 12 with INH) and mean age of 54.66 ΁ 25.86 days were enrolled. Total and direct bilirubin, serum glutamic oxaloacetic transaminase, serum glutamic pyruvic transaminase and ASMA titres were highly not significant (P > 0.05) in patients with INH. GGT (P = 0.008) and ALP (P = 0.01) had statistically significant differences that were higher in patients with EHBA. The sensitivity, specificity, PPV and NPV, accuracy, LR+ and LR- of SMA in differentiating cases with BA were 66.7%, 75%, 80% 60%, 70%, 2.68 and 0.44, respectively. For GGT, the values were 88.9%, 66.7%, 80%, 80%, 79.1%, 3.08 and 0.31, respectively. Finally, for ALP, the values were 77.8%, 75%, 82.4%, 69.2%, 80%, 2.66 and 0.24, respectively.

CONCLUSION

Our study showed that ASMA may be a useful biomarker for differentiation of EHBA from INH. Further studies with larger samples are recommended for confirming the results of this study.

Etiologies of conjugated hyperbilirubinemia in infancy: a systematic review of 1692 subjects

Background

The etiologies of conjugated hyperbilirubinemia in infancy are diverse.

Objective

Determine the prevalence rates of the specific etiologies of conjugated hyperbilirubinemia in infancy.

Data sources

EMBASE and Pubmed were searched electronically and the bibliographies of selected studies were search manually. The search was conducted independently by two authors.

Study selection

(1) prospective or retrospective case series or cohort study with 10 or more subjects; (2) consecutive infants who presented with conjugated hyperbilirubinemia; (3) subjects underwent appropriate diagnostic work-up for conjugated hyperbilirubinemia; (4) no specific diagnoses were excluded in the studied cohort.

Data extraction

Patient number, age range, country of origin, and categorical and specific etiologies.

Results

From 237 studies identified, 17 studies encompassing 1692 infants were selected. Idiopathic neonatal hepatitis (INH) occurred in 26.0 % of cases; the most common specific etiologies were extrahepatic biliary atresia (EHBA) (25.89 %), infection (11.47 %), TPN- associated cholestasis (6.44 %), metabolic disease (4.37 %), alpha-1 anti-trypsin deficiency (4.14 %), and perinatal hypoxia/ischemia (3.66 %). CMV was the most common infection identified (31.51 %) and galactosemia (36.49 %) was the most common metabolic disease identified.

Limitations

Major limitations are: (1) inconsistencies in the diagnostic evaluations among the different studies and (2) variations among the sample populations.

Conclusions

INH is the most common diagnosis for conjugated hyperbilirubinemia in infancy while EHBA and infection are the most commonly identified etiologies. The present review is intended to be a guide to the differential diagnosis and evaluation of the infant presenting with conjugated hyperbilirubinemia.

Analysis of mutations of MDR3 exons 9 and 23 in infants with parenteral nutrition-associated cholestasis

The aim of this study was to investigate mutations of multidrug resistance 3 (MDR3) exons 9 and 23 in infants with parenteral nutrition-associated cholestasis (PNAC). A total of 41 infants with PNAC were enrolled in the study. Genomic DNA was extracted from the peripheral venous blood leukocytes of each patient and MDR3 exons 9 and 23 were amplified by polymerase chain reaction. One patient was identified who carried a frameshift mutation in MDR3 exon 23 (C.2793) that was caused by the insertion of a single adenine residue, while mutations were not found in MDR3 exon 23 in the other 40 patients. The clinical features of the patient with the MDR3 exon 23 frameshift mutation included high serum γ-glutamyl transferase levels, the absence of biliary dilatation and deformity in magnetic resonance cholangiopancreatography, and abnormal electrical capacitance tomography imaging of the liver. No mutations in MDR3 exon 9 were identified in any of the patients. All 41 PNAC patients recovered following oral ursodeoxycholic acid treatment. The C.2793 frameshift mutation in MDR3 exon 23 is potentially associated with the development of PNAC in infants.

Correlation between mutation of MDR3 gene exon 6 and parenteral nutrition-associated cholestasis of preterm infants

The aim of this study was to investigate the association between the mutation of multidrug resistance 3 (MDR3) exon 6 and parenteral nutrition-associated cholestasis (PNAC) in preterm infants. A total of 41 preterm infants with PNAC formed the experimental group, and 56 preterm infants receiving total parenteral nutrition (TPN) for >14 days but without cholestasis formed the control group. Genomic DNA was extracted from peripheral venous blood leukocytes. Polymerase chain reaction was used to amplify exon 6 of the MDR3 gene. The target band of MDR3 gene exon 6 was identified in all blood samples from all cases. We identified five cases with C. 504 C>T heterozygous mutations of exon 6 of the MDR3 gene and 14 cases with C. 504 C>T homozygous mutations in the experimental group. In the control group, we identified seven cases with the C. 504 C>T homozygous mutation and six cases with the C. 504 C>T heterozygous mutation. The distribution of the T/C allele frequency of C. 504 in exon 6 of the MDR3 gene between the experimental group and control group was statistically significant (P<0.05). Further analysis revealed the odds ratio of the T/C allele frequency of the C. 504 mutation in exon 6 of the MDR3 gene between the experimental group and control group to be 0.316. Point mutation C. 485 T>A was detected in one case in the experimental group. The C. 504 C>T and C. 485 T>A MDR3 mutations in exon 6 are possibly responsible for the development of PNAC in infants. C. 504 C>T may not be the only risk factor of neonatal PNAC. In order to further confirm the association between exon 6 of the MDR3 gene and PNAC, a large-sample multicenter study should be carried out.

Ultrasound findings in biliary atresia: the role of triangular cord sign

In this prospective study, 49 infants with prolonged jaundice, were studied between January 2005 to April 2007 in Tabriz Children's Hospital. All of these infants were evaluated with ultrasonography and isotopscan and finally biopsy was done in all of them under guide of sonography. In their sonographic evaluation, absence or presence of gall bladder, its size and also its evacuation after feeding was checked and beside this triangular cord sign was controlled. The PPV and specificity of triangular cord sign in diagnosis of extrahepatic biliary atresia (EHBA) was 100% but its NPV was only 78.5%. The overall accuracy, PPV, NPV, specificity and sensitivity ofultrasonographic findings in diagnosis of EHBA was about 94, 92, 94, 97 and 86%. Ultrasonography is a reliable screening method in early diagnosis of EHBA and triangular cord sign increases its accuracy especially its specificity.