Cystic fibrosis transmembrane conductance regulator (CFTR) expression in human platelets: impact on mediators and mechanisms of the inflammatory response.

Inflammatory lung disease is a primary cause of morbidity and mortality in cystic fibrosis (CF). Mechanisms of unresolved acute inflammation in CF are not completely known, although the involvement of cystic fibrosis transmembrane conductance regulator (CFTR) in nonrespiratory cells is emerging. Here we examined CFTR expression and function in human platelets (PLTs) and found that they express a biologically active CFTR. CFTR blockade gave an ∼50% reduction in lipoxin A(4) (LXA(4)) formation during PLT/polymorphonuclear leukocytes (PMN) coincubations by inhibiting the lipoxin synthase activity of PLT 12-lipoxygenase. PLTs from CF patients generated ∼40% less LXA(4) compared to healthy subject PLTs. CFTR inhibition increased PLT-dependent PMN viability (33.0±5.7 vs. 61.2±8.2%; P=0.033), suppressed nitric oxide generation (0.23±0.04 vs. 0.11±0.002 pmol/10(8) PLTs; P=0.004), while reducing AKT (1.02±0.12 vs. 0.71±0.007 U; P=0.04), and increasing p38 MAPK phosphorylation (0.650±0.09 vs. 1.04±0.24 U; P=0.03). Taken together, these findings indicate that PLTs from CF patients are affected by the molecular defect of CFTR. Moreover, this CF PLT abnormality may explain the failure of resolution in CF.

Stunting is an independent predictor of mortality in patients with cystic fibrosis.

BACKGROUND & AIMS: Some studies have shown a direct relationship between nutritional status and survival in Cystic Fibrosis (CF) patients. Body wasting, defined as a percentage of the ideal body weight for age, has been shown to be an independent predictor of mortality in CF. With respect to height only two studies were performed and these studies suggested that stunting is an important determinant of survival but both did not adjust statistical analysis for confounding variables. We aimed at determining the association between stunting and risk of mortality in CF patients. METHODS: 393 CF patients older than 6 years of age, 95 deceased, as cases, and 298 live, as controls, were enrolled in a nested case-control study. Stunting was defined by a height percentile < 5th. We performed a multivariate statistical analysis including height percentile and the following possible confounding variables: age, gender, Body Mass Index (BMI), Forced Expiratory Volume in 1 s (FEV1), genotype, pancreatic status, CF-related diabetes, colonization with Pseudomonas aeruginosa and/or Burkholderia cepacia. RESULTS: In the adjusted analyses stunting (OR 2.22 [IC 95%1.10-4.46]), wasting (OR 5.27 [IC 95% 2.66-10.41]), and FEV1 < 40% of predicted (OR 10.60 [IC 95% 5.43-20.67]) resulted the covariates that significantly predict the risk of mortality. CONCLUSIONS: Our study shows, for the first time, that stunting is a significant and independent risk factor for mortality in CF patients, and warrants an intervention of nutritional rehabilitation. Considering that nutritional interventions in stunted patients should be prolonged, are invasive and expensive, and might affect self-esteem and body image, their efficacy should be fully assessed by Randomised Controlled Trials.

Nebulized hypertonic saline containing hyaluronic acid improves tolerability in patients with cystic fibrosis and lung disease compared with nebulized hypertonic saline alone: a prospective, randomized, double-blind, controlled study.

BACKGROUND: Hypertonic saline inhalation has been shown to be effective in patients with cystic fibrosis and lung disease. However, adverse events including marked airway narrowing are reported and a bronchodilator must be given before the administration of the product. METHODS: We carried out a prospective, randomized, double-blind, parallel-group, controlled study of a hypertonic saline solution containing hyaluronic acid (Hyaneb) versus standard hypertonic saline therapy to assess whether the presence of hyaluronic acid would improve the tolerability of hypertonic saline. RESULTS AND CONCLUSIONS: The results showed that nebulized Hyaneb was more effective in reducing the need for ß(2) bronchodilators and caused a significant reduction in the incidence of adverse effects compared with nebulized hypertonic saline solution alone. Its safety profile indicates that Hyaneb can be used for the treatment of lung disease in cystic fibrosis.

An overview of international literature from cystic fibrosis registries. Part 4: update 2011.

A total of 53 national cystic fibrosis (CF) patient registry studies published between July 2008 and November 2011 have been reviewed, focusing on the following topics: CF epidemiology, nutrition, microbiology, clinical complications, factors influencing diagnosis and lung disease, effects of socioeconomic status, therapeutic strategy evaluation, clinical trial methodology. The studies describe the clinical characteristics of CF patients, the incidence and prevalence of disease and role of gender gap, as well as the influence of socioeconomic status and environmental factors on clinical outcomes, covering a variety of countries and ethnic groups. Original observations describe patients as they get older, with special reference to the adult presentation of CF and long-term survival. Methodological aspects are discussed, covering the design of clinical trials, survival analysis, auxometry, measures of quality of life, follow up of lung disease, predictability of disease progression and life expectancy. Microbiology studies have investigated the role of selected pathogens, such as Burkholderia species and MRSA. Pulmonary exacerbations are discussed both as a factor influencing morbidity and an endpoint in clinical trials. Finally, some studies give insights on complications, such as CF-related diabetes and hemoptysis, and emerging problems, such as chronic nephropathy.

Validation of a predictive survival model in Italian patients with cystic fibrosis.

BACKGROUND: In 2001 Liou published a 5-year survival model using CFF Registry data. AIMS: To evaluate its validity in predicting survival in Italian CF patients. METHODS: In a retrospective study on 945 patients, the 9 variables selected by Liou were analyzed, vital status on December 2008 recorded and observed and expected deaths compared. To develop a new model, patients were randomly divided into a derivation (n=475) and a validation sample (n=470). RESULTS: A significant difference was found between observed and expected deaths based on Liou's model (62 vs 94), with a 34% reduction in mortality (p<0.05). A new model (based on FEV1, Staphylococcus aureus and Burkholderia cepacia complex infection, number of pulmonary exacerbations/year) was generated, that correctly predicted survival in the validation sample (31 observed vs 29 expected deaths, p=0.660). CONCLUSIONS: The Liou model did not adequately predict 5-year survival in our CF population that, compared to the one in which it was originally tested, could benefit from 10 years of improvement in treatments and practice patterns. A new generated model, based on only four variables, was more accurate in predicting 5-year survival in Italian CF patients.

Totally implantable central venous access ports in patients with cystic fibrosis: a multicenter prospective cohort study.

PURPOSE: The aim of this study was to assess the incidence of late onset complications of totally implantable venous access devices (TIVAD) in patients with cystic fibrosis (CF) and to investigate possible associations between the rate of complications and different policies of TIVAD management. METHODS: A multicenter prospective cohort study was performed in 11 Italian CF Centers. Patients with CF and a TIVAD were recruited and followed-up. RESULTS: The study commenced on May 2008 and ended on September 2010. Eighty subjects were studied (77.5% women--mean age 27.2 years). Eighteen late complications of ports were observed (22.5%; incidence 0.96 per 1000 days of observation): three lumen occlusions, seven catheter-related infections , three port-related venous thrombosis, in addition to five other complications. A statistically significant association was found between the onset of catheter-related infection and the presence of CF-related diabetes (CFRD) (P=.0064) CONCLUSIONS: Our data suggest that TIVADs represent a safe and effective device for the intermittent IV administration of drugs in people with CF. However, people with CFRD have a higher risk of developing TIVAD-related infection.

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.

An overview of international literature from cystic fibrosis registries 2. Neonatal screening and nutrition/growth.

BACKGROUND: This is the second article related to a review of the literature based on data from national cystic fibrosis (CF) registries up to June 2008 and covering a total of 115 studies. It focuses on two topics: neonatal screening (NS) and nutritional status, with particular reference to growth. METHODS: Ten papers meeting the inclusion criteria were found on the topic of NS and its impact on the course of the disease, and were analyzed according to a dedicated grid. The issue of nutrition was addressed by 14 studies, analyzed according to similar criteria. RESULTS: Most of the studies report benefits of early diagnosis by NS, albeit to variable degrees. The benefits were assessed in terms of better nutritional status and growth, but also in terms of lower overall morbidity rate as compared to subjects diagnosed by symptoms. The main biases of these studies, which partly undermine the validity of their results, are also analyzed. A part of our analysis on nutrition/growth is dedicated to the identification of the most suitable parameters to define malnutrition: in children older than two years the body mass index percentile (BMIp) appears to be the most sensitive and significantly associated with respiratory function. Better nutritional status and satisfactory growth appear to be associated with better lung function and lower risk of death. The relationship between nutritional status and socio-economic status is also of interest. CONCLUSIONS: CF registry studies support the outcome of cohort observational studies i.e. that pre-symptomatic early diagnosis is beneficial, especially in terms of nutritional status and growth. Studies on nutrition indicate that good nutritional status is associated with better respiratory function and prognosis. Regarding methods, the need emerged to manage potential biases of this kind of non randomized studies, resorting to suitable statistical techniques, such as matching and stratification and, above all, to multivariate methods able to provide estimates adjusted for the main covariates tested.