Gabriel Bellon

Sclerosing cholangitis in adults with cystic fibrosis: a magnetic resonance cholangiographic prospective study

BACKGROUND/AIMS Liver disease is a leading cause of morbidity in adult patients with cystic fibrosis. Diagnosis of limited liver involvement in asymptomatic patients is important since a safe and effective treatment with ursodeoxycholic acid can be used. We carried out a prospective open study to describe the intrahepatic biliary lesions using magnetic resonance cholangiography. METHODS Twenty-seven adult patients with cystic fibrosis were prospectively enrolled, whatever their hepatobiliary status. All patients underwent liver function tests, ultrasonography and magnetic resonance cholangiography. Magnetic resonance cholangiograms were acquired on a Philips 1.5 Tesla unit using a 3D TSE MR sequence. Acquisition parameters (120 slices, 1.6 mm thickness, interslice overlap 0.8 mm) were followed by MIP reconstruction in two orthogonal planes. Magnetic resonance cholangiography images were assessed for the presence of stenosis, dilatations and rigidity corresponding to current criteria of cholangitis. Among the 27 cystic fibrosis patients, 18 (Group I) fulfilled none of the clinical, biological or ultrasonographic criteria of liver disease; the remaining nine (Group II) fulfilled the criteria for liver disease. In every patient, current causes of secondary sclerosing cholangitis had been excluded. RESULTS All the Group II patients had abnormal magnetic resonance cholangiograms with features resembling those of primary sclerosing cholangitis in five, and simple biliary lesions in four. Nine Group I patients had abnormal magnetic resonance cholangiograms with primary sclerosing cholangitis-like lesions in five and simple biliary lesions in four. Magnetic resonance cholangiography anomalies were always dilatations, either isolated or associated with strictures and rigidity, both resembling those seen in cholangitis. They were seen in all the patients with known liver disease and in half the patients without evidence of liver disease. CONCLUSION This study confirms the high frequency of intrahepatic biliary abnormalities in CF patients, which is probably underestimated by clinical, biological and ultrasonographic evaluation. The magnetic resonance cholangiography technique could be useful to detect early intrahepatic biliary tract involvement in cystic fibrosis patients.

Lipid peroxidation and antioxidant defenses in cystic fibrosis patients.

Abstract Lipid peroxidation biomarkers and antioxidant status were measured in 76 cystic fibrosis (CF) patients and compared to 40 control subjects. Univariate and multivariate statistics were performed in this study. Results showed that indicators of lipid peroxidation were higher in CF patients than in controls; thiobarbituric acid reactants and autoantibodies against oxidized low-density lipoproteins were significantly increased in CF patients. Red blood cells and whole blood glutathione peroxidase activities were lower in CF patients than in controls. No difference in red blood cell superoxide dismutase activity was observed. Measured concentration of glutathione peroxidase in plasma showed a higher mean value of this protein in CF patients than in controls. Retinol, α-tocopherol and β-carotene concentrations were all reduced in CF patients as compared to controls; this was particularly pronounced for β-carotene. The decreased α-tocopherol concentration was associated with higher percent hemolysis in CF patients. The results of this study indicate that both lipid peroxidation biomarkers and antioxidant status were disturbed in CF patients, despite medical assistance. Measures of oxidative stress parameters, such as thiobarbituric acid reactants, glutathione peroxidase, and β-carotene concentrations can be considered as significant indicators to discriminate CF patients and control subjects.

Pooled analysis of two large randomised phase III inhaled mannitol studies in cystic fibrosis

BACKGROUND To evaluate safety and efficacy of inhaled mannitol treatment in subgroups of a large global CF population. METHODS Data were pooled from two multicentre, double-blind, randomised, controlled, parallel group phase III studies in which 600 patients inhaled either mannitol (400 mg) or control (mannitol 50 mg) twice a day for 26 weeks. RESULTS Both the mean absolute change in FEV(1) (mL) and relative change in FEV(1) by % predicted from baseline for mannitol (400 mg) versus control were statistically significant (73.42 mL, 3.56%, both p<0.001). Increases in FEV(1) were observed irrespective of rhDNase use. Significant improvements in FEV1 occurred in adults but not children (6-11) or adolescents (aged 12-17). Pulmonary exacerbation incidence was reduced by 29% (p=0.039) in the mannitol (400 mg) group. CONCLUSIONS Sustained six-month improvements in lung function and decreased pulmonary exacerbation incidence indicate that inhaled mannitol is an important additional drug in the treatment of CF.

Clinical phenotype and genotype of children with borderline sweat test and abnormal nasal epithelial chloride transport.

RATIONALE The diagnosis of cystic fibrosis (CF) is based on a characteristic clinical picture in association with a sweat chloride (Cl(-)) concentration greater than 60 mmol/L or the identification of two CF-causing mutations. A challenging problem is the significant number of children for whom no definitive diagnosis is possible because they present with symptoms suggestive of CF, a sweat chloride level in the intermediate range between 30 and 60 mmol/L, and only one or no identified CF-causing mutation. OBJECTIVES To investigate the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in the airways of children with intermediate sweat tests and inconclusive genetic findings in correlation with clinical phenotype and genotype. METHODS We developed a composite nasal potential difference (NPD) diagnostic score to discriminate patients with CF from non-CF patients. We tested NPD in 50 children (age, 6 mo to 18 yr) with equivocal diagnoses and correlated the NPD diagnostic score with clinical phenotypes and genotypes. MEASUREMENTS AND MAIN RESULTS Fifteen of the 50 children had NPD scores in the CF range. Eight of the 15 carried two CFTR mutations compared with only 5 of the 35 children with normal NPD scores (P = 0.01). They were significantly younger at evaluation and had recurrent lower respiratory tract infections, chronic productive coughs, and chronic Staphylococcus aureus colonization significantly more often than the 35 children with normal NPD results. CONCLUSIONS Evaluation of CFTR function in the nasal epithelium of children with inconclusive CF diagnoses can be a useful diagnostic tool and help clinicians to individualize therapeutic strategy.

Relative contribution of Prevotella intermedia and Pseudomonas aeruginosa to lung pathology in airways of patients with cystic fibrosis

Background Patients with cystic fibrosis (CF) with Pseudomonas aeruginosa lung infections produce endobronchial mucus plugs allowing growth of obligate anaerobes including Prevotella spp. Whether obligate anaerobes contribute to the pathophysiology of CF lung disease is unknown. Methods The virulence of Prevotella intermedia and Ps aeruginosa was investigated in vitro and in mice, antibodies against P intermedia in CF sera were assessed and a culture-independent detection method for P intermedia/P nigrescens in CF sputum was tested. Results P intermedia reached cell numbers of >105–>107 colony-forming units (CFU)/ml sputum. The majority of patients with CF (16/17; 94.1%) produced antibodies against two immunoreactive antigens of P intermedia. Culture supernatant fluids, collected from 109 P intermedia cells, were more cytotoxic to respiratory epithelial cells in vitro and inflammatory in mouse lungs than respective fluids from anaerobically grown Ps aeruginosa, while fluids from aerobically grown Ps aeruginosa had the highest cytotoxicity and inflammation. Both pathological effects were largely reduced when culture supernatant fluids from 107 cells of either species were used. P intermedia cells (∼106CFU/lung) did not induce mortality in the agar beads lung infection mouse model, while Ps aeruginosa cells caused death in 30% of mice due to rapid multiplication. A P intermedia/P nigrescens-specific PNA probe was significantly more sensitive than culture-dependent diagnostic assays to detect these strict anaerobes. Conclusion Ps aeruginosa and P intermedia become significantly virulent in vitro and in vivo when cell numbers exceed 108 CFU/lung.

Regulation of Staphylococcus aureus CapsularPolysaccharideType 5: CO2 InhibitionIn Vitro andIn Vivo

Staphylococcus aureus capsular polysaccharide type 5 (CP5) expression was investigated in lung tissue and nasal polyps of two cystic fibrosis (CF) patients, in rats, and in vitro using ELISA and IFA. In CF tissues, S. aureus expressed protein A and teichoic acid but only 1%-5% of cells expressed CP5. When rats were challenged with CP5-positive S. aureus in the granuloma pouch model, only 1%-5% of CP5-positive cells were detectable in pouch exudates. CF and pouch isolates, however, reexpressed CP5 (70%-90% of cells) when grown in vitro with air. Addition of > or = 1% CO2 to air or to O2/N2 gas mixtures reduced CP5 expression significantly (P < .001) in a dose-dependent manner (6%-1% CP5-positive cells). The results show that S. aureus does not produce CP5 in CF airways and in rat granuloma pouches and that CO2 is an environmental signal that regulates CP5 expression.

Post-translational Tyrosine Nitration of Eosinophil Granule Toxins Mediated by Eosinophil Peroxidase

Nitration of tyrosine residues has been observed during various acute and chronic inflammatory diseases. However, the mechanism of tyrosine nitration and the nature of the proteins that become tyrosine nitrated during inflammation remain unclear. Here we show that eosinophils but not other cell types including neutrophils contain nitrotyrosine-positive proteins in specific granules. Furthermore, we demonstrate that the human eosinophil toxins, eosinophil peroxidase (EPO), major basic protein, eosinophil-derived neurotoxin (EDN) and eosinophil cationic protein (ECP), and the respective murine toxins, are post-translationally modified by nitration at tyrosine residues during cell maturation. High resolution affinity-mass spectrometry identified specific single nitration sites at Tyr349 in EPO and Tyr33 in both ECP and EDN. ECP and EDN crystal structures revealed and EPO structure modeling suggested that the nitrated tyrosine residues in the toxins are surface exposed. Studies in EPO-/-, gp91phox-/-, and NOS-/- mice revealed that tyrosine nitration of these toxins is mediated by EPO in the presence of hydrogen peroxide and minute amounts of NOx. Tyrosine nitration of eosinophil granule toxins occurs during maturation of eosinophils, independent of inflammation. These results provide evidence that post-translational tyrosine nitration is unique to eosinophils.

Fas and Fas ligand expression in cystic fibrosis airway epithelium

BACKGROUND Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and defective expression of CFTR protein in epithelial cells. The main cause of mortality in CF is linked to chronic inflammatory and infectious airway processes. Recent studies have suggested perturbations in the apoptotic process in CF cell lines and enterocytes. A study was undertaken to investigate the expression of Fas and Fas ligand (FasL) in CF bronchial epithelium and CF tracheal cell lines. METHODS Immunohistochemical staining for Fas (alkaline phosphatase anti-alkaline phosphatase) and FasL (immunoperoxidase) was performed in eight CF bronchial epithelial samples and four controls and immunohistochemical DNA fragmentation (TUNEL) was carried out in four CF patients and four controls. Immunofluorescence staining and flow cytometric analysis of Fas and FasL expression was performed in two human tracheal epithelial cell lines (HTEC) with normal and CF genotype. The dosage of serum soluble FasL was examined in 21 patients with CF and 14 healthy volunteers. RESULTS FasL expression was markedly increased in patients with CF in both the ciliated and submucosal glandular bronchial epithelium compared with controls; Fas was similarly expressed in bronchial samples from controls and CF patients in both the ciliated epithelium and submucosal glands. High levels of DNA fragmentation were observed in CF but with some epithelial cell alterations. Serum concentrations of soluble FasL were frequently undetectable in patients with CF. In vitro, HTEC expressed Fas and FasL in both genotypes. A higher mean fluorescence intensity for FasL expression was noted in CF genotype HTEC with median (range) for six experiments of 74 (25–101) for CF cells and 42 (21–70) for non-CF cells. CONCLUSION Fas/FasL interaction is probably implicated in the human CF airway apoptotic pathway. The mechanisms of induction of FasL expression and its role in inducing tissue damage or remodelling or in controlling local inflammatory cell apoptosis remain to be determined.

BILATERAL CYSTIC PLEUROPULMONARY BLASTOMA IN EARLY INFANCY

We report 2 cases of multifocal cystic (type 1) pleuropulmonary blastoma, diagnosed during the first 6 months of life. This rare entity must be recognized before evolution into the prognostically unfavorable type 2 or type 3 pleuropulmonary blastoma.

Cost of home and hospital care for patients with cystic fibrosis followed up in two reference medical centers in France

OBJECTIVES In France, new guidelines for clinical practices concerning cystic fibrosis came out in 2002, underscoring the need for early and intensive management of this disease. Because no recent health economic studies on cystic fibrosis in France were available, we conducted a cost-analysis study before the new guidelines were put into practice, with a view to a later study on the medical and economic impact of these guidelines. METHODS A cost-analysis study was performed of the inpatient and outpatient costs of patients with cystic fibrosis for the 2000-2001 period. The various direct costs were estimated on a sample of sixty-five adult and pediatric patients managed for cystic fibrosis in two reference medical centers. Data were obtained from medical records, and questionnaires were filled out by the patients. Analysis was made from the perspective of the French healthcare system. RESULTS We studied sixty-five patients, 54 percent male patients and 72 percent children under 18 years of age. The total cost of cystic fibrosis care totaled 16,189 euros per year and per patient. Outpatient costs accounted for 88 percent of the total cost versus 12 percent for inpatient costs; medication costs were the highest with 21 percent of the total cost for home intravenous antibiotic treatments and 49 percent of the total cost for chronic medications. CONCLUSIONS The results show that outpatient costs were higher than inpatient costs, which could be related to the importance granted to home health care in France, notably for intravenous antibiotic treatments given for pulmonary complications.