Dubin-Johnson Syndrome as Differential Diagnosis for Neonatal Cholestasis

Case Report: A case of Dubin-Johnson syndrome in a newborn

Background

Dubin-Johnson Syndrome (DJS) is a rare autosomal recessive genetic disorder, with most cases presenting in adolescence, but rare in newborns.

Objective

To investigate the clinical characteristics and treatment outcomes of DJS in a newborn.

Methods

We present the clinical features of a newborn diagnosed with DJS through molecular genetic testing.

Results

The patient was a male newborn who developed jaundice and scleral icterus on the 6th day of life. Both direct and indirect bilirubin levels were elevated. After treatment with phototherapy, indirect bilirubin levels decreased, but direct bilirubin remained unchanged, and the stool color gradually lightened. At 56 days of age, the patient underwent laparoscopic cholecystostomy, which revealed viscous bile plugs in the bile ducts. Following the surgery, the patient received oral ursodeoxycholic acid, compound glycyrrhizin, and methylprednisolone. Follow-up until one year post-surgery showed a gradual reduction in direct bilirubin levels to the normal range. Molecular genetic testing revealed three heterozygous mutations in the ABCC2 gene on chromosome 10, with one pathogenic variant inherited from the father and two from the mother, confirming the diagnosis of DJS.

Conclusion

DJS is a benign condition with a favorable prognosis. In newborns, it should be differentiated from other causes of cholestasis, and compared to cholestasis, jaundice in newborns with DJS responds more slowly to treatment.

Diagnostic algorithm for neonatal intrahepatic cholestasis integrating single-gene testing and next-generation sequencing in East Asia

BACKGROUND AND AIM

Advances in molecular genetics have uncovered causative genes responsible for neonatal cholestasis. Panel-based next-generation sequencing has been used clinically in infants with neonatal cholestasis. We aimed to evaluate the clinical application of single-gene testing and next-generation sequencing and to develop a diagnostic algorithm for neonatal intrahepatic cholestasis.

METHODS

From January 2010 to July 2021, patients suspected of having neonatal intrahepatic cholestasis were tested at the Seoul National University Hospital. If there was a clinically suspected disease, single-gene testing was performed. Alternatively, if it was clinically difficult to differentiate, a neonatal cholestasis gene panel test containing 34 genes was performed.

RESULTS

Of the total 148 patients examined, 49 (33.1%) were received a confirmed genetic diagnosis, including 14 with Alagille syndrome, 14 with neonatal intrahepatic cholestasis caused by citrin deficiency, 7 with Dubin-Johnson syndrome, 5 with arthrogryposis-renal dysfunction-cholestasis syndrome, 5 with progressive familial intrahepatic cholestasis type II, 1 with Rotor syndrome, 1 with Niemann-Pick disease type C, 1 with Kabuki syndrome, and 1 with Phenylalanyl-tRNA synthetase subunit alpha mutation. Sixteen novel pathogenic or likely pathogenic variants of neonatal cholestasis were observed in this study. Based on the clinical characteristics and laboratory findings, we developed a diagnostic algorithm for neonatal intrahepatic cholestasis by integrating single-gene testing and next-generation sequencing.

CONCLUSIONS

Alagille syndrome and neonatal intrahepatic cholestasis caused by citrin deficiency were the most common diseases associated with genetic neonatal cholestasis. Single-gene testing and next-generation sequencing are important and complementary tools for the diagnosis of genetic neonatal cholestasis.

Neonatal Dubin-Johnson Syndrome and its Differentiation from Biliary Atresia

BACKGROUND AND AIMS

The aim was to determine if liver biochemistry indices can be used as biomarkers to help differentiate patients with neonatal Dubin-Johnson syndrome (nDJS) from those with biliary atresia (BA).

METHODS

Patients with genetically-confirmed nDJS or cholangiographically confirmed BA were retrospectively enrolled and randomly assigned to discovery or verification cohorts. Their liver chemistries, measured during the neonatal period, were compared. Predictive values were calculated by receiver operating characteristic curve analysis.

RESULTS

A cohort of 53 nDJS patients was recruited, of whom 13 presented with acholic stools, and 14 underwent diagnostic cholangiography or needle liver biopsy to differentiate from BA. Thirty-five patients in the cohort, with complete biochemical information measured during the neonatal period, were compared with 133 infants with cholangiographically confirmed BA. Total and direct bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bile acids, alkaline phosphatase, and gamma-glutamyl transferase were significantly lower in nDJS than in BA. In the discovery cohort, the areas under the curve for ALT and AST were 0.908 and 0.943, respectively. In the validation cohort, 13/15 patients in the nDJS group were classified as nDJS, and 10/53 in the BA control group were positive (p<0.00001) with an ALT biomarker cutoff value of 75 IU/L. Thirteen of 15 patients were classified as nDJS and none were classified positive in the BA group (13/15 vs. 0/53, p<0.00001) with an AST cutoff of 87 IU/L.

CONCLUSIONS

Having assembled and investigated the largest cohort of nDJS patients reported to date, we found that nDJS patients could be distinguished from BA patients using the serum AST level as a biomarker. The finding may be clinically useful to spare cholestatic nDJS patients unnecessary invasive procedures.

Urinary coproporphyrins as a diagnostic biomarker of Dubin-Johnson syndrome in neonates: A diagnostic pathway is proposed

BACKGROUND

Dubin-Johnson syndrome (DJS) presents during the neonatal period with a phenotype that overlaps with a broad list of causes of neonatal cholestasis (NC), which makes the identification of DJS challenging for clinicians. We conducted a case-controlled study to investigate the utility of urinary coproporphyrins (UCP) I% as a potential diagnostic biomarker.

METHODS

We reviewed our database of 533 cases of NC and identified 28 neonates with disease-causing variants in ATP-binding cassette-subfamily C member 2 (ABCC2) gene "Cases" (Study period 2008-2019). Another 20 neonates with cholestasis due to non-DJS diagnoses were included as "controls." Both groups underwent UCP analysis to measure CP isomer I percentage (%).

RESULTS

Serum alanine aminotransferase (ALT) levels were within the normal range in 26 patients (92%) and mildly elevated in 2 patients. ALT levels were significantly lower in neonates with DJS than in NC from other causes (P < 0.001). The use of normal serum ALT levels to predict DJS among neonates with cholestasis had a sensitivity of 93%, specificity 90%, positive predictive value (PPV) 34%, and negative predictive value (NPV) 99.5%. The median UCPI% was significantly higher in DJS patients [88%, interquartile range (IQR) 1-IQR3, 84.2%-92.7%] than in NC from other causes [67%, (IQR1-IQR3, 61%-71.5%; Confidence interval 0.18-0.28; P< 0.001)]. The use of UCPI% >80% to predict DJS had a sensitivity, specificity, PPV, and NPV of 100%.

CONCLUSION

Based on the results from our study, we propose sequencing of the ABCC2 gene in neonates with normal ALT, presence of cholestasis and UCP1% >80%.

Genotype-Phenotype Association in ABCC2 Exon 18 Missense Mutation Leading to Dubin-Johnson Syndrome: A Case Report

We report a case of a patient with Dubin-Johnson syndrome confirmed by a genetic study. A 50-year-old woman who had symptoms of intermittent right upper quadrant abdominal pain was diagnosed with calculous cholecystitis at another institute and was presented to our hospital for a cholecystectomy. She had no history of liver disease, and her physical examination was normal. Abdominal computed tomography showed a gallbladder stone with chronic cholecystitis. During a laparoscopic cholecystectomy for cholecystitis, a smooth, black-colored liver was noted, and a liver biopsy was performed. The biopsy specimen showed coarse, dark brown granules in centrilobular hepatocytes via hematoxylin and eosin staining. We performed a genetic study using the blood samples of the patient. In the adenosine triphosphate-binding cassette subfamily C member 2 (ABCC2) mutation study, a missense mutation in exon 18 was noted. Based on the black-colored liver without nodularity, conjugated hyperbilirubinemia, the liver biopsy results of the coarse pigment in centrilobular hepatocytes, and the ABCC2 mutation, Dubin-Johnson syndrome was diagnosed. The patient was managed with conservative care using hepatotonics. One month after follow-up, total bilirubin and direct bilirubin remained in a similar range. Another follow-up was planned a month later, and the patient maintained her use of hepatotonics.

Multidrug Resistance-Associated Protein 2 Deficiency Aggravates Estrogen-Induced Impairment of Bile Acid Metabolomics in Rats

Multidrug resistance-associated protein 2 (Mrp2) mediates biliary secretion of anionic endobiotics and xenobiotics. Genetic alteration of Mrp2 leads to conjugated hyperbilirubinemia and predisposes to the development of intrahepatic cholestasis of pregnancy (ICP), characterized by increased plasma bile acids (BAs) due to mechanisms that are incompletely understood. Therefore, this study aimed to characterize BA metabolomics during experimental Mrp2 deficiency and ICP. ICP was modeled by ethinylestradiol (EE) administration to Mrp2-deficient (TR) rats and their wild-type (WT) controls. Spectra of BAs were analyzed in plasma, bile, and stool using an advanced liquid chromatography–mass spectrometry (LC–MS) method. Changes in BA-related genes and proteins were analyzed in the liver and intestine. Vehicle-administered TR rats demonstrated higher plasma BA concentrations consistent with reduced BA biliary secretion and increased BA efflux from hepatocytes to blood via upregulated multidrug resistance-associated protein 3 (Mrp3) and multidrug resistance-associated protein 4 (Mrp4) transporters. TR rats also showed a decrease in intestinal BA reabsorption due to reduced ileal sodium/bile acid cotransporter (Asbt) expression. Analysis of regulatory mechanisms indicated that activation of the hepatic constitutive androstane receptor (CAR)-Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway by accumulating bilirubin may be responsible for changes in BA metabolomics in TR rats. Ethinylestradiol administration to TR rats further increased plasma BA concentrations as a result of reduced BA uptake and increased efflux via reduced Slco1a1 and upregulated Mrp4 transporters. These results demonstrate that Mrp2-deficient organism is more sensitive to estrogen-induced cholestasis. Inherited deficiency in Mrp2 is associated with activation of Mrp3 and Mrp4 proteins, which is further accentuated by increased estrogen. Bile acid monitoring is therefore highly desirable in pregnant women with conjugated hyperbilirubinemia for early detection of intrahepatic cholestasis.

Clinical, Biochemical, and Molecular Characterization of Neonatal-Onset Dubin-Johnson Syndrome in a Large Case Series From the Arabs

Background: There are only a few case reports and small case series on neonatal-onset Dubin-Johnson syndrome (DJS), particularly from Far-East Asia, Iranian and Moroccan Jews, and Europe. Objectives: In this first study from the Arabs and the largest series reported to date, we characterized the clinical, laboratory, and molecular features and outcome of gene-confirmed neonatal-onset DJS. Methods: We reviewed our database of 533 cases of neonatal cholestasis that presented to our center during the period from 2008 to 2019. We identified neonates with a disease-causing mutation in ABCC2 gene. Results: Twenty-eight neonates with DJS were diagnosed (5.3%). All of the 28 were full-term, well looking neonates without hepatosplenomegaly, with cholestasis, and normal liver synthetic function since the 1 week of life that resolved within 3-6 months of age, followed by a benign course punctuated by recurrent episodes of jaundice in 43% during a median follow up period of 9.25 (range 2.5-14 years). Alanine aminotransferase levels were within normal range in 26 patients (92%) and mildly elevated in two patients. ALT levels were significantly lower in neonates with DJS than in other cases with neonatal cholestasis from other causes (p < 0.001). The median urinary coproporphyrin I% was 88% (IQ1-IQ3 = 84.2-92.7%). We identified four homozygous variants in the ABCC2 gene (from 22 unrelated families), one splicing variant (c.3258+1G>A; p.?), and three were missense variants; two of which were novel missense variants [c.1594G>A (p.Glu532Lys) and c.2439G>C (p.Lys813Asn)]. The p.Gly758Val mutation has occurred in 23 patients (from 19 unrelated families). Conclusions: Our study suggests that normal ALT-cholestasis in a well-looking neonate should trigger evaluation for DJS. The p.Gly758Val variant in ABCC2 is the most predominant mutation among Arabs with "founder effects." Identification of the predominant ABCC2 variant in any population is likely to facilitate rapid molecular analysis by future targeting of that specific mutation.