Identifying people living with cystic fibrosis in the Danish National Patient Registry: A validation study.

BACKGROUND: The Danish National Patient Registry (DNPR) serves as a valuable resource for scientific research. However, to ensure accurate results in cystic fibrosis (CF) studies that rely on DNPR data, a robust case-identification algorithm is essential. This study aimed to develop and validate algorithms for the reliable identification of CF patients in the DNPR. METHODS: Using the Danish Cystic Fibrosis Registry (DCFR) as a reference, accuracy measures including sensitivity and positive predictive value (PPV) for case-finding algorithms deployed in the DNPR were calculated. Algorithms were based on minimum number of hospital contacts with CF as the main diagnosis and minimum number of days between first and last contact. RESULTS: An algorithm requiring a minimum of one hospital contact with CF as the main diagnosis yielded a sensitivity of 96.1 % (95 % CI: 94.2 %; 97.4 %) and a PPV of 84.9 % (82.0 %; 87.4 %). The highest-performing algorithm required minimum 2 hospital visits and a minimum of 182 days between the first and the last contact and yielded a sensitivity of 95.9 % (95 % CI: 94.1 %; 97.2 %), PPV of 91.0 % (95 % CI: 88.6 %; 93.0 %) and a cohort entry delay of 3.2 months at the 75th percentile (95th percentile: 38.7 months). CONCLUSIONS: The DNPR captures individuals with CF with high sensitivity and is a valuable resource for CF-research. PPV was improved at a minimal cost of sensitivity by increasing requirements of minimum number of hospital contacts and days between first and last contact. Cohort entry delay increased with number of required hospital contacts.

Widespread alterations in systemic immune profile are linked to lung function heterogeneity and airway microbes in cystic fibrosis.

BACKGROUND: Excessive inflammation and recurrent airway infections characterize people with cystic fibrosis (pwCF), a disease with highly heterogeneous clinical outcomes. How the overall immune response is affected in pwCF, its relationships with the lung microbiome, and the source of clinical heterogeneity have not been fully elucidated. METHODS: Peripheral blood and sputum samples were collected from 28 pwCF and an age-matched control group. Systemic immune cell subsets and surface markers were quantified using multiparameter flow cytometry. Lung microbiome composition was reconstructed using metatranscriptomics on sputum samples, and microbial taxa were correlated to circulating immune cells and surface markers expression. RESULTS: In pwCF, we found a specific systemic immune profile characterized by widespread hyperactivation and altered frequencies of several subsets. These included substantial changes in B-cell subsets, enrichment of CD35+/CD49d+ neutrophils, and reduction in dendritic cells. Activation markers and checkpoint molecule expression levels differed from healthy subjects. CTLA-4 expression was increased in Tregs and, together with impaired B-cell subsets, correlated with patients' lung function. Concentrations and frequencies of key immune cells and marker expression correlated with the relative abundance of commensal and pathogenic bacteria in the lungs. CONCLUSION: The CF-specific immune signature, involving hyperactivation, immune dysregulation with alteration in Treg homeostasis, and impaired B-cell function, is a potential source of lung function heterogeneity. The activity of specific microbes contributes to disrupting the balance of the immune response. Our data provide a unique foundation for identifying novel markers and immunomodulatory targets to develop the future of cystic fibrosis treatment and management.

Changes in exercise capacity in people with Cystic Fibrosis after one year of Elexacaftor/Tezacaftor/Ivacaftor treatment - A Danish prospective cohort.

BACKGROUND: Cystic Fibrosis (CF) is an inherited multiorgan disease that causes lung damage and early death. People with CF (pwCF) experience diminished exercise capacity compared to the general population. This is due to an accelerated decline in lung function resulting from recurrent lung infections, declining lung function and nutritional challenges. Since 2020 the CFTR-modulator Elexacaftor/Tezacaftor/Ivacaftor (ETI) has been approved for pwCF aged 12 and above in Denmark. Initial experiences with the medication have shown promising results, including improved lung function and disease stability. To date a limited number of studies have evaluated the impact of CFTR-modulators on exercise capacity in pwCF. OBJECTIVE: The study aims to assess the impact of one year of ETI treatment, without any further intervention, on exercise capacity measured through cardiopulmonary exercise test (CPET) in pwCF aged 12 years and above. METHODS: A Danish prospective registry cohort study including pwCF from CF-Center Copenhagen, Copenhagen University Hospital and CF-Center Aarhus, Aarhus University Hospital. Participants underwent CPET before initiating ETI and at follow up one year later. Primary outcomes were VO2 peak (ml/kg/min), secondary outcomes were VO2 peak (ml/min), VO2 peak (% pred), watt-max, HR-max and saturation at max. The difference between baseline and follow-up was assessed using a paired-sample t-test and regression analyses were applied to relevant outcomes. RESULTS: We included 229 pwCF in the analyses. An increase in oxygen uptake, VO2 peak (ml/kg/min) from baseline to follow-up was observed; 0.6, 95% CI [0.06; 1.09] p = 0.03. Moreover, significant increase was noted for all other CPET outcomes. Regression analysis showed that changes in FEV1% pred and BMI could explain some of the differences, 0.05 ml/kg/min, 95% CI [0.01, 0.1] p = 0.02 and -0.5 ml/kg/min, 95% CI [-0.8, -0.2] p = 0.002 respectively. CONCLUSION: Among Danish pwCF we found a significant, but not clinically relevant, increase in oxygen uptake, after one year of ETI treatment.

Improved early growth in Danish children with cystic fibrosis from 2000-2022.

BACKGROUND: Improved growth in children with CF may have resulted from advances in treatment for cystic fibrosis (CF) over the past two decades, including the implementation of newborn screening in Denmark in 2016. This observational cohort study focuses on changes in early growth in Danish children with CF born between 2000 and January 2022. METHODS: Age, length/height, and weight data of children 0-5 years old were obtained from the Danish CF Cohort. Data were stratified to four birth cohorts born between 2000 and 2022. Weight-for-age (WAZ), length-for-age (LAZ), height-for-age (HAZ) and body-mass-index (BMZ) z-scores were computed using WHO growth curves. Cubic spline mixed effects models were used to evaluate growth over 5 years between birth cohorts. RESULTS: We included 255 children in the analyses. Cubic spline mixed effects models show that catch-up growth improved in birth cohorts over time, with the 2016-2022 birth cohort achieving growth reference curve values in WAZ, LAZ/HAZ and BMZ the earliest. The proportion of underweight and stunting observations among children born 2000-2004 decreased by the 2016-2022 birth cohort, while the proportion of overweight, low BMZ and high BMZ observations increased. CONCLUSION: Advances in care for young children with CF have led to improvements in growth - with the 2016-2022 birth cohort approaching potential for overweight. Nonetheless, low BMZ remains. Immediate, individualized nutrition care throughout early childhood remain crucial in mitigating malnutrition.

Education, employment, and income among people living with cystic fibrosis across three decades - A matched cohort study using Danish health registries.

BACKGROUND: Past and ongoing advancements in cystic fibrosis (CF) care warrant long-term analysis of the societal impact of the condition. This study aims to evaluate changes in key socioeconomic factors across three decades among people living with CF (pwCF), compared with both the general population and an early-onset chronic disease population. METHODS: This nationwide, registry-based, matched cohort study included all pwCF ≥ 18 years in Denmark in the years 1990, 2000, 2010, and 2018. Each person living with CF was matched to five individuals in the general population and five individuals living with type 1 diabetes or juvenile arthritis based on age, sex, and municipality. RESULTS: The Danish adult CF population increased nearly fourfold from 88 in 1990 to 331 in 2018, and mean age increased by ten years. The educational level of pwCF was similar to the two comparator cohorts, while pwCF were less often in employment and more often permanently outside the labor force. Personal and household income levels of the CF cohort were higher than those of the comparator cohorts. CONCLUSIONS: The disadvantage in employment for pwCF remained, but, over time, the societal profiles of the one-year CF cohorts increasingly converged with those of the comparator cohorts, indicative of improved clinical management, extended life expectancy, and the supportive role of the Danish welfare system in reducing health inequalities. Further research should be done to evaluate the effects of the newly introduced modulator therapies on employment, considering the broader societal impact and impact on quality of life.

Decline in HbA1c during the first year of elexacaftor/tezacaftor/ivacaftor treatment in the Danish cystic fibrosis cohort: Short title: Decline in HbA1c after elexacaftor/tezacaftor/ivacaftor treatment.

BACKGROUND: Elexacaftor/tezacaftor/ivacaftor (ETI) has improved the clinical status of individuals with cystic fibrosis (CF), however, whether ETI impacts glucose tolerance remains unknown. We aimed to study the change in glycated hemoglobin (HbA1c) and CF related diabetes (CFRD) status after initiation of ETI. METHODS: We included individuals ≥12 years treated with ETI in Denmark in a longitudinal observational study. HbA1c was measured at baseline, 3, 6, 9 and 12 months after treatment initiation. Change in HbA1c was assessed in mixed models adjusted for age, sex, glucose tolerance and prior CFTR modulator treatment. In a sub-population with CFRD, we assessed the change in insulin usage, hypoglycemic events and the 30-day continuous glucose monitoring (CGM) parameters (i.e., average blood glucose, time below (≤3.9 mM) and above (>10.0 mM) normal range, and the variation in glucose) after 12 months of treatment. RESULTS: Among 321 individuals with CF, HbA1c declined by 2.1 mmol/mol [95 % confidence interval (CI): -2.6; -1.5 mmol/mol] after 3 months and by 2.3 mmol/mol [95 %CI: -2.8; -1.9 mmol/mol] after 12 months of ETI treatment. The decline was independent of glucose tolerance status at baseline. In 26 individuals with CFRD at baseline, the mean decline in HbA1c was 3.6 mmol/mol [95 %CI: -6.9; -0.4 mmol/mol] after 12 months, but we did not observe any change in insulin usage, weekly number of hypoglycemic events or CGM parameters. CONCLUSION: In the Danish CF cohort, HbA1c declined over 12 months of ETI treatment, however, among a subset with CFRD, we observed no change in insulin usage and CGM glucose levels.

Standards for the care of people with cystic fibrosis; establishing and maintaining health.

This is the second in a series of four papers updating the European Cystic Fibrosis Society (ECFS) standards for the care of people with CF. This paper focuses on establishing and maintaining health. The guidance is produced using an evidence-based framework and with wide stakeholder engagement, including people from the CF community. Authors provided a narrative description of their topic and statements, which were more directive. These statements were reviewed by a Delphi exercise, achieving good levels of agreement from a wide group for all statements. This guidance reinforces the importance of a multi-disciplinary CF team, but also describes developing models of care including virtual consultations. The framework for health is reinforced, including the need for a physically active lifestyle and the strict avoidance of all recreational inhalations, including e-cigarettes. Progress with cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy is reviewed, including emerging adverse events and advice for dose reduction and interruption. This paper contains guidance that is pertinent to all people with CF regardless of age and eligibility for and access to modulator therapy.

Nationwide lung function monitoring from infancy in newborn-screened children with cystic fibrosis.

Background: Cystic fibrosis (CF) lung disease starts in infancy and can be assessed for structural lung abnormalities using computed tomography or magnetic resonance scans, or for lung function impairment using multiple breath washout (MBW). However, in infancy these two methods are not well correlated. Trajectories of CF lung disease assessed by MBW in infants and toddlers remain poorly described, which is why we aimed to 1) describe the trajectory of lung function, 2) explore risk factors for progression and 3) explore the real-life effect of lumacaftor/ivacaftor. Methods: This was a nationwide observational cohort study (2018-2021) using data collected as part of the routine clinical surveillance programme (including MBW and monthly endo-laryngeal suction sampling for bacterial pathogens) in children born after implementation of newborn screening for CF (May 2016). Lumacaftor/ivacaftor commenced from age 2 years in children homozygous for F508del. Ventilation distribution efficiency (VDE), recently described to have advantages over lung clearance index (LCI), was reported as the primary MBW outcome after z-score calculations based on published reference data. Mixed effect linear regression models were the main statistical analyses performed in this study. Results: 59 children, aged 2-45 months, contributed with 211 MBW occasions (median (interquartile range (IQR)) 3 (2-5) MBW occasions per child) with a median (IQR) follow-up time of 10.8 (5.2-22.3) months. An overall mean annual deterioration rate of -0.50 (95% CI -0.78- -0.22) z-VDE was observed, starting from an estimated mean z-VDE of -1.68 (95% CI -2.15- -1.22) at age 0.0 years (intercept). Pseudomonas aeruginosa "ever" (n=14, MBWs 50) had a significantly worse z-VDE trajectory versus P. aeruginosa "never" (mean difference 0.53 (95% CI 0.16-0.89) per year; p=0.0047) and lumacaftor/ivacaftor treatment (n=22, MBWs 46) significantly improved the trajectory of z-VDE (mean difference 1.72 (95% CI 0.79-2.66) per year; p=0.0004), leading to a stable mean z-VDE trajectory after start of treatment. Conclusions: Infants and toddlers with CF demonstrated progressive deterioration in z-VDE over the first years of life. P. aeruginosa isolation "ever" was associated with an accelerated deterioration in lung function, while lumacaftor/ivacaftor therapy significantly improved and stabilised the trajectory.

Characterization of impaired beta and alpha cell function in response to an oral glucose challenge in cystic fibrosis: a cross-sectional study.

Aims: The purpose of the study was to further elucidate the pathophysiology of cystic fibrosis (CF)-related diabetes (CFRD) and potential drivers of hypoglycaemia. Hence, we aimed to describe and compare beta cell function (insulin and proinsulin) and alpha cell function (glucagon) in relation to glucose tolerance in adults with CF and to study whether hypoglycaemia following oral glucose challenge may represent an early sign of islet cell impairment. Methods: Adults with CF (≥18 years) were included in a cross-sectional study using an extended (-10, -1, 10, 20, 30, 45, 60, 90, 120, 150, and 180 min) or a standard (-1, 30, 60, and 120 min) oral glucose tolerance test (OGTT). Participants were classified according to glucose tolerance status and hypoglycaemia was defined as 3-hour glucose <3.9 mmol/L in those with normal glucose tolerance (NGT) and early glucose intolerance (EGI). Results: Among 93 participants, 67 underwent an extended OGTT. In addition to worsening in insulin secretion, the progression to CFRD was associated with signs of beta cell stress, as the fasting proinsulin-to-insulin ratio incrementally increased (p-value for trend=0.013). The maximum proinsulin level (pmol/L) was positively associated with the nadir glucagon, as nadir glucagon increased 6.2% (95% confidence interval: 1.4-11.3%) for each unit increase in proinsulin. Those with hypoglycaemia had higher 60-min glucose, 120-min C-peptide, and 180-min glucagon levels (27.8% [11.3-46.7%], 42.9% [5.9-92.85%], and 80.3% [14.9-182.9%], respectively) and unaltered proinsulin-to-insulin ratio compared to those without hypoglycaemia. Conclusions: The maximum proinsulin concentration was positively associated with nadir glucagon during the OGTT, suggesting that beta cell stress is associated with abnormal alpha cell function in adults with CF. In addition, hypoglycaemia seemed to be explained by a temporal mismatch between glucose and insulin levels rather than by an impaired glucagon response.

Changes in glucose tolerance in people with cystic fibrosis after initiation of first-generation CFTR modulator treatment.

BACKGROUND: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have been shown to have a beneficial effect on pulmonary function and nutritional status in patients with cystic fibrosis (CF), but the extent to which they affect glucose tolerance is not fully understood. In the current study, we evaluated the change in glucose tolerance and insulin secretion after first-generation CFTR modulator treatment in adults with CF. METHODS: We performed a longitudinal observational study with an oral glucose tolerance test performed at baseline and after three and a half years of follow-up. The test comprised glucose, C-peptide and insulin measured at fasting, 1 h, and 2 h, and HbA1c at fasting. We compared changes in parameters of glucose tolerance and insulin secretion from baseline to follow-up. RESULTS: Among 55 participants, 37 (67%) were treated with a first-generation CFTR modulator for a median of 21 months. Glucose levels were unchanged in both the treated and untreated group. In the treated group, C-peptide levels declined, yet no significant differences in glucose, insulin, and C-peptide levels were observed between the groups. HbA1c increased in both groups, while no significant change in the insulin sensitivity indices was detected in either group. However, homeostatic model assessment for insulin resistance tended to decline in the treated group, whilst tending towards an increase in the untreated group. The difference between the groups reached statistical significance (p = 0.040). CONCLUSION: Treatment with first-generation CFTR modulators, mainly tezacaftor/ivacaftor, did not seem to be associated with glucose tolerance nor insulin secretion in adults with CF. However, CFTR modulators may still have a beneficial effect on insulin sensitivity.

Antimicrobial resistance of Pseudomonas aeruginosa in a cystic fibrosis population after introduction of a novel cephalosporin/ß-lactamase inhibitor combination.

Ceftolozane-tazobactam is a new ß-lactam/ß-lactamase inhibitor combination approved by the U.S. Food and Drug Administration in 2019 for the treatment of hospital-acquired and ventilator-associated pneumonia. The combination is a particularly potent inhibitor of penicillin-binding proteins with higher affinity than other ß-lactam agents. Persons with cystic fibrosis (pwCF) often harbour resistant Gram-negative bacteria in the airways and need antibiotics to prevent declining lung function. To test whether the introduction of ceftolozane-tazobactam in the period 2015-2020 led to a bacterial population level increase in cephalosporin resistance in a Danish CF population. In vitro, activity of ceftolozane-tazobactam was evaluated by susceptibility testing of clinical Pseudomonas aeruginosa isolated from pwCF from January 1, 2015, to June 1, 2020. Six thousand three hundred thirty two isolates collected from 210 adult pwCF were included. Thirty pwCF were treated with ceftolozane-tazobactam at least once. Ceftolozane-tazobactam exposure did not increase cephalosporin resistance on an individual or population level. However, resistance to ceftolozane-tazobactam was recorded despite no prior exposure in four pwCF. Compared to ceftazidime, ceftolozane-tazobactam had a better in vitro activity on P. aeruginosa. The percentage of non-mucoid P. aeruginosa isolates susceptible to ceftolozane-tazobactam were higher or equal to 5 other ß-lactams. Ceftolozane-tazobactam expands the armamentaria against P. aeruginosa with acceptable levels for a selection of drug resistance.

Antimicrobial Strategies for Cystic Fibrosis.

Lung infection is the leading cause of death in cystic fibrosis (CF), and antimicrobial therapies are the backbone of infection management. While many different strategies may be applied, rigorous microbiological surveillance, intensive eradication therapy, and long-term maintenance therapy based on inhaled antibiotics may be considered the main strategy for infection control in individuals with CF. While most of the existing evidence is based on infection with Pseudomonas aeruginosa, other important pathogens causing lung inflammation and deterioration exist and should be treated despite the evidence gap. In this chapter, we describe the approaches to the antimicrobial treatment of the most important pathogens in CF and the evidence behind.

Outcome of elexacaftor/tezacaftor/ivacaftor therapy in patients with cystic fibrosis and solid organ transplantation.

We report a case series of four patients with cystic fibrosis (CF) and previous solid organ transplantation (SOT) receiving elexacaftor/tezacaftor/ivacaftor therapy for 6 months or more. Data was collected retrospectively. The treatment was well tolerated and all patients reported subjective improvements.

Efficacy and Safety of Elexacaftor/Tezacaftor/Ivacaftor in Children 6 Through 11 Years of Age with Cystic Fibrosis Heterozygous for F508del and a Minimal Function Mutation: A Phase 3b, Randomized, Placebo-controlled Study.

Rationale: The triple-combination regimen elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) was shown to be safe and efficacious in children aged 6 through 11 years with cystic fibrosis and at least one F508del-CFTR allele in a phase 3, open-label, single-arm study. Objectives: To further evaluate the efficacy and safety of ELX/TEZ/IVA in children 6 through 11 years of age with cystic fibrosis heterozygous for F508del and a minimal function CFTR mutation (F/MF genotypes) in a randomized, double-blind, placebo-controlled phase 3b trial. Methods: Children were randomized to receive either ELX/TEZ/IVA (n = 60) or placebo (n = 61) during a 24-week treatment period. The dose of ELX/TEZ/IVA administered was based on weight at screening, with children <30 kg receiving ELX 100 mg once daily, TEZ 50 mg once daily, and IVA 75 mg every 12 hours, and children ⩾30 kg receiving ELX 200 mg once daily, TEZ 100 mg once daily, and IVA 150 mg every 12 hours (adult dose). Measurements and Main Results: The primary endpoint was absolute change in lung clearance index2.5 from baseline through Week 24. Children given ELX/TEZ/IVA had a mean decrease in lung clearance index2.5 of 2.29 units (95% confidence interval [CI], 1.97-2.60) compared with 0.02 units (95% CI, -0.29 to 0.34) in children given placebo (between-group treatment difference, -2.26 units; 95% CI, -2.71 to -1.81; P < 0.0001). ELX/TEZ/IVA treatment also led to improvements in the secondary endpoint of sweat chloride concentration (between-group treatment difference, -51.2 mmol/L; 95% CI, -55.3 to -47.1) and in the other endpoints of percent predicted FEV1 (between-group treatment difference, 11.0 percentage points; 95% CI, 6.9-15.1) and Cystic Fibrosis Questionnaire-Revised Respiratory domain score (between-group treatment difference, 5.5 points; 95% CI, 1.0-10.0) compared with placebo from baseline through Week 24. The most common adverse events in children receiving ELX/TEZ/IVA were headache and cough (30.0% and 23.3%, respectively); most adverse events were mild or moderate in severity. Conclusions: In this first randomized, controlled study of a cystic fibrosis transmembrane conductance regulator modulator conducted in children 6 through 11 years of age with F/MF genotypes, ELX/TEZ/IVA treatment led to significant improvements in lung function, as well as robust improvements in respiratory symptoms and cystic fibrosis transmembrane conductance regulator function. ELX/TEZ/IVA was generally safe and well tolerated in this pediatric population with no new safety findings.

Increased sputum lactate during oral glucose tolerance test in cystic fibrosis.

Blood glucose levels exceeding 8 mM are shown to increase glucose levels in airway surface in cystic fibrosis (CF). Moreover, high levels of endobronchial glucose are proposed to increase the growth of common CF bacteria and feed the neutrophil-driven inflammation. In the infected airways, glucose may be metabolized by glycolysis to lactate by both bacteria and neutrophils. Therefore, we aimed to investigate whether increased blood glucose may fuel the glycolytic pathways of the lung inflammation by determining sputum glucose and lactate during an oral glucose tolerance test (OGTT). Sputum from 27 CF patients was collected during an OGTT. Sputum was collected at fasting and one and two hours following the intake of 75 g of glucose. Only participants able to expectorate more than one sputum sample were included. Glucose levels in venous blood and lactate and glucose content in sputum were analyzed using a regular blood gas analyzer. We collected 62 sputum samples: 20 at baseline, 22 after 1 h, and 20 after 2 h. Lactate and glucose were detectable in 30 (48.4%) and 43 (69.4%) sputum samples, respectively. The sputum lactate increased significantly at 2 h in the OGTT (p = 0.024), but sputum glucose was not changed. As expected, plasma glucose level significantly increased during the OGTT (p < 0.001). In CF patients, sputum lactate increased during an OGTT, while the sputum glucose did not reflect the increased plasma glucose. The increase in sputum lactate suggests that glucose spills over from plasma to sputum where glucose may enhance the inflammation by fueling the anaerobic metabolism in neutrophils or bacteria.

Adaptive Immune Response to Mycobacterium abscessus Complex (MABSC) in Cystic Fibrosis and the Implications of Cross-Reactivity.

Background: We aimed to characterise the adaptive immune response to Mycobacterium abscessus complex (MABSC) and its cross-reactivity with Mycobacterium avium complex (MAC) and Mycobacterium bovis (Bacille Calmette-Guérin, BCG) in cystic fibrosis (CF) patients and non-CF controls in terms of lymphocyte proliferation and immunophenotyping, cytokine production and anti-MABSC IgG plasma levels. Methods: In this cross-sectional analysis, peripheral blood mononuclear cells (PBMC) from CF patients with MABSC (CF/MABSC, n=12), MAC infection history (CF/MAC, n=5), no NTM history (CF/NTM-, n=15), BCG-vaccinated (C/BCG+, n=9) and non-vaccinated controls (C/BCG-, n=8) were cultured for four days under stimulation with an in-house MABSC lysate and we used flow cytometry to assess lymphocyte proliferation (given by lymphoblast formation) and immunophenotypes. Cytokine production was assessed after overnight whole blood stimulation with the same lysate, and anti-MABSC IgG levels were measured in plasma from non-stimulated blood. Results: All CF/MABSC patients had increased CD3+ and CD19+ lymphoblast formation upon PBMC stimulation with MABSC lysate. There was a higher rate of CD3+ than CD19+ lymphoblasts, predominance of CD4+ over CD8+ lymphoblasts, IFN-γ, TNF-α and IL-2 production, low production of the Th17-associated IL-17, and discrete or no production of Th2/B cell-associated cytokines soluble CD40 ligand (CD40L), IL-4 and IL-5, indicating a Th1-dominated phenotype and infection restricted to the lungs. A similar pattern was seen in C/BCG+ controls, and CF/MAC patients, pointing to cross-reactivity. MABSC-IgG levels were higher in CF/MABSC patients than in both control groups, but not CF/NTM- patients, most of whom also had CD3+ and/or CD19+ lymphoblast formation upon PBMC stimulation, indicating previous exposure, subclinical or latent infection with MABSC or other NTM. Conclusion: The anti-MABSC immune response is Th1-skewed and underlines the cross-reactivity in the anti-mycobacterial immune response. The results, together with published clinical observations, indicate that BCG vaccination may cross-react against NTM in CF patients, and this should be investigated. Due to cross-reactivity, it would also be interesting to investigate whether a combination of MABSC-induced cytokine production by blood cells and anti-MABSC IgG measurement can be useful for identifying latent or subclinical infection both with MABSC and other NTM in CF patients.

Use of inhaled antibiotics among Danish patients with cystic fibrosis.

BACKGROUND: Inhaled antibiotics are an important part of cystic fibrosis (CF) airway disease management and should be individualized to fit the microorganism and match patient needs. To investigate the implementation of personalized treatment, this study mapped the use of different types of inhaled antibiotics and adherence patterns. METHODS: We performed individual structured interviews in a cross-sectional study at the CF Centre in Copenhagen, Denmark. Patients with CF older than 15 years attending clinical consultations were included. Clinical data were obtained from centralized databases. RESULTS: Among 149 participants, 107 (72%) had indication for treatment with inhaled antibiotics. In this group, 97 (91%) reported the use of inhaled antibiotics within the last 12 months. Change from one inhaled antibiotic to another during that period was reported by 31 (29%), and 17 (25%) with Pseudomonas aeruginosa had used off-label antibiotics. Adherence to a minimum of one daily dose of antibiotic was reported by 78%, while adherence to all daily doses was 28 percentage points lower. Skipping inhalations was due to side effects and doubt about the effect in less than 5% of cases. CONCLUSION: Change of inhaled antibiotics and use of off-label antibiotics for inhalation were common and side effects were a rare cause of nonadherence. This suggests satisfactory implementation of the principle of tailored antibiotic inhalation prescription in the Copenhagen CF population. Adherence to at least one daily inhalation dose was markedly higher than adherence to multiple daily inhalations.

Correlates of Pancreatic Enzyme Replacement Therapy Intake in Adults with Cystic Fibrosis: Results of a Cross-Sectional Study.

Most people with cystic fibrosis (pwCF) develop pancreatic insufficiency and are treated with pancreatic enzyme replacement therapy (PERT). We aimed to describe the use of PERT and assess the correlates of PERT dose in adult pwCF. In a cross-sectional study at the Copenhagen CF Centre, the participants reported PERT intake, gastrointestinal (GI) symptoms and the use of concomitant treatments. Demographic and clinical characteristics were extracted from the Danish CF Registry. We used linear regression to assess the correlates of PERT dose per kg bodyweight (U-lipase/kg). We included 120 pwCF with a median age of 32.9 years, 46% women and 72% F508delta homozygote. The PERT dose ranged from 0 to 6160 U-lipase/kg per main meal (mean 1828; SD 1115). The PERT dose was associated with participants' sex (men vs. women: 661; 95% CI: 302; 1020 U-lipase/kg), age (-16; 95% CI: -31; -1 U-lipase/kg per year) and weight (-45; 95% CI: -58; -31 U-lipase/kg per kg). Having less frequent constipation and being lung transplanted were also associated with a higher PERT dose. A third of participants did not take PERT for snacks, and this was associated with the frequency of diarrhoea. These findings indicate that PERT intake may be improved to reduce GI symptoms.

Contemporary N2 and SF6 multiple breath washout in infants and toddlers with cystic fibrosis.

INTRODUCTION: Multiple breath washout (MBW) is used for early detection of cystic fibrosis (CF) lung disease, with SF6 MBW commonly viewed as the reference method. The use of N2 MBW in infants and toddlers has been questioned for technical and physiological reasons, but a new correction of the N2  signal has minimized the technical part. The present study aimed to assess the remaining differences and the contributing mechanisms for the differences between SF6 and N2 MBW,corrected-such as tidal volume reduction during N2 washout with pure O2 . METHOD: This was a longitudinal multicenter cohort study. SF6 MBW and N2 MBW were performed prospectively at three CF centers in the same visits on 154 test occasions across 62 children with CF (mean age: 22.7 months). Offline analysis using identical algorithms to the commercially available program provided outcomes of N2,original and N2,corrected for comparison with SF6 MBW. RESULTS: Mean functional residual capacity, FRCN2,corrected was 14.3% lower than FRCN2, original , and 1.0% different from FRCSF6 . Lung clearance index, LCIN2,corrected was 25.2% lower than LCIN2,original , and 7.3% higher than LCISF6 . Mean (SD) tidal volume decreased significantly during N2 MBWcorrected , compared to SF6 MBW (-13.1 ml [-30.7; 4.6], p < 0.0001, equal to -12.0% [-25.7; 1.73]), but this tidal volume reduction did not correlate to the differences between LCIN2,corrected and LCISF6 . The absolute differences in LCI increased significantly with higher LCISF6 (0.63/LCISF6 ) and (0.23/LCISF6 ), respectively, for N2,original and N2,corrected , but the relative differences were stable across disease severity for N2,corrected , but not for N2,original . CONCLUSION: Only minor residual differences between FRCN2,corrected and FRCSF6 remained to show that the two methods measure gas volumes very similar in this age range. Small differences in LCI were found. Tidal volume reduction during N2 MBW did not affect differences. The corrected N2 MBW can now be used with confidence in young children with CF, although not interchangeably with SF6 .

Impact of timing of PERT on gastrointestinal symptoms in Danish children and adolescents with CF.

AIM: Gastrointestinal (GI) symptoms are often reported by CF patients. Despite a proven relation to exocrine pancreatic insufficiency (PI), it remains unclear whether GI symptoms are related to the timing of pancreatic enzyme replacement therapy (PERT). Whereas most international recommendations suggest administration of PERT at the beginning of meals, it has not been studied whether such a proceeding is associated with lower burden of symptoms. METHODS: Thirty CF patients aged 0-17 years of age with PI were randomised to four weeks of PERT prior to meals followed by four weeks of PERT after meals or vice versa. Using the CF-specific validated CFAbd-Score, abdominal pain, dysfunctional bowel habits and Quality of Life (QoL) related to GI symptoms were assessed in relation to the timing of PERT. Data were analysed using a linear mixed model. RESULTS: There was no significant difference regarding abdominal pain, bowel habits or QoL related to GI symptoms when timing of PERT was changed from prior to after meals. CONCLUSION: No significant difference was found when administration mode of PERT changed from prior to after meals or vice versa. However, after an individual assessment, some patients may profit from changing administration mode of PERT from prior to after meals.