[International registry on mucoviscidosis: comparison of the French data with the European data for 1995]

Staphylococcus aureus and Cystic Fibrosis-A Close Relationship. What Can We Learn from Sequencing Studies?

Staphylococcus aureus is next to Pseudomonas aeruginosa the most isolated pathogen from the airways of cystic fibrosis (CF) patients, who are often infected by a dominant S. aureus clone for extended periods. To be able to persist, the pathogen has to adapt to the hostile niche of the airways to counteract host defence, antibiotic therapy and the competition with coinfecting pathogens. S. aureus is equipped with many virulence factors including adhesins, toxins that are localized on the chromosome, on plasmids or are phage-related. S. aureus is especially versatile and adaptation and evolution of the pathogen occurs by the acquisition of new genes by horizontal gene transfer (HGT), changes in nucleotides (single nucleotide variations, SNVs) that can cause a selective advantage for the bacteria and become fixed in subpopulations. Methicillin-resistant S. aureus are a special threat to CF patients due to the more severe lung disease occurring in infected patients. Today, with decreasing costs for sequencing, more and more studies using S. aureus isolates cultured from CF patients are being published, which use whole genome sequencing (WGS), multilocus sequence typing (MLST) or spa-sequence typing (spa-typing) to follow the population dynamics of S. aureus, elucidate the underlying mechanisms of phenotypic variants, newly acquired resistance or adaptation to the host response in this particular niche. In the first part of this review, an introduction to the genetic make-up and the pathogenesis of S. aureus with respect to CF is provided. The second part presents an overview of recent studies and their findings using genotypic methods such as single or multilocus sequencing and whole genome sequencing, which identify factors contributing to the adaptation of S. aureus and its evolution in the airways of individuals with CF.

An overview of international literature from cystic fibrosis registries. Part 3. Disease incidence, genotype/phenotype correlation, microbiology, pregnancy, clinical complications, lung transplantation, and miscellanea

This is the third article related to a review of the literature based on data from national cystic fibrosis (CF) patient registries up to June 2008 and covering a total of 115 published studies. It focuses on several topics: CF incidence, genotype/phenotype correlation, microbiology, pregnancy/paternity, clinical complications, lung transplantation, and others. Seventy seven papers meeting the inclusion criteria were found to be related to the topics listed above. Another seven studies, already evaluated in previous papers of this series, were recalled for specific topics. Incidence is described by several studies, results being quite different from one country to another and quite inhomogeneous among regions within the same country. Studies on genetics address the genotype/phenotype correlation and look for a predictive value of CFTR mutations in terms of clinical outcome, with controversial results. Papers on microbiology describe the clinical relevance of different pathogens and their role in the progress of CF lung disease. A few articles give information on the features of CF women undergoing a pregnancy and try to identify the ones associated with a better outcome. Studies on clinical complications discuss prevalence and the role of haemoptysis, pneumothorax, CF related diabetes, ABPA and cancer. Papers on lung transplantation focus on models able to improve the selection criteria for transplantation candidates and the factors linked to post transplantation survival. Finally, several studies deal with a number of interesting topics related to CF epidemiology: clinical trial methodology, quality of care comparison among countries and centers, relationship between diagnosis and age/gender, and evaluation of pharmacological therapy. On the whole, CF Registries have already contributed to important advances in the knowledge of the natural history of CF, establishing the foundations for future improvement in CF research and care.

Dornase alfa is well tolerated: data from the epidemiologic registry of cystic fibrosis

After closure of the Epidemiologic Registry of Cystic Fibrosis (ERCF), a comprehensive safety analysis of dornase alfa was performed. A planned subanalysis focused on children under 5 years old. Reported serious adverse events (SAEs) were assigned a preferred term and ascribed to a specific organ system. Possible serious adverse reactions to dornase alfa (SADRs) were identified by reporting clinics. Twenty-eight of 15,865 SAEs (0.18%), occurring in 26 of 6,829 patients ever treated with dornase alfa (0.38%), and no deaths were reported as possible SADRs: most were typical complications of cystic fibrosis (CF). There was no evidence of any unrecognized risk of treatment. During 24,586 patient-years of follow-up (FU) of ever-treated patients, SAEs (mostly typical respiratory complications of CF) were more frequent on-treatment (0.4999/patient-year; 95% CI 0.4921-0.5076) than off-treatment (0.3889; 0.3787-0.3992). This was likely caused by within-patient prescription bias. During 655 patient-years of FU in 328 ever-treated patients under 5 years old, SAEs (mostly pulmonary exacerbations of CF) were slightly less frequent during treatment: 0.2911 (0.2367-0.3455) versus 0.3563 (0.3086-0.4040; ns). Results confirm the safety of dornase alfa in CF patients of all ages. Children under 5 years old tolerate dornase alfa at least as well as older patients.

Traitements inhales bronchodilatateurs et fluidifiants dans la mucoviscidose

Poor clearance of airway secretions contributes to the pulmonary disease in cystic fibrosis (CF). Bronchodilator therapy might benefit in CF, but the efficacy is controversial. Effects of mucolytic agents have not been demonstrated conclusively. Only, efficacy of recombinant human deoxyribonuclease (rhDNase) is established with a rapid onset of benefit.

Development of the Cystic Fibrosis Questionnaire (CFQ) for assessing quality of life in pediatric and adult patients

To assess the impact of cystic fibrosis (CF) and treatment on quality of life (QOL) from childhood throughout adult age, two versions of the Cystic Fibrosis Questionnaire (CFQ), were developed and validated in France: the CFQ 14+ for teenagers and adults, the CFQ Child P, a parent-proxy evaluation for children aged 8-13. They include three modules for assessing QOL, symptoms and health perception. Nine QOL dimensions were identified: physical functioning, energy/well-being, emotions, social limitations, role, embarrassment, body image, eating disturbances and treatment burden. Items were derived from 33 interviews with patients and parents. Item reduction and assessment of internal consistency, convergent and discriminant validity were based on a large cross-sectional survey among 393 patients and parents. A second study was conducted among 124 patients and 85 parents to test reproducibility and responsiveness, confirm the subscale structure and assess scalar properties using Rasch analysis. All psychometric properties were successfully demonstrated and both the CFQ 14+ and the CFQ Child P French questionnaires are now well validated. German and Spanish validated adaptations are available, an English validation is in progress.

CONCLUSION

The CFQ 14+ and CFQ Child P are well validated, multilingual measures which allow QoL assessment in children, teenagers and adults with CF.