Hepatobiliary pathology in patients with cystic fibrosis

Cholic acid induces a Cftr dependent biliary secretion and liver growth response in mice

The cause of Cystic fibrosis liver disease (CFLD), is unknown. It is well recognized that hepatic exposure to hydrophobic bile salts is associated with the development of liver disease. For this reason, we hypothesize that, CFTR dependent variations, in the hepatic handling of hydrophobic bile salts, are related to the development CFLD. To test our hypothesis we studied, in Cftr^-/- and control mice, bile production, bile composition and liver pathology, in normal feeding condition and during cholate exposure, either acute (intravenous) or chronic (three weeks via the diet). In Cftr^-/- and control mice the basal bile production was comparable. Intravenous taurocholate increased bile production to the same extent in Cftr^-/- and control mice. However, chronic cholate exposure increased the bile flow significantly less in Cftr^-/- mice than in controls, together with significantly higher biliary bile salt concentration in Cftr^-/- mice. Prolonged cholate exposure, however, did not induce CFLD like pathology in Cftr^-/- mice. Chronic cholate exposure did induce a significant increase in liver mass in controls that was absent in Cftr^-/- mice. Chronic cholate administration induces a cystic fibrosis-specific hepatobiliary phenotype, including changes in bile composition. These changes could not be associated with CFLD like pathological changes in CF mouse livers. However, chronic cholate administration induces liver growth in controls that is absent in Cftr^-/- mice. Our findings point to an impaired adaptive homeotrophic liver response to prolonged hydrophobic bile salt exposure in CF conditions.

Ursodeoxycholic acid therapy in cystic fibrosis liver disease--a retrospective long-term follow-up case-control study

BACKGROUND

The prevention and treatment of liver disease associated with cystic fibrosis remain a significant unresolved problem.

AIM

To assess the long-term effects of continuous ursodeoxycholic acid (UDCA) therapy in cystic fibrosis patients with constantly elevated serum liver enzymes.

METHODS

The primary endpoint was the incidence of overt liver disease. Between 1989 and 2005, UDCA treatment was started in 98 subjects from a cohort of 382 cystic fibrosis patients. These subjects were compared with a historic control group of 352 subjects who attended our centre between 1975 and 1989 before UDCA became standard treatment. For the long-term comparison of liver function and lung function tests, a group of 98 matched contemporary cystic fibrosis patients were compared with the 98 subjects treated with UDCA.

RESULTS

Overt liver disease developed in only one of the 382 patients who was treated with UDCA for increased serum liver enzymes compared with nine patients in the historic control group (P < 0.05). Serum liver enzyme levels declined in most patients receiving UDCA treatment during the 17-year follow-up (87/98, P < 0.05). No difference was seen in lung function between subjects with cystic fibrosis-related liver disease and the matched controls.

CONCLUSIONS

Regular and systematic screening for liver involvement enables early introduction of UDCA therapy in affected cystic fibrosis patients, reduces the development of severe liver disease and leads to a significant and persistent improvement in serum liver tests, without impairing long-term pulmonary outcome.

Partial splenectomy in cystic fibrosis patients with hypersplenism

We report three cystic fibrosis (CF) patients with hypersplenism who underwent partial splenectomy. The postoperative course was uneventful in two patients; one patient developed a complication necessitating resection of the rest of the spleen. Haematological parameters improved and oesophageal varices regressed in all patients. On follow up, one patient showed a normal spleen, the other a normally functioning accessory spleen; the third patient again developed splenomegaly with hypersplenism. Partial splenectomy is a promising therapeutic option for CF patients with hypersplenism.

Chronic mucoid Pseudomonas aeruginosa cholangitis complicating ERCP in a CF patient

We report a case of P. aeruginosa cholangitis in an adult with cystic fibrosis (CF). The patient had a past history of cholecystectomy and a new finding of intrahepatic biliary duct stricture. Evaluation and treatment with endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous biliary tract drainage was complicated by post-procedure pain and fever. The only organism recovered from biliary drainage was P. aeruginosa. Southern blot analysis of respiratory and biliary cultures confirmed that the isolates were identical. Despite aggressive antibiotic therapy and drainage, persistent cholangitis and infection have not been eradicated after 6 months. The most likely mechanism of infection of the biliary tract was direct introduction of the upper respiratory tract pathogen during the diagnostic procedure.

Serum hyaluronic acid concentrations are increased in cystic fibrosis patients with liver disease

AIM

To determine whether serum hyaluronic acid (HA) concentrations are abnormal in patients with cystic fibrosis (CF) liver disease, and if so, whether the abnormality is associated with disease severity.

METHODS

A total of 74 patients with CF were assessed for evidence of liver involvement as indicated by clinical, ultrasound, and biochemical findings. Serum hyaluronic acid concentrations were measured and compared with concentrations in 293 normal controls. Lung function in the CF patients was also recorded.

RESULTS

Thirty four CF patients had no evidence of liver disease; in these, serum HA concentrations were similar to those in healthy controls (median (range): 16.1 (9.4-75.1) v 15 (1-77) microg/l). Nineteen CF patients had established liver disease detected by clinical and ultrasound examination, with significantly increased HA concentrations (56.1 (26-355) microg/l). Serum HA concentrations were also significantly increased, although to a lesser extent, in 21 CF patients with an abnormal liver ultrasound scan alone (22.4 (9.5-43.4) microg/l). There was no correlation between serum HA concentration and lung function.

CONCLUSION

Serum HA concentrations were significantly increased in children with clinical or ultrasound evidence of liver disease, being higher in those with more advanced hepatic damage. Despite the inflammation and fibrosis present in CF lungs there was no correlation between HA concentration and lung function, suggesting that high concentrations were a failure of hepatic clearance rather than overproduction in the lung. Longitudinal measurement of HA concentrations may prove a useful marker for the development of significant liver damage in CF patients.

The major histocompatibility complex influences the development of chronic liver disease in male children and young adults with cystic fibrosis

BACKGROUND/AIMS

Chronic liver disease is a well-recognised complication of cystic fibrosis. Recent reports suggest that its development is not determined by specific mutations within the cystic fibrosis gene; however, familial clustering of portal hypertension cases and inappropriate immune responses against liver membrane antigens demonstrated in children with cystic fibrosis and chronic liver disease suggest that other genetic loci may be relevant. As the major histocompatibility complex has an important immunoregulatory role, we have investigated for associations with this complex and chronic liver disease in cystic fibrosis.

METHODS

We have determined human leucocyte antigen class I (A and B) and class II (DR) phenotypes by serological tissue typing and class II (DR and DQ) and class III (complement component C4 and 21-hydroxylase) gene polymorphisms in 274 children and young adults with cystic fibrosis, of whom 82 had evidence of chronic liver disease with portal hypertension in 49, and 146 healthy controls.

RESULTS

A marked difference in human leucocyte antigen frequency was limited to DQ6, which was found in 66.7% of cystic fibrosis patients with liver disease compared to 32.9% of patients with no liver disease (Pc < 0.03) and 28.8% of controls (Pc < 0.006). An increased frequency of the two antigens in strong linkage disequilibrium with DQ6 was also observed within this patient group, namely DR15 and B7. When the patients were stratified for the presence of portal hypertension, these observations were confirmed, but the human leucocyte antigen associations were significant only for male patients and there was no association with the age of onset of liver disease.

CONCLUSIONS

These data suggest that the haplotype B7-DR15-DQ6 may carry an increased risk of development of liver disease in male cystic fibrosis patients.

Liver cirrhosis in cystic fibrosis--therapeutic implications and long term follow up

Experience gained from liver studies in 450 patients with cystic fibrosis, seen in a 38 year period from 1964 to 1992, is surveyed. Of these, 31 (7%) showed findings that indicated multilobular cirrhosis. There was a slight but not significant male predominance: 19 males against 12 females. Liver disease had its onset during childhood in most cases. The natural course of liver disease and of cirrhosis is protracted. All patients were routinely evaluated by way of: (i) clinical examination, (ii) biochemical studies and specifically estimation of transaminases and gamma glutamyltransferase, and (iii) liver imaging, ultrasonography, and computed tomography. The study aimed to detect early liver disease, that is multilobular cirrhosis and its complications, with a view to optimal introduction of treatment with ursodeoxycholic acid as this drug shows promise for preventing or stabilising the cirrhotic process. Effects of surgical treatment on portal hypertension are surveyed. These include portacaval shunting, partial splenectomy (considered the procedure of choice), liver transplant in the event of liver failure, or a triple transplant (liver, lungs, and heart) if necessary. One triple transplant was successfully performed in a boy of 10 years with a 2 year follow up.

Effects of ursodeoxycholic acid on liver function in patients with cystic fibrosis and chronic cholestasis

Ursodeoxycholic acid, 10 to 20 mg/kg per day, was administered for 1 year to 22 patients with cystic fibrosis and chronic cholestasis, resulting in significantly improved liver enzyme values. However, evidence of cholestasis continued, as shown by the pattern of alkaline phosphatase isoenzymes.

Genotype analysis for delta F508, G551D and R553X mutations in children and young adults with cystic fibrosis with and without chronic liver disease

Genetic factors have been implicated in the pathogenesis of liver disease in cystic fibrosis. To investigate whether liver disease is associated with particular mutations of the defective gene in cystic fibrosis, we have determined the frequencies of three mutations--delta F508, G551D and R553X--in 111 children and young adults with cystic fibrosis by analysis of genomic DNA segments amplified by the polymerase chain reaction. Twenty-nine patients had severe liver disease with portal hypertension, 19 had clinical and/or biochemical evidence of liver disease but no associated portal hypertension and 63 had no evidence of liver disease. No significant differences in the frequencies of the delta F508, G551D or R553X mutations in the three clinical subgroups were found, and we conclude that the development of liver disease in cystic fibrosis is unlikely to be associated with a specific mutation in the gene. However, because 27% of cystic fibrosis chromosomes do not have a defined mutation, this possibility cannot be ruled out. A familial concordance for clinical liver disease of 20% in this study, compared with a reported prevalence of 4.7%, suggests that genes outside the cystic fibrosis locus and/or environmental factors are involved in the pathogenesis of liver disease in cystic fibrosis.

Relation between essential fatty acid metabolism and gastrointestinal symptoms in cystic fibrosis

Studies in our laboratory have supported the hypothesis, that the basic defect in cystic fibrosis increases the metabolism of essential fatty acids and thereby gradually gives rise to essential fatty acid deficiency, which is a well documented finding in most cases with this disease. Both the increased metabolism--giving high liberation of arachidonic acid and its metabolic products, i.e. different eicosanoids--and the subsequent essential fatty acid deficiency will cause gastrointestinal symptoms and the sequence of this development will mirror the natural history of the disease. Clinical data and results from animal research are discussed in relation to gastrointestinal symptoms and signs of cystic fibrosis.