[Cystic fibrosis in Morroco : what do words mean without action ?] / Mucoviscidose au Maroc : que valent les mots sans les actes ?

It is estimated that in highly medicalised countries, median life expectancy for most newborns with cystic fibrosis now exceeds 70 years, approaching that of the general population. However, socio-economic disparities between countries continue to have a devastating impact on the prognosis of patients in Eastern Europe, Africa, India and South America. In Morocco, very limited genetic data suggest that the prevalence of this disease is at least of the same order as in Belgium. But as it is not really recognised by the national health system, patients are denied access even to symptomatic treatment. As a result, their outcome is tragic, similar to what it was 60 years ago in the most medicalised countries. A pilot project for a first paediatric reference centre in Casablanca is currently being set up. If properly resourced, this project can only be a success and should be the first step on the road towards cystic fibrosis care in this country. In a very humble way, several Belgian stakeholders are trying to support this project.

Dans les pays les plus médicalisés, l'espérance de vie médiane de la plupart des nouveau-nés atteints de mucoviscidose excède aujourd'hui 70 ans et se rapproche de celle de la population générale. Ailleurs, en Europe de l'Est comme en Afrique, en Inde ou en Amérique du Sud, les disparités socio-économiques des pays continuent à impacter très durement le pronostic des patients. Au Maroc, des données génétiques très fragmentaires suggèrent que la prévalence de la mucoviscidose est au moins du même ordre qu'en Belgique. Mais la maladie n'y est pas réellement reconnue par le système de santé, de telle sorte que même le traitement symptomatique reste inaccessible aux patients et leur pronostic est tragique, similaire à ce qu'il était il y a 60 ans dans les pays les plus médicalisés. À Casablanca, le projet pilote d'un premier Centre pédiatrique de Référence est en train de se mettre en place. S'il bénéficie d'un support adéquat, ce projet ne peut être qu'un succès et doit constituer un tout premier pas sur le chemin vers une prise en charge des patients dans ce pays. Très modestement, plusieurs intervenants belges tentent d'y apporter leur soutien.

[Cystic fibrosis - ETI and type 2 N-of-1 trials : the next step]. / Mucoviscidose : valider un traitement révolutionnaire par de brefs essais thérapeutiques individuels bien supervisés.

In evidence-based medicine, N-of-1 trials are increasingly attractive for rare and heterogeneous conditions. A recent French study illustrates this convincingly in the field of cystic fibrosis. A highly effective triple therapy (ETI) is currently available in Europe, which will eventually help the 85 % of Belgian patients carrying at least one copy of the F508del mutation. Most other 2.000 or so putative mutations of this gene are poorly characterised and very rare or private. To predict the efficacy of ETI at the individual level in currently ineligible patients, sophisticated tools are advocated, but they are expensive, not widely available, often partially standardised and there still remains a «grey area¼ concerning their reliability in this context. With-out using them, the French study suggests that more than half of these patients show clinically meaningful responses to a 4-6 weeks trial of ETI. What makes this pragmatic, cost-effective, non-invasive and simplified approach possible (type 2 N-of-1 trials) is the dramatic and rapid efficacy of a life-saving treatment without alternative and the fact that it can be assessed using simple and robust clinical and paraclinical outcomes. Here, we describe one such trial and discuss the value and limitations of this approach.

Dans la médecine basée sur les preuves, les essais de taille 1 suscitent un intérêt croissant dans les affections rares et hétérogènes. Une récente étude française l'illustre de manière convaincante dans la mucoviscidose. Une trithérapie extrêmement efficace (ETI) est actuellement disponible en Europe, concernant à terme en Belgique les 85 % de patients porteurs d'au moins une copie de la mutation F508del. La majorité des quelque 2.000 autres mutations putatives de ce gène sont mal caractérisées et rarissimes. Des techniques sophistiquées sont évoquées pour prédire, à l'échelle individuelle, l'efficacité d'ETI chez les patients actuellement non éligibles, mais elles sont peu disponibles, coûteuses, souvent imparfaitement standardisées et leur interprétabilité conserve une «zone grise¼. Sans y recourir, l'étude française montre que plus de la moitié de ces patients répondent d'une manière évidente à un essai d'ETI pendant quelques semaines seulement. Ce qui permet cette approche pragmatique, économique, non invasive et simplifiée (essai de taille 1, de type 2), c'est l'efficacité spectaculaire et rapide d'un traitement salvateur sans alternative et le fait qu'elle puisse être appréhendée à partir de critères cliniques et paracliniques simples et robustes. Nous rapportons ici un essai de ce type et discutons l'intérêt et les limites de cette approche.

[Recurrent atelectasis in an infant : about one case of false-negative newborn screening for cystic fibrosis]. / Atélectasie récidivante chez un nourrisson : à propos d'un cas de faux-négatif du dépistage néonatal pour la mucoviscidose.

In infants as well as in older children, persistent or recurrent atelectasis remains a classic indication for sweat testing, even if neonatal screening for cystic fibrosis has been considered normal. Atelectasis is a common complication of cystic fibrosis. Yet, it has rarely been reported in infants. In cystic fibrosis, chronic atelectasis worsens the prognosis, especially when involving a lower lobe. Therefore, early and effective intervention is required. Antibiotic therapy, intensive chest physiotherapy together with inhaled mucolytics often allow to relieve bronchial obstruction but bronchoscopy with local aspiration and Dornase alpha instillation is sometimes necessary. In a two-month-old infant, we describe here the first reported case of false-negative cystic fibrosis newborn screening in Belgium.

Chez le nourrisson comme chez l'enfant plus âgé, une atélectasie persistante ou récidivante reste une indication classique de test à la sueur, même si le dépistage néonatal de la mucoviscidose a été considéré comme normal. Rarement rapportées chez le nourrisson, les atélectasies sont une complication commune de la mucoviscidose. Dans cette affection, l'atélectasie chronique d'un territoire péjore le pronostic, en particulier si elle concerne un lobe inférieur. Une intervention précoce et efficace est donc requise. Antibiothérapie, kinésithérapie respiratoire intensive et recours aux fluidifiants par voie de nébulisation suffisent souvent à lever l'obstruction bronchique, mais une endoscopie avec aspiration locale et instillation de dornase alpha est parfois nécessaire. Chez un nourrisson de 2 mois, nous rapportons ici le premier cas de faux-négatif du programme belge de dépistage néonatal de la mucoviscidose.

[How I treat vitamin D intoxication in a child with cystic fibrosis]. / Comment je traite une intoxication à la vitamine D chez un enfant atteint de mucoviscidose.

At least 80 % of persons with cystic fibrosis are pancreatic insufficient and benefit from daily supplementation with fat-soluble vitamins (ADEK). Magistral formulations offer ideal flexibility for prescriptions tailored to vitamin A, D and E blood levels. However, they expose to human errors, mainly leading to vitamin D intoxication whose clinical features are related to hypercalcaemia. Symptoms are mostly digestive (vomiting, constipation, abdominal pain …) and, less frequently, renal (nycturia …) complaints. When symptoms and/or serum calcium levels ≥ 14 mg/100 ml are present, prompt management is required. Besides interruption of supplementation, rapid intravenous hyperhydration (saline) is essential. Once hydration has been restored, and still under close biological supervision, a loop diuretic (furosemide) may be used but the drug of choice to achieve rapid normalization of blood calcium levels will often be intravenous pamidronate. Normalization of serum vitamin 25(OH)-D levels may take several months but the prognosis is very good. In Belgium, the very late reimbursement of a fixed combination of fat-soluble vitamins (Dekas®) meeting the standards of the pharmaceutical industry is expected to reduce the incidence of these intoxications, at the price, however, of less flexible prescription.

Au moins 80 % des patients atteints de mucoviscidose présentent une insuffisance pancréatique exocrine et bénéficient quotidiennement d'une supplémentation en vitamines liposolubles (ADEK). Une préparation magistrale offre alors une souplesse idéale de prescription. Elle expose cependant à des erreurs humaines, qui mènent surtout à des intoxications à la vitamine D. Les symptômes, souvent surtout digestifs (vomissements, constipation, douleurs abdominales …), voire rénaux (nycturie …), sont liés à l'hypercalcémie. En cas de symptômes et/ou de calcémie ≥ 14 mg/100 ml, une prise en charge immédiate est nécessaire. Outre l'interruption de la supplémentation, elle inclut d'abord une hyperhydratation rapide, par voie intraveineuse (sérum physiologique). Une fois l'hydratation restaurée, et toujours sous contrôles biologiques rapprochés, un diurétique de l'anse (furosémide) peut être utilisé, mais c'est souvent une administration intraveineuse de pamidronate qui permettra la normalisation rapide de la calcémie. Le taux sérique de vitamine 25(OH)-D peut mettre plusieurs mois à se normaliser, mais le pronostic est très bon. Remboursée tardivement en Belgique, une combinaison fixe de vitamines liposolubles (Dekas®), répondant aux normes de l'industrie pharmaceutique, devrait limiter le nombre de ces intoxications au prix, toutefois, d'une moindre souplesse de prescription.

Needle-free iontophoresis-driven ß-adrenergic sweat rate test.

OBJECTIVES: Two CFTR-dependent ß-adrenergic sweat rate tests applying intradermal drug injections were reported to better define diagnosis and efficacy of CFTR-directed therapies. The aim of this work was to develop and test a needle-free image-based test and to provide an accurate analysis of the responses. METHODS: The modified method was conducted by applying two successive iontophoresis sessions using the Macroduct device. Efficiency of drug delivery was tested by evaporimetry. Cholinergically stimulated sweating was evoked by pilocarpine iontophoresis. ß-adrenergically stimulated sweating was obtained by iontophoresis of isoproterenol and aminophylline in the presence of atropine and ascorbic acid. A nonlinear mixed-effects (NLME) approach was applied to model volumes of sweat and subject-specific effects displaying inter- and intra-subject variability. RESULTS: Iontophoresis provided successful transdermal delivery of all drugs, including almost neutral isoproterenol and aminophylline. Pilocarpine was used at a concentration ∼130-times lower than that used in the classical Gibson and Cooke sweat test. Addition of ascorbic acid lowered the pH of the solution, made it stable, prevented isoproterenol degradation and promoted drug iontophoresis. Maximal secretory capacity and kinetic rate of ß-adrenergic responses were blunted in CF. A cutoff of 5.2 minutes for ET50, the time to reach the half maximal secretion, discriminated CF from controls with a 100% sensitivity and specificity. Heterozygous showed an apparently reduced kinetic rate and a preserved secretory capacity. CONCLUSION: We tested a safe, well-tolerated needle-free image-based sweat test potentially applicable in children. Modelling responses by NLME allowed evaluating metrics of CFTR-dependent effects reflecting secretory capacity and kinetic rate.

Impact of PEGylation on the mucolytic activity of recombinant human deoxyribonuclease I in cystic fibrosis sputum.

Highly viscous mucus and its impaired clearance characterize the lungs of patients with cystic fibrosis (CF). Pulmonary secretions of patients with CF display increased concentrations of high molecular weight components such as DNA and actin. Recombinant human deoxyribonuclease I (rhDNase) delivered by inhalation cleaves DNA filaments contained in respiratory secretions and thins them. However, rapid clearance of rhDNase from the lungs implies a daily administration and thereby a high therapy burden and a reduced patient compliance. A PEGylated version of rhDNase could sustain the presence of the protein within the lungs and reduce its administration frequency. Here, we evaluated the enzymatic activity of rhDNase conjugated to a two-arm 40 kDa polyethylene glycol (PEG40) in CF sputa. Rheology data indicated that both rhDNase and PEG40-rhDNase presented similar mucolytic activity in CF sputa, independently of the purulence of the sputum samples as well as of their DNA, actin and ions contents. The macroscopic appearance of the samples correlated with the DNA content of the sputa: the more purulent the sample, the higher the DNA concentration. Finally, quantification of the enzymes in CF sputa following rheology measurement suggests that PEGylation largely increases the stability of rhDNase in CF respiratory secretions, since 24-fold more PEG40-rhDNase than rhDNase was recovered from the samples. The present results are considered positive and provide support to the continuation of the research on a long acting version of rhDNase to treat CF lung disease.

Comparison of the RGM medium and the mycobacterial growth indicator tube automated system for isolation of non-tuberculous mycobacteria from sputum samples of cystic fibrosis patients in Belgium.

PURPOSE: Pulmonary infections due to non-tuberculous mycobacteria (NTM) are an emerging issue in the cystic fibrosis (CF) population. Due to bacterial and fungal overgrowth, isolation of mycobacteria from the sputum samples of these patients remains challenging. RGM medium, a novel agar-based culture medium was evaluated for the isolation of NTM from sputum samples of CF patients. METHODOLOGY: Sputum samples were inoculated onto RGM medium and conventional Mycobacterial Growth Indicator Tube (MGIT™, Becton Dickinson, USA). Agar plates were incubated at 35 °C and growth was recorded once a week during 42 days. We compared the yield of the two media. RESULTS: 217 samples were obtained from 124 CF patients. 20 samples (13 patients) had a positive culture for NTM. 79/217 (36.4%) MGIT had to be discontinued due to contamination compared to 18/217 (8.3%) for RGM. We reported equivalent NTM detection performances for RGM and MGIT (P = 0.579): these media enabled the isolation of 15 and 12 NTM strains respectively. CONCLUSION: RGM medium increases the proportion of interpretable results and the number of NTM cultured. Taking into account the non-inferiority compared to conventional methods and ease of use of RGM medium, we estimate that this test can replace current approaches for the screening of NTM among people with CF. Additionally, RGM provides semi-quantitative results (number of colonies) and information on the morphology of colonies, which may be clinically relevant information.

Agreement between multiple-breath nitrogen washout systems in children and adults.

BACKGROUND: Comparability of multiple breath washout (MBW) systems has been little explored. We assessed agreement in lung clearance index (LCI) from two similar, commercial nitrogen MBW setups in patients with Cystic Fibrosis (CF) and controls. METHODS: The EasyOne Pro (NDD) and Exhalyzer D (EM) were randomly applied in 85 adults (34 with CF) and 97 children (47 with CF and normal forced expiratory volume in one second). We assessed differences between setups in LCI, lung volumes and breathing pattern and diagnostic performance for detecting abnormal lung function. RESULTS: Compared to NDD, EM measured higher LCI, functional residual capacity and cumulative expired volume while respiratory rate was lower. Mean difference (limits of agreement) in LCI was 1.30 (-2.34 to 4.94). In CF, prevalence of abnormal LCI was greater in children and similar in adults using EM compared to NDD. CONCLUSIONS: Agreement of MBW outcomes between setups is poor and explained by nitrogen measurement techniques and breathing pattern.

DRESS syndrome in a patient with cystic fibrosis: A case report.

Drug reaction with eosinophilia and systemic symptom (DRESS) syndrome is a rare and severe side-effect, mainly described after intake of anticonvulsants, allopurinol, or antibiotics. It usually begins within 2 months after drug introduction. Symptoms include cutaneous rash, hematologic abnormalities, and internal organ involvement and the diagnosis might be challenging. This case report illustrates for the first time this life-threatening complication in a patient with cystic fibrosis (CF). In this case, withdrawal of the offending drug was sufficient for full recovery. Clinicians involved in CF care should be aware of DRESS syndrome, as they commonly prescribe several potentially culprit drugs. Pediatr Pulmonol. 2017;52:E18-E21. © 2016 Wiley Periodicals, Inc.

Variability of gait speed during six minutes walking test in COPD and cystic fibrosis patients.

BACKGROUND: Recently, gait speed reached an increasing importance in the management of respiratory patients. The aim of this retrospective study was to compare walking speed and physiological adaptations during the 6MWT in COPD and CF patients. METHODS: 6MWT performed by COPD and CF patients were retrospectively reviewed. Global and sequential walking speeds were measured on six minutes and every sequence of two minutes respectively. Heart rate, oxygen saturation and dyspnea were analyzed. RESULTS: 78 and 246 tests from CF and COPD patients were reviewed respectively. FEV1 (52.3 vs 56.2% pred) and FVC (72.5 vs 73.8% pred) were similar between both diseases. However, 6MWT in patients with CF were characterized by significantly higher heart rate, global walking speed and walking distance (+68%) while dyspnea evolutions and the proportions of patients presenting walking speed decline over the 6min were significantly lower. CONCLUSION: Walking speed and cardio-respiratory parameters evolution during 6MWT differ between COPD and CF patients.

Impact of MIF gene promoter polymorphism on F508del cystic fibrosis patients.

Macrophage migration Inhibitory Factor (MIF) is a pro-inflammatory cytokine sustaining the acute response to gram-negative bacteria and a regulatory role for MIF in Cystic Fibrosis has been suggested by the presence of a functional, polymorphic, four-nucleotide repeat in this gene's promoter at position -794, with the 5-repeat allele displaying lower promoter activity. We aimed at assessing the association of this polymorphism with disease severity in a group of Cystic Fibrosis patients homozygous for F508del CFTR gene mutation. Genotype frequencies were determined in 189 Cystic Fibrosis and 134 control subjects; key clinical features of patients were recorded and compared among homozygous 5-allele patients and the other MIF genotypes. Patients homozygous for the 5-repeat allele of MIF promoter displayed a slower rate of lung function decline (p = 0.027) at multivariate survival analysis. Multiple regression analysis on age-normalized respiratory volume showed no association of the homozygous 5-repeat genotype with lung function under stable conditions and no correlation with P.aeruginosa chronic colonization. Therefore, only the Homozygous 5-repeat genotype at MIF -794 is associated with milder disease in F508del Cystic Fibrosis patients.

Dysregulated proinflammatory and fibrogenic phenotype of fibroblasts in cystic fibrosis.

Morbi-mortality in cystic fibrosis (CF) is mainly related to chronic lung infection and inflammation, uncontrolled tissue rearrangements and fibrosis, and yet the underlying mechanisms remain largely unknown. We evaluated inflammatory and fibrosis responses to bleomycin in F508del homozygous and wild-type mice, and phenotype of fibroblasts explanted from mouse lungs and skin. The effect of vardenafil, a cGMP-specific phosphodiesterase type 5 inhibitor, was tested in vivo and in culture. Responses of proinflammatory and fibrotic markers to bleomycin were enhanced in lungs and skin of CF mice and were prevented by treatment with vardenafil. Purified lung and skin fibroblasts from CF mice proliferated and differentiated into myofibroblasts more prominently and displayed higher sensitivity to growth factors than those recovered from wild-type littermates. Under inflammatory stimulation, mRNA and protein expression of proinflammatory mediators were higher in CF than in wild-type fibroblasts, in which CFTR expression reached similar levels to those observed in other non-epithelial cells, such as macrophages. Increased proinflammatory responses in CF fibroblasts were reduced by half with submicromolar concentrations of vardenafil. Proinflammatory and fibrogenic functions of fibroblasts are upregulated in CF and are reduced by vardenafil. This study provides compelling new support for targeting cGMP signaling pathway in CF pharmacotherapy.

Objective study of sensor relevance for automatic cough detection.

The development of a system for the automatic, objective, and reliable detection of cough events is a need underlined by the medical literature for years. The benefit of such a tool is clear as it would allow the assessment of pathology severity in chronic cough diseases. Even though some approaches have recently reported solutions achieving this task with a relative success, there is still no standardization about the method to adopt or the sensors to use. The goal of this paper is to study objectively the performance of several sensors for cough detection: ECG, thermistor, chest belt, accelerometer, contact, and audio microphones. Experiments are carried out on a database of 32 healthy subjects producing, in a confined room and in three situations, voluntary cough at various volumes as well as other event categories which can possibly lead to some detection errors: background noise, forced expiration, throat clearing, speech, and laugh. The relevance of each sensor is evaluated at three stages: mutual information conveyed by the features, ability to discriminate at the frame level cough from these latter other sources of ambiguity, and ability to detect cough events. In this latter experiment, with both an averaged sensitivity and specificity of about 94.5%, the proposed approach is shown to clearly outperform the commercial Karmelsonix system which achieved a specificity of 95.3% and a sensitivity of 64.9%.

Molecular typing and antifungal susceptibility of Exophiala isolates from patients with cystic fibrosis.

The black yeast Exophiala dermatitidis is a frequent agent of colonization of the lungs of patients with cystic fibrosis (CF). A total of 71 clinical isolates of Exophiala from 13 patients were identified at the species level by sequencing the internal transcribed spacer (ITS) regions 1 and 2 of the rDNA genes and typed by random amplification of polymorphic DNA (RAPD), using two different primers, BG-2 and ERIC-1. In vitro susceptibility of these isolates to some systemic antifungal drugs was investigated using the CLSI method. Almost all the isolates were identified as E. dermatitidis, but long-term colonization with the closely related species E. phaeomuriformis was observed in one patient. No clustering was found according to the geographical origin of the isolates, the isolation date or the antifungal susceptibility. Variations were seen in the susceptibility of studied isolates to antifungals but most of them exhibited low susceptibility to amphotericin B and although some patients were successively colonized by two distinct genotypes, most of the isolates were distributed in patient-specific clusters. This phenomenon may be due to genomic variations of E. dermatitidis in the lung environment of CF patients. These results are typical of colonization of the airways of patients by a poorly distributed environmental fungus, which occupies particular reservoirs that need to be defined.

A randomized placebo-controlled trial of miglustat in cystic fibrosis based on nasal potential difference.

BACKGROUND: Preclinical data suggest that miglustat could restore the function of the cystic fibrosis transmembrane conductance regulator gene in cystic fibrosis cells. METHODS: Single-center, randomized, double-blind, placebo-controlled, crossover Phase II study in 11 patients (mean±SD age, 26.3±7.7 years) homozygous for the F508del mutation received oral miglustat 200 mgt.i.d. or placebo for two 8-day cycles separated by a 14-day washout period. The primary endpoint was the change in total chloride secretion (TCS) assessed by nasal potential difference. RESULTS: No statistically significant changes in TCS, sweat chloride values or FEV(1) were detected. Pharmacokinetic and safety were similar to those observed in patients with other diseases exposed to miglustat. CONCLUSIONS: There was no evidence of a treatment effect on any nasal potential difference variable. Further studies with miglustat need to adequately address criteria for assessment of nasal potential difference.

The objective assessment of cough frequency: accuracy of the LR102 device.

BACKGROUND: The measurement of cough frequency is problematic and most often based on subjective assessment. The aim of the study was to assess the accuracy of the automatic identification of cough episodes by LR102, a cough frequency meter based on electromyography and audio sensors. METHODS: Ten adult patients complaining of cough were recruited in primary care and hospital settings. Participants were asked to wear LR102 for 4 consecutive hours during which they were also filmed. RESULTS: Measures of cough frequency by LR102 and manual counting were closely correlated (r = 0.87 for number of cough episodes per hour; r = 0.89 for number of single coughs per hour) but LR102 overestimated cough frequency. Bland-Altman plots indicate that differences between the two measurements were not influenced by cough frequency. CONCLUSIONS: LR102 offers a useful estimate of cough frequency in adults in their own environment, while significantly reducing the time required for analysis.

Impact of polymorphism of Multidrug Resistance-associated Protein 1 (ABCC1) gene on the severity of cystic fibrosis.

A 5'FR/G-260C (NCBI reference: 010393.16:g.15983174C>G) functional polymorphism of Multidrug Resistance-associated Protein 1 (ABCC1) promoter has been reported which influences ABCC1 expression including inflammatory related events. We aimed at investigating the impact of this polymorphism on the severity of CF disease. In this multicentric study, key clinical features of 203 CF patients homozygous for the F508del mutation were recorded. Kaplan-Meier analysis showed that patients with the rare CC genotype were chronically colonized by PA around 6 years earlier (mean ± SD: 11.2 year ± 7.8, 95% CI for the mean: 5.7-16.8) than those with the GG or the CG alleles (p<=0.01) and a FEV1 <60% predicted was first observed earlier in this group (p<0.05). Concordant trends to better nutritional status and FEV1 were observed in the slightly older GG subgroup. The potential role of ABCC1 promoter as a modifier gene deserves further study.