Lung function decline is mitigated following liver transplantation in people with cystic fibrosis: A retrospective cohort study.

There is paucity of literature on the health outcomes following liver transplantation (LT) in people with cystic fibrosis (pwCF). We aim to evaluate changes in lung function following LT in pwCF. We performed a retrospective cohort study of pwCF who underwent LT between 1987 and 2019 in the United States and Canada. Simultaneous lung-liver transplants and individuals who had lung transplant prior to LT were excluded. We analyzed pre-LT and post-LT percent predicted forced expiratory volume in 1 second, body mass index, rates of pulmonary exacerbation, and post-LT overall survival. A total of 402 LT recipients were included. The median age of transplant was 14.9 years and 69.7% of the transplants were performed in children less than 18 years old. The rate of decline in percent predicted forced expiratory volume in 1 second was attenuated after LT from -2.2% to -0.7% predicted per year with a difference of 1.5% predicted per year (95% CI, 0.8, 2.2; p < 0.001). Following LT, the rate of decline in body mass index was reduced, and there were fewer pulmonary exacerbations (0.6 pre vs. 0.4 post; rate ratio 0.7, p < 0.01). The median survival time post-transplant was 13.9 years and the overall probability of survival at 5 years was 77.6%. Those with higher lung function pre-LT had a lower risk of death post-LT, and those with genotypes other than F508 deletion had worse survival. LT in pwCF occurs most often in children and adolescents and is associated with a slower rate of decline in lung function and nutritional status, and a reduction in pulmonary exacerbations.

"We'll deal with it as it comes": A Qualitative Analysis of Romantic Partners' Dyadic Coping in Cystic Fibrosis.

Background: Although cystic fibrosis (CF) is a progressive, life-limiting, genetic disease, recent advances have extended survival, allowing persons with CF the time and physical and mental health to form romantic relationships. Previous studies have shown the importance of dyadic coping to positive psychosocial functioning and relationship satisfaction for people with serious chronic illness and their romantic partners, but little work has been done with persons with CF and their partners. The present study examines dyadic coping processes in persons with CF and their romantic partners. Methods: Sixteen adults with moderate to severe CF (Mage=42.3, 43.8% identified as cisgender male, 56.2% identified as cisgender female) and their romantic partners (Mage=43.8, 56.3% identified as cisgender male, 43.7% identified as cisgender female) participated in individual semi-structured interviews focused on topics related to quality of life, communication, and palliative care. We conducted a directed content analysis utilizing Berg and Upchurch's (2007) developmental-contextual theoretical model to examine dyadic coping processes in persons with CF and their romantic partners. Results: Consistent with the developmental-contextual model of dyadic coping, couples described adapting to health and functional declines that occurred over time. Dyads were aligned in their appraisals of illness representation, illness ownership, and perspectives of illness as a shared stressor; they used shared coping mechanisms that included supportive and collaborative actions rather than uninvolved or controlling strategies. Conclusions: We recommend family-based approaches to medical decision-making and goals of care conversations with persons with CF and their partners, aligning those approaches with supportive and collaborative coping configurations. This may improve psychosocial outcomes for patients and their partners.

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

INTRODUCTION: 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). METHODS: 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. RESULTS: 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%). CONCLUSIONS: 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.

Computed tomography body composition and clinical outcomes following lung transplantation in cystic fibrosis.

BACKGROUND: Low muscle mass is common in patients approaching lung transplantation and may be linked to worse post-transplant outcomes. Existing studies assessing muscle mass and post-transplant outcomes include few patients with cystic fibrosis (CF). METHODS: Between May 1993 and December 2018, 152 adults with CF received lung transplants at our institution. Of these, 83 met inclusion criteria and had usable computed tomography (CT) scans. Using Cox proportional hazards regression, we evaluated the association between pre-transplant thoracic skeletal muscle index (SMI) and our primary outcome of death after lung transplantation. Secondary outcomes, including days to post-transplant extubation and post-transplant hospital and intensive care unit (ICU) length of stay, were assessed using linear regression. We also examined associations between thoracic SMI and pre-transplant pulmonary function and 6-min walk distance. RESULTS: Median thoracic SMI was 26.95 cm2/m2 (IQR 23.97, 31.32) for men and 22.83 cm2/m2 (IQR 21.27, 26.92) for women. There was no association between pre-transplant thoracic SMI and death after transplant (HR 1.03; 95% CI 0.95, 1.11), days to post-transplant extubation, or post-transplant hospital or ICU length of stay. There was an association between pre-transplant thoracic SMI and pre-transplant FEV1% predicted (b = 0.39; 95% CI 0.14, 0.63), with higher SMI associated with higher FEV1% predicted. CONCLUSIONS: Skeletal muscle index was low for men and women. We did not identify a significant relationship between pre-transplant thoracic SMI and post-transplant outcomes. There was an association between thoracic SMI and pre-transplant pulmonary function, confirming the potential value of sarcopenia as a marker of disease severity.

A Framework for Using Real-World Data and Health Outcomes Modeling to Evaluate Machine Learning-Based Risk Prediction Models.

OBJECTIVES: We propose a framework of health outcomes modeling with dynamic decision making and real-world data (RWD) to evaluate the potential utility of novel risk prediction models in clinical practice. Lung transplant (LTx) referral decisions in cystic fibrosis offer a complex case study. METHODS: We used longitudinal RWD for a cohort of adults (n = 4247) from the Cystic Fibrosis Foundation Patient Registry to compare outcomes of an LTx referral policy based on machine learning (ML) mortality risk predictions to referral based on (1) forced expiratory volume in 1 second (FEV1) alone and (2) heterogenous usual care (UC). We then developed a patient-level simulation model to project number of patients referred for LTx and 5-year survival, accounting for transplant availability, organ allocation policy, and heterogenous treatment effects. RESULTS: Only 12% of patients (95% confidence interval 11%-13%) were referred for LTx over 5 years under UC, compared with 19% (18%-20%) under FEV1 and 20% (19%-22%) under ML. Of 309 patients who died before LTx referral under UC, 31% (27%-36%) would have been referred under FEV1 and 40% (35%-45%) would have been referred under ML. Given a fixed supply of organs, differences in referral time did not lead to significant differences in transplants, pretransplant or post-transplant deaths, or overall survival in 5 years. CONCLUSIONS: Health outcomes modeling with RWD may help to identify novel ML risk prediction models with high potential real-world clinical utility and rule out further investment in models that are unlikely to offer meaningful real-world benefits.

Characteristics and Outcomes of Children With Cystic Fibrosis Hospitalized With Cirrhosis in the United States.

INTRODUCTION: To describe the characteristics and outcomes of children with cystic fibrosis (CF) hospitalized with cirrhosis in the United States. METHODS: We conducted a population-based cohort study of hospitalizations among children with CF using the 2016 Kid's Inpatient Database. RESULTS: In total, 9,615 admissions were analyzed. Diagnosis of cirrhosis was present in 509 (5.3%) and was significantly associated with increased mortality, length of stay, and hospital charges compared with those without cirrhosis. Hepatic encephalopathy was significantly associated with death in children with cirrhosis. DISCUSSION: Future interventions should be designed to support children with CF who have cirrhosis to improve clinical outcomes.

Incorporating patient and caregiver feedback into lung transplant referral guidelines for individuals with cystic fibrosis-Preliminary findings from a novel paradigm.

BACKGROUND: Lung transplantation is a common therapeutic option for individuals with cystic fibrosis (CF) and advanced lung disease, yet many individuals with CF are not appropriately referred for evaluation. The present study sought to enhance CF transplant referral guidelines by integrating patient-centered input to identify possible psychosocial barriers contributing to suboptimal referral for appropriate CF transplant candidates. METHODS: As a component of developing the Cystic Fibrosis Foundation (CFF) Lung Transplant Referral Consensus Guidelines, we convened a focus group of lung transplant recipients with CF and two spouses of CF recipients. Each session involved standardized approaches to elicit qualitative, thematic content. RESULTS: CF patients and caregivers characterized five areas for improvement, which were integrated into formal CFF referral guidelines. These included (a) timing of transplant discussion with CF providers, (b) accuracy of transplant-related knowledge and expectations, (c) stigma associated with the need for transplantation, (d) treatment team transition issues, and (e) social support and mental health concerns. Earlier introduction of transplant, greater details regarding manageable aspects of treatment, and greater provision of social support were all associated with better psychosocial experiences. CONCLUSIONS: Integrating patient-centered input into guideline development yielded important and previously unknown psychosocial barriers contributing to suboptimal transplant referral.

Changing Rates of Chronic Pseudomonas aeruginosa Infections in Cystic Fibrosis: A Population-Based Cohort Study.

Background: Chronic Pseudomonas aeruginosa lung infection is associated with significant morbidity and mortality in cystic fibrosis (CF). It is not known whether recent advances in care have affected the rates of chronic infection. We aimed to determine if the rates of developing new chronic P. aeruginosa infection among adolescents and adults with CF significantly changed over time. Methods: The cohort consisted of individuals with CF followed in the Cystic Fibrosis Foundation Patient Registry aged ≥13 years without chronic P. aeruginosa at baseline. Multivariable regression models accounting for within-patient correlation were used to assess the change in rate of developing chronic P. aeruginosa infection between 2003 and 2012. Results: A total of 15504 individuals were followed for a median of 5 (interquartile range, 2-9) years. The annual rates of developing new chronic P. aeruginosa decreased from 14.3% in 2003 to 6.4% in 2012. After adjusting for potential confounders, relative risk (RR) of developing chronic P. aeruginosa infection decreased significantly over time compared to 2003 (P value test of trend < .001). Compared with 2003, the RR of developing chronic P. aeruginosa infection in 2012 was 0.33 (95% confidence interval, 0.30-0.37). No significant increases in risk of chronic infections with other major CF bacterial pathogens relative to 2003 were identified. Conclusions: Among individuals with CF, a significant decrease in the risk and rates of developing chronic P. aeruginosa infection between 2003 and 2012 was observed. Whether this decline results in changes in clinical outcomes warrants further exploration.

Cystic Fibrosis is Associated with Adverse Neonatal Outcomes in Washington State, 1996-2013.

OBJECTIVE: To determine whether cystic fibrosis (CF) is associated with adverse neonatal outcomes in a recent birth cohort in the US. STUDY DESIGN: A retrospective matched cohort study of infants born in Washington State from 1996 to 2013 was identified through birth certificate data and linked to statewide hospital discharge data. Infants with CF were identified by hospitalization (through age 5 years) in which a CF-specific International Classification of Diseases, Ninth Revision code was recorded. "Unexposed" infants lacked CF-related International Classification of Diseases, Ninth Revision codes and were randomly selected among births, frequency-matched to "exposed" infants on birth year. Associations of CF with adverse neonatal outcomes (low birth weight [LBW], small for gestational age [SGA], preterm birth, and infant mortality) were estimated through Poisson regression. We performed extreme value imputation to address possible ascertainment bias. RESULTS: We identified 170 infants with CF and 3400 unexposed infants. CF was associated with increased relative risk (95% CI) of 3.5 (2.5-4.9), 1.6 (1.1-2.4), 3.0 (2.2-4.0), and 6.8 (1.7-26.5) for LBW, SGA, preterm birth, and infant death, respectively. The estimated relative risks were similar among infants born from 2006 to 2013, except SGA was no longer associated with CF diagnosis. Results were robust to extreme value imputation and exclusion of infants with meconium ileus. CONCLUSIONS: Observed associations of CF with LBW, preterm birth, and infant death are unlikely to be due to ascertainment bias. Further work is needed to determine how to prevent these adverse neonatal outcomes.

Cystic fibrosis physicians' perspectives on the timing of referral for lung transplant evaluation: a survey of physicians in the United States.

BACKGROUND: Prior studies reveal that a significant proportion of patients with cystic fibrosis (CF) and advanced lung disease are not referred for lung transplant (LTx) evaluation. We sought to assess expert CF physician perspectives on the timing of LTx referral and investigate their LTx knowledge. METHODS: We developed an online anonymous survey that was distributed by the Cystic Fibrosis Foundation (CFF) to the medical directors of all CFF-accredited care centers in the United States in 2015. The survey addressed only adult patients (≥18 years old) and was sent to 119 adult CF physicians, 86 CFF-affiliated CF physicians (who see adults and children, but have smaller program sizes than adult or pediatric centers), and 127 pediatric CF physicians (who see some adults, but mostly children). The focus of the questions was on CFF-care center characteristics, physician experience and indications/contraindications to referral for LTx evaluation. RESULTS: There were 114/332 (34%) total responses to the survey. The response rates were: 57/119 (48%) adult physicians, 12/86 (14%) affiliate physicians and 43/127 (34%) pediatric physicians; 2 physicians did not include their CFF center type. Despite the poor ability of FEV1 < 30% to predict death within 2 years, 94% of responding CF physicians said they would refer an adult patient for LTx evaluation if the patient's lung function fell to FEV1 < 30% predicted. Only 54% of respondents report that pulmonary hypertension would trigger referral. Pulmonary hypertension is an internationally recommended indication to list a patient for LTx (not just for referral for evaluation). Very few physicians (N = 17, 15%) employed components of the lung allocation score (LAS) to determine the timing of referral for LTx evaluation. Interestingly, patient preference not to undergo LTx was "often" or "always" the primary patient-related reason to defer referral for LTx evaluation for 41% (47/114) of respondents. CONCLUSIONS: Some potential barriers to timely LTx referral for patients with CF include physician knowledge regarding non-lung function-based recommendations related to timing of referral and listing for LTx, and patient preference not to undergo LTx. Further exploration of physician-level and CF patient-level barriers to timely LTx referral is warranted.

Change in Pseudomonas aeruginosa prevalence in cystic fibrosis adults over time.

BACKGROUND: Little is known about risk factors for chronic and mucoid Pseudomonas aeruginosa (Pa) infection in cystic fibrosis (CF) adults, and whether the prevalence is changing. METHODS: We employed a retrospective cohort to analyze data from a single adult CF center (2002 to 2012). Regression models were used to assess independent predictors and change in prevalence of chronic and mucoid Pa infection over time. RESULTS: The odds ratio of mucoid Pa infection was significantly less in individuals with better baseline lung function (OR 0.84,95%CI:0.77-0.92) and those diagnosed after the age of 25 (OR 0.21, 95%CI:0.05-0.95). The prevalence of chronic Pa and mucoid Pa decreased during the time interval. After adjusting for confounders, the observed decrease in chronic and mucoid Pa between 2002 and 2012 was no longer significant. CONCLUSIONS: The prevalence of chronic and mucoid Pa is decreasing. Larger studies are needed to confirm these regional trends and their significance.

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.

A longitudinal analysis of respiratory symptoms in people with cystic fibrosis with advanced lung disease on and off ETI.

People with CF (PwCF), particularly those with advanced lung disease (ALD), experience frequent respiratory symptoms. A major CF breakthrough was the approval of elexacaftor/tezacaftor/ivacaftor (ETI) in 2019, which has been shown to improve symptoms and lung function in the CF population, and decrease pulmonary exacerbations. The purpose of this study was to analyze longitudinal changes in respiratory symptoms over 24 months in ETI-treated and untreated PwCF with ALD Symptoms were measured among CF adults with ppFEV1 < 40% (N = 48, 24 ETI-treated, 24 untreated) using the CFRSD-CRISS and the CFQ-R [respiratory]. Two multilevel growth models assessed the rate of change in symptoms overall and within the ETI-treated and untreated groups. PwCF on ETI had significantly lower symptom severity over 24 months than those not on ETI as measured by the CRISS and CFQ-R. The ETI-treated group maintained an -11.7 and +19.3 point difference(p<0.01) in CRISS and CFQ-R scores over the study compared to the non-ETI group, achieving minimal clinically important differences on average between groups on both instruments. No change in the symptom burden trajectory between groups was observed (p = 0.58). Even with ALD, ETI-treated PwCF have a lower respiratory burden than those not on ETI. This may be confounded by survivorship bias in the non-ETI group. Of note, in this ALD cohort, neither instrument demonstrated ceiling effects. Our results suggest that, while ETI has significantly improved the lived experience, PwCF with ALD are still plagued by respiratory symptoms.

Historic Use of Race-Based Spirometry Values Lowered Transplant Priority for Black Patients.

BACKGROUND: The lung allocation score (LAS) is a tool used to prioritize patients for lung transplantation. For patients with interstitial lung diseases (ILDs), spirometry data are used for the LAS calculation. Spirometry values such as a FVC are subjected to race-specific equations that determine expected values. The effect of race-specific equations in LAS score remains unknown. RESEARCH QUESTION: Did the use of a race-based spirometry equation lead to longer waitlist times for Black patients? STUDY DESIGN AND METHODS: We performed a retrospective analysis of patients listed for lung transplantation from 2005 through 2020 using publicly available data from the United Network for Organ Sharing. We recalculated LAS scores for Black patients using White-specific equations with the available variables. The primary objective was to evaluate the effect of race-specific equations on LAS scores and time on the transplant waitlist. RESULTS: A total of 33,845 patients listed for lung transplantation were included in the analysis. White patients were listed at lower LAS scores, a higher proportion of White patients underwent transplantation, and White patients died on the waitlist at lower rates. When recalculating LAS scores using White-specific equations, Black patients with ILD had up to a 1.9-point higher score, which resulted in additional waitlist time. INTERPRETATION: Race-specific equations led to longer wait times in Black patients listed for lung transplantation. The use of race-based equations widened already known disparities in pulmonary transplantation.

The association between cystic fibrosis-related diabetes and periodontitis in adults: A pilot cross-sectional study.

OBJECTIVES: Periodontitis is a highly prevalent complication of diabetes. However, the association between cystic fibrosis-related diabetes (CFRD) and periodontitis has not yet been evaluated. The objective of this study was to assess if: 1) CFRD is associated with periodontitis among adults with CF, and 2) periodontitis prevalence differs by CF and diabetes status. METHODS: This was a pilot cross-sectional study of the association between CFRD and periodontitis in adults with cystic fibrosis (CF) (N = 32). Historical non-CF controls (N = 57) from the U.S. National Health and Nutrition Examination Survey (NHANES) dataset were frequency matched to participants with CF on age, sex, diabetes status, and insulin use. We defined periodontitis using the U.S. Centers for Disease Control and Prevention and the American Academy of Periodontology (CDC/AAP) case definition, as the presence of two or more interproximal sites with CAL ≥3 mm and two or more interproximal sites with PD ≥4 mm (not on the same tooth) or one site with PD ≥5 mm. Because NHANES periodontal data were only available for adults ages ≥30 years, our analysis that included non-CF controls focused on this age group (CF N = 19, non-CF N = 57). Based on CF and diabetes status, we formed four groups: CFRD, CF and no diabetes, non-CF with diabetes, and non-CF and no diabetes (healthy). We used the Fisher's exact test for hypotheses testing. RESULTS: There was no association between CFRD and periodontitis for participants with CF ages 22-63 years (CFRD 67% vs. CF no diabetes 53%, P = 0.49), this was also true for those ages ≥30 years (CFRD 78% vs. CF no diabetes 60%, P = 0.63). For the two CF groups, the prevalence of periodontitis was significantly higher than for healthy controls (CFRD 78% vs. healthy 7%, P<0.001; CF no diabetes 60% vs. healthy 7%, P = 0.001) and not significantly different than the prevalence for non-CF controls with diabetes (CFRD 78% vs. non-CF with diabetes 56%, P = 0.43; CF no diabetes 60% vs. non-CF with diabetes 56%, P = 0.99). CONCLUSION: Among participants with CF, CFRD was not associated with periodontitis. However, regardless of diabetes status, participants with CF had increased prevalence of periodontitis compared to healthy controls.