Clinician’s Corner

Case 1: Cholestatic jaundice in an infant with Down syndrome

A

term male infant with Down syndrome was admitted to the neonatal intensive care unit at birth for possible sepsis, given suspected maternal chorioamnionitis and the need for resuscitation (including 2 min of positive-pressure ventilation) at delivery. Shortly after admission, he developed seizures requiring treatment with phenobarbital and fosphenytoin/phenytoin for three weeks. Magnetic resonance imaging revealed that a large infarct provoked his seizures. Blood and cerebrospinal fluid cultures were negative. His cerebrospinal fluid leukocyte count was elevated (88×106/L). Because meningitis could not be definitively excluded, he received ampicillin and gentamicin for two weeks. There were no cardiac or gastrointestinal malformations, nor was there bone marrow pathology. The infant was doing well but developed mild scleral icterus, dark urine and intermittent pale stools during the fourth week of life. There was no diarrhea or vomiting. Direct bilirubin was markedly elevated (111 μmol/L, normal 0.6 μmol/L to 20.1 μmol/L). His total bilirubin was 155 μmol/L. There was no family history of liver disease. He had never received parenteral nutrition. On examination, he exhibited features consistent with Down syndrome. He had scleral icterus and jaundice. His abdomen was soft and nontender. His liver was palpable 4 cm below the costal margin, with no splenomegaly. His examination was otherwise normal. Table 1 outlines laboratory investigations. Liver enzyme levels were mildly elevated. A TORCH screen was negative. Abdominal ultrasound showed a normal gall bladder, with no choledochal cyst. Slit-lamp examination, chest radiograph and echocardiogram were normal. Hepatobiliary scintigraphy after phenobarbital did not show excretion into the duodenum.

Correspondence (Case 1): Pushpa Sathya, Assistant Professor of Pediatrics, Memorial University, Paediatric Gastroenterologist, Janeway Children’s Health and Rehabilitation Centre, 300 Prince Philip Drive, St John’s, Newfoundland and Labrador A1B 3V6. Telephone 709-777-4531, fax 709-777-6400, e-mail [email protected] Case 1 accepted for publication February 18, 2015.

Paediatr Child Health Vol 20 No 6 August/September 2015

©2015 Pulsus Group Inc. All rights reserved

289

Clinician’s Corner

TABLE 1 Summary of laboratory investigations Investigation

Result 86 ↑

20–60

Alanine aminotransferase, U/L

57 ↑

8.7–39

Alkaline phosphatase, U/L

513 ↑

150–507

Gamma-glutamyl transpeptidase,U/L

309 ↑

12–23

29

28–47

International normalized ratio

0.88

0.80–1.20

Partial thromboplastin time, s

24.6↓

25.1–36.3

Thyroid stimulating hormone, mIU/L

4.55

0.88–5.42

Alpha-1-antitrypsin, g/L

1.55

0.90–2.00

77.4

>10*

Anti-rubella IgG, IU/mL

B

C

D

Normal range

Aspartate aminotransferase, U/L

Albumin, g/L

A

Anti-CMV IgG

Reactive

Figure 1) Liver biopsy. An ultrasound-guided percutaneous liver biopsy

Anti-CMV IgM

Non-reactive

Anti-toxoplasma IgG

Non-reactive

Anti-toxoplasma IgM

Non-reactive

Urine succinylacetone

Negative

Galactosemia screen

Normal

Urine organic acids

Hyperoxaluria†

Serum amino acids

Not consistent with metabolic disorder

was conducted at six weeks of age. Nine portal areas were identified. A Liver biopsy showing intrahepatic cholestatic changes with liver cell swelling (star), bile stasis (arrowhead), apoptosis (dotted arrow) and giant cell transformation (solid arrow). B Portal area in the liver showing absence of interlobular bile duct. C A rare portal area showing a small bile duct (solid arrow) with no evidence of bile plug. D Periportal areas showing bile ductular reaction with proliferation of cholangioles (cytokeratin 7 immunostain, brown colour)

Urine culture

Initial sample was a contaminant, repeat culture negative

Karyotype

47,XY,+21

Laboratory investigations were conducted to rule out various causes of cholestasis. Most tests were conducted between four to six weeks of age. The results for each investigation are shown, with a range of normal listed for quantitative investigations. *Considered to be protective; †Hyperoxaluria was deemed secondary to fat malabsorption according to consultation with a clinical biochemist. ↑ Elevated value; ↓ Low value. CMV Cytomegalovirus; Ig Immunoglobin

Case 1 diagnosis: Nonsyndromic paucity of intrahepatic bile ducts

A percutaneous liver biopsy was performed using ultrasound guidance. Histopathology revealed intrahepatic cholestatic liver changes (Figure 1A), paucity of interlobular bile ducts in the portal areas (Figure 1B), small bile ductule with absence of bile plugs (Figure 1C) and early bile ductular reaction in the periportal areas. This was consistent with nonsyndromic paucity of intrahepatic bile ducts. He was started on ursodeoxycholic acid (15 mg/kg/day) and fat-soluble vitamin supplements. The direct bilirubin peaked at 152  μmol/L at six weeks of age. He was discharged home at seven weeks of age. His scleral icterus, jaundice, liver enzyme and bilirubin levels gradually improved over the next few weeks. His stool colour normalized around two months of age. His direct bilirubin was 121 μmol/L at two months of age and 8 μmol/L at three months of age. Ursodeoxycholic acid and fat-soluble vitamins were discontinued. His alanine aminotransferase (ALT) level increased to a maximum of 111 U/L at two months of age, and then decreased to 49 U/L at four months of age. By nine months of age, his ALT had normalized to 25 U/L. His interim growth is acceptable (third percentile for weight and 15th percentile for height on WHO growth chart). He remained well at last follow-up. Nonsyndromic paucity of intrahepatic bile ducts (NSPIBD) is characterized by a paucity of interlobular bile ducts on liver biopsy in the absence of clinical features of Alagille syndrome. Liver biopsy findings are identical in the two conditions. NSPIBD can be idiopathic or associated with metabolic diseases (alpha-1-antitrypsin deficiency), viral infections (notably cytomegalovirus or rubella) or 290

chromosomal disorders such as Down syndrome. Its incidence and prevalence have not been precisely established. Treatment for NSPIBD consists of supportive management of cholestasis. The reported prognosis is variable, ranging from complete resolution to mortality in infancy. The clinician must differentiate NSIPBD from Alagille syndrome (Online Mendelian Inheritance in Man, code 118450), a welldescribed autosomal dominant syndrome with a prevalence of approximately one in 70,000 (1). In case series, Alagille syndrome is more common than NSIPBD. Alagille syndrome is characterized by cholestasis caused by bile duct paucity, congenital heart disease (peripheral pulmonic stenosis), characteristic facies, skeletal abnormalities (butterfly vertebrae) and ocular abnormalities (posterior embryotoxon). Neonates with Down syndrome are at an increased risk for developing cholestasis. In a retrospective study involving 206 infants with Down syndrome, 3.9% developed neonatal cholestasis (2). This represents a 100-fold increase over the general population incidence. NSPIBD has been reported in infants with Down syndrome. However, cholestasis in infants with Down syndrome is more likely to result from congenital hypothyroidism, transient myeloproliferative disorder or parenteral nutrition.

Clinical Pearls • Clinicians evaluating a child with cholestatic jaundice must consider a broad differential diagnosis. Neonatal cholestasis can result from infections, genetic and metabolic conditions, toxins, endocrine disorders or anatomical obstruction. • NSPIBD is a rare cause of neonatal cholestasis. The diagnosis is made using liver biopsy in the absence of clinical features of Alagille syndrome. The diagnosis of NSPIBD should be entertained in infants with cholestasis who have consistent clinical and laboratory findings. • Infants with Down syndrome are at increased risk for developing cholestatic jaundice. Causes of cholestasis in this patient population include congenital hypothyroidism, transient myeloproliferative disorder and parenteral nutrition. Paediatr Child Health Vol 20 No 6 August/September 2015

Clinician’s Corner

Acknowledgements: The authors thank Dr Ernest Cutz, Senior Staff Pathologist at The Hospital for Sick Children in Toronto, for his consultation on this case.

Peter MacPherson MD Pushpa Sathya MSc MD FRCPC Discipline of Pediatrics

References

1. Turnpenny PD, Ellard S. Alagille syndrome: Pathogenesis, diagnosis and management. Eur J Hum Genet 2012;20:251-7. 2. Arnell H, Fischler B. Population-based study of incidence and clinical outcome of neonatal cholestasis in patients with Down syndrome. J Pediatr 2012;161:899-902.

Chitra Pushpanathan MBBS FRCPC Discipline of Pathology, Faculty of Medicine, Memorial University St John’s, Newfoundland and Labrador

Paediatr Child Health Vol 20 No 6 August/September 2015

291

Case 1: Cholestatic jaundice in an infant with Down syndrome.

Case 1: Cholestatic jaundice in an infant with Down syndrome. - PDF Download Free
NAN Sizes 1 Downloads 19 Views