Patient and Caregiver Perceptions of Airway Clearance Methods Used for Cystic Fibrosis.

Introduction: Cystic Fibrosis Foundation guidelines recommend people with CF perform daily airway clearance. This can be difficult for patients, as some find it time consuming or uncomfortable. Data comparing airway clearance methods are limited. We surveyed patients and their families to understand which methods are preferred and identify obstacles to performing airway clearance. Methods: We designed a REDCap survey and enrolled participants in 2021. Respondents reported information on airway clearance usage, time commitment, and medication use. They rated airway clearance methods for effectiveness, comfort, time commitment, importance, and compatibility with other treatments. The analysis included descriptive statistics and clustering. Results: 60 respondents started and 52 completed the survey. The median patient age was 20 years. Respondents experienced a median of four airway clearance methods in their lifetime, including chest wall oscillation (vest, 92%), manual chest physical therapy (CPT, 88%), forced expiration technique (huff or cough, 77%), and exercise (75%). Past 30-day use was highest for exercise (62%) and vest (57%). The time commitment was generally less than 2 hours daily. Of those eligible for CFTR modulators, 53% reported decreased time commitment to airway clearance after starting treatment. On a scale of 0-100, respondents rated CFTR modulators as their most important treatment (median 99.5), followed by exercise (88). Discussion. Patients and caregivers are familiar with several methods of airway clearance for CF. They report distinct strengths and limitations of each method. Exercise and vest are the most common methods of airway clearance. The use of CFTR modulators may reduce patient-reported time commitment to airway clearance.

Impact of elexacaftor/tezacaftor/ivacaftor on bacterial cultures from people with cystic fibrosis.

BACKGROUND: Cystic fibrosis transmembrane conductance regulator (CFTR) modulators have shown beneficial effects on both forced expiratory volume in 1 s (FEV1 ) and frequency of pulmonary exacerbations in people with cystic fibrosis (CF). These positive outcomes may be related to changes in bacterial colonization within the lungs. Elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) is the first triple therapy CFTR modulator approved for use in people with CF 6 years and older. This study aimed to determine the impact of ELX/TEZ/IVA on the isolation of Pseudomonas aeruginosa (Pa), methicillin-resistant and methicillin-susceptible Staphylococcus aureus (MRSA and MSSA, respectively) in respiratory cultures. METHODS: A retrospective chart review of the electronic medical record at the University of Iowa was completed for individuals 12 years and older taking ELX/TEZ/IVA for at least 12 months. The primary outcome was determined by assessing bacterial cultures pre- and postinitiation of ELX/TEZ/IVA. Baseline demographic and clinical characteristics were summarized using mean and standard deviation for continuous outcomes and count and percentage for categorical outcomes. Culture positivity for Pa, MSSA, and MRSA was compared among enrolled subjects between pre- and posttriple combination therapy periods using an exact McNemar's test. RESULTS: One hundred and twenty-four subjects prescribed ELX/TEZ/IVA for at least 12 months met the requirements for inclusion within our analysis. Culture positivity for Pa, MSSA, and MRSA was approximately 54%, 33%, and 31%, respectively, for the pre-ELX/TEZ/IVA period. Prevalence decreased to approximately 30%, 32%, and 24% (-24.2% [p < 0.0001], -0.7% [p = 1.00], and -6.5% [p = 0.0963], respectively) post-ELX/TEZ/IVA. The source of bacterial culture was predominantly sputum (70.2%) in the pre-ELX/TEZ/IVA group, whereas a throat source (66.1%) was more common post-ELX/TEZ/IVA. CONCLUSIONS: ELX/TEZ/IVA treatment has an appreciable impact on the detection of common bacterial pathogens in CF respiratory cultures. While previous studies have found a similar effect with single and double CFTR modulator therapies, this is the first single-center study to show the impact of triple therapy, ELX/TEZ/IVA, on bacterial isolation from airway secretions.

Impact of elexacaftor/tezacaftor/ivacaftor on vitamin D absorption in cystic fibrosis patients.

BACKGROUND: Cystic fibrosis (CF) is a multisystem disorder that results in the buildup of mucus in various organs. Ninety percent of CF patients are classified as pancreatic insufficient, leading to malabsorption of nutrients and fat-soluble vitamins without the assistance of exogenous pancreatic enzymes. This study was designed to determine if serum 25-hydroxyvitamin D concentrations were impacted by initiation of elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA). METHODS: Serum 25-hydroxyvitamin D concentrations were measured before and 1 year post-ELX/TEZ/IVA initiation. A Wilcoxon signed-rank test was used to compare values. RESULTS: Seventy-six patients were included in the final analysis. The average age of our population was 25.8 years (SD = 13.2 years) with a majority being male, homozygous F508del, pancreatic insufficient, and not modulator-naive. The median increase of serum vitamin D concentration after initiating ELX/TEZ/IVA was 5 ng/ml (interquartile range = -4, 13; p = .0035). CONCLUSIONS: We suggest that ELX/TEZ/IVA may improve fat-soluble vitamin absorption, specifically serum 25-hydroxyvitamin D. These results may lead to adjustments in vitamin supplementation in patients receiving cystic fibrosis transmembrane conductance regulator modulator therapy.

MRSA strains with distinct accessory genes predominate at different ages in cystic fibrosis.

RATIONALE: Methicillin resistant Staphylococcus aureus (MRSA) is prevalent and consequential in cystic fibrosis (CF). Whole genome sequencing (WGS) could reveal genomic differences in MRSA associated with poorer outcomes or detect MRSA transmission. OBJECTIVES: To identify MRSA genes associated with low lung function and potential MRSA transmission in CF. METHODS: We collected 97 MRSA isolates from 74 individuals with CF from 2017 and performed short-read WGS. We determined sequence type (ST) and the phylogenetic relationship between isolates. We aligned accessory genes from 25 reference genomes to genome assemblies, classified isolates by accessory gene content, and correlated the accessory genome to clinical outcomes. RESULTS: The most prevalent ST were ST5 (N = 55), ST8 (N = 15), and ST105 (N = 14). Closely related MRSA strains were shared by family members with CF, but rarely between unrelated individuals. Three clusters of MRSA were identified by accessory genome content. Cluster A, including ST5 and ST105, was highly prevalent at all ages. Cluster B, including ST8, was more limited to younger patients. Cluster C included 6 distantly related strains. Patients 20 years old and younger infected with Cluster A had lower forced expiratory volume in the first second (FEV1 ) and higher sputum biomass compared to similar-aged patients with Cluster B. CONCLUSIONS: In this CF cohort, we identified MRSA subtypes that predominate at different ages and differ by accessory gene content. The most prevalent cluster of MRSA, including ST5 and ST105, was associated with lower FEV1 . ST8 MRSA was more common in younger patients and thus has the potential to rise in prevalence as these patients age.

Sustained Coinfections with Staphylococcus aureus and Pseudomonas aeruginosa in Cystic Fibrosis.

Rationale: Staphylococcus aureus and Pseudomonas aeruginosa often infect the airways in cystic fibrosis (CF). Because registry studies show higher prevalence of P. aeruginosa versus S. aureus in older patients with CF, a common assumption is that P. aeruginosa replaces S. aureus over time. In vitro, P. aeruginosa can outgrow and kill S. aureus. However, it is unknown how rapidly P. aeruginosa replaces S. aureus in patients with CF.Methods: We studied a longitudinal cohort of children and adults with CF who had quantitative sputum cultures. We determined the abundance of P. aeruginosa and S. aureus in cfu/ml. We determined the duration and persistence of infections and measured longitudinal changes in culture positivity and abundance for each organism.Measurements and Main Results: Between 2004 and 2017, 134 patients had ≥10 quantitative cultures, with median observation time of 10.15 years. One hundred twenty-four patients had at least one positive culture for P. aeruginosa, and 123 had at least one positive culture for S. aureus. Both species had median abundance of >106 cfu/ml. Culture abundance was stable over time for both organisms. There was an increase in the prevalence of S. aureus/P. aeruginosa coinfection but no decrease in S. aureus prevalence within individuals over time.Conclusions: S. aureus and P. aeruginosa are abundant in CF sputum cultures. Contrary to common assumption, we found no pattern of replacement of S. aureus by P. aeruginosa. Many patients with CF have durable long-term coinfection with these organisms. New strategies are needed to prevent and treat these infections.

High Prevalence of Staphylococcus aureus Enterotoxin Gene Cluster Superantigens in Cystic Fibrosis Clinical Isolates.

BACKGROUND: Staphylococcus aureus is a highly prevalent respiratory pathogen in cystic fibrosis (CF). It is unclear how this organism establishes chronic infections in CF airways. We hypothesized that S. aureus isolates from patients with CF would share common virulence properties that enable chronic infection. METHODS: 77 S. aureus isolates were obtained from 45 de-identified patients with CF at the University of Iowa. We assessed isolates phenotypically and used genotyping assays to determine the presence or absence of 18 superantigens (SAgs). RESULTS: We observed phenotypic diversity among S. aureus isolates from patients with CF. Genotypic analysis for SAgs revealed 79.8% of CF clinical isolates carried all six members of the enterotoxin gene cluster (EGC). MRSA and MSSA isolates had similar prevalence of SAgs. We additionally observed that EGC SAgs were prevalent in S. aureus isolated from two geographically distinct CF centers. CONCLUSIONS: S. aureus SAgs belonging to the EGC are highly prevalent in CF clinical isolates. The greater prevalence in these SAgs in CF airway specimens compared to skin isolates suggests that these toxins confer selective advantage in the CF airway.

Impact of pharmacy services on cystic fibrosis transmembrane conductance regulator modulator prescribing at a pediatric cystic fibrosis center.

BACKGROUND: This study was undertaken to determine if the presence of a clinical pharmacy team impacted patients' access to cystic fibrosis transmembrane conductance regulator (CFTR) modulators. METHODS: A retrospective chart review of electronic medical records from the University of Iowa Hospitals and Clinics (UIHC) was conducted. Data were collected regarding the timing of prior authorization (PA) submissions and approvals from 2012 to 2018. The Wilcoxon rank-sum test was used to compare the meantime (days) between prescription and PA submission dates, and PA submission and approval date for all patients included in the analysis. Comparisons were made for pre- and postpharmacy services eras as well as the UIHC Specialty Pharmacy versus a non-UIHC Specialty Pharmacy. RESULTS: Sixty-three patients were included in the final analysis. The average time between prescription date and PA submission was 12.5 days (standard deviation [SD] = 17.4 days) in the preclinical pharmacy services era and 3.5 days (SD = 5.8 days; P = .028) in the postclinical pharmacy services era. The average time to PA submission significantly decreased from 9.8 days (SD = 13.1 days) to 1.3 days (SD = 4.2 days; P < .0001) when prescriptions were filled by the UIHC Specialty Pharmacy vs a non-UIHC Specialty Pharmacy. CONCLUSIONS: There was a significant benefit to CFTR modulator prescribing when clinical pharmacy services were incorporated in our cystic fibrosis (CF) care team, which will become increasingly important with the anticipation of new CF medications in the near future.

Pathogen acquisition in patients with cystic fibrosis receiving ivacaftor or lumacaftor/ivacaftor.

BACKGROUND: The cystic fibrosis transmembrane conductance regulator (CFTR) modulators ivacaftor and lumacaftor/ivacaftor improve the status of existing infections in patients with cystic fibrosis (CF). It is unknown how well these drugs protect patients against incident infections. We hypothesized that CFTR modulator treatment would decrease new infections with Pseudomonas aeruginosa or Staphylococcus aureus. METHODS: We retrospectively studied a single-center cohort of patients with CF during two time periods (2008-2011, Era 1) and (2012-2015, Era 2) based on the January 2012 approval of ivacaftor. Using Kaplan-Meier analysis, we compared the time to any new infection with P. aeruginosa, methicillin-resistant S. aureus (MRSA), or methicillin-sensitive S. aureus (MSSA) that was absent during a 2-year baseline. We stratified the analysis based on whether patients received ivacaftor or lumacaftor/ivacaftor during Era 2. We used the log-rank test and considered P < 0.05 statistically significant. RESULTS: For patients receiving ivacaftor or lumacaftor/ivacaftor in Era 2, there was a statistically significant delay in the time to new bacterial acquisition in Era 2 vs. Era 1 ( P = 0.008). For patients who did not receive CFTR modulators, there was a trend toward slower acquisition of new bacterial infections in Era 2 compared to Era 1, but this was not statistically significant ( P = 0.10). CONCLUSIONS: Patients receiving ivacaftor or lumacaftor/ivacaftor for CF had significantly delayed acquisition of P. aeruginosa and S. aureus after these drugs were released. This method for analyzing incident infections may be useful for future studies of CFTR modulators and bacterial acquisition in CF registry cohorts.

Impact of a cystic fibrosis transmembrane conductance regulator (CFTR) modulator on high-dose ibuprofen therapy in pediatric cystic fibrosis patients.

BACKGROUND: This study was undertaken to determine if a clinically relevant drug-drug interaction occurred between ibuprofen and lumacaftor/ivacaftor. METHODS: Peak ibuprofen plasma concentrations were measured prior to and after lumacaftor/ivacaftor initiation. A Wilcoxon signed rank sum test was used to compare the values. RESULTS: Nine patients were included in the final analysis. Peak ibuprofen plasma concentrations decreased an average of 36.4 mcg/mL after initiation of lumacaftor/ivacaftor with a relative reduction of 41.7%. The average peak plasma concentration was 84.2 mcg/mL (SD = 10.9) prior to lumacaftor/ivacaftor initiation and 47.9 mcg/mL (SD = 16.4) following initiation (P = 0.0039). Peak concentrations occurred at an average of 100 min (SD = 30) and 107 min (SD = 40) prior to and following lumacaftor/ivacaftor initiation, respectively. CONCLUSIONS: We suggest a clinically relevant drug-drug interaction exists between ibuprofen and lumacaftor/ivacaftor. Lumacaftor may cause subtherapeutic ibuprofen plasma concentrations due to the induction of CYP enzymes and increased metabolism of ibuprofen. Based on this analysis, we have modified our use of ibuprofen in several patients after evaluation of this drug-drug interaction.

Implementation of cystic fibrosis clinical pathways improved physician adherence to care guidelines.

INTRODUCTION: There is significant variability in clinical outcomes, including growth and lung function, between the various cystic fibrosis (CF) centers. No specific or unique therapeutic practices have been identified to account for these differences. However, more uniform care within centers was associated with better outcomes. The objective of this study was to implement clinical pathways for diagnosis and treatment of nutritional failure and lung inflammation in order to achieve better health care provider adherence to center-specific, agreed-on practices. METHODS: Agreed-on clinical pathway treatment plans for both nutrition and lower airway inflammation were implemented on January 1, 2010. The primary outcome measure was to evaluate if patients' diagnoses and treatments were consistent with the agreed-on clinical pathways. RESULTS: The proportion of clinic visits from baseline to 18 months post-intervention where the provider completely followed nutrition clinical pathway increased from 57.72% to 79.49% (P = 0.049) and the proportion for lower airway inflammation clinical pathway increased from 65.85% to 86.32% (P = 0.035). The use of nutritional diagnosis and documentation of associated clinical pathway in the clinical plan increased from 16.26% to 61.54% and 56.10% to 94.87%, respectively. Similarly, diagnosis of lower airway inflammation and documentation related to their treatment plans increased from 1.63% to 43.59% and 30.08% to 87.18%, respectively. CONCLUSION: Implementation of clinical pathways for nutrition and lower airway inflammation issues resulted in more uniform care of CF patients. Having objective criteria for diagnoses and agreed-on treatment plans for each of those diagnoses allowed for monitoring and individual feedback. Increases in utilization of correct diagnoses and discussion of specific therapeutic interventions in the clinic notes were associated with increased adherence to clinical pathways. Pediatr Pulmonol. 2017;52:175-181. © 2016 Wiley Periodicals, Inc.

Development of an in vitro colonization model to investigate Staphylococcus aureus interactions with airway epithelia.

Staphylococcus aureus is a bacterial pathogen responsible for a wide range of diseases and is also a human commensal colonizing the upper respiratory tract. Strains belonging to the clonal complex group CC30 are associated with colonization, although the colonization state itself is not clearly defined. In this work, we developed a co-culture model with S. aureus colonizing the apical surface of polarized human airway epithelial cells. The S. aureus are grown at the air-liquid interface to allow an in-depth evaluation of a simulated colonization state. Exposure to wild-type, S. aureus bacteria or conditioned media killed airway epithelial cells within 1 day, while mutant S. aureus strains lacking alpha-toxin (hla) persisted on viable cells for at least 2 days. Recent S. aureus CC30 isolates are natural hla mutants, and we observed that these strains displayed reduced toxicity toward airway epithelial cells. Quantitative real-time polymerase chain reaction of known virulence factors showed the expression profile of S. aureus grown in co-culture correlates with results from previous human colonization studies. Microarray analysis indicated significant shifts in S. aureus physiology in the co-culture model toward lipid and amino acid metabolism. The development of the in vitro colonization model will enable further study of specific S. aureus interactions with the host epithelia.

Tracheomalacia is associated with lower FEV1 and Pseudomonas acquisition in children with CF.

BACKGROUND: Tracheomalacia (TM) occurs in approximately 1 in 2,100 children. Because the trachea develops abnormally in animal models of cystic fibrosis (CF), we hypothesized this may also occur in children with CF, increasing their risk of TM. PURPOSE: To examine the prevalence and clinical consequences of TM in children with CF. METHODS: We studied children with CF born between 1995 and 2012. TM was defined as dynamic collapse of the trachea, and the severity was recorded as described in the chart. The effect of TM on patient outcomes, including FEV1 , CT changes, and acquisition of CF pathogens, was assessed using a longitudinal patient dataset. RESULTS: Eighty-nine percent of children with CF had at least one bronchoscopy (n = 97/109). Fifteen percent of these children had TM described in any bronchoscopy report (n = 15/97). Of the patients with TM, eight had meconium ileus (P = 0.003) and all were pancreatic insufficient. Pseudomonas aeruginosa infection occurred 1.3 years earlier among children with TM (P = 0.01). Starting FEV1 values by age 8 were diminished by over 18% of predicted for patients with TM. Life-threatening episodes of airway obstruction occurred in 3 of 15 patients with CF and TM, including one leading to death. Gender, prematurity, and hepatic disease were not associated with TM. No difference was observed in the frequency of bronchiectasis. CONCLUSIONS: TM is significantly more common in infants and children with CF than in the general population and is associated with airway obstruction and earlier Pseudomonas acquisition.

Growth of preschool age children receiving daily inhaled corticosteroids.

Data on the effects of inhaled corticosteroid (ICS) on linear growth in children <5 years old are limited with conflicting results from existing studies. This study was designed to investigate growth effects of inhaled corticosteroid use in children <5 years of age treated for asthma with ICS administered through a valved holding chamber (VHC). A retrospective cohort study was performed of 145 children in three treatment groups: (1) metered-dose inhaler (MDI) containing ultrafine beclomethasone dipropionate (n = 62), (2) MDI containing fluticasone propionate (n = 32), and (3) oral montelukast sodium (n = 51). Children <5 years of age between 2000 and 2009 treated for asthma with one of the three drugs were included in the study. Linear mixed model analysis was used to examine and compare growth during sustained treatment with each of the three medications. The three treatment groups did not differ significantly in their effect on growth rates (p = 0.64). However, female subjects had significantly slower growth than male subjects (p = 0.017), and the addition of intranasal corticosteroids (INS; p = 0.013) and the presence of atopy (p = 0.015) had a significant negative effect on growth. In children <5 years of age receiving maintenance therapy for chronic asthma, low-to-medium doses of ultrafine beclomethasone or fluticasone administered through a VHC were not associated with growth inhibition compared with children receiving oral montelukast. A small but statistically significant decrease in growth was seen in subjects with positive skin testing to inhalant allergens in female subjects and in subjects receiving INS.