Microbiology of cystic fibrosis persons not chronically infected with P. aeruginosa: A quasi-experimental study on two different upper airways' sampling methods.

Background: The upper airways of cystic fibrosis (CF) persons are an evolutionary niche where genetically adapted bacterial strains are selected for lung infection. The microbiological studies conducted up to now on the upper airways are not easily comparable. Methods: Using classical culture methods, we simultaneously studied the microbiological status of upper and lower airways in persons not chronically infected with P. aeruginosa. Each person had a single upper airways sampling and a concomitant lower airways sampling. Lower airways sampling was performed by oropharyngeal swab or sputum collection. Using a quasi-experimental design of study, we evaluated the performance of 2 different upper airways' sampling methods, nasal lavage according to method described by Mainz or nasal lavage with a rhino-set. Pain was measured with appropriate scales. Results: A total of 194 persons were enrolled in this study. Pathogenic flora was found in 128 (6.6%) of 194 upper airways samples and in 164 (84.6%) lower airways samples. A statistically significant difference between the upper airways and the lower airways was found in the isolation of S. aureus and non-fermenter gram negatives. Nasal lavage according to Mainz resulted in the isolation of more non-fermenter gramnegatives than the rhino-set (p < 0.05). No differences were found in the pain caused bythe two methods. Conclusions: In our study population, cultures of the upper airway and lower airway differ in CF persons. In people sampled with nasal lavage according to Mainz more non-fermenter gram negatives were detected than with rhino-set. The two sampling methods were comparable with regard to the caused pain, nasal lavage according to Mainz method being quicker to perform.

Nutritional Status and Circulating Levels of Fat-Soluble Vitamins in Cystic Fibrosis Patients: A Cohort Study and Evaluation of the Effect of CFTR Modulators.

BACKGROUND: Improved therapy in CF has led to an overall improvement in nutritional status. The objectives of our study are: to cross-sectionally assess nutritional status and serum levels of fat-soluble vitamins; to retrospectively evaluate the efficacy of modulators on nutritional status and fat-soluble vitamin levels. METHODS: In patients younger than 2 years of age, we evaluated growth, in patients aged 2-18 years, we assessed BMI z-scores, and in adults, we assessed absolute BMI values. Levels of 25(OH)D, vitamins A, and E were measured. RESULTS: A cross-sectional analysis was conducted on 318 patients, 109 (34.3%) with pancreatic sufficiency. Only three patients were under 2 years old. In 135 patients aged 2-18 years, the median BMI z-score was 0.11, and 5 (3.7%) patients had malnutrition (z-score ≤ 2SD). In 180 adults, the median BMI was 21.8 kg/m2. Overall, 15 (13.7%) males (M) and 18 (25.3%) females (F) were underweight (18 < BMI > 20); 3 (2.7%) M and 5 (7.0%) F had a BMI < 18. Suboptimal 25(OH)D levels were found in patients with pancreatic insufficiency. The prevalence of deficiency of vitamins A and E is low. After one year of treatment with modulators, the increase in BMI was more consistent (M: 1.58 ± 1.25 kg/m2 F: 1.77 ± 1.21 kg/m2) in elexacaftor/tezacaftor/ivacaftor (ETI)-treated patients compared with other modulators, with a significant increase in levels of all fat-soluble vitamins. CONCLUSIONS: Malnutrition is present in a limited number of subjects. The prevalence of subjects with suboptimal 25(OH)D levels is high. ETI showed a beneficial effect on nutritional status and circulating levels of fat-soluble vitamins.

Cystic fibrosis in Tuscany: evolution of newborn screening strategies over time to the present.

BACKGROUND: Cystic fibrosis (CF) is a life-threatening disease affecting about 1:3000 newborns in Caucasian populations. The introduction of newborn screening for cystic fibrosis (CF NBS) has improved the clinical outcomes of individuals with CF through early diagnosis and early treatment. NBS strategies have been implemented over time. CF NBS was introduced extensively in 1984 in Tuscany, a region with 3.7 million people, characterized by a high allelic heterogeneity of CFTR gene. AIM AND METHODS: The aim of the study is to present the results from 34 years (1984-2018) of CF NBS, retrospectively evaluating the sensitivity, specificity and predictive values of the tests. In particular, we studied the impact of the introduction of DNA molecular analysis in NBS in a region with high allelic heterogeneity, such as Tuscany. RESULTS: Over these 34 years, 919,520 neonates were screened, using four different NBS strategies. From 1984 to 1991, CF NBS was performed by the determination of albumin on dried meconium (sensitivity 68.75%; specificity 99.82%). Subsequently, the analysis of immunoreactive trypsinogen on a blood spot was adopted as CF NBS protocol (sensitivity 83.33%; specificity 99.77%). From 1992 to 2010, this strategy was associated with lactase meconium dosage: IRT1/IRT2 + LACT protocol (sensitivity 87.50%; specificity 99.82%). From 2011, when the existing algorithm was integrated by analysis of CF causing variants of the CFTR gene (IRT1/IRT2 + LACT + IRT1/DNA protocol), a substantial improvement in sensitivity was seen (senisitivity 96.15%; specificity 99.75%). Other improved parameters with DNA analysis in the NBS programme, compared with the previous method, were the diagnosis time (52 days vs. 38 days) and the recall rate (0.58 to 0.38%). CONCLUSION: The inclusion of DNA analysis in the NBS was a fundamental step in improving sensitivity, even in a region with high allelic variability.

Clinical and Genotypical Features of False-Negative Patients in 26 Years of Cystic Fibrosis Neonatal Screening in Tuscany, Italy.

Cystic fibrosis (CF) is a life-threatening and common genetic disorder. Cystic fibrosis newborn screening (CF NBS) has been implemented in many countries over the last 30 years, becoming a widely accepted public health strategy in economically developed countries. False-negative (FN) cases can occur after CF NBS, with the number depending on the method. We evaluated the delayed diagnosis of CF, identifying the patients who had false-negative CF NBS results over 26 years (1992-2018) in Tuscany, Italy. The introduction of DNA analysis to the newborn screening protocol improved the sensitivity of the test and reduced the FNs. Our experience showed that, overall, at least 8.7% of cases of CF received FNs (18 cases) and were diagnosed later, with an average age of 6.6 years (range: 4 months to 22 years). Respiratory symptoms and salt-loss syndrome (metabolic hypochloremic alkalosis) are suggestive symptoms of CF and were commons events in FN patients. In Tuscany, a region with a high CFTR allelic heterogeneity, the salt-loss syndrome was a common event in FNs. Therefore, we provided evidence to support the claim that the FN patients had CFTR mutations rarer compared with the true-positive cases. We underline the importance of vigilance toward clinical manifestations suggestive of CF on the part of the primary care providers and hospital physicians in a region with an efficient newborn screening program.

Chronic infection sustained by a Pseudomonas aeruginosa High-Risk clone producing the VIM-1 metallo-ß-lactamase in a cystic fibrosis patient after lung transplantation.

BACKGROUND: The significance of chronic lung infection by multidrug-resistant (MDR) pathogens in Cystic Fibrosis (CF) transplanted patients remains controversial, and the available information is overall limited. Here we describe the case of a chronic infection, sustained by a metallo-ß-lactamase (MBL)-producing P. aeruginosa strain, in a CF patient following lung transplantation. METHODS: Twelve P. aeruginosa isolates collected from a CF patient over a 15-years follow-up period after lung transplantation were analysed for their antibiotic susceptibility profile, MBL production and clonal relatedness. Available clinical and microbiological records were reviewed. RESULTS: The transplanted CF patient was chronically infected by an MBL-producing P. aeruginosa strain which harboured a blaVIM-1 determinant inserted into a novel class 1 integron. The strain exhibited an MDR phenotype and belonged to the globally widespread ST235 epidemic clonal lineage, which however is not a typical CF-associated epidemic clone. Despite the chronic infection, the long-term outcome of this patient during the post-transplant period was characterized by the absence of acute exacerbations and by a mostly stable pulmonary function. CONCLUSIONS: This report provides one of the few descriptions of MBL-producing P. aeruginosa infections in CF patients, and the first description of such an infection after lung transplantation in these patients. Infection with the MBL-producing strain apparently did not significantly affect the patient pulmonary function.

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.

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.