BACKGROUND: Lung function is a key outcome used in the evaluation of disease progression in cystic fibrosis. The variability of individual lung function measurements over time (within-individual variability) has been shown to predict subsequent lung function changes. Nevertheless, the association between within-individual lung function variability and demographic and genetic covariates has not been quantified.
METHODS: We performed a longitudinal analysis of data from a cohort of 7099 adults with cystic fibrosis (between 18 and 49 years old) from the UK cystic fibrosis registry, containing annual review data between 1996 and 2020. A mixed-effects location-scale model is used to quantify mean FEV1 (forced expiratory volume in 1 s) trajectories and FEV1 within-individual variability as a function of sex, age at annual review, diagnosis after first year of life, homozygous F508 genotype and birth cohort.
RESULTS: Mean FEV1 decreased with age and lung function variability showed a near-quadratic trend by age. Males showed higher FEV1 mean and variability than females across the whole age range. Earlier diagnosis and homozygous F508 genotype were also associated with higher FEV1 mean and variability. Individuals who died during follow-up showed on average higher lung function variability than those who survived.
CONCLUSIONS: Key variables known to be linked with mean lung function in cystic fibrosis are also associated with an individual\'s lung function variability. This work opens new avenues to understand the role played by lung function variability in disease progression and its utility in predicting key outcomes such as mortality.

BACKGROUND: Effective detection of early lung disease in cystic fibrosis (CF) is critical to understanding early pathogenesis and evaluating early intervention strategies. We aimed to compare ability of several proposed sensitive functional tools to detect early CF lung disease as defined by CT structural disease in school aged children.
METHODS: 50 CF subjects (mean±SD 11.2 ± 3.5y, range 5-18y) with early lung disease (FEV1≥70 % predicted: 95.7 ± 11.8 %) performed spirometry, Multiple breath washout (MBW, including trapped gas assessment), oscillometry, cardiopulmonary exercise testing (CPET) and simultaneous spirometer-directed low-dose CT imaging. CT data were analysed using well-evaluated fully quantitative software for bronchiectasis and air trapping (AT).
RESULTS: CT bronchiectasis and AT occurred in 24 % and 58 % of patients, respectively. Of the functional tools, MBW detected the highest rates of abnormality: Scond 82 %, MBWTG RV 78 %, LCI 74 %, MBWTG IC 68 % and Sacin 51 %. CPET VO2peak detected slightly higher rates of abnormality (9 %) than spirometry-based FEV1 (2 %). For oscillometry AX (14 %) performed better than Rrs (2 %) whereas Xrs and R5-19 failed to detect any abnormality. LCI and Scond correlated with bronchiectasis (r = 0.55-0.64, p < 0.001) and AT (r = 0.73-0.74, p < 0.001). MBW-assessed trapped gas was detectable in 92 % of subjects and concordant with CT-assessed AT in 74 %.
CONCLUSIONS: Significant structural and functional deficits occur in early CF lung disease, as detected by CT and MBW. For MBW, additional utility, beyond that offered by LCI, was suggested for Scond and MBW-assessed gas trapping. Our study reinforces the complementary nature of these tools and the limited utility of conventional oscillometry and CPET in this setting.

BACKGROUND: Sociodemographic status (SDS) including race/ethnicity and socioeconomic status as approximated by education, income, and insurance status impact pulmonary disease in people with cystic fibrosis (PwCF). The relationship between SDS and chronic rhinosinusitis (CRS) remains understudied.
METHODS: In a prospective, multi-institutional study, adult PwCF completed the 22-Question SinoNasal Outcome Test (SNOT-22), Smell Identification Test (SIT), Questionnaire of Olfactory Disorder Negative Statements (QOD-NS), and Cystic Fibrosis Questionnaire-Revised (CFQ-R). Lund-Kennedy scores, sinus computed tomography, and clinical data were collected. Data were analyzed across race/ethnicity, sex, and socioeconomic factors using multivariate regression.
RESULTS: Seventy-three PwCF participated with a mean age of 34.7 ± 10.9 years and 49 (67.1%) were female. Linear regression identified that elexacaftor/tezacaftor/ivacaftor (ETI) use (β = ‒4.09, 95% confidence interval [CI] [‒6.08, ‒2.11], p < 0.001), female sex (β = ‒2.14, 95% CI [‒4.11, ‒0.17], p = 0.034), and increasing age (β = ‒0.14, 95% CI [‒0.22, ‒0.05], p = 0.003) were associated with lower/better endoscopy scores. Private health insurance (β = 17.76, 95% CI [5.20, 30.32], p = 0.006) and >16 educational years (β = 13.50, 95% CI [2.21, 24.80], p = 0.020) were associated with higher baseline percent predicted forced expiratory volume in one second (ppFEV1). Medicaid/Medicare insurance was associated with worse endoscopy scores, CFQ-R respiratory scores, and ppFEV1 (all p < 0.017), and Hispanic/Latino ethnicity was associated with worse SNOT-22 scores (p = 0.047), prior to adjustment for other cofactors. No other SDS factors were associated with SNOT-22, QOD-NS, or SIT scores.
CONCLUSIONS: Differences in objective measures of CRS severity exist among PwCF related to sex, age, and ETI use. Variant status and race did not influence patient-reported CRS severity measures or olfaction in this study. Understanding how these factors impact response to treatment may improve care disparities among PwCF.
RESULTS: NCT04469439.

We report a metaproteomic analysis of the gut microbiota of eight infants with cystic fibrosis, during the first year of life. This is the first study in this disease that uses metaproteomics to analyze stool samples from patients at such a young age.

UNASSIGNED: Cystic fibrosis related diabetes (CFRD) is correlated with worsening of nutritional status and greater deterioration of lung function. The role of new technologies for the treatment of CFRD is little explored. The aim of the study was to evaluate the efficacy of Advanced Hybrid Closed Loop (AHCL) systems on glycemic control in CF patients.
UNASSIGNED: A single-center retrospective study on CFRD patients using AHCL systems was performed. Glycated hemoglobin (HbA1c) values and Continuous Glucose Monitoring (CGM) metrics were collected at T0 (AHCL placement), T1 (1-month), T2 (6-months) and T3 (1-year) to evaluate glycemic control.
UNASSIGNED: 10 patients were included in the study. Data showed a reduction of HbA1c value (7.31 ± 0.34 to 6.35 ± 1.00; p=0.03), glycemic variability (p=0.05) and insulin requirement (p=0.03). The study population reached American Diabetes Association (ADA) recommended glycemic targets at 1-year. An increase in the Time in Range (TIR) and a reduction in time in hyperglycemia were also observed, although not statistically significant.
UNASSIGNED: In patients with CFRD, the use of AHCL leads to an improvement in glycemic control in terms of HbA1c and glycemic variability. The increase in TIR and the reduction of time in hyperglycemia, although not statistically significant, are extremely encouraging from a clinical point of view. Further studies with a larger population and a longer follow-up are needed. The results of this study demonstrate the importance of proposing the use of AHCL even in CF patients, who could benefit from glycemic improvement also in terms of nutritional status and respiratory function.

BACKGROUND: In July 2011, Cystic Fibrosis (CF) was added to the Newborn Bloodspot Screening Programme in Ireland. The Irish Comparative Outcomes Study (ICOS) is a historical cohort study established to compare outcomes between clinically-detected and screen-detected children with CF. Here we present the results of economic analysis comparing direct healthcare costs in the first 2 years of life of children born between mid-2008 and mid-2016, in the pre-CF transmembrane conductance regulator modulator era.
METHODS: Healthcare resource use information was obtained from Cystic Fibrosis Registry of Ireland (CFRI), medical records and parental questionnaire. Hospital admissions, emergency department visits, outpatient appointments, antibiotics and maintenance medications were included. Costs were estimated using the Health Service Executive Casemix, Irish Medicines Formulary and hospital pharmacy data, adjusted for inflation using Consumer Price Index data from the Central Statistics Office. A Negative Binomial regression was used, with time in the study as an offset.
RESULTS: Overall participation was 93 %. After exclusion of those with meconium ileus, data from 139 patients, with follow-up to 2 years of age, were available. 72 (51.8 %) were from the clinically diagnosed cohort. In the final model (n=105), clinically diagnosed children had 2.62-fold higher costs per annum (p<0.0001), when adjusted for confounders, including homozygous ΔF508 or G511D mutation, socio-demographic factors and time between diagnosis and first CFRI interaction.
CONCLUSIONS: There are few studies evaluating economic aspects of newborn screening for CF using routine care data. These results imply that the benefits of newborn screening extend to direct healthcare costs borne by the State.

Ivacaftor is the first clinically approved monotherapy potentiator to treat CFTR channel dysfunction in people with cystic fibrosis. Ivacaftor (Iva) is a critical component for all current modulator therapies, including highly effective modulator therapies. Clinical studies show that CF patients on ivacaftor-containing therapies present various clinical responses, off-target effects, and adverse reactions, which could be related to metabolites of the compound. In this study, we reported the concentrations of Iva and two of its major metabolites (M1-Iva and M6-Iva) in capillary plasma and estimated M1-Iva and M6-Iva metabolic activity via the metabolite parent ratio in capillary plasma over 12 hours. We also used the ratio of capillary plasma versus human nasal epithelial cell concentrations to evaluate entry into epithelial cells in vivo. M6-Iva was rarely detected by LC-MS/MS in epithelial cells from participants taking ivacaftor, although it was detected in plasma. To further explore this discrepancy, we performed in vitro studies, which showed that M1-Iva, but not M6-Iva, readily crossed 16HBE cell membranes. Our studies also suggest that metabolism of these compounds is unlikely to occur in airway epithelia despite evidence of expression of metabolism enzymes. Overall, our data provide evidence that there are differences between capillary and cellular concentrations of these compounds that may inform future studies of clinical response and off-target effects.

Cystic fibrosis is one of the most common genetic diseases among caucasian population. This disease is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene encoding for the CFTR protein. Lumacaftor, elexacaftor, tezacaftor, and ivacaftor were currently used as the treatment to Cystic fibrosis. In this study, we describe a new method for the simultaneous quantification of four molecules: lumacaftor, elexacaftor, tezacaftor, and ivacaftor, alongside two metabolites of ivacaftor, specifically hexyl-methyl ivacaftor and ivacaftor carboxylate by liquid chromatography-tandem mass spectrometry. This method holds significant utility for therapeutic drug monitoring and the optimization of treatments related to CFTR modulators. Molecules were extracted from 100 µL of plasma by a simple method of protein precipitation using acetonitrile. Following extraction, chromatographic separation was carried out by reverse chromatography on a C18 analytical column, using a gradient elution of water (0.05 % formic acid, V/V) and acetonitrile (0.05 % formic acid, V/V). The run time was 7 minutes at a flow rate of 0.5 mL/min. After separation, molecules were detected by electrospray ionization on a Xevo TQD triple-quadrupole-mass-spectrometer (Waters®, Milford, USA). The calibration range were: 0.053-20.000 mg/L for elexacaftor, tezacaftor and lumacaftor, 0.075-14.000 mg/L for ivacaftor, and 0.024-6.500 mg/L for hexyl-methyl ivacaftor and ivacaftor carboxylate. The proposed method underwent throughout validation demonstrating satisfactory precision (inter- and intra-day coefficients of variation less than 14.3 %) and a good accuracy (inter- and intra-day bias ranging between -13.7 % and 14.7 %) for all the analytes. The presented method for the simultaneous quantification of CFTR modulators and their metabolites in human plasma has undergone rigorous validation process yielding good results including strong precision and accuracy for all analytes. This method has been effectively used in routine analytical analysis and clinical investigations within our laboratory.

The major human bacterial pathogen Pseudomonas aeruginosa causes multidrug-resistant infections in people with underlying immunodeficiencies or structural lung diseases such as cystic fibrosis (CF). We show that a few environmental isolates, driven by horizontal gene acquisition, have become dominant epidemic clones that have sequentially emerged and spread through global transmission networks over the past 200 years. These clones demonstrate varying intrinsic propensities for infecting CF or non-CF individuals (linked to specific transcriptional changes enabling survival within macrophages); have undergone multiple rounds of convergent, host-specific adaptation; and have eventually lost their ability to transmit between different patient groups. Our findings thus explain the pathogenic evolution of P. aeruginosa and highlight the importance of global surveillance and cross-infection prevention in averting the emergence of future epidemic clones.

OBJECTIVE: Telehealth and home spirometry feasibility for children has been established, but their impact on cystic fibrosis (CF) disease progression remains unassessed. We aimed to evaluate the effects of telehealth and home spirometry on CF disease progression and care.
METHODS: Children with CF aged 5-17 years from all Swedish CF centers were provided with home spirometers. A minimum of two in-person visits were replaced with telemedicine visits and participants were instructed to conduct home spirometry before visits. Linear mixed-effects models were used to compare annual CF disease trajectories during the intervention period and prepandemic period (1 January 2019 to 28 February 2020). Participants and caregivers completed study questionnaires.
RESULTS: A total of 59 individuals completed the study over a mean (SD) period of 6.8 (1.4) months, made 3.1 (1.0) physical visits and 2.2 (0.6) telehealth visits per patient year during the study period. The mean difference (95% CI) between the intervention and prepandemic period progression rate for FEV1%, lung clearance index and BMI were -0.4 (-1.3 to 0.5, p = 0.39), 0.11 (-0.07 to 0.28, p = 0.25) and -0.02 (-0.13 to 0.08, p = 0.70), respectively. There were no major shifts in the incidence of airway pathogens, sputum cultures, or antibiotics use between the periods (p > 0.05). The intervention did not increase stress. Almost all participants and caregivers expressed a desire to continue with home spirometry and telemedicine.
CONCLUSIONS: Combining telehealth and physical visits with access to home spirometry demonstrated comparable effectiveness as exclusively in-person care with enhanced flexibility and personalization of CF care.