Michelle Hadchouel

Hepatocyte Nuclear Factor 1 Inactivation Results in Hepatic Dysfunction, Phenylketonuria, and Renal Fanconi Syndrome

HNF1 is a transcriptional activator of many hepatic genes including albumin, alpha1-antitrypsin, and alpha- and beta-fibrinogen. It is related to the homeobox gene family and is predominantly expressed in liver and kidney. Mice lacking HNF1 fail to thrive and die around weaning after a progressive wasting syndrome with a marked liver enlargement. The transcription rate of genes like albumin and alpha1-antitrypsin is reduced, while the gene coding for phenylalanine hydroxylase is totally silent, giving rise to phenylketonuria. Mutant mice also suffer from severe Fanconi syndrome caused by renal proximal tubular dysfunction. The resulting massive urinary glucose loss leads to energy and water wasting. HNF1-deficient mice may provide a model for human renal Fanconi syndrome.

Hepatocanalicular bile salt export pump deficiency in patients with progressive familial intrahepatic cholestasis

BACKGROUND & AIMS Progressive familial intrahepatic cholestasis (PFIC), an inherited liver disease of childhood, is characterized by cholestasis and either normal or increased serum gamma-glutamyltransferase activity. Patients with normal gamma-glutamyltransferase activity have mutations of the FIC1 locus on chromosome 18q21 or mutations of the BSEP gene on chromosome 2q24. Also, patients with bile acid synthesis defects have low gamma-glutamyltransferase activity. We investigated expression of the bile salt export pump (BSEP) in liver samples from patients with a PFIC phenotype and correlated this with BSEP gene mutations. METHODS BSEP and multidrug resistance protein 2 (MRP2) expressions were studied by immunohistochemistry in liver specimens of 28 patients and BSEP gene mutation analysis in 19 patients. Bile salt kinetics were studied in 1 patient. RESULTS Sixteen of 28 liver samples showed no canalicular BSEP staining. Staining for MRP2 showed a normal canalicular pattern in all but 1 of these samples. Ten of 19 patients showed BSEP gene mutations; BSEP protein expression was lacking in all 10 patients. No mutations were found in 9 of 19 patients, and in all except 1, BSEP protein expression was normal. Bile salt concentration in bile of BSEP-negative/MRP2-positive PFIC patients was 0.2 +/- 0.2 mmol/L (n = 9; <1% of normal) and in BSEP-positive PFIC patients 18.1 +/- 9.9 mmol/L (n = 3; 40% of normal). The kinetic study confirmed the dramatic decrease of bile salt secretion in BSEP-negative patients. CONCLUSIONS The findings show a close correlation between BSEP gene mutations and canalicular BSEP expression. Biliary secretion of bile salts is greatly reduced in BSEP-negative patients.

DETECTION OF HEPATITIS B VIRUS DNA IN LIVER AND SERUM: A DIRECT APPRAISAL OF THE CHRONIC CARRIER STATE

The detection of hepatitis B virus (HBV) DNA in the liver and the serum permits direct study of the interaction between the virus and the liver cell. 40 HBV chronic carriers were studied by the blot technique of Southern to detect HBV DNA, and the results were compared with the serological status and histological status of the patients. It was possible to define two different chronic carrier states. The first is characterised by free viral DNA in the liver, with viral DNA and hepatitis B e antigen (HBeAG) in the serum; integrated HBV DNA is also present, at least in some patients. The second carrier state is characterised by the presence of only integrated HBV DNA sequences in the liver: viral DNA and HBeAg are not present in the serum. In one HBeAg-negative patient, however, free HBV DNA was detected in the liver and HBV DNA was present in the serum. The hybridisation technique appears to be a very sensitive test which could reflect viral multiplication better than HBeAg radioimmunoassay. Since a needle biopsy sample provides sufficient tissue for the Southern blot technique, it should be useful in understanding chronic hepatitis, the selection of patients for antiviral therapy, and the estimation of its efficiency.

Acute hemorrhagic, hepatic, and neurologic manifestations in juvenile rheumatoid arthritis: Possible relationship to drugs or infection

Seven children with juvenile rheumatoid arthritis had a syndrome characterized by hemorrhage and neurologic, hepatic, hematologic, and metabolic manifestations. The disease did not seem to conform clearly to the characteristics of Reye syndrome or any other well-known entity. This severe complication may be induced by macrophage activation secondary to a drug or intercurrent infection. Our data suggest that a sudden fall in erythrocyte sedimentation rate or in platelet and fibrinogen levels may mark the start of this complication and may be an indication for rapid steroid therapy.

Sclerosing cholangitis in children

We report on 56 children with sclerosing cholangitis (SC) seen between 1972 and 1992. The first symptoms occurred at a mean age of 3.7 years; 15 infants had neonatal cholestatic jaundice. At diagnosis, cholestatic jaundice was present in 25 children, hepatomegaly in 54, splenomegaly in 41, and ascites in 12. Serum alkaline phosphatase activity was increased in 49 patients and gamma-glutamyltransferase activity in all patients tested. Most often the histopathologic findings were extensive portal fibrosis and neoductular proliferation. Cholangiography showed abnormal intrahepatic bile ducts in all children and abnormal extrahepatic bile ducts in 35 (63%). The children were separated into three groups: (1) those with SC of neonatal onset (27%); (2) those with SC of postneonatal onset associated with another disease (55%)--histiocytosis X in 14 children, immunodeficiency syndromes in 8, chronic inflammatory bowel disease or autoimmune hepatitis in 8, and congenital psoriasis in 1; and (3) those with SC of postneonatal onset without an associated disease (18%). Biliary cirrhosis was present in all but three children after 6 months to 19.3 years of follow-up. Eleven children died of portal hypertension or liver failure, and six died of a complication related to the associated disease. Fifteen children had liver transplantation; 11 of these are alive 6 months to 6 1/2 years later without recurrence of SC. The overall estimated median survival time of children with SC was 10 years from clinical onset. These results indicate that SC should be suspected in all children with a chronic cholestatic disease and increased serum gamma-glutamyl transferase activity, especially when diseases known to be associated with SC are present. The prognosis is poor, but liver transplantation should be considered except in those with severe immunodeficiency syndromes.

Mutations in JAGGED1 gene are predominantly sporadic in Alagille syndrome.

BACKGROUNDS & AIMS Mutations in the JAGGED1 gene are responsible for the Alagille syndrome, an autosomal dominant disorder characterized by neonatal jaundice, intrahepatic cholestasis, and developmental disorders affecting the liver, heart, vertebrae, eyes, and face. We screened a large group of patients for mutations in JAGGED1 and studied transmission of the mutations. METHODS The coding sequence of the JAGGED1 gene was searched by single-strand conformation polymorphism and sequence analysis for mutations in 109 unrelated patients with the Alagille syndrome and their family if available. RESULTS Sixty-nine patients (63%) had intragenic mutations, including 14 nonsense mutations, 31 frameshifts, 11 splice site mutations, and 13 missense mutations. We identified 59 different types of mutation of which 54 were previously undescribed; 8 were observed more than once. Mutations were de novo in 40 of 57 probands. CONCLUSIONS Most of the observed mutations other than the missense mutations in JAGGED1 are expected to give rise to truncated and unanchored proteins. All mutations mapped to the extracellular domain of the protein, and there appeared to be regional hot spots, although no clustering was observed. Thus, the sequencing of 7 exons of JAGGED1 would detect 51% of the mutations. Transmission analysis showed a high frequency of sporadic cases (70%).

Progressive familial intrahepatic cholestasis type 1 and extrahepatic features: no catch-up of stature growth, exacerbation of diarrhea, and appearance of liver steatosis after liver transplantation

BACKGROUND/AIMS Progressive familial intrahepatic cholestasis characterized by normal serum gamma-glutamyltransferase activity can be due to mutations in familial intrahepatic cholestasis type 1 (FIC1) (ATP8B1), a gene expressed in several organs. In some cases, it is associated with extrahepatic features. We searched for FIC1 mutations and analyzed the outcome of extrahepatic features after liver transplantation in two children with this form of progressive familial intrahepatic cholestasis associated with chronic unexplained diarrhea and short stature. METHODS FIC1 sequence was determined after polymerase chain reaction (PCR) of genomic lymphocyte DNA and/or reverse transcription-PCR of liver or lymphocyte RNA. RESULTS A homozygous amino acid change deletion was found in one child. The second child harboured compound heterozygous missense and nonsense mutations. In both children, despite successful liver transplantation, evolution (follow-up: 9.5-11 years) was characterized by exacerbation of diarrhea and no catch-up of stature growth, and appearance of liver steatosis. CONCLUSIONS Progressive familial intrahepatic cholestasis characterized by normal serum gamma-glutamyltransferase activity and extrahepatic features corresponds to progressive familial intrahepatic cholestasis type 1. Extrahepatic symptomatology is not corrected or may be aggravated by liver transplantation, impairing life quality.

Congenital hepatic fibrosis in children

Twenty-seven children with congenital hepatic fibrosis were followed for three months to 12 years. Hepatosplenomegaly, normal liver function tests, and kidney abnormalities were present in most patients, indicating that a correct diagnosis of congenital hepatic fibrosis could be made using simple clinical, biologic, and radiologic criteria. Esophageal endoscopy showed varices in 21 patients. Sixteen children underwent portal-systemic shunt surgery. Follow-up examinations did not show any impairment of liver function or any sign of hepatic encephalopathy. Cholangitis was present in only three children.

Long-term outcome after surgery for biliary atresia: Study of 40 patients surviving for more than 10 years

To define long-term prognosis of children who underwent surgery for biliary atresia, a retrospective study was undertaken in 122 children who underwent one of the Kasaï procedures between 1968 and 1977. Forty of the 122 children (32.7%) were alive after 10 years. Firm hepatomegaly was present in 31 and splenomegaly in 29 children. Serum bilirubin or all liver function tests were normal in 21 and 11 children, respectively; survival rate decreased with the age at operation, but no significant difference was observed in the rate of children surviving with normal serum bilirubin whether they underwent surgery before age 2 months or between 2 and 3 months. Twenty-four had esophageal varices and 15 experienced gastrointestinal bleeding. Normal liver-function tests and absence of portal hypertension were observed in 11 of 122 children. These results indicate that Kasaïs procedures were helpful in a significant proportion of children with biliary atresia who underwent surgery during this period. However, 80% of children who initially underwent surgery with Kasaïs procedures should eventually undergo liver transplantation.

Autoimmune Hepatitis Associated with Anti-actin Antibodies in Children and Adolescents

Summary The clinical, biochemical, morphological, and evolutive features of autoimmune hepatitis associated with serum smooth muscle antibodies of anti-actin specificity were retrospectively analyzed in 31 children and adolescents. Cirrhosis was present at diagnosis in all but six patients, including nine of the 12 diagnosed within 6 months from the onset. In 15 children, one or more associated diseases of an immune-mediated mechanism were present, including chronic arthritis, sclerosing cholangitis, inflammatory bowel disease, and cutaneous vasculitis. All patients were treated with prednisone and azathioprine with normalization or improvement of liver function tests: 28 children are currently alive after a mean follow-up of 4 years, 10 months. Treatment was inter rupted in four patients only. Two patients died of liver failure in spite of immunosuppressive therapy before the era of liver transplantation. In spite of prolonged therapy, five other patients ultimately required liver transplantation during adolescence or early adulthood. These results (a) further define a group of autoimmune hepatitis in children characterized by the presence of serum anti-actin antibodies; (b) indicate that immunosuppressive therapy improves liver function, although in most cases it must be continued for a long period to maintain remission; and (c) suggest that progressive liver failure may occur in early adulthood and may require liver transplantation.