Ursodeoxycholic acid improves the hepatic metabolism of essential fatty acids and retinol in children with cystic fibrosis

Cystic fibrosis screening, evaluation, and management of hepatobiliary disease consensus recommendations

Cystic fibrosis (CF) may cause a spectrum of hepatobiliary complications, including portal hypertension, multilobular cirrhosis, and liver failure. Current guidelines on the detection and monitoring of hepatobiliary complications in CF were published in 1999. The CF Foundation assembled a committee to evaluate research advances and formulate revised guidelines for CF-associated liver disease. A committee of hepatologists, gastroenterologists, pulmonologists, pharmacists, nurses, dietitians, individuals with CF, and the parents of a child with CF devised "population, intervention, comparison, and outcome" questions regarding hepatobiliary disease in CF. PubMed literature searches were performed for each population, intervention, comparison, and outcome question. Recommendations were voted on with 80% agreement required to approve a recommendation. Public comment on initial recommendations was solicited prior to the formulation of final recommendations. Thirty-one population, intervention, comparison, and outcome questions were assembled, 6401 manuscripts were title screened for relevance, with 1053 manuscripts undergoing detailed full-text review. Seven recommendations were approved for screening, 13 for monitoring of existing disease, and 14 for treatment of CF-associated hepatobiliary involvement or advanced liver disease. One recommendation on liver biopsy did not meet the 80% threshold. One recommendation on screening ultrasound was revised and re-voted on. Through a multidisciplinary committee and public engagement, we have assembled updated recommendations and guidance on screening, monitoring, and treatment of CF-associated hepatobiliary involvement and advanced liver disease. While research gaps remain, we anticipate that these recommendations will lead to improvements in CF outcomes through earlier detection and increased evidence-based approaches to monitoring and treatment.

Management of liver disease and portal hypertension in cystic fibrosis: a review

INTRODUCTION

Cystic fibrosis (CF)-associated liver disease can significantly affect the quality of life and survival of people with CF. The hepatobiliary manifestations in CF are various, with focal/multilobular biliary cirrhosis more common in children and porto-sinusoidal vascular disease (PSVD) in young adults. Portal hypertensive complications, particularly bleeding from esophagogastric varices and hypersplenism are common, while liver failure is rarer and mainly linked to biliary disease.

AREAS COVERED

This review explores current therapeutic options for CF-associated liver disease, presenting ongoing studies and new insights into parthenogenesis for potential future therapies.

EXPERT OPINION

Monitoring for signs of portal hypertension is essential. Limited evidence supports ursodeoxycholic acid (UDCA) efficacy in halting CF liver disease progression. The effect of cystic fibrosis transmembrane conductance regulator (CFTR) modulators on liver outcomes lacks definitive data, since patients with CF-related liver disease were excluded from trials due to potential hepatotoxicity. A proposed approach involves using UDCA and modulators in early stages, along with anti-inflammatory agents, with further therapeutic strategies awaiting randomized trials. Prevention of portal hypertensive bleeding includes endoscopic sclerotherapy or ligation of esophageal varices. Nonselective beta-blockers may also prevent bleeding and could be cautiously implemented. Other non-etiological treatments require investigation.

Changing paradigms in the treatment of gastrointestinal complications of cystic fibrosis in the era of cystic fibrosis transmembrane conductance regulator modulators

Cystic fibrosis (CF) - although primarily a lung disease - also causes a variety of gastrointestinal manifestations which are important for diagnosis, prognosis and quality of life. All parts of the gastrointestinal tract can be affected by CF. Besides the well-known pancreatic insufficiency, gastroesophageal reflux disease, liver disease and diseases of the large intestine are important pathologies that impact on prognosis and also impair quality of life. Diagnosis and management of gastrointestinal manifestations will be discussed in this review. Since optimisation of CF therapy is associated with a significantly longer life-span of CF patients nowadays, also gastrointestinal malignancies, which are more common in CF than in the non-CF population need to be considered. Furthermore, novel evidence on the role of the gut microbiome in CF is emerging. The introduction of cystic fibrosis transmembrane conductance regulator (CFTR) protein modulators gives hope for symptom alleviation and even cure of gastrointestinal manifestations of CF.

Current Treatment Options for Cystic Fibrosis-Related Liver Disease

Cystic Fibrosis-related liver disease (CFLD) has become a leading cause of morbidity and mortality in patients with Cystic Fibrosis (CF), and affects children and adults. The understanding of the pathogenesis of CFLD is key in order to develop efficacious treatments. However, it remains complex, and has not been clarified to the last. The search for a drug might be additionally complicated due to the diverse clinical picture and lack of a unified definition of CFLD. Although ursodeoxycholic acid has been used for decades, its efficacy in CFLD is controversial, and the potential of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators and targeted gene therapy in CFLD needs to be defined in the near future. This review focuses on the current knowledge on treatment strategies for CFLD based on pathomechanistic viewpoints.

Interventions for preventing and managing advanced liver disease in cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive inherited defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene resulting in abnormal regulation of salt and water movement across the membranes. In the liver this leads to focal biliary fibrosis resulting in progressive portal hypertension and end-stage liver disease in some individuals. This can be asymptomatic, but may lead to splenomegaly and hypersplenism, development of varices and variceal bleeding, and ascites; it has negative impact on overall nutritional status and respiratory function in this population. Prognosis is poor once significant portal hypertension is established. The role and outcome of various interventions for managing advanced liver disease (non-malignant end stage disease) in people with cystic fibrosis is currently unidentified. This is an updated version of a previously published review.

OBJECTIVES

To review and assess the efficacy of currently available treatment options for preventing and managing advanced liver disease in children and adults with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 19 November 2019. We also searched the reference lists of relevant articles and reviews and online trials registries. Date of last search: 01 January 2020.

SELECTION CRITERIA

Any published and unpublished randomised controlled trials and quasi-randomised controlled trials of advanced liver disease in cystic fibrosis with cirrhosis or liver failure, portal hypertension or variceal bleeding (or both).

DATA COLLECTION AND ANALYSIS

Authors independently examined titles and abstracts to identify potentially relevant trials, but none were eligible for inclusion in this review.

MAIN RESULTS

A comprehensive search of the literature did not identify any published eligible randomised controlled trials.

AUTHORS' CONCLUSIONS

In order to develop the best source of evidence, there is a need to undertake randomised controlled trials of interventions for preventing and managing advanced liver disease in adults and children with cystic fibrosis.

Ursodeoxycholic acid for cystic fibrosis-related liver disease

BACKGROUND

Abnormal biliary secretion leads to the thickening of bile and the formation of plugs within the bile ducts; the consequent obstruction and abnormal bile flow ultimately results in the development of cystic fibrosis-related liver disease. This condition peaks in adolescence with up to 20% of adolescents with cystic fibrosis developing chronic liver disease. Early changes in the liver may ultimately result in end-stage liver disease with people needing transplantation. One therapeutic option currently used is ursodeoxycholic acid. This is an update of a previous review.

OBJECTIVES

To analyse evidence that ursodeoxycholic acid improves indices of liver function, reduces the risk of developing chronic liver disease and improves outcomes in general in cystic fibrosis.

SEARCH METHODS

We searched the Cochrane CF and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. We also contacted drug companies and searched online trial registries.Date of the most recent search of the Group's trials register: 09 April 2017.

SELECTION CRITERIA

Randomised controlled trials of the use of ursodeoxycholic acid for at least three months compared with placebo or no additional treatment in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and quality. The authors used GRADE to assess the quality of the evidence.

MAIN RESULTS

Twelve trials have been identified, of which four trials involving 137 participants were included; data were only available from three of the trials (118 participants) since one cross-over trial did not report appropriate data. The dose of ursodeoxycholic acid ranged from 10 to 20 mg/kg/day for up to 12 months. The complex design used in two trials meant that data could only be analysed for subsets of participants. There was no significant difference in weight change, mean difference -0.90 kg (95% confidence interval -1.94 to 0.14) based on 30 participants from two trials. Improvement in biliary excretion was reported in only one trial and no significant change after treatment was shown. There were no data available for analysis for long-term outcomes such as death or need for liver transplantation.

AUTHORS' CONCLUSIONS

There are few trials assessing the effectiveness of ursodeoxycholic acid. The quality of the evidence identified ranged from low to very low. There is currently insufficient evidence to justify its routine use in cystic fibrosis.

Interventions for preventing and managing advanced liver disease in cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive inherited defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene resulting in abnormal regulation of salt and water movement across the membranes. In the liver this leads to focal biliary fibrosis resulting in progressive portal hypertension and end-stage liver disease in some individuals. This can be asymptomatic, but may lead to splenomegaly and hypersplenism, development of varices and variceal bleeding, and ascites; it has negative impact on overall nutritional status and respiratory function in this population. Prognosis is poor once significant portal hypertension is established. The role and outcome of various interventions for managing advanced liver disease (non-malignant end stage disease) in people with cystic fibrosis is currently unidentified.

OBJECTIVES

To review and assess the efficacy of currently available treatment options for preventing and managing advanced liver disease in children and adults with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books.Date of last search: 06 April 2017.We also searched the reference lists of relevant articles and reviews and online trials registries. Date of last search: 04 January 2017.

SELECTION CRITERIA

Any published and unpublished randomised controlled trials and quasi-randomised controlled trials of advanced liver disease in cystic fibrosis with cirrhosis or liver failure, portal hypertension or variceal bleeding (or both).

DATA COLLECTION AND ANALYSIS

Authors independently examined titles and abstracts to identify potentially relevant trials, but none were eligible for inclusion in this review.

MAIN RESULTS

A comprehensive search of the literature did not identify any published eligible randomised controlled trials.

AUTHORS' CONCLUSIONS

In order to develop the best source of evidence, there is a need to undertake randomised controlled trials of interventions for preventing and managing advanced liver disease in adults and children with cystic fibrosis.

Dietary intake and lipid profile in children and adolescents with cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) patients are advised to derive 35% of their daily energy intake from dietary fat. Whether this high fat intake is associated with dyslipidaemia is unknown. We described the lipid profile and dietary intake in paediatric patients with CF.

METHODS

110 fasting lipid concentrations of 110 Dutch patients with CF were studied, along with 86 measurements of dietary intake. For the total group and for boys and girls separately, the lipid profile and the dietary intake were investigated. The cross-sectional relationship between the lipid concentrations and dietary intake was determined.

RESULTS

The mean dietary fat intake was ≥35% of the total energy intake, along with a considerable consumption of saturated fat. We found lower concentrations of cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol, and increased concentrations of triglyceride and triglyceride to high-density lipoprotein cholesterol ratios. Lipid concentrations were not associated with dietary fat intake.

CONCLUSION

This study lacks variation in dietary fat intake to exclude an effect on lipid concentrations as the distribution of dietary fat intake remained constant at a high level. Elevated triglyceride concentrations and triglyceride to high-density lipoprotein cholesterol ratios suggest an increased risk of cardiovascular disease. Any negative consequences of a high dietary fat intake on the overall lipid profile later in life cannot be excluded.

Ursodeoxycholic acid for cystic fibrosis-related liver disease

BACKGROUND

Abnormal biliary secretion leads to the thickening of bile and the formation of plugs within the bile ducts; the consequent obstruction and abnormal bile flow ultimately results in the development of cystic fibrosis-related liver disease. This condition peaks in adolescence with up to 20% of adolescents with cystic fibrosis developing chronic liver disease. Early changes in the liver may ultimately result in end-stage liver disease with people needing transplantation. One therapeutic option currently used is ursodeoxycholic acid.

OBJECTIVES

To analyse evidence that ursodeoxycholic acid improves indices of liver function, reduces the risk of developing chronic liver disease and improves outcomes in general in cystic fibrosis.

SEARCH METHODS

We searched the Cochrane CF and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. We also contacted drug companies.Date of the most recent search of the Group's trials register: 29 May 2014.

SELECTION CRITERIA

Randomised controlled trials of the use of ursodeoxycholic acid for at least three months compared with placebo or no additional treatment in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and quality.

MAIN RESULTS

Ten trials have been identified, of which three trials involving 118 participants were included; the dose of ursodeoxycholic acid ranged from 10 to 20 mg/kg/day for up to 12 months. The complex design used in two trials meant that data could only be analysed for subsets of participants. There was no significant difference in weight change, mean difference -0.90 kg (95% confidence interval -1.94 to 0.14) based on 30 participants from two trials. Improvement in biliary excretion was reported in only one trial and no significant change after treatment was shown. There were no data available for analysis for long-term outcomes such as death or need for liver transplantation.

AUTHORS' CONCLUSIONS

There are few trials assessing the effectiveness of ursodeoxycholic acid. There is insufficient evidence to justify its routine use in cystic fibrosis.

Ursodeoxycholic acid inhibits liver X receptor α-mediated hepatic lipogenesis via induction of the nuclear corepressor SMILE

Small heterodimer partner interacting leucine zipper protein (SMILE) has been identified as a nuclear corepressor of the nuclear receptor (NRs) family. Here, we examined the role of SMILE in the regulation of nuclear receptor liver X receptor (LXR)-mediated sterol regulatory element binding protein-1c (SREBP-1c) gene expression. We found that SMILE inhibited T0901317 (T7)-induced transcriptional activity of LXR, which functions as a major regulator of lipid metabolism by inducing SREBP-1c, fatty acid synthase (FAS), and acetyl-CoA carboxylase (ACC) gene expression. Moreover, we demonstrated that SMILE physically interacts with LXR and represses T7-induced LXR transcriptional activity by competing with coactivator SRC-1. Adenoviral overexpression of SMILE (Ad-SMILE) attenuated fat accumulation and lipogenic gene induction in the liver of T7 administered or of high fat diet (HFD)-fed mice. Furthermore, we investigated the mechanism by which ursodeoxycholic acid (UDCA) inhibits LXR-induced lipogenic gene expression. Interestingly, UDCA treatment significantly increased SMILE promoter activity and gene expression in an adenosine monophosphate-activated kinase-dependent manner. Furthermore, UDCA treatment repressed T7-induced SREBP-1c, FAS, and ACC protein levels, whereas knockdown of endogenous SMILE gene expression by adenovirus SMILE shRNA (Ad-shSMILE) significantly reversed UDCA-mediated repression of SREBP-1c, FAS, and ACC protein levels. Collectively, these results demonstrate that UDCA activates SMILE gene expression through adenosine monophosphate-activated kinase phosphorylation, which leads to repression of LXR-mediated hepatic lipogenic enzyme gene expression.

Ursodeoxycholic acid for cystic fibrosis-related liver disease

BACKGROUND

Cystic fibrosis-related liver disease peaks in adolescence with up to 20% of people with cystic fibrosis developing chronic liver disease. Early changes in the liver may ultimately result in end-stage liver disease with people needing transplantation. One therapeutic option currently used is ursodeoxycholic acid.

OBJECTIVES

To analyse evidence that ursodeoxycholic acid improves indices of liver function, reduces the risk of developing chronic liver disease and improves outcomes in general in cystic fibrosis.

SEARCH METHODS

We searched the Cochrane CF and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings. We also contacted drug companies.Date of the most recent search of the Group's trials register: 10 July 2012.

SELECTION CRITERIA

Randomised controlled trials of the use of ursodeoxycholic acid for at least three months compared with placebo or no additional treatment in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and quality.

MAIN RESULTS

Ten trials have been identified, of which three trials involving 118 participants were included. The complex design used in two trials meant that data could only be analysed for subsets of participants. There was no significant difference in weight change, mean difference -0.90 kg (95% confidence interval -1.94 to 0.14) based on 30 participants from two trials. Improvement in biliary excretion was reported in only one trial and no significant change after treatment was shown. Long-term outcomes such as death or need for liver transplantation were not reported.

AUTHORS' CONCLUSIONS

There are few trials assessing the effectiveness of ursodeoxycholic acid. There is insufficient evidence to justify its routine use in cystic fibrosis.

Abnormal endocrine pancreas function at birth in cystic fibrosis ferrets

Diabetes is a common comorbidity in cystic fibrosis (CF) that worsens prognosis. The lack of an animal model for CF-related diabetes (CFRD) has made it difficult to dissect how the onset of pancreatic pathology influences the emergence of CFRD. We evaluated the structure and function of the neonatal CF endocrine pancreas using a new CFTR-knockout ferret model. Although CF kits are born with only mild exocrine pancreas disease, progressive exocrine and endocrine pancreatic loss during the first months of life was associated with pancreatic inflammation, spontaneous hyperglycemia, and glucose intolerance. Interestingly, prior to major exocrine pancreas disease, CF kits demonstrated significant abnormalities in blood glucose and insulin regulation, including diminished first-phase and accentuated peak insulin secretion in response to glucose, elevated peak glucose levels following glucose challenge, and variably elevated insulin and C-peptide levels in the nonfasted state. Although there was no difference in lobular insulin and glucagon expression between genotypes at birth, significant alterations in the frequencies of small and large islets were observed. Newborn cultured CF islets demonstrated dysregulated glucose-dependent insulin secretion in comparison to controls, suggesting intrinsic abnormalities in CF islets. These findings demonstrate that early abnormalities exist in the regulation of insulin secretion by the CF endocrine pancreas.

Fatty acid composition of serum phospholipids in cystic fibrosis (CF) patients with or without CF related liver disease

BACKGROUND

In cystic fibrosis (CF), changes in fatty acid (FA) composition of serum phospholipids (PL) and cell membranes can account, in part, for the inflammatory state of the disease. The severity of the genotype is known to correlate with the degree of FA changes. Liver diseases, such as cholestasis and cirrhosis are also known to influence FA status. Until now, there is no data on the influence of CF related liver disease (CFRLD) on the FA status of CF patients. The aim of this study was to evaluate, whether the presence of CFRLD influences FA status.

METHODS

A fasting blood sample for the determination of serum vitamin E and PL-FA composition was collected from 79 CF patients with stable pulmonary disease and under good control in our CF centre. Patients with CFRLD (n=13) were compared to CF patients with the same severity of genotype (n=66) but without CFRLD.

RESULTS

The CF patients with CFRLD had lower docosahexaenoic acid (DHA, 22:6n-3) and increased docosatetraenoic acid (22:4n-6). There were no significant differences in the precursors of these FAs.

CONCLUSIONS

DHA concentration in patients with CFRLD is decreased more substantially compared with their genotype controls. The presence of CFRLD should be taken into account in future FA studies in CF patients.

Hepatobiliary disease in patients with cystic fibrosis

PURPOSE OF REVIEW

This review explores the recent advances in knowledge regarding hepatobiliary disease in patients with cystic fibrosis.

RECENT FINDINGS

Hepatobiliary abnormalities associated with cystic fibrosis are varied in nature and range from defects attributable to the underlying genetic defect to those related to systemic disease and malnutrition. Novel research into the underlying pathogenesis of cystic fibrosis liver disease and the primary role of cystic fibrosis transmembrane conductance regulator in biliary secretory epithelium is presented. This work has been fostered by the development of new animal models of cystic fibrosis transmembrane conductance regulator dysfunction. Of the wide range of hepatobiliary complications associated with cystic fibrosis the most clinically relevant problem is progression of focal biliary cirrhosis to multilobular cirrhosis with its attendant complications of portal hypertension and potentially end-stage liver disease. However, recent studies suggest that liver transplantation may not improve survival in patients with cystic fibrosis and significant portal hypertension.

SUMMARY

Hepatobiliary disease is a common finding in patients with cystic fibrosis; the pathogenesis is multifactorial in nature. As new therapeutic strategies emerge, life expectancy will continue to increase as will the impact of liver disease on quality of life and survival of patients with cystic fibrosis. This review will discuss novel insights into pathogenesis as well as diagnostic and management options.

Dislipidemia relacionada à fibrose cística

Esse artigo tem por objetivo rever o conhecimento atual sobre a fisiopatologia, o diagnóstico e a abordagem da dislipidemia relacionada à fibrose cística (DFC). A pesquisa bibliográfica utilizou os bancos de dados Medline e Literatura Latino-Americana e do Caribe em Ciências da Saúde (1987-2007), selecionando os artigos mais relevantes sobre o tema. A DFC é caracterizada por hipertrigliceridemia e/ou hipocolesterolemia e deficiência de ácidos graxos essenciais. Seus principais fatores de risco são: insuficiência pancreática, dieta rica em carboidratos, hepatopatias, estado inflamatório e corticoterapia. Não existem recomendações específicas sobre a triagem, que habitualmente é realizada a partir do diagnóstico e, em intervalos regulares, com maior freqüência, nos indivíduos pertencentes aos grupos de risco. O tratamento inclui: dieta balanceada, reposição de micronutrientes, vitaminas e fibras, além de exercício físico regular de acordo com a tolerância individual. Na grande maioria dos casos, a hipertrigliceridemia da DFC não atinge valores que indiquem o uso de hipolipemiantes. Conclui-se que existem poucos trabalhos na literatura sobre a freqüência, etiologia e manejo da DFC. A recomendações preventivas e terapêuticas para a hipertrigliceridemia são extrapoladas de diretrizes para indivíduos sem fibrose cística. Mais pesquisas são necessárias para investigar a associação da deficiência de ácidos graxos essenciais com a fisiopatologia da fibrose cística. Como a hipertrigliceridemia é um importante fator de risco para doença arterial coronariana, estudos prospectivos irão contribuir para o melhor entendimento da história natural dessa complicação bem como definir maneiras de preveni-la e tratá-la.

Liver disease in cystic fibrosis

PURPOSE OF REVIEW

This review highlights recent developments in liver disease associated with cystic fibrosis.

RECENT FINDINGS

The broad spectrum of hepatobiliary problems in cystic fibrosis includes specific alterations ascribable to the underlying defect as well as lesions of iatrogenic origin or that reflect the effects of a disease process occurring outside the liver. Focal biliary cirrhosis, resulting from biliary obstruction and progressive periportal fibrosis, is the most clinically relevant problem, because extension of the initially focal fibrogenic process may lead to multilobular biliary cirrhosis, portal hypertension and eventually liver failure. Cystic fibrosis associated liver disease is presently classified among genetic cholangiopathies and results from lack or dysfunction of the cystic fibrosis transmembrane regulator at the apical membrane of bile duct cells. Major advances have been achieved regarding characterization of natural history, risk factors, diagnostic modalities and treatment options.

SUMMARY

Liver disease is a relatively frequent and early complication of cystic fibrosis. The pathogenesis is apparently multifactorial, with contributions from environmental and genetic determinants. Its impact on quality of life and survival will increase in future years, and its early detection and treatment will become increasingly important issues. Ursodeoxycholic acid is the only treatment currently available, but novel therapeutic options are being evaluated.

Vitamin A levels in patients with CF are influenced by the inflammatory response

BACKGROUND

Serum vitamin A, normally depressed in inflammatory conditions, is frequently low in people with CF. Vitamin A is important in respiratory epithelial regeneration and repair. We hypothesised that serum vitamin A would be associated with inflammation and disease severity.

METHODS

Serum vitamin A (as retinol), C-reactive protein (CRP), vitamin E, 25-hydroxy vitamin D (25OHD), 1,25-dihydroxy vitamin D (1,25(OH)(2)D), weight, and lumbar spine bone mineral density (LSBMD) were measured in 138 subjects with CF (5-56 years) and 138 control subjects (5-48 years). FEV(1), presence of CF liver disease (CFLD) and hospital admissions were recorded in those with CF.

RESULTS

Serum vitamin A level was lower in CF subjects than in controls (mean, 95% CI: 1.29, 1.0-1.37 vs. 1.80, 1.7-1.87 micromol/l, p < 0.0001), and inversely correlated with CRP (r(s) = -0.37, p < 0.0001). CF subjects with low vitamin A (45%) level had poorer FEV(1), weight z-score, LSBMD z-score, and higher CRP compared with those with normal levels. In the CF group CRP, vitamin E, 1,25(OH)(2)D, presence of CFLD, admissions, and age were associated with vitamin A level.

CONCLUSIONS

Serum vitamin A is negatively associated with CRP in subjects with CF, consistent with normal population studies. It is important to distinguish between low serum vitamin A associated with the inflammatory response and that due to poor nutritional stores. The role of vitamin A in CF warrants further study, in the contexts both of chronic recurrent inflammatory disease and acute pulmonary exacerbation.

Mechanisms of lipid malabsorption in Cystic Fibrosis: the impact of essential fatty acids deficiency

Transport mechanisms, whereby alimentary lipids are digested and packaged into small emulsion particles that enter intestinal cells to be translocated to the plasma in the form of chylomicrons, are impaired in cystic fibrosis. The purpose of this paper is to focus on defects that are related to intraluminal and intracellular events in this life-limiting genetic disorder. Specific evidence is presented to highlight the relationship between fat malabsorption and essential fatty acid deficiency commonly found in patients with cystic fibrosis that are often related to the genotype. Given the interdependency of pulmonary disease, pancreatic insufficiency and nutritional status, greater attention should be paid to the optimal correction of fat malabsorption and essential fatty acid deficiency in order to improve the quality of life and extend the life span of patients with cystic fibrosis.

Epidemiology of liver disease in cystic fibrosis: a longitudinal study

BACKGROUND/AIMS

To describe the prevalence of liver disease in a cohort of 241 cystic fibrosis (CF) patients.

METHODS

241 CF patients were followed-up every 3 months with clinical and biological assessment, and every year with ultrasonography of the liver. The presence of liver disease was studied using a multivariate Cox's regression analysis including variables such as history of meconium ileus, pulmonary function, pancreatic insufficiency and CFTR gene mutations.

RESULTS

The prevalence of liver disease was 18, 29, and 41% after 2, 5 and 12 years, respectively, and did not increase thereafter. In multivariate analysis, the probability of liver disease was independently associated with history of meconium ileus (P = 0.001) and pancreatic insufficiency (P = 0.004). CFTR mutations and severity of pulmonary disease were not associated with liver disease. Cirrhosis occurred in 19 (7.8%) patients at a median age of 10 years, and liver transplantation was required in five patients.

CONCLUSIONS

This study shows that CF related-liver disease occurs mainly in the first decade of life with a prevalence of 41% of patients at 12 years of age. A history of meconium ileus and pancreatic insufficiency are predictive of liver disease. Preventive treatment with ursodesoxycholic acid could be considered in patients with meconium ileus.

Nutrition in patients with cystic fibrosis: a European Consensus

This document is the result of an European Consensus conference which took place in Artimino, Tuscany, Italy, in March 2001 involving 33 experts on nutrition in patients with cystic fibrosis, organised by the European Cystic Fibrosis Society, and sponsored by Axcan-Scandipharm, Baxter, Dr Falk Pharma, Fresenius, Nutricia, SHS International, Solvay Pharmaceuticals (major sponsor). The purpose of the conference was to develop a consensus document on nutrition in patients with cystic fibrosis based on current evidence.

Transition of care between paediatric and adult gastroenterology. Cystic fibrosis

Advancement in treatment has resulted in a dramatic increase in life expectancy of patients with cystic fibrosis (CF) to well beyond 30 years of age in most centres. What was once a fatal genetic disease in childhood now sees over a third of its CF populations in adult clinics. The improved survival is multifactorial, but most attribute the reasons to more aggressive nutritional care along with better management of the gastrointestinal and pulmonary systems. Many of the nutritional and GI issues of paediatric patients remain similar when they become adults, except that there is the added psychosocial stress associated with this transition. This chapter aims to highlight the gastrointestinal and nutritional issues manifesting at the different stages of life from infancy to adulthood, and the recommended management.

Steatohepatitis in children

Steatohepatitis in children occurs in the childhood version of non-alcoholic fatty liver disease (NAFLD), as a result of hepatotoxicity and with certain genetic/metabolic diseases. Until recently, NAFLD was considered to be rare in children. It is now recognized as an important childhood liver disease, especially because childhood obesity is much more common. Children with NAFLD may present as young as 4 years old; males tend to predominate; fibrosis is often found on liver biopsy and cirrhosis has been reported. Treatment for childhood NAFLD currently consists of weight reduction plus regular aerobic exercise; vitamin E may be an effective adjunctive therapy. Drug hepatotoxicity and genetic/metabolic diseases that can cause fatty liver, such as Wilson's disease and cystic fibrosis, must be excluded since treatment is radically different. Other causes of chronic hepatitis, such as chronic viral hepatitis, must also be excluded. Multisystemic inherited diseases with hyperinsulinaemia plus insulin resistance may have NAFLD as hepatic involvement and should be identified.

Effect of an organized lipid matrix on lipid absorption and clinical outcomes in patients with cystic fibrosis

OBJECTIVES

To compare the absorption of a lysophosphatidylcholine, monoglyceride, and fatty acid matrix (organized lipid matrix, OLM) with that of a triacylglycerol (TG)-based fat meal in patients with cystic fibrosis (CF).

STUDY DESIGN

Five adolescents with CF and 3 control patients were given fat meals supplemented with retinyl palmitate of either OLM or TG at a 2-week interval. In a clinical trial, 73 patients with CF were randomly assigned to nutritional supplements containing either OLM or TG for a 1-year double-blind trial followed by a 6-month observation period.

RESULTS

The peak increases and areas under the curve for TG and retinyl palmitate after the fat meal were 10-fold higher after OLM than after the TG fat load and did not differ from values obtained in control patients. OLM led to better clinical outcomes in terms of energy intake from the diet, weight-for-age Z score, essential fatty acid status, vitamin E, and retinol binding protein. Height-for-age Z score and FEV(1) only reached statistical significance at the end of the 6-month observation period.

CONCLUSIONS

These results suggest that OLM is a readily absorbable source of fat and energy in CF and is an effective nutritional supplement.

Abnormal lipid concentrations in cystic fibrosis

BACKGROUND

Concentrations of cholesterol and triacylglycerol are commonly believed to be low in persons with cystic fibrosis and thus not of concern.

OBJECTIVE

The goal was to determine whether concentrations of cholesterol and triacylglycerol are related to glucose tolerance or nutritional status in patients with cystic fibrosis.

DESIGN

Fasting lipid profiles were measured in 192 patients ( +/- SD age: 21 +/- 11 y) in conjunction with an oral-glucose-tolerance test.

RESULTS

Cystic fibrosis patients in all age groups had higher triacylglycerol (1.51 +/- 0.95 mmol/L) and lower cholesterol (3.57 +/- 0.96 mmol/L) concentrations than US population means. Thirty patients (16%) had hypertriglyceridemia (3.22 +/- 1.22 mmol/L), and 8 patients (4%) had elevated cholesterol (6.05 +/- 1.32 mmol/L). In most cases, hypertriglyceridemia was isolated; only 3 subjects had elevation of both cholesterol and triacylglycerol. Lipid concentrations were not related to body mass index, weight, glucose tolerance, the areas under the curve for glucose or insulin, or glycated hemoglobin. Lipid concentrations also did not correlate with cystic fibrosis genotype, use of systemic steroids, blood pressure, liver enzymes, C-reactive protein, or pulmonary function.

CONCLUSIONS

Isolated hypertriglyceridemia appears to be common in cystic fibrosis, whereas cholesterol concentrations are generally low. Hypertriglyceridemia may be related to chronic low-grade inflammation or to a dietary macronutrient imbalance with excessive simple carbohydrate absorption relative to fat absorption. Whether it is associated with a risk of cardiovascular disease in this population is uncertain, but the clinical significance of triacylglycerol elevation may become important as survival improves.

Role of electroretinography in the assessment of retinal function as an indicator of vitamin A status

Hypovitaminosis A is associated with exocrine pancreatic insufficiency in cystic fibrosis. Peripheral retinal dysfunction is an early finding of vitamin A deficiency. We evaluated serum retinol and zinc as well as visual adaptation in 41 patients with cystic fibrosis, receiving generous pancreatic enzyme and micronutrient supplementation. Forty-one normal individuals matched for age and sex served as controls. Peripheral retinal function was measured by clinical electroretinography using an Electrophysiologic Personal Interfaced Computer and applying a standard protocol. Serum retinol in cystic fibrosis was significantly lower than that of the control group (0.30+/-0.01 versus 0.39+/-0.02 mg/l, p<0.001). Serum zinc concentrations were normal in the cystic fibrosis group (1.21+/-0.03 mg/l) and significantly higher than that of the control group (1.02+/-0.01 mg/l, p<0.001). The overall visual adaptation, however, was found to be normal and comparable in the two groups. It is concluded that, in cystic fibrosis, despite appropriate vitamin A supplementation, retinol serum concentration may be low. As serum retinol does not reflect vitamin A status, evaluation of visual adaptation may be a more appropriate way to monitor for vitamin A deficiency in cystic fibrosis.

Possible role of endogenous retinoid (Vitamin A) toxicity in the pathophysiology of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of unknown etiology commonly affecting women. It is characterized by progressive destruction of the small intrahepatic bile ducts and portal inflammation, leading to fibrosis and cirrhosis. The major signs and symptoms of PBC, which include pruritus, lethargy, the sicca syndrome, and osteoporosis, closely resemble the manifestations of hypervitaminosis A. Based on a review of the literature and other observations connecting PBC with retinoid metabolism (vitamin A and its derivatives), the hypothesis is proposed that exposure to excess endogenous retinoids contributes to the pathogenesis of PBC and may be to the cause of some of the signs and symptoms associated with the disease.

Malnutrition-associated rash of cystic fibrosis

Rash is a rare presenting sign of cystic fibrosis (CF) complicated by protein-calorie malnutrition. We measured essential fatty acid (EFA) levels in the serum of a 4-month-old girl with an erythematous, desquamating, periorificially accentuated rash in association with malnutrition and her 2-year-old sister who was diagnosed concurrently with CF but had no rash or signs of malnutrition. Both patients had biochemical evidence of EFA deficiency, suggesting that development of the rash is multifactorial. Clinical presentation, management, and possible modes of pathogenesis of the rash are reviewed. Pathogenesis of the rash appears to involve a complex interaction among deficiencies of EFAs, zinc, protein, and possibly copper, leading to disordered prostaglandin metabolism or cytokine production, or free radical-induced damage to cellular membranes due to a lack of nutrient-derived protective antioxidants.

Altered lipid profile, lipoprotein composition, and oxidant and antioxidant status in pediatric Crohn disease

BACKGROUND

Growing evidence supports a role for peroxidation in the pathogenesis of Crohn disease (CD). The activation of inflammatory cells, the release of their mediators, and the excessive production of free radicals may affect circulating lipids.

OBJECTIVE

We examined the lipid profile, lipoprotein composition, and oxidant-antioxidant status of children with CD.

DESIGN

We studied 22 pediatric CD patients and 10 healthy control subjects.

RESULTS

The proportion of saturated and monounsaturated fatty acids in plasma of CD patients was higher but that of polyunsaturated fatty acids was lower than in control subjects. This resulted in higher ratios in CD patients of palmitoleic acid to linoleic acid (P < 0. 05) and of eicosatrienoic acid to arachidonic acid (P < 0.04), 2 established indexes of essential fatty acid deficiency. Hypocholesterolemia was noted in CD patients as a result of lower LDL-cholesterol concentrations than in control subjects (P < 0.02). Plasma apolipoproteins B (P < 0.02) and A-I (P < 0.02) were also lower in CD patients, whereas plasma triacylglycerols were higher (P < 0.005). Lipoprotein composition was altered in CD patients, with relative triacylglycerol depletion and protein enrichment in VLDL. In contrast, intermediate-density lipoprotein of CD patients was characterized by an increased percentage of triacylglycerol and protein (P < 0.005) and a reduced proportion of phospholipids (P < 0. 01). Additional abnormalities were observed in the chemical distribution of HDL(2) and HDL(3) moieties. Lipid peroxidation was documented by higher plasma malondialdehyde concentrations in CD patients (P < 0.05), accompanied by lower retinol concentrations (P < 0.02).

CONCLUSION

Disturbances in the lipid profile, in lipoprotein concentrations and composition, and in oxidant-antioxidant status occur in CD patients.

Ursodeoxycholic acid for cystic fibrosis-related liver disease

BACKGROUND

Cystic fibrosis-related liver disease peaks in adolescence with up to 20% of patients developing chronic liver disease. Early changes in the liver may ultimately result in end stage liver disease with patients needing transplantation. One therapeutic option currently used is ursodeoxycholic acid.

OBJECTIVES

To assess the effectiveness of ursodeoxycholic acid in cystic fibrosis liver disease.

SEARCH STRATEGY

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group trials register, and contacted drug companies. Date of the most recent search of the Group's specialised register: June 1999.

SELECTION CRITERIA

Randomised and quasi-randomised trials of use of ursodeoxycholic acid for at least three months compared with placebo or no additional treatment in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial eligibility and quality.

MAIN RESULTS

Three trials involving 118 patients were included. The complex study design used in two trials meant that data could only be analysed for subsets of patients. There was no difference in weight change (weighted mean difference -0.496, 95% confidence interval -1.545 to +0.553) based on 30 patients from two trials. Improvement in biliary excretion was reported in only one study and no significant change after treatment was shown. Long term outcomes such as death or need for liver transplantation were not reported.

REVIEWER'S CONCLUSIONS

There are few trials assessing the effectiveness of ursodeoxycholic acid. There is insufficient evidence to justify is its routine use in cystic fibrosis.

Mechanism of hepatoprotective action of bile salts in liver disease

Ursodeoxycholic acid (UDCA) improves liver enzymes and in many instances liver histology in cholestatic liver diseases such as primary biliary cirrhosis and primary sclerosing cholangitis. Besides classic cholestatic diseases, UDCA also improves liver biochemistry in alcoholic liver disease and in chronic viral hepatitis C. The main target of UDCA treatment, however, is cholestasis, and consequently the mechanisms responsible for the beneficial effects in these diseases are of interest, and are discussed in detail in this article.

Nutritional imperatives in cystic fibrosis therapy

Patients with CF who receive optimal nutrition have better growth, maintain better nutritional reserves, and have better pulmonary function than patients with CF who have poor nutrition. These factors influence quality of life as well as survival. The metabolic and immunologic response to infection, as well as the increased work of breathing, escalates calorie requirements in this patient population. No single strategy works for every patient. Therefore, close monitoring of growth, symptoms, and changes in respiratory status that could increase calorie requirements is necessary.

Ursodeoxycholic acid improves cholestasis in infants with cystic fibrosis

OBJECTIVE

To describe two infants with cholestatic jaundice treated with ursodeoxycholic acid (UDCA).

CASE SUMMARY

Two infants with cystic fibrosis (CF)-associated hepatobiliary disease, manifesting as cholestatic jaundice and elevated liver enzymes within the first 6 weeks of life, had improved biochemical indices of liver function following treatment with UDCA 20-40 mg/kg/d.

DISCUSSION

To our knowledge, this is the first report of UDCA treatment in infants with CF-associated cholestatic jaundice. Infants and children require treatment with increased doses of UDCA to compensate for reduced intestinal absorption of bile acid and immaturity of the enterohepatic circulation.

CONCLUSIONS

UDCA appears to be a cost-effective treatment for CF-associated hepatobiliary disease in infants and children.