Cystic Fibrosis Foundation Research Articles

Factors associated with pubertal growth outcomes in cystic fibrosis: Early Growth and Puberty in CF

BackgroundPubertal delays in children with cystic fibrosis (CF) have historically been common. It is unclear to what degree puberty is affected in the new era of CF care or the role of early nutritional status. We hypothesized that more favorable early growth trajectories are associated with improved pubertal growth outcomes. MethodsWe used data from the United States CF Foundation Patient Registry to analyze associations between early weight-for-length/body mass index (WFL-BMI) growth trajectories and pubertal outcomes, using peak height velocity (PHV) and age at PHV (APHV) as proxy measures for puberty in addition to adult height (defined as height at age 18 years). Our analysis consisted of shape invariant mixed modeling and multivariable linear regression. ResultsOur sample consisted of 9,186 people with CF aged 18 to 21 years between 2010-2019. APHV was earliest and PHV/adult height were highest in those with WFL-BMI always >50th percentile from 0-6 years. However, there was no difference after adjusting for key covariates. Receiving CF transmembrane conductance regulator (CFTR) modulator therapy in childhood was associated with being taller at 18 years, by 0.92 cm in males (p=0.048) and 1.02 cm in females (p=0.010) in adjusted models. Higher height z-score at 2 years was associated with improved APHV and PHV for males and improved adult height for both males and females (p<0.001) in adjusted models. ConclusionsEarly height, but not early WFL-BMI trajectories, may be associated with pubertal growth outcomes. CFTR modulator therapy shows the potential to improve pubertal growth outcomes, but further research is necessary.

Association of Pseudomonas aeruginosa incident infections with adherence to cystic fibrosis foundation care guidelines

BackgroundCare guidelines for cystic fibrosis (CF) have been developed to enhance consistent care and to improve health outcomes. We determined if adherence to CF care guidelines predicted P. aeruginosa incidence rates (Pa-IR) at U.S. CF centers in 2018. MethodsThis cross-sectional CF Foundation Patient Registry study included 82 adult and 132 pediatric centers. Adherence to 12 guidelines was defined categorically (guideline met) or as a continuous measure (proportion of patients being treated/evaluated per guideline). Association of adherence to individual guidelines with Pa-IR, accounted for center and patient characteristics relevant to Pa-IR and were modeled using random forests and weighted-least-squares (WLS) analyses. ResultsThe mean Pa-IR was 0.2 cases/patient-years at risk (SE 0.0074) for all centers combined. Guideline adherence was lowest for ≥4 bacterial cultures/year (54% of centers) and annual oral glucose tolerance test (OGTT) (48% of centers), and highest for annual non-tuberculous mycobacteria (NTM) sputum culture (98%). The mean number of guidelines met was 6.7 and higher for pediatric (7.3) than adult (5.6) centers, (p<0.001). The number of guidelines met correlated negatively with Pa-IR (β=-0.007, p = 0.043). Macrolide prescription and annual OGTT per guideline were associated with lower and higher Pa-IR, respectively. Centers with lower center-wide lung function, higher proportion of pwCF with low body-mass index, and location in the Southwest had higher Pa-IR. ConclusionOverall adherence to guidelines was high except for performing ≥4 bacterial cultures/year and OGTT. Higher Pa-IR was associated with center characteristics and lower guideline adherence. The lower Pa-IR with greater adherence to guidelines suggests that focusing on quality care can positively impact Pa-IR.

Predictors of Transition Outcomes in Cystic Fibrosis: Analysis of National Patient Registry and CF RISE (Responsibility. Independence. Self-care. Education) Data

ObjectiveTo identify predictors of change in lung function and body weight during healthcare transition in cystic fibrosis (CF). MethodsWe conducted a retrospective cohort study using data from the CF Foundation Patient Registry (CFFPR) and the web-based transition program CF RISE (Responsibility. Independence. Self-care. Education) for patients ages 16 to 25 who transitioned to adult care from 2013 through 2019. We modeled change in FEV1 % predicted and weight using linear regression fit with generalized estimating equations. Predictors included gap in care (time between last pediatric and first adult outpatient visit), transition program engagement, and sociodemographic and medical factors. ResultsAmong 12,420 adolescents and young adults (AYAs), 3,876 transitioned to adult care with a median gap in care of 7.6 months. Patients from CF centers with higher rates of CF RISE engagement had improved lung function and weight at their first adult outpatient visit. Coverage on a parent’s insurance plan and absence of CF complications predicted increased lung function. History of a non-lung transplant and sinus disease predicted increased weight. Comorbid diabetes mellitus and gaps in care >3 months predicted decreased lung function with longer gaps in care associated with greater decrease. A gap in care of 6-9 months predicted decreased weight. Control variables including baseline FEV1 and weight, and exacerbation status were also statistically significant. ConclusionsFindings suggest two promising targets to improve transition of AYAs with CF: increasing AYA engagement in CF RISE and reducing gaps in care during the transition period.

Lung Allocation Score Exceptions in Persons with Cystic Fibrosis Undergoing Lung Transplant.

Rationale: Lung transplantation can extend the lives of individuals with advanced cystic fibrosis (CF). Until March 2023, the Lung Allocation Score (LAS) was used in the United States to determine transplant priority. Certain clinical events or attributes ("risk events") that are not included in the LAS (e.g., massive hemoptysis) are relatively common and prognostically important in CF and may prompt an exception request to increase priority for donor lungs. The new Lung Composite Allocation Score (CAS) also allows for exceptions based on the same principles. Objectives: To evaluate the frequency of LAS exceptions in persons with CF (PwCFs) listed for lung transplantation and assess whether LAS exceptions are associated with improved waitlist outcomes for PwCFs compared with similarly "at-risk" individuals without LAS exceptions. Methods: A merged dataset combining data from the CF Foundation Patient Registry and the Organ Procurement and Transplantation Network (2005-2019) was used to identify PwCFs listed for lung transplantation. We compared waitlist outcomes between PwCFs with a LAS exception versus those without an exception despite having a risk event. Risk events were defined as an episode of massive hemoptysis, pneumothorax, at least three moderate/severe pulmonary exacerbations, and/or a decrease in forced expiratory volume in 1 second by ⩾30% predicted (absolute) in the prior 12 months. Analyses were performed using competing risk regression with time to transplantation as the primary outcome and death without a transplant as a competing risk. Results: Of 3,538 listings from 3,309 candidates, 2% of listings (n = 81) had at least one exception. Candidates with an exception and those with a risk event but no exception received lung transplants more slowly than people without an exception or risk event (subdistribution hazard ratio [95% confidence interval]: LAS exception cohort, 0.66 [0.52-0.85]; risk event cohort without exceptions, 0.79 [0.72-0.86]). There was no difference between those with LAS exceptions and those at risk without LAS exceptions: subdistribution hazard ratio, 0.84 (0.66-1.08). Conclusions: LAS exceptions are rare in PwCFs listed for lung transplantation. LAS exceptions resulted in a similar time to transplantation for PwCFs compared with similarly at-risk individuals. As we enter the CAS era, these LAS-based results are pertinent to improve risk stratification among PwCFs being considered for lung transplantation.

Incidence of fibrosing colonopathy with pancreatic enzyme replacement therapy in patients with cystic fibrosis

BackgroundHigh daily doses of pancreatic enzyme replacement therapy (PERT) were historically associated with risk of fibrosing colonopathy (FC) in people with cystic fibrosis (pwCF), leading to development of PERT dosing guidelines and reformulated products. This study quantified incidence of FC in pwCF treated with PERT following those measures. MethodsThis large prospective cohort study included eligible pwCF enrolled in the Cystic Fibrosis Foundation Patient Registry with ≥1 clinic visit in 2012–2014 and follow-up through 2020. Data on PERT exposure, demographics, and medical history were collected. Clinical data, imaging, and histopathology of suspected cases were examined by an independent adjudication panel of physicians familiar with this complication. ResultsBase Study Population included 26,025 pwCF who contributed 155,814 person-years [mean (SD) 6.0 (2.0) years] of follow-up. Over 7.8 years, 29 pwCF had suspected FC; three cases were confirmed by adjudication, 22 cases were confirmed as not FC, and four cases were indeterminate. There were 22,161 pwCF exposed to any PERT, with mean PERT use time of 5.583 person-years and mean daily dose of 8328 U lipase per kg per day. All three confirmed cases and four indeterminate cases of FC occurred during current use of PERT. Incidence rates per 1000 person-years exposed were 0.0242 (95 % CI [0.0050, 0.0709]) for confirmed FC and 0.0566 (95 % CI [0.0227, 0.1166]) for indeterminate or confirmed FC. ConclusionsThe incidence of FC in pwCF is very low in the era of current treatment guidelines and more stringent quality standards for PERT products.

Education-related needs for children with cystic fibrosis: Perspectives of US pediatric care teams.

Patients with cystic fibrosis (CF) often bring education-related concerns to their medical teams. Concerns around the ability for CF care teams to identify and address these concerns exist. We sought to describe CF care team perceptions of (1) patient and family education-related needs, (2) how these needs are identified, documented and addressed, and (3) education-related resource gaps. A survey was emailed to pediatric care teams in the CF Foundation Care Center Network in April 2022. Individuals or care teams could complete the survey. Responses were aggregated for descriptive analysis. Sixty-seven programs responded representing 52% of United States pediatric CF centers. Most centers (88%) indicated social workers primarily address school concerns. Care teams often complete school forms (99%), coach families to communicate with schools (96%), communicate with schools directly (90%), and develop educational plans (76%). Formal education risk assessment and support programs are relatively uncommon (19%). Common student-specific needs include carrying medications (75%) and leaving class for gastrointestinal issues (54%). Needs reported are informational materials for families and schools (94%), staff education about school concerns and how to address them (91%), additional staff for education-related issues (65%), and expertise in education plan development (62%). CF care teams often lack comprehensive resources to identify and address education-related concerns. Systematically performing needs assessments, improving training for providers, and evaluating the benefits of education specialists on care teams may better identify and address education-related needs. Supporting educational progression will foster continued independence and well-being in adulthood.

617 Characteristics of patients diagnosed with CFTR-related disorder in U.S. Cystic Fibrosis Foundation Patient Registry data

617 Characteristics of patients diagnosed with CFTR-related disorder in U.S. Cystic Fibrosis Foundation Patient Registry data

328 Cystic Fibrosis Foundation Therapeutics Lab: Omics data repository from cystic fibrosis–relevant in vitro cell models

328 Cystic Fibrosis Foundation Therapeutics Lab: Omics data repository from cystic fibrosis–relevant in vitro cell models

244 Cystic Fibrosis Foundation Therapeutics Lab: Biorepository expansion to represent a broad range of cystic fibrosis patients

244 Cystic Fibrosis Foundation Therapeutics Lab: Biorepository expansion to represent a broad range of cystic fibrosis patients

621 Linking Cystic Fibrosis Foundation Patient Registry and national Medicaid databases: assessment of hospital admissions and emergency department visits

621 Linking Cystic Fibrosis Foundation Patient Registry and national Medicaid databases: assessment of hospital admissions and emergency department visits

606 Social determinants of overweight and obesity in children with cystic fibrosis in the United States: a longitudinal analysis of Cystic Fibrosis Foundation Patient Registry data (2009-2019)

606 Social determinants of overweight and obesity in children with cystic fibrosis in the United States: a longitudinal analysis of Cystic Fibrosis Foundation Patient Registry data (2009-2019)

405 Impact of unaffordable or inadequate coverage through medical debt calls to Cystic Fibrosis Foundation Compass

405 Impact of unaffordable or inadequate coverage through medical debt calls to Cystic Fibrosis Foundation Compass

The risk of pulmonary NTM infections and water-quality constituents among persons with cystic fibrosis in the United States, 2010-2019.

The prevalence of nontuberculous mycobacterial (NTM) pulmonary disease varies geographically in the United States. Previous studies indicate that the presence of certain water-quality constituents in source water increases NTM infection risk. To identify water-quality constituents that influence the risk of NTM pulmonary infection in persons with cystic fibrosis in the United States. We conducted a population-based case-control study using NTM incidence data collected from the Cystic Fibrosis Foundation Patient Registry during 2010-2019. We linked patient zip code to the county and associated patient county of residence with surface water data extracted from the Water Quality Portal. We used logistic regression models to estimate the odds of NTM infection as a function of water-quality constituents. We modeled two outcomes: pulmonary infection due to Mycobacterium avium complex (MAC) and Mycobacterium abscessus species. We identified 484 MAC cases, 222 M. abscessus cases and 2816 NTM-negative cystic fibrosis controls resident in 11 states. In multivariable models, we found that for every 1-standardized unit increase in the log concentration of sulfate and vanadium in surface water at the county level, the odds of infection increased by 39% and 21%, respectively, among persons with cystic fibrosis with MAC compared with cystic fibrosis-NTM-negative controls. When modeling M. abscessus as the dependent variable, every 1-standardized unit increase in the log concentration of molybdenum increased the odds of infection by 36%. These findings suggest that naturally occurring and anthropogenic water-quality constituents may influence the NTM abundance in water sources that supply municipal water systems, thereby increasing MAC and M. abscessus infection risk.

550 Prevalence of acid blockade use and its association with social determinants of health in people with cystic fibrosis: preliminary analysis of Cystic Fibrosis Foundation registry data

550 Prevalence of acid blockade use and its association with social determinants of health in people with cystic fibrosis: preliminary analysis of Cystic Fibrosis Foundation registry data

Longitudinal bacterial prevalence in cystic fibrosis airways: Fact and artifact

BackgroundOpportunistic bacterial infection is a hallmark of cystic fibrosis (CF) lung disease and early mortality. Poorly characterized prevalence changes have accompanied two decades of health improvements, with CFTR modulators likely to further affect infection epidemiology. MethodsBacterial prevalence change trends across birth cohorts were assessed with linear regression using 2001–2019 US CF Foundation Patient Registry data. Informative missingness was assessed, as was age-to-age infection status. ResultsBacterial prevalence constantly changed from 2001 to 2019, with changes differing across birth cohorts. Informative censoring affected prevalence change for some organisms. Age-to-age infection status changes were greater than net changes in bacterial prevalence and varied by age. ConclusionsCF infection epidemiology changed over two decades and will continue to do so. Understanding how modulators affect infection epidemiology will require creative designs for longitudinal prevalence change studies emphasizing prevalence changes independent of effects on lung biology.

Improvement in cystic fibrosis newborn screening program outcomes with genetic counseling via telemedicine.

The Cystic Fibrosis Foundation (CF Foundation) recommends the provision of genetic counseling (GC) to help educate families and decrease anxiety around the cystic fibrosis (CF) newborn screening process. Unfortunately, access to genetic counselors is limited, especially for CFtrained genetic counselors. We hypothesized that the GC process for families could be improved by utilizing telemedicine to leverage the availability of two dedicated, CF trained genetic counselors to provide access to GC for several CF centers. In addition, we hoped to demonstrate that use of trained CF genetic counselors, delivering GC via telemedicine at the time of sweat testing, would provide families with understanding of CF genetics as well as result in high satisfaction with the newborn screening process. GC was provided by CF trained genetic counselors via telemedicine at the time of sweat testing. Following the counseling session, families were administered an anonymous written survey to evaluate their impression of the services provided. A subset of 50 families was recruited for an assessment of gained knowledge regarding CF genetics using the Ciske knowledge inventory. Using χ2 analysis, Ciske knowledge inventory data from our telemedicine GC families was compared to counseled and uncounseled Ciske historical controls. Lastly, in-depth interviews about the newborn screening process for CF were performed with 10families and interviews were coded for emerging themes. During the 4years of the study, 250 patients received GC. Overall comfort with the counseling rated 4.77 out of 5 using a Likert scale. After counseling by telemedicine, parents demonstrated improved understanding of the genetic implications of an abnormal CF newborn screen for their family, with 100% of families understanding that their child was a carrier for CF as compared to 97.2% of counseled (p = .023) and 78.5% of uncounseled (p = .0007) from Ciske historical controls. The study group also showed improvement in understanding of both parents possibly being carriers, with an 87.7% correct response rate compared to a 37.0% correct response rate in the counseled group (p < .0001) and a 35.4% correct response rate in the non-counseled group (p < .0001) from Ciske historical controls. Subgroup analysis at one site showed a significant increase in the number of infants with completed sweat tests from previous years (49% in 2013 vs. 80% in 2017 during the study, p < .0001). GC by telemedicine was well received by families and demonstrated improved family knowledge acquisition and understanding of CF as it related to risks for their child as well as identification of risks for other family members. Furthermore, in addition to an increase is those receiving GC, a subgroup analysis demonstrated a significant increase in the number of infants receiving sweat tests. This study demonstrates that GC via telemedicine for CF is feasible and demonstrates improvement in parent understanding of CF genetics. Furthermore, this method can be implemented effectively across a wide geographical area with a limited number of CF trained genetic counselors to improve access to care for patients and families.

Cystic fibrosis survival outcomes following second lung transplant: The north American experience.

Re-transplant is an option for those who develop end-stage lung disease due to rejection; however, little data exist following re-transplantation in cystic fibrosis (CF). Data from the Canadian CF Registry and US CF Foundation Patient Registry supplemented with data from United Network for Organ Sharing were used. Individuals who underwent a 2nd lung transplant between 2005 and 2019 were included. The Kaplan-Meier method was used to estimate the probability of survival post-second transplant at 1, 3, and 5-years. Of those people who were waitlisted for a second transplant (N=818), a total of 254 (31%) died waiting, 395 (48%) were transplanted and 169 (21%) people were alive on the waitlist. Median survival time after 2nd lung transplant was 3.3 years (95% CI: 2.8-4.1). The 1-, 3- and 5-year survival rates were 77.4% (95% CI: 73.1-82%), 52% (95% CI: 46.7-58%) and 39.4% (95% CI: 34.1-45.6%). Survival following second lung transplant in CF patients is lower than estimates following the first transplant. Over half of subjects who are potentially eligible for a second transplant die without receiving a second organ. This warrants further investigation.

Why cystic fibrosis newborn screening programs have failed to meet original expectations… thus far

This Commentary summarizes what the author has learned in 46 years of research on newborn screening (NBS) for cystic fibrosis (CF) combined with healthcare and public health practice. The original expectation was that screening for this relatively common, life-threatening genetic disorder would lead to consistently timely diagnoses in the neonatal period and be equitable. Unfortunately, this ambitious goal has not been achieved in the USA despite the availability of an excellent, although imperfect, 2-tiered screening test employing immunoreactive trypsinogen (IRT) and DNA analysis for pathogenic variants in the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR). In fact, variations in the quality of NBS programs, inconsistencies in their operations, and disparities in outcomes have been prominent features. The causes include leadership challenges and deficiencies among both CF centers and NBS labs; failures to form effective partnerships among CF centers and with NBS programs; relatively rapid implementation after 2005 with variable quality planning; misunderstandings and erroneous dogma about CF; data limitations regarding IRT, especially cutoff values, and CFTR genetics; tolerance of suboptimal protocols and false negative results; problems in dried blood spot collections plus a lack of transparency and national oversight; partial lack of readiness, qualifications, funding and/or willingness to innovate with floating IRT cutoffs and DNA/CFTR analyses; follow up challenges/deficiencies impairing timeliness, including sweat testing limitations; and published guidelines that are more descriptive than sufficiently critical and directive. But the lessons learned through uniquely intensive CF NBS research have been enlightening and guided the U.S. Cystic Fibrosis Foundation to nationwide quality improvement initiatives.

Impact of loss to follow-up on survival estimation for cystic fibrosis

PurposeDeaths among those lost to follow-up (LTFU) in the Cystic Fibrosis Foundation Patient Registry (CFFPR) are critically important to the epidemiology of cystic fibrosis (CF). Unreported deaths could impact estimates of survival if LTFU is associated with disease trajectory. MethodsWe characterized the LTFU population (1986-2017) from the CFFPR and identified deaths via linkage with the National Death Index (NDI). Median predicted survival age and conditional survival were estimated with and without additional deaths and person-time from the NDI. ResultsOf the 10,582 individuals LTFU in the CFFPR, 2,460 (23.2%) matched to an NDI death record. Individuals who died after LTFU with a CF diagnosis were 43% female, 91% White/non-Hispanic, 59% had advanced CF lung disease based on last CFFPR recorded forced expiratory volume in one second (FEV1) %predicted <40 and 18% were post-lung transplant. Median predicted survival age during the most recent period available, 2013-2017, increased from 44.3 years (95% CI: 43.2, 45.7) to 45.8 years (95% CI 44.5, 47.1) with the inclusion of NDI data. ConclusionsInclusion of deaths and additional person-time among those LTFU changed the point estimate of median predicted survival for most time periods and increased the point estimate from 2009 onwards.

International consensus recommendations for the use of prolonged-infusion beta-lactam antibiotics: Endorsed by the American College of Clinical Pharmacy, British Society for Antimicrobial Chemotherapy, Cystic Fibrosis Foundation, European Society of Clinical Microbiology and Infectious Diseases, Infectious Diseases Society of America, Society of Critical Care Medicine, and Society of Infectious Diseases Pharmacists.

Intravenous β-lactam antibiotics remain a cornerstone in the management of bacterial infections due to their broad spectrum of activity and excellent tolerability. β-lactams are well established to display time-dependent bactericidal activity, where reductions in bacterial burden are directly associated with the time that free drug concentrations remain above the minimum inhibitory concentration (MIC) of the pathogen during the dosing interval. In an effort to take advantage of these bactericidal characteristics, prolonged (extended and continuous) infusions (PIs) can be applied during the administration of intravenous β-lactams to increase time above the MIC. PI dosing regimens have been implemented worldwide, but implementation is inconsistent. We report consensus therapeutic recommendations for the use of PI β-lactams developed by an expert international panel with representation from clinical pharmacy and medicine. This consensus guideline provides recommendations regarding pharmacokinetic and pharmacodynamic targets, therapeutic drug-monitoring considerations, and the use of PI β-lactam therapy in the following patient populations: severely ill and nonseverely ill adult patients, pediatric patients, and obese patients. These recommendations provide the first consensus guidance for the use of β-lactam therapy administered as PIs and have been reviewed and endorsed by the American College of Clinical Pharmacy (ACCP), the British Society for Antimicrobial Chemotherapy (BSAC), the Cystic Fibrosis Foundation (CFF), the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), the Infectious Diseases Society of America (IDSA), the Society of Critical Care Medicine (SCCM), and the Society of Infectious Diseases Pharmacists (SIDP).