Dominique Hubert

High Prevalence of Azole-Resistant Aspergillus fumigatus in Adults with Cystic Fibrosis Exposed to Itraconazole

ABSTRACT Aspergillus fumigatus is the most frequent fungus found in the sputum of cystic fibrosis (CF) subjects. Itraconazole is prescribed for allergic bronchopulmonary aspergillosis (ABPA) or Aspergillus bronchitis in CF subjects. We hypothesized that A. fumigatus isolates in the sputum of CF subjects with previous exposure to itraconazole was associated with higher prevalence of azole resistance. From June 2010 to April 2011, sputum samples from adult CF subjects at Cochin University Hospital (France) were examined systematically for the detection of A. fumigatus. MICs of A. fumigatus isolates against azoles were screened using Etest, and reduced susceptibility to azoles was confirmed using the CLSI broth microdilution method. A. fumigatus was isolated from the sputum of 131/249 (52.6%) adult CF subjects, and 47/131 (35.9%) subjects had received previous treatment with itraconazole. Reduced A. fumigatus susceptibility to itraconazole (MIC, ≥2 mg/liter) was confirmed in 6/131 (4.6%) subjects. All 6 isolates also had reduced susceptibility to posaconazole (MIC, ≥0.5 mg/liter), and 3/6 isolates had reduced susceptibility to voriconazole (MIC, ≥2 mg/liter). Mutations in the cyp51A gene were detected at positions previously implicated to cause resistance in 5 isolates. Azole-resistant A. fumigatus isolates were found in 5/25 (20%) subjects exposed to itraconazole within the previous 3 years. High rates of azole-resistant A. fumigatus isolates were present in adult CF subjects and were associated with recent itraconazole exposure. Although the clinical implications of these findings will require further studies, the cautious use of itraconazole in adult CF subjects can be recommended.

Genistein Inhibits Constitutive and Inducible NFκB Activation and Decreases IL-8 Production by Human Cystic Fibrosis Bronchial Gland Cells

The inflammatory pathogenesis in airways of patients with cystic fibrosis (CF) is still unresolved. We demonstrate here that in in situ human DeltaF508 homozygous CF bronchial tissues, submucosal gland cells exhibit an absence of inhibitor factor kappaBalpha (IkappaBalpha) and high levels of chemokine interleukin-8 (IL-8) expression. These results were confirmed by cultured human CF bronchial gland cells in which a lack of cytosolic IkappaBalpha and high levels of constitutively activated nuclear factor kappaB (NFkappaB) associated with an up-regulation of IL-8 production (13-fold increase) were found when compared to non-CF (control) disease bronchial gland cells. We also demonstrated that the isoflavone genistein, a well known CFTR mutant Cl(-) channel stimulator, significantly reduces the endogenous and Pseudomonas aeruginosa lipopolysaccharide-induced IL-8 production in cultured CF bronchial gland cells by increasing cytosolic IkappaBalpha protein levels. Overall, results show that genistein is a potent inhibitor of the activated NFkappaB identified in CF gland cells. This strong inhibition of constitutively activated NFkappaB and the resulting down-regulation of IL-8 production by genistein in the CF gland cells highlights the key role played by cytosolic IkappaBalpha in the regulation of inflammatory processes in CF human airway cells.

High Susceptibility for Cystic Fibrosis Human Airway Gland Cells to Produce IL-8 Through the IκB Kinase α Pathway in Response to Extracellular NaCl Content

Increasing evidence suggests that in airways from cystic fibrosis (CF) patients, inflammation may precede bacterial infection and be related to an endogenous dysregulation of proinflammatory cytokines in airway epithelial cells. Several investigators have reported that, in CF airway fluids, elevated NaCl concentrations may also contribute to the diseased state by inhibiting the bactericidal properties of airway fluid. Because many proinflammatory cytokines are transcriptionally regulated by the NF-κB, we investigated whether an elevated extracellular NaCl content in airway fluids significantly impaired the regulation of the NF-κB/IκBα complex and the chemokine IL-8 production in primary non-CF and CF human bronchial gland epithelial cells. Exposure of non-CF gland cells to hypotonic (85 mM) NaCl solution, compared with isotonic (115 mM) NaCl and hypertonic (170 mM) NaCl solutions, resulted in a significant decrease in IL-8 production that was paralleled by a strong inhibition of activated NF-κB associated with an increased cytosolic expression of IκBα and a decrease in the IκB kinase α protein level. In CF gland cells, we demonstrated that, compared with the high IL-8 in an hypertonic solution, the release of IL-8 was significantly reduced 2-fold in an isotonic solution and 5-fold in a hypotonic solution. Strikingly, exposure of CF bronchial gland cells to either hypotonic or isotonic milieu did not result in a marked inhibition of the activated NF-κB/IκBα system. This is the first demonstration that primary human CF bronchial gland cells exhibit abnormally high IL-8 production through constitutively activated NF-κB and high IκB kinase α level, whatever the hypo-, iso-, and hypertonic NaCl milieu.

Distal intestinal obstruction syndrome in adults with cystic fibrosis

BACKGROUND & AIMS With the improved survival of patients with cystic fibrosis (CF), gastrointestinal complications become more evident in adults with this condition. The aims of this study were to determine the prevalence and clinical features of distal intestinal obstruction syndrome (DIOS) and its relationship with the cystic fibrosis transmembrane conductance regulator (CFTR) genotype in an adult CF population. METHODS Cross-sectional study was conducted in an adult CF cohort. RESULTS Among 171 adults with CF (mean age, 28.9 years), 27 patients (15.8%) reported 43 episodes of DIOS. No significant association was found between DIOS and a history of meconium ileus. The first episode of DIOS occurred in adulthood in 21 cases (77.8%). DIOS recurred in 13 patients (48.1%). All patients who developed DIOS had pancreatic insufficiency. Pulmonary function was significantly more altered in patients with DIOS than in the other patients, but pancreatic insufficiency and age might act as confounding factors. DIOS occurred in 21.9% of patients with a severe CFTR genotype and in only 2.4% of patients with a mild CFTR genotype (P < 0.005). CONCLUSIONS DIOS is frequent in adults with CF with a severe CFTR genotype and/or advanced-stage pulmonary disease. The relative contributions of malabsorption and impaired intestinal secretion in the development of DIOS are discussed.

Characteristics and consequences of airway colonization by filamentous fungi in 201 adult patients with cystic fibrosis in France

A total of 657 sputum samples from 201 cystic fibrosis adult patients were collected during a 24-month period (2005-2006). We retrospectively analyzed the fungal colonization of the respiratory tract of these individuals by linking medical records and microbiological data. Filamentous fungi were isolated from specimens of 65.6% of the patients, with Aspergillus fumigatus being the predominant species recovered as it was found in specimens of 56.7% of the patients. We observed no difference for gender, pancreatic status and cirrhosis in patients with or without A. fumigatus colonization. We found a higher percentage of recovery of Pseudomonas aeruginosa, Stenotrophomonas maltophilia and nontuberculous mycobacteria in patients with A. fumigatus colonization. During the follow-up period of the study, 8.9% of the patients were diagnosed with allergic bronchopulmonary aspergillosis (ABPA). By a multivariate analysis we demonstrated that Scedosporium apiospermum was significantly associated with ABPA (Odds ratio = 13 [2-80]) as opposed to A. fumigatus (Odds ratio = 1.58 [0.49-5.05]).

The very low penetrance of cystic fibrosis for the R117H mutation: a reappraisal for genetic counselling and newborn screening

Background: Cystic fibrosis (CF) is caused by compound heterozygosity or homozygosity of CF transmembrane conductance regulator gene (CFTR) mutations. Phenotypic variability associated with certain mutations makes genetic counselling difficult, notably for R117H, whose disease phenotype varies from asymptomatic to classical CF. The high frequency of R117H observed in CF newborn screening has also introduced diagnostic dilemmas. The aim of this study was to evaluate the disease penetrance for R117H in order to improve clinical practice. Methods: The phenotypes in all individuals identified in France as compound heterozygous for R117H and F508del, the most frequent CF mutation, were described. The allelic prevalences of R117H (pR117H), on either intron 8 T5 or T7 background, and F508del (pF508del) were determined in the French population, to permit an evaluation of the penetrance of CF for the [R117H]+[F508del] genotype. Results: Clinical details were documented for 184 [R117H]+[F508del] individuals, including 72 newborns. The disease phenotype was predominantly mild; one child had classical CF, and three adults’ severe pulmonary symptoms. In 5245 healthy adults, pF508del was 1.06%, pR117H;T7 0.27% and pR117H;T5<0.01%. The theoretical number of [R117H;T7]+[F508del] individuals in the French population was estimated at 3650, whereas only 112 were known with CF related symptoms (3.1%). The penetrance of classical CF for [R117H;T7]+[F508del] was estimated at 0.03% and that of severe CF in adulthood at 0.06%. Conclusions: These results suggest that R117H should be withdrawn from CF mutation panels used for screening programmes. The real impact of so-called disease mutations should be assessed before including them in newborn or preconceptional carrier screening programmes.

Acute Respiratory Failure Involving an R Variant of Mycobacterium abscessus

ABSTRACT We report the case of a cystic fibrosis patient colonized with a smooth-morphotype form of Mycobacterium abscessus who developed acute respiratory failure with the emergence of an isogenic rough (R) variant while he was recovering from peritonitis-induced shock. This report emphasizes the role of R forms in severe M. abscessus infections.

Relationship between IκBα deficiency, NFκB activity and interleukin-8 production in CF human airway epithelial cells

Abstract. Several recent reports have suggested that airway inflammation may precede infection and relate to an endogenous dysregulation of pro-inflammatory cytokines in cystic fibrosis (CF) airways. Evidence suggests that activation of the nuclear factor kappa B (NFκB), which regulates the inflammatory gene transcription, depends on the degradation of the inhibitory factor IκBα. We show that, in in situ human ΔF508 CF bronchial tissues, inhibitor factor IκBα is not present in gland cells, although endogenous levels of chemokine IL-8 are high. These data are confirmed by studying cultured CF human bronchial gland cells, in which a lack of cytosolic IκBα and high levels of activated NFκB, concomitant with IL-8 overproduction (a 13-fold increase) are found when compared to non-CF bronchial gland cells. Interestingly, treatment of CF gland cells with the isoflavone genistein, a well known CFTR mutant Cl– channel stimulator, results in a significant decrease (P<0.001) in IL-8 production down to levels released by non-CF gland cells. The addition of genistein also reverses the effects of lipopolysaccharide (LPS) Pseudomonas-aeruginosa-induced nuclear translocation of NFκB by increasing IκBα protein level (65%) in CF gland cells. Our data indicate that the induction of IκBα protein in CF airway glandular epithelial cells may be a novel mechanism by which IL-8-mediated lung inflammatory events are markedly reduced in CF patients, at least at the airway glandular level.

Cystic Fibrosis Transmembrane Conductance Regulator Channel Dysfunction in Non–Cystic Fibrosis Bronchiectasis

RATIONALE Although in patients with diffuse bronchiectasis (DB) and a normal sweat test the presence of one mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) gene is frequently observed, its pathogenic role in the development of DB remains unclear. OBJECTIVES To evaluate the association between CFTR heterozygosity and CFTR protein dysfunction in the airways of patients with DB. METHODS Nasal potential difference was measured in 122 patients with DB of unknown origin and with a normal sweat test (Cl(-) < 60 mmol/L). They were classified according to the presence of CFTR mutations: zero (85 patients), one (22 patients), or two mutations (15 patients). Control groups comprised 26 healthy subjects, 38 obligate heterozygotes for CFTR, and 92 patients with classic cystic fibrosis (CF) with an abnormal sweat test (Cl(-) > or = 60 mmol/L). Patients classified as mild-CF were carrying at least one mild mutation and patients classified as severe-CF were homozygous for the F508del mutation. MEASUREMENTS AND MAIN RESULTS There was a continuum of airway CFTR dysfunction in the study population as shown by nasal potential difference measurements, ranging from normal values in healthy subjects, to intermediate values in subjects with DB, to highly abnormal values in subjects classified as severe-CF. This continuum of airway CFTR dysfunction was thus strongly associated with defects in the CFTR gene. Moreover, among patients with DB, a similar continuum in intermediate nasal potential difference was identified that was associated with the bearing of zero, one, or two CFTR mutations. These electrophysiological phenotypes and CFTR genotypes were also associated with the clinical phenotype, as shown by the frequency of Staphylococcus aureus and Pseudomonas aeruginosa bronchial colonization. CONCLUSIONS Our study supports the hypothesis that a unique CFTR mutation may have pathogenic consequences in patients with DB.

Pharmacokinetics and safety of tobramycin administered by the PARI eFlow ® rapid nebulizer in cystic fibrosis ☆

BACKGROUND Nebulization times have been identified as an issue in patient compliance with tobramycin solution for inhalation (TSI) therapy in cystic fibrosis (CF). METHODS In this randomized, open-label, multicentre, two-period, crossover study, patients (n=25) with CF and chronic pulmonary pseudomonal infection received TSI for 15 days via eFlow rapid or LC PLUS nebulizer. Nebulization times and sputum/serum tobramycin concentrations were determined, and safety evaluated. RESULTS Nebulization times were significantly shorter for eFlow rapid versus LC PLUS on Day 1 (least squares mean estimate of the difference -10.5 min, 95% confidence intervals [CI] -12.6, -8.3, p<0.0001) and Day 15 (difference -7.7 min, 95% CI -9.0, -6.5, p<0.0001). Broadly comparable sputum/systemic exposure to tobramycin was observed and the incidence of adverse events was similar for both nebulizers. CONCLUSION Use of the eFlow rapid nebulizer reduced TSI nebulization time. The systemic exposure to tobramycin appeared to be broadly similar in this exploratory study.