[Endocrinologic and metabolic complications of Alagille syndrome]

BACKGROUND

Patients with gastrointestinal and hepatobiliary disorders, either congenital or acquired early in childhood, are at high risk for various endocrine and metabolic abnormalities.

CASE REPORT

A 27-year-old woman with Alagille's syndrome presented with progressive jaundice and gait disturbances following surgery and ingestion of oral contraceptives. On physical examination, short stature, facial dysmorphism and neuromuscular symptoms such as polyneuropathy and spinocerebellar ataxia were noted. Serum concentrations of total bilirubin (54 mg/dl) and alkaline phosphatase were markedly increased, whereas serum levels of haptoglobin, zinc, vitamin D and E were decreased. Although prehepatic or intrahepatic etiologies of jaundice were more likely in this patient, posthepatic etiologies were ruled out by abdominal ultrasound and endoscopic retrograde cholangio-pancreaticography. Based on a working diagnosis of acute drug-induced cholestasis, treatment with high doses of lipid-soluble vitamins and ursodeoxycholic acid was initiated. In response to therapy, her abnormal laboratory results normalized and her neurologic symptoms markedly improved.

CONCLUSION

This clinicopathological conference of a patient with Alagille's syndrome illustrates the clinical presentation and therapy of metabolic and endocrine complications in chronic cholestasis.

Danazol induced cholestasis: pathogenetic hypothesis

Numerous mechanisms have been proposed to account for deficient bilirubin excretion and the pathogenesis of estrogen and steroid (danazol) induced intrahepatic cholestasis. Our hypothesis is based on the fact that danazol is administered in the treatment of pulmonary emphysema because it stimulates synthesis of alpha-1 antitrypsin and that other estrogen glucuro-conjugated metabolites are P-glycoprotein substrates. We believe that genetic alterations of alpha-1 antitrypsin and P-glycoprotein, either alone or in association with known pathogenetic mechanisms, may explain the onset of danazol induced cholestasis and justify the difference in its varying duration and intensity.

Terbinafine-induced prolonged cholestasis with reduction of interlobular bile ducts

The antifungal drug terbinafine has infrequently been incriminated in the occurrence of acute liver injury. We report a case of prolonged cholestasis that occurred in a 75-year-old woman, following terbinafine administration. Jaundice followed by pruritus appeared after four weeks of therapy and was associated with mixed hepatocellular and cholestatic liver tests abnormalities. Following drug withdrawal, serum bilirubin returned to normal values within three months, but anicteric cholestasis persisted for over six months. A liver biopsy performed after six months showed centrilobular cholestasis, discrete portal fibrosis, and a reduction in the number of interlobular biliary ducts. Terbinafine should be added to the list of drugs that can cause reduction in interlobular bile ducts.

Ketone potentiation of intrahepatic cholestasis: effect of two aliphatic isomers

Occupational exposure to methyl isobutyl ketone (MiBK) or methyl n-butyl ketone (MnBK) normally occurs by inhalation. The present study reports that exposure to both ketones can potentiate cholestasis experimentally induced by taurolithocholic acid (TLC, 30 mumol/kg) or by a combination of manganese (Mn, 4.5 mg/kg) and bilirubin (BR, 25 mg/kg). Male Sprague-Dawley rats were exposed for 3 d, 4 h/d, to MiBK or MnBK vapors using 0.5, 1, 1.5, or 2 times the minimal effective concentration (MEC). The estimated MiBK or MnBK MEC for potentiating TLC- or Mn-BR-induced cholestasis were 400 and 150 ppm, respectively. Eighteen hours after ketone exposure, rats were injected i.v. with TLC or Mn-BR. Bile flow was measured from 15 to 150 min after the cholestatic regimen. Rats exposed to MiBK or MnBK exhibited an enhanced diminution in bile flow compared to controls that was dose-dependent with the inhaled ketone dose. The dose-effect characteristics of the potentiation phenomenon were established. Results indicate that MiBK or MnBK inhalation potentiated both TLC and Mn-BR cholestasis in a dose-related fashion. Quantitative differences, however, exist between both ketones with respect to their ability to potentiate both models. Comparison between the two isomers was established, and MnBK was found to be more potent than MiBK.

[Severe protracted cholestasis after general anesthesia in a patient with Alagille syndrome]

A 27-year-old female patient with partial Alagille's syndrome (hypoplasia of the intrahepatic bile ducts, typical facial dysmorphism and skeletal anomalies) developed a marked cholestasis (total bilirubin 59 mg/dl), decrease of liver synthesis tests and ascites four weeks after gynecological surgery with general anesthesia involving propofol, isoflurane and nitrous oxide. Slow recovery could be achieved under treatment with ursodeoxycholic acid, spironolactone and substitution of fat-soluble vitamins A, D, E and K. Four months after admission the ascites had disappeared, liver synthesis had increased and the total bilirubin level had dropped to 3.8 mg/dl. Since all other possible causes were excluded during the hospital stay, the prolonged episode of cholestasis in this patient is best explained by the preceding general anesthesia with propofol which is known to be metabolized in the liver and impedes hepatic cytochrome P450 and hepatic blood flow.

Modulation of hepatic content and biliary excretion of P-glycoproteins in hepatocellular and obstructive cholestasis in the rat

BACKGROUND/AIMS

Release into bile of canalicular membrane enzymes, such as alkaline phosphatase and gamma-glutamyl transpeptidase, is significantly increased in rats subjected to experimental models of hepatocellular or obstructive cholestasis. This effect appears to be related to a greater susceptibility of these membrane intrinsic proteins to the solubilizing effects of secreted bile acids. It is not known whether canalicular membrane transport proteins, such as P-glycoprotein isoforms, involved in ATP-dependent xenobiotic biliary excretion and phospholipid secretion, are excreted into bile and whether this process is modified in cholestasis. The aims of this work have been to investigate in the rat: a) whether P-glycoproteins are normally excreted into bile, b) whether their excretion is modified in two experimental models of cholestasis, i.e., hepatocellular cholestasis induced by ethynylestradiol and obstructive cholestasis, and c) whether observed changes correlate with bile acid and phospholipid secretion and enzyme release into bile and with relative P-glycoprotein content in hepatic tissue and isolated and purified canalicular membranes.

METHODS

P-glycoproteins in bile and hepatic tissue were identified and quantitated by Western-blotting and immunohistochemistry using the C219 MAb. Changes in total mdr mRNA were analyzed by Northern-blotting.

RESULTS

Like canalicular membrane enzymes, P-glycoproteins are normally excreted into bile. Ethynylestradiol-induced cholestasis was associated with a 4.9-fold increase in P-glycoprotein excretion compared with controls while, in contrast, the excretion of the carrier decreased markedly in obstructive cholestasis to 2% of control values. P-glycoprotein excretion per nmol of secreted bile acids increased 4.4-fold in ethynylestradiol-induced cholestasis but decreased to 2% of control values in obstructive cholestasis. Total mdr mRNA levels in hepatic tissue were markedly increased (3.4-fold) in rats subjected to obstructive cholestasis and moderately increased (1.6-fold) in the ethynylestradiol group, compared with controls. P-glycoprotein content in isolated canalicular membranes was slightly decreased by 15% in ethynylestradiol-induced cholestasis, while it increased 4.7-fold in obstructive cholestasis. Immunohistochemistry of rat livers showed that P-glycoprotein reaction at the canalicular domain of hepatocytes at acinar zone 1 was decreased in ethynylestradiol-treated rats and markedly increased in obstructive cholestasis.

CONCLUSIONS

Ethynylestradiol-induced cholestasis is associated with increased P-glycoprotein biliary excretion and decreased hepatic content. In contrast, obstructive cholestasis results in decreased P-glycoprotein biliary excretion and increased hepatic content. These results suggest that biliary P-glycoprotein excretion might be a modulating factor in canalicular membrane P-glycoprotein content. Increased P-glycoprotein release into bile in ethynylestradiol-treated rats is apparently not a consequence of cholestasis, but it might be a primary event and play a pathogenetic role in ethynylestradiol-induced cholestasis.

Intrahepatic cholestasis without hepatitis induced by amoxycillin/clavulanic acid

Amoxycillin/clavulanic acid liver injury is very rare. We describe an exceptional case of intrahepatic cholestasis without hepatitis induced by amoxycillin/clavulanic acid. Recognition of this benign cholestatic syndrome as a side-effect may obviate unnecessary complementary and costly procedures.

Vanishing bile duct syndrome temporally associated with ibuprofen use

Nonsteroidal anti-inflammatory drugs are widely used, but the potential hepatotoxic side effects are not always appreciated. Herein, we report the first case, to our knowledge, of an atopic patient in whom severe cholestatic jaundice from bile ductopenia developed 3 wk after initiation of ibuprofen therapy. This drug-induced vanishing bile duct syndrome is probably an immunological (hypersensitivity) reaction. Vanishing bile duct syndrome as a consequence of ibuprofen use should be considered as a potential cause of chronic cholestasis when other more common etiologies have been excluded.

'Relapse' of chronic active hepatitis--not always what it seems

Immune chronic active hepatitis is a disease notorious for its unpredictability. In a patient with chronic hepatitis who has already suffered relapses a search for a second cause of jaundice is not usually necessary. This report emphasises the essential role of liver biopsy.

[Antibiotic-induced prolonged cholestasis: suspected induction by ceftibuten]

We report on a 43-year-old female diabetic patient who was treated with ceftibuten because of Pseudomonas aeruginosa induced otitis externa. Thereafter she developed a prolonged seven-months-persisting irreversible cholestasis. Liver puncutre revealed a canalicular and hepatocellular cholestasis without liver cell necrosis or bile duct injury. After seven-months the patient died because of antibiotic-resistant Pseudomonas-septicemia.

Terbinafine-induced cholestatic liver disease

Hepatobiliary disorders associated with orally administered terbinafine have rarely been reported. We describe a case of prolonged terbinafine-induced cholestatic liver disease. Extrahepatic cholestasis, viral hepatitis and autoimmune liver disorders were excluded. The histological findings of marked cholestasis without evidence of extrahepatic biliary obstruction or acute hepatitis were compatible with the diagnosis of drug-induced liver disease. Biochemical parameters of liver cell damage returned to normal levels 6 months later.

Structure-function correlation of tight junctional impairment after intrahepatic and extrahepatic cholestasis in rat liver

BACKGROUND & AIMS

Tight junctions, the only barrier between blood and bile, are crucial in bile formation. The aim of this study was to correlate changes in morphology and permeability by comparing structural parameters with marker secretion into normal and cholestatic rat bile.

METHODS

Cholestasis was induced by bile duct ligation of 5 and 21 days of ethinylestradiol administration. Quantitated structural parameters induced junctional length, strand number, junctional depth, and spacing of junctional particles. Junctional permeability was probed with horseradish peroxidase and dextrans of increasing sizes.

RESULTS

Junctional length was decreased slightly by ethinylestradiol (-16% after 21 days) but increased by ligation (77%). Mean strand number decreased from 4.6 to 3.7 after 21 days of ethinylestradiol and 3.4 after ligation associated with increased junctional depth. The proportions of morphologically horseradish peroxidase-positive junctions increased from 4% to 15% after 21 days of ethinylestradiol and to 56% after ligation. Horseradish peroxidase secretion was increased twofold by ethinylestradiol and 6.5-fold by ligation, paralleled by an increase of dextran size selectivity from 70,000 to 79,000 daltons after ethinylestradiol and to 266,000 daltons after ligation.

CONCLUSIONS

Impairment of junctional integrity is paralleled with the degree of cholestasis, whereas correlation of morphological and physiological alterations shows a close structure-function relationship.

Abnormal lipoproteins in the ANIT-treated rat: a transient and reversible animal model of intrahepatic cholestasis

The alpha-naphthylisothiocyanate (ANIT)-treated rat was evaluated as a model for lipoprotein metabolism in cholestatic liver disease. Alterations in lipoprotein composition over a period of 120 h after ANIT treatment (100 mg/kg) were studied. Eighteen hours after treatment, plasma bilirubin and bile acid levels began to rise, together with significant increases in free cholesterol. C-18/16, C-18/18, and C-18/20 phospholipid molecular species. By 48 h, plasma lipid levels were maximal, free cholesterol was 935%, cholesteryl ester 294%, phospholipid 611%, and triacylglycerols 176% of controls, and the cholesteryl ester to free cholesterol ratio began to recover with a modest shift from cholesteryl esters containing C-20 fatty acids to those containing C-18 fatty acids. Lecithin: cholesterol acyltransferase activity was near normal, lipoprotein lipase activity was increased, and hepatic triacylglycerol lipase activity was decreased. Density gradient ultracentrifugation of rat plasma demonstrated a marked shift in lipoprotein density towards the low density lipoprotein range, with the increased lipid being associated with apolipoproteins A-I and E. The presence of large 300-400 A particles and the high surface to core lipid ratio in this density range was consistent with the presence of lipoprotein-X-like vesicles. Apolipoprotein B-48 accumulation was observed in the high density fractions (d15 > 1.063 g/ml) suggesting that these rats have impaired lipoprotein remnant removal. All of these increased levels returned to near normal by 120 h. This study demonstrates that ANIT-treatment induces a transient, fully reversible, non-surgical intrahepatic cholestasis that results in many of the plasma lipoprotein abnormalities associated with human hepatic cholestasis and the bile duct-ligated rat.

Excess zinc associated with severe progressive cholestasis in Cree and Ojibwa-Cree children

BACKGROUND

High hepatic copper concentrations have been reported in several liver disorders. We report six Native Canadian children with severe chronic cholestatic liver disease, who had excess hepatic copper and zinc.

METHODS

The children, aged 22 months to 8 years, came from northern Ontario, Canada. All were referred for possible liver transplantation because of end-stage liver disease. We examined explanted liver samples (or liver biopsy material in one case) by scanning transmission electronmicroscopic (STEM) X-ray elemental microanalysis and atomic absorption spectrophotometry. Samples from four controls (two with no liver pathology, one with biliary atresia, and one with Wilson's disease) were also analysed by atomic absorption spectrophotometry.

FINDINGS

The explanted livers showed similar distinctive signs of advanced biliary cirrhosis, and on electronmicroscopy there were dense deposits in enlarged lysosomes and in cytoplasm. Hepatic copper concentrations were many times higher in the five patients with measurements (47.6-56.9 microgram/g dry weight) than in two samples of normal control liver tissue (2.3 and 2.9 microgram/g). Similarly, hepatic zinc concentrations were many times higher in the patients than in controls (104-128 vs 1.9-3.2 microgram/g dry weight).

INTERPRETATION

The excess copper may be due to chronic cholestasis but the excess zinc is unexplained. Since three of the patients are related (shared grandparents), a genetic disorder of metal metabolism is possible, but we cannot exclude environmental factors.