Effect of ursodeoxycholic acid therapy on hepatic function in children with intrahepatic cholestatic liver disease

Diagnosis and management of Alagille and progressive familial intrahepatic cholestasis

Alagille syndrome and progressive familial intrahepatic cholestasis are conditions that can affect multiple organs. Advancements in molecular testing have aided in the diagnosis of both. The impairment of normal bile flow and secretion leads to the various hepatic manifestations of these diseases. Medical management of Alagille syndrome and progressive familial intrahepatic cholestasis remains mostly targeted on supportive care focusing on quality of life, cholestasis, and fat-soluble vitamin deficiency. The most difficult therapeutic issue is typically related to pruritus, which can be managed by various medications such as ursodeoxycholic acid, rifampin, cholestyramine, and antihistamines. Surgical operations were previously used to disrupt enterohepatic recirculation, but recent medical advancements in the use of ileal bile acid transport inhibitors have shown great efficacy for the treatment of pruritus in both Alagille syndrome and progressive familial intrahepatic cholestasis.

Periductal bile acid exposure causes cholangiocyte injury and fibrosis

INTRODUCTION

Bile duct integrity is essential for the maintenance of the structure and function of the biliary tree. We previously showed that cholangiocyte injury in a toxic model of biliary atresia leads to increased monolayer permeability. Increased epithelial permeability was also shown in other cholangiopathies. We hypothesized that after initial cholangiocyte injury, leakage of bile acids into the duct submucosa propagates cholangiocyte damage and fibrosis. We thus aimed to determine the impact of bile acid exposure on cholangiocytes and the potential therapeutic effect of a non-toxic bile acid.

MATERIALS AND METHODS

Extrahepatic bile duct explants were isolated from adult and neonatal BALB/c mice. Explants were cultured with or without glycochenodeoxycholic acid and ursodeoxycholic acid. They were then fixed and stained.

RESULTS

Explants treated with glycochenodeoxycholic acid demonstrated cholangiocyte injury with monolayer disruption and partial lumen obstruction compared to control ducts. Masson's trichrome stains revealed increased collagen fibers. Myofibroblast marker α-SMA stains were significantly elevated in the periductal region. The addition of ursodeoxycholic acid resulted in decreased cholangiocyte injury and reduced fibrosis.

CONCLUSIONS

Bile acid leakage into the submucosa after initial cholangiocyte injury may serve as a possible mechanism of disease propagation and progressive fibrosis in cholangiopathies.

A Current Understanding of Bile Acids in Chronic Liver Disease

Chronic liver disease (CLD) is one of the leading causes of disability-adjusted life years in many countries. A recent understanding of nuclear bile acid receptor pathways has increased focus on the impact of crosstalk between the gut, bile acids, and liver on liver pathology. While conventionally used in cholestatic disorders and to dissolve gallstones, the discovery of bile acids' influence on the gut microbiome and human metabolism offers a unique potential for their utility in early and advanced liver diseases because of diverse etiologies. Based on these findings, preclinical studies using bile acid-based molecules have shown encouraging results at addressing liver inflammation and fibrosis. Emerging data also suggest that bile acid profiles change distinctively across various causes of liver disease. We summarize the current knowledge and evidence related to bile acids in health and disease and discuss culminated and ongoing therapeutic trials of bile acid derivatives in CLD. In the near future, further evidence in this area might help clinicians better detect and manage liver diseases.

Alagille Syndrome: A Focused Review on Clinical Features, Genetics, and Treatment

Alagille syndrome (ALGS) is an autosomal dominant disorder caused by pathogenic variants in JAG1 or NOTCH2, which encode fundamental components of the Notch signaling pathway. Clinical features span multiple organ systems including hepatic, cardiac, vascular, renal, skeletal, craniofacial, and ocular, and occur with variable phenotypic penetrance. Genotype-phenotype correlation studies have not yet shown associations between mutation type and clinical manifestations or severity, and it has been hypothesized that modifier genes may modulate the effects of JAG1 and NOTCH2 pathogenic variants. Medical management is supportive, focusing on clinical manifestations of disease, with liver transplant indicated for severe pruritus, liver synthetic dysfunction, portal hypertension, bone fractures, and/or growth failure. New therapeutic approaches are under investigation, including ileal bile acid transporter (IBAT) inhibitors and other approaches that may involve targeted interventions to augment the Notch signaling pathway in involved tissues.

Alagille Syndrome

Alagille syndrome is a complex multisystem autosomal dominant disorder with a wide variability in penetrance of clinical features. A majority of patients have pathogenic mutations in either the JAG1 gene, encoding a Notch pathway ligand, or the receptor NOTCH2. No genotype-phenotype correlations have been found in any organ system. Liver disease is a major cause of morbidity in this population, whereas cardiac and vascular involvement accounts for most of the mortality. Current therapies are supportive, but the future is promising for the development of targeted interventions to augment Notch pathway signaling in involved tissues.

Management of cholestatic pruritus in children with Alagille syndrome: Case report and literature review

Alagille syndrome causes intractable pruritus and disfiguring xanthomas because of retained bile acids and cholesterol. Drug therapy in addition to surgical intervention may be effective in many patients in reducing serum bile acids, cholesterol levels, pruritus, and skin xanthomas. In this report, we describe a child with Alagille syndrome who presented with severe pruritus and xanthomas as a consequence of severe hypercholesterolemia and discuss the treatment modalities.

Increase of Serum γ-Glutamyltransferase Associated With Development of Cirrhotic Cystic Fibrosis Liver Disease

BACKGROUND

Identification of patients at risk for developing cirrhotic cystic fibrosis liver disease (CCFLD) is essential for targeting potentially preventive treatment. We studied the evolution of serum liver enzymes and thrombocyte counts as predictors of CCFLD development.

METHODS

For this study, we defined the diagnosis of CCFLD as the combination of splenomegaly (on either physical examination or ultrasound scan) and macronodularity of the liver on ultrasound scan. We reviewed the medical records of 277 pediatric patients with CF for the diagnosis of CCFLD. In each patient with CCFLD, we reviewed serum liver enzymes and thrombocyte counts in the 2-year period preceding the diagnosis of CCFLD. We compared these results with a non-CCFLD control group (patients with CF older than 15 years with no reported signs or symptoms of CCFLD).

RESULTS

In the 2 years preceding the diagnosis, the γ-glutamyltranspeptidase (GGT) levels of patients with CCFLD were significantly higher compared to non-CCFLD controls (42 ± 5 vs 17 ± 2 U/L, respectively; P < 0.001). Corresponding aspartate aminotransferase and alanine aminotransferase levels did not significantly differ between patients with CCFLD and controls. The thrombocyte counts in patients with CCFLD were significantly lower than those in controls (252 ± 108 vs 320 ± 94 × 10 /L, respectively; P < 0.05). The predictive value for CCFLD of a single GGT measurement was low; however, for patients with CF with a mean GGT > 35 U/L, based on repeated measurements, the odds ratio for developing CCFLD was 39 (95% confidence interval 9-175, specificity was 95%, sensitivity was 64%, positive predictive value was 50%). For the thrombocytes, however, no reliable cutoff value could be identified.

CONCLUSIONS

In pediatric patients with CF, a persistently high-normal GGT is strongly associated with the diagnosis of CCFLD within 2 years. The prognostic value of a single GGT measurement is limited, but repeated GGT measurements may allow the identification of groups of patients at increased risk for CCFLD.

Advances in pathogenesis and management of pruritus in cholestasis

Chronic pruritus is a burdensome feature of numerous hepatobiliary disorders such as primary biliary cirrhosis, primary sclerosing cholangitis, cholangiocarcinoma, inherited forms of cholestasis and intrahepatic cholestasis of pregnancy. Bile salts, μ-opioids, serotonin, histamine and steroids have been controversially discussed in the pathogenesis of cholestatic pruritus. However, for these substances neither a correlation with itch severity nor a causative link has ever been established. Recent findings indicate that the potent neuronal activator lysophosphatidic acid and autotaxin, the enzyme forming lysophosphatidic acid, may play a key element in the pathogenesis of cholestatic pruritus. Serum activity of autotaxin correlated with itch intensity and response to antipruritic treatment in patients with cholestatic pruritus, but not other forms of pruritus. Autotaxin activity thereby represents the first biomarker for pruritus and had a positive predictive value of 70% in differentiating cholestatic pruritus from other forms of pruritus. Treatment options for patients with cholestatic pruritus include the anion exchange resin colestyramine, the PXR agonist rifampicin, the μ-opioid antagonist naltrexone, and the serotonin reuptake inhibitor sertraline. These drugs are recommended by evidence-based guidelines as a stepwise therapeutic approach. Patients unresponsive to these drugs should be referred to specialized centers to receive experimental approaches such as UVB phototherapy, albumin dialysis, plasmapheresis or nasobiliary drainage. This review discusses pruritogen candidates in cholestasis, gives novel insights into the neuronal signaling pathway of pruritus and summarizes evidence-based treatment options for patients suffering from pruritus in cholestasis.

Parenteral nutrition-associated liver disease: a retrospective study of ursodeoxycholic Acid use in neonates

OBJECTIVES

To verify the effect of ursodeoxycholic acid (UDCA) on the duration of neonatal parenteral nutrition-associated liver disease.

METHODS

Retrospective cohort study of neonates in intensive care between 2004 and 2007 presenting with parenteral nutrition-associated liver disease.

RESULTS

Of 118 eligible infants, 64 received UDCA. Cholestasis lasted longer in the UDCA group (79 vs. 50 days, p=0.001). However, treatment was delayed for a median of 24 days after cholestasis onset. Multivariate Cox regression analysis showed no association between UDCA and cholestasis duration. The rate of decline of conjugated bilirubin was greater in treated patients (median 0.084 mg/dL/day vs. 0.60 mg/dL/day; p=0.009) and weight gain was greater (22.8 vs. 17.7 g/kg/day, p=0.010).

CONCLUSIONS

UDCA therapy was not associated with the duration of parenteral nutrition-associated liver disease. A delay in treatment initiation might explain this result. UDCA therapy was associated with a faster decline of conjugated bilirubin and greater weight gain.

Management of cholestatic pruritus in paediatric patients with alagille syndrome: the King's College Hospital experience

OBJECTIVES

The aims of the study were to perform a retrospective observational review of the present management and outcome of cholestatic pruritus in children with Alagille syndrome (AGS) at King's College Hospital and to use results to inform appropriate guidelines.

METHODS

A retrospective review of 62 patients diagnosed as having AGS from January 1995 to November 2010 treated at King's College Hospital was performed. The departmental database of the Paediatric Liver Centre was searched to identify all patients and the clinical records were then analysed.

RESULTS

Fifty-one (82.3%) patients experienced pruritus and 50 (80.6%) received antipruritic medication. Ursodeoxycholic acid was the most prescribed drug (n = 40). Other drugs prescribed were rifampicin (n = 39), cholestyramine (n = 18), naltrexone (n = 14), alimemazine (n = 13), nonsedating antihistamine agents (n = 7), ondansetron (n = 5), and phenobarbitone (n = 1). Albumin dialysis using the molecular adsorbent recirculation system was used in 1 patient. Sixteen patients (25.8%) were listed for liver transplantation, and 11 had undergone transplantation by November 2010. Patient survival was high at 95.2%. Pruritus resolved permanently in 39.2% (n = 20) of patients. Fifty-five percent (n = 11) of such patients had undergone liver transplantation. Pruritus was controlled by medication in 41.2% (n = 21). Itching remained a significant problem, affecting quality of life in 19.6% of patients (n = 10).

CONCLUSIONS

The management of cholestatic pruritus in AGS is difficult and often suboptimal. Pruritus may remain intractable even with combination medical treatment, and at this stage, surgery or liver transplantation is indicated. At our centre, pruritus was successfully treated in 80.4% of patients with medical and surgical management.

Pathogenesis and management of pruritus in cholestatic liver disease

Patients with cholestatic liver diseases such as primary biliary cirrhosis, primary sclerosing cholangitis and intrahepatic cholestasis of pregnancy commonly complain of pruritus. The underlying pathogenesis remains obscure with several mediators possibly playing an important role; these include lysophosphatidic acid, bile salts, opioids, histamine and progesterone metabolites. We describe in this review novel insights into the pathogenesis and management of pruritus in patients with cholestasis.

Current management of primary sclerosing cholangitis in pediatric patients

Primary sclerosing cholangitis (PSC) is a chronic cholestatic condition affecting the extrahepatic and intrahepatic biliary tree. The incidence is seemingly increasing in children as a result of increased use of cholangiographic screening techniques in children with inflammatory bowel disease. The clinical presentation of PSC in childhood is variable and frequently without obvious cholestatic features, and cholangiography is essential for the diagnosis of this disorder. Histologic findings may help to exclude autoimmune sclerosing cholangitis. The underlying pathogenesis remains poorly understood and, as a result, therapeutic agents that halt disease progression and improve prognosis are lacking. PSC treatment is mainly supportive and directed at controlling cholestatic symptoms and preventing complications. Ursodeoxycholic acid is helpful in inducing biochemical improvement; long-term pediatric studies to determine a benefit of this agent in young patients are lacking, although results from adult studies have not been promising. Some agents such as antibiotics are under investigation with some promising results. Liver transplantation is required for children who progress to end-stage liver disease. Prospective multicenter trials in children with PSC are needed.

Age-dependency of galactose elimination capacity in healthy children and children with chronic liver disease

OBJECTIVE

Galactose elimination capacity (GEC) is used as a quantitative measure of liver metabolic function with prognostic value in adults with acute and chronic liver failure. Almost no data are available regarding GEC in children, however. This study thus aims to meet the previously unmet clinical need for age-related data on GEC in children.

MATERIAL AND METHODS

We studied galactose elimination in 10 healthy children (median age 10.7 years; range 7 months to 16 years) and 30 children with chronic liver disease (median age 8.6 years; range 3 months to 16 years). GEC was estimated from the linear decrease in concentration of galactose in arterialized capillary blood from the ear following intravenous infusion of galactose.

RESULTS

In both groups of children, GEC (μmol/min/kg body weight) was highest in the youngest children and decreased with age, although at a significantly lower level in the children with liver disease (p = 0.05). GEC was significantly higher in healthy children than in healthy adults, diminishing to the adult level by the age of 16 years.

CONCLUSIONS

GEC was found to be higher in children than in adults until the age of 16 years. Moreover, GEC was significantly lower in children with chronic liver disease than in healthy children, underlining that GEC testing also has potential clinical usefulness as a quantitative measure of liver metabolic function in children.

Pathophysiology and current management of pruritus in liver disease

Pruritus is frequently reported by patients with cholestatic hepatobiliary diseases such as primary biliary cirrhosis, primary sclerosing cholangitis, intrahepatic cholestasis of pregnancy and hereditary cholestatic syndromes, but may accompany almost any other liver disease. Increased concentrations of bile salts, histamine, progesterone metabolites or endogenous opioids have been controversially discussed as potential pruritogens in cholestasis in the past. Most recently, novel insights unravelled lysophosphatidic acid (LPA), a potent neuronal activator, as a potential pruritogen in pruritus of cholestasis. Nevertheless, the pathogenesis of pruritus in cholestasis is still not clearly defined and current antipruritic treatment strategies provide relief only in a part of the affected patients. Based on recent experimental and clinical findings, this review outlines the actual insight in pathogenesis of pruritus in cholestasis and summarizes evidence-based and experimental therapeutic interventions for cholestatic patients suffering from itch.

Cholecystoappendicostomy for progressive familial intrahepatic cholestasis

We report a rare case of progressive familial intrahepatic cholestasis type 2 from India. The diagnosis was confirmed on the basis of gene mutation analysis. The child had intense pruritus refractory to conventional medical management. As liver biopsy did not reveal any cirrhosis, partial external biliary diversion was considered as an alternative to liver transplant. We performed cholecystoappendicostomy rather than the conventional method of using an ileal loop as a conduit between the gall bladder and abdominal wall. Child recovered completely.

Medical management of Alagille syndrome

Alagille syndrome is a highly variable, autosomal dominant disorder that affects the liver, heart, eyes, face, skeleton, kidneys, and vascular system. Much has been learned about the genetics of this disorder, which is caused primarily by mutations in the Notch signaling pathway ligand JAGGED1; however, the medical management of this condition is complex and continues to generate controversy. The significant variability of organ involvement requires the managing physician to have an understanding of the breadth and interplay of the variable manifestations. Furthermore, the liver disease in particular requires an appreciation of the natural history and evolution of the profound cholestasis.

Pathogenesis and treatment of pruritus in cholestasis

Pruritus is an enigmatic, seriously disabling symptom accompanying cholestatic liver diseases and a broad range of other disorders. Most recently, novel itch-specific neuronal pathways, itch mediators and their relevant receptors have been identified. In addition, new antipruritic therapeutic strategies have been developed and/or are under evaluation. This review highlights recent experimental and clinical findings focusing on the pathogenesis and actual treatment of pruritus in cholestatic liver disease. Evidence-based therapeutic recommendations, including the use of anion exchange resins cholestyramine, colestipol and colesevelam, the microsomal enzyme inducer rifampicin, the opioid receptor antagonists naltrexone and naloxone, and the serotonin reuptake inhibitor sertraline, are provided.

Treatment of cholestatic pruritus in children

PURPOSE

The treatment of cholestatic pruritus in children is reviewed.

SUMMARY

Cholestasis is characterized by an accumulation of substances that are normally secreted in the bile. Pruritus is a well-known feature of chronic cholestasis in both adults and children and has been reported as the most incapacitating symptom in children with chronic liver disease. Traditional agents, such as antihistamines, are typically ineffective as monotherapy in controlling cholestatic pruritus. As a result, clinicians have looked to other agents, such as rifampin, phenobarbital, ursodiol, opioid antagonists, and bile-binding resins, for attaining better control of pruritic symptoms. Each agent demonstrates different levels of efficacy in pediatric and adult literature. There are no guidelines or algorithms to guide therapy with these agents for children. As a result, an agent should be selected based on the patient's concurrent diseases and current medication regimen. Cholestyramine and ursodiol are both safe and inexpensive, with documented efficacy for cholestatic pruritus in children. Because cholestatic pruritus is likely a result of multiple mechanisms, combination therapy with agents that have differing mechanisms of action might be beneficial and could capitalize on potential synergy between the agents used. Future therapy for cholestatic pruritus may include serotonin antagonists, selective serotonin-reuptake inhibitors, and leukotriene antagonists.

CONCLUSION

Depending on the underlying disease state resulting in cholestasis, phenobarbital, ursodiol, bile sequestering agents, and opioid antagonists appear to be most effective for treating pruritus related to intrahepatic cholestasis. Alternatively, rifampin appears to be the only agent with reported treatment efficacy for pruritus related to extrahepatic cholestasis.

Treatment options for chronic cholestasis in infancy and childhood

Altered bile flow physiology leads to many complications commonly seen in patients with cholestatic liver disease, regardless of the etiology. For each individual patient, a coordinated and effective treatment strategy must address the presence and the severity spectrum of malabsorption, malnutrition, vitamin and micronutrient deficiencies, pruritus, xanthomata, ascites, and liver failure, which are attributed directly or indirectly to diminished bile flow. An aggressive approach to maximizing the nutritional status of the child is vital to ensure optimal growth and development. Protein-calorie and/or fat supplementation is best discussed early. Decreasing the percentage of dietary long-chain triglycerides, providing medium-chain triglycerides, and ensuring adequate essential fatty acid and adequate protein intake may be helpful. Fat-soluble vitamin (A, D, E, and K) levels and micronutrient levels must be carefully and serially monitored and supplemented as necessary. Because the mechanisms that mediate pruritus of cholestasis remain to be determined, the use of empirical therapies continues to be standard practice. Ursodeoxycholic acid may ameliorate pruritus. Antihistamines and rifampicin may also provide temporary relief for some children. Based on the evidence that increased central opioidergic tone is present in chronic cholestasis, the use of opiate antagonists is promising but has not been evaluated in children. Selected patients with refractory pruritus that have failed maximal medical therapy have benefited from partial external biliary diversion. Ongoing dialogue with the family regarding the indications for liver transplantation is reasonable. Optimization and adherence with the pretransplant medical management enhance the chances for a successful outcome from liver transplantation. Specific to the pediatric patient, optimizing growth, development and nutrition, minimizing discomfort and disability, and aiding the child and family in coping with the stress, social, and emotional effects of chronic liver disease remain paramount.

Treatment of Pediatric Cholestatic Liver Disease

Cholestatic liver disease affects a small percentage of children, but therapy results in millions of healthcare dollars being spent each year. Close monitoring of nutritional status, pruritus, and complications from portal hypertension should improve the patient's quality of life and survival without liver transplantation. Other comorbid conditions, such as cardiac or renal disease, must also be integrated into the care plan and will affect the overall prognosis of the patient. Portal hypertension leads to ascites, variceal hemorrhage, and infection, which can result in significant mortality if not promptly recognized and treated. Surgical shunts are being used less because the expertise to perform endoscopic sclerotherapy and endoscopic band ligation is available at most medical centers. However, many cholestatic diseases, including biliary atresia, progressive familial intrahepatic cholestasis (PFIC) I, II, and III, and Alagille syndrome, may still require liver transplantation (Table 1). The cost of this procedure can exceed several hundred thousand dollars per patient, without including the annual costs of immunosuppressant therapy and medical monitoring. Meticulous medical management of nutrition and the sequelae of portal hypertension may prolong survival and reduce the potential morbidity and mortality of liver transplantation.

Treatment of Gastrointestinal Problems in Cystic Fibrosis

The gastrointestinal (GI) manifestations of cystic fibrosis (CF) are varied and include pancreatic insufficiency, meconium ileus, distal intestinal obstruction syndrome (DIOS), liver disease, and other less common manifestations. Treatment of pancreatic insufficiency consists of providing appropriate pancreatic enzyme replacement therapy and may include raising duodenal pH to allow for optimal action of these enzymes. Despite a number of pancreatic enzyme replacement products, malabsorption cannot be normalized. Management of DIOS depends on the severity of the symptoms; adequate hydration is very important. Polyethylene glycol solutions are being increasingly used. The precipitating cause of the episode of DIOS should be looked for so future episodes can be prevented. Liver disease is relatively silent and annual monitoring of liver function and status is recommended. Treatment is mainly supportive and the role of ursodeoxycholic acid in the prevention of cirrhosis needs to be better defined. Nutritional status is an important part of management of all GI and liver manifestations of CF. A team approach and the assistance of a registered dietitian are extremely valuable in managing the GI and liver manifestations of CF.

Hepatic dysfunction following the Fontan procedure

OBJECTIVES

The Fontan procedure offers a palliation for the hemodynamic derangements associated with congenital heart lesions characterized by a single functional ventricle, but it causes a chronically elevated systemic venous pressure that may result in hepatic congestion. The objective of this study was to characterize hepatic function and its relationship to cardiac function in children who had undergone the Fontan procedure.

METHODS

In a cross-sectional study of 11 children aged 38 months to 216 months (mean, 149 months), the authors evaluated indices of cardiac and hepatic function, including galactose clearance, Doppler hepatic ultrasonography, synthetic function, and markers of liver injury, at 9 months to 176 months (mean, 100 months) after children had undergone the Fontan procedure.

RESULTS

The most common biochemical abnormality of hepatic function was a prolongation of the prothrombin time and a low factor V level. There was a trend toward progressive abnormality in prothrombin time with increasing interval since the Fontan procedure. Galactose elimination half-life and galactose elimination capacity were inversely correlated with the time after Fontan (R2= 0.65, P = 0.004). There was no relationship between cardiac functional measurements and liver function.

CONCLUSIONS

Prothrombin time and galactose elimination half-life are abnormal in children who have undergone the Fontan procedure and may be useful markers of hepatic function in the longitudinal assessment of these patients.

Parenteral nutrition-associated liver complications in children

Parenteral nutrition is a life-saving therapy for patients with intestinal failure. It may be associated with transient elevations of liver enzyme concentrations, which return to normal after parenteral nutrition is discontinued. Prolonged parenteral nutrition is associated with complications affecting the hepatobiliary system, such as cholelithiasis, cholestasis, and steatosis. The most common of these is parenteral nutrition-associated cholestasis (PNAC), which may occur in children and may progress to liver failure. The pathophysiology of PNAC is poorly understood, and the etiology is multifactorial. Risk factors include prematurity, long duration of parenteral nutrition, sepsis, lack of bowel motility, and short bowel syndrome. Possible etiologies include excessive caloric administration, parenteral nutrition components, and nutritional deficiencies. Several measures can be undertaken to prevent PNAC, such as avoiding overfeeding, providing a balanced source of energy, weaning parenteral nutrition, starting enteral feeding, and avoiding sepsis.

Long-term prospective study of the effect of ursodeoxycholic acid on cystic fibrosis-related liver disease

GOALS

To evaluate the efficacy of UDCA in arresting the progression of the early multifocal hepatic lesion to overt CF-related NBC.

BACKGROUND

Focal biliary cirrhosis is an early hepatic pathologic change related to the ion transport defect in cystic fibrosis. The factors involved in the progression of focal to nodular biliary cirrhosis are not clear. Ursodeoxycholic--a hydrophilic, nontoxic, choleretic, and hepatoprotective exogenous bile acid--has been reported to be effective in the management of cholestatic liver disease.

STUDY

For 10 years at 6-month intervals, 70 individuals with cystic fibrosis (38 men and 32 women; age range, 2--29 years) were examined using hepatosplenomegaly, liver function tests, and ultrasound liver scan. Patients demonstrating evidence of liver involvement at the onset or during the study received ursodeoxycholic acid 20 mg/kg body weight.

RESULTS

After the administration of ursodeoxycholic acid, the progression of nodular biliary cirrhosis ultrasound changes was arrested, hepatic function was preserved, and no variceal bleeding was observed. No case of focal biliary cirrhosis progressed to nodular biliary cirrhosis. Furthermore, the multifocal, multilobular changes suggestive of focal biliary cirrhosis on ultrasound scan were reversed to normal.

CONCLUSION

Ursodeoxycholic acid is effective in improving cholestasis and hepatic dysfunction in nodular biliary cirrhosis and, also, in reversing the early sonography findings suggestive of focal biliary cirrhosis. It is speculated that ursodeoxycholic acid may prove to affect the natural history of cystic fibrosis-related liver disease.

Bile acid transport

Bile acids undergo a unique enterohepatic circulation, which allows them to be efficiently reused with minimal loss. With the cloning of key bile acid transporter genes in the liver and intestine, clinicians now have a detailed understanding of how the different components in the enterohepatic circulation operate. These advances in basic knowledge of this process have directly led to a rapid and highly detailed understanding of rare genetic disorders of bile acid transport, which usually present as pediatric cholestatic disorders. Mutations in specific bile acid or lipid transporters have been identified within specific cholestatic disorders, which allows for genetic tests to be established for specific diseases and provides a unique opportunity to understand how these genes operate together. These same transporters may also prove useful for development of novel drug delivery systems, which can either enhance intestinal absorption of drugs or be used to target delivery to the liver or biliary system. Knowledge gained from these transporters will provide new therapeutic modalities to treat cholestatic disorders caused by common diseases.