Liver disease caused by disorders of bile acid synthesis

Variable clinical spectrum of the most common inborn error of bile acid metabolism--3beta-hydroxy-Delta 5-C27-steroid dehydrogenase deficiency

OBJECTIVE

We studied the clinical features of children with 3beta-hydroxy-Delta 5-C27-steroid dehydrogenase (3beta-HSDH) deficiency presenting to King's College and Great Ormond Street hospitals between 1989 and 2005. The diagnosis was made biochemically by detection of sulphated dihydroxycholenoic acids and trihydroxycholenoic acids in urine by fast atom bombardment mass spectrometry or electrospray ionisation tandem mass spectrophotometry and a plasma bile acid profile showing absent or low cholic and chenodeoxycholic acid levels and high concentrations of 3beta-7 alpha-dihydroxy-5-cholenoic acid and 3beta-7 alpha-12 alpha-trihydroxy-5-cholenoic acid.

RESULTS

Eighteen children (12 male) with 3beta-HSDH deficiency were identified and diagnosed at a median age of 1.35 years (range 8 weeks-11 years). The presenting features included neonatal cholestasis (n = 11), rickets (n = 8, 1 of whom also had hypocalcaemic tetany, seizures, and normal liver biochemical markers), hepatomegaly (n = 7), pruritus (n = 3), and steatorrhoea and failure to thrive (n = 3). Ten children had low serum 25-OH vitamin D levels, of whom 8 also had low vitamin E and 6 had low vitamin A serum levels. Liver histology showed giant cell change and hepatocyte disarray in all with added features of cholestasis in 11, bridging fibrosis in 6, micronodular cirrhosis in 1, fatty change in 1, and active lobular and portal inflammation in 1. Five patients were treated with cholic acid and chenodeoxycholic acid (7 mg x kg(-1) x day(-1) of each), 7 with chenodeoxycholic acid only (7-18 mg x kg(-1) x day(-1)), and 1 with cholic acid (8 mg x kg(-1) x day(-1)) only. Repeated liver biopsies performed in 4 patients 6 months after starting replacement therapy showed improved histological changes. Three children died untreated before 5 years of age. After a median follow-up of 5.5 years (range 1-17 years) 12 out of 13 treated children have no clinical signs of liver disease or of fat-soluble vitamin deficiency.

CONCLUSIONS

3beta-HSDH deficiency is a rare inborn error of metabolism with diverse clinical features. Early replacement treatment leads to clinical and biochemical control and prevents chronic liver and bone disease, at least in the medium term.

Nonobstructive neonatal cholestasis: clinical outcome and scoring of the histopathological changes in liver biopsies

The clinical outcome of nonobstructive neonatal cholestasis (NC) cases varies greatly and the prognosis is generally unpredictable. In this study, we aimed to evaluate the prognostic benefits of qualitative analysis of histopathological changes in nonobstructive NC cases. A total of 28 nonobstructive NC cases (18 neonatal hepatitis; 10 intrahepatic bile duct paucity) were studied. We analyzed the relationship between histopathological and clinical parameters. Hepatic inflammation, bridging necrosis, pericellular fibrosis, giant cell transformation, and extramedullary hematopoiesis were evaluated and scored according to their absence or presence in each case. The sum of the histopathological scores was accepted as "total pathological injury score." The height percentiles, the presence and the degree of hepatomegaly and ascites, and serum alanine aminotransferase (ALT), albumin, and bilirubin levels and prothrombin time were also evaluated and scored. The patients were divided into 2 clinical course groups considered "good" or "bad" according to the total clinical scores. For statistical analysis, Pearson's chi-square test, Mann-Whitney U-test, and receiver operating characteristic curve were used. We found a statistically significant negative relation between the clinical course and total pathological injury score (P = 0.042) and pericellular fibrosis (P = 0.016). In conclusion, during the interpretation of liver biopsies of nonobstructive NC, scoring of histopathological changes should be done for assessing the clinical prognostic outcome.

Neonatal hepatitis syndrome

Conjugated hyperbilirubinaemia in an infant indicates neonatal liver disease. This neonatal hepatitis syndrome has numerous possible causes, classified as infective, anatomic/structural, metabolic, genetic, neoplastic, vascular, toxic, immune and idiopathic. Any infant who is jaundiced at 2-4 weeks old needs to have the serum conjugated bilirubin measured, even if he/she looks otherwise well. If conjugated hyperbilirubinaemia is present, a methodical and comprehensive diagnostic investigation should be performed. Early diagnosis is critical for the best outcome. In particular, palliative surgery for extrahepatic biliary atresia has the best chance of success if performed before the infant is 8 weeks old. Definitive treatments available for many causes of neonatal hepatitis syndrome should be started as soon as possible. Alternatively, liver transplantation may be life saving. Supportive care, especially with attention to nutritional needs, is important for all infants with neonatal hepatitis syndrome.

Common diagnostic problems in pediatric liver pathology

The role of the pathologist in dealing with common problems of liver disease in children is likely to change dramatically as the molecular genetic revolution progresses. For example, microchip arrays for genes involved in bile salt synthesis and transport will pinpoint the specific mutations responsible for infantile cholestasis and similar methods will sort out infectious agents of acute and chronic hepatitis. But even as biochemistry, microbiology, and immunology laboratories already provide essential diagnostic information in such settings, informed histopathologic interpretation will continue to guide investigations of etiology and therapeutics and will remain an important medical necessity [95,96,100,102,104].

Update on the etiologies and management of neonatal cholestasis

The early detection of cholestatic liver disease is one of the major challenges facing pediatricians when evaluating the jaundiced infant. Early recognition of liver disease greatly facilitates the care and outcome of infants, because several serious life-threatening disorders may have cholestasis as a major presenting sign of underlying neonatal liver disease. A key component of the work-up is measurement of serum conjugated bilirubin levels, which if elevated should prompt the clinician to initiate a work-up to determine the cause of neonatal cholestasis. In general, if a patient is developing progressive jaundice soon after birth, is still jaundiced at 2 weeks of life, or develops jaundice within the first month of life, a work-up for neonatal cholestasis should begin. A number of previously undiagnosed causes of neonatal cholestasis are beginning to be assigned genetic and infectious etiologies, with significant implications for the work-up and management of cholestatic infants.