Cystic fibrosis year in review 2019: Section 1 CFTR modulators

Cystic fibrosis-related mortality in the United States from 1999 to 2020: an observational analysis of time trends and disparities

Cystic fibrosis transmembrane conductance regulator modulators have revolutionized cystic fibrosis (CF) care in the past decade. This study explores the CF-related mortality trends in the US from 1999 to 2020. We extracted CF-related mortality data from the CDC WONDER database. CF age-standardized mortality rates (ASMRs) were identified by ICD-10 code E84 and were stratified by demographic and geographical variables. Temporal trends were analyzed using Joinpoint modeling. CF-related ASMRs decreased from 1.9 to 1.04 per million population (p = 0.013), with a greater reduction in recent years. This trend was replicated in both sexes. The median age of death increased from 24 to 37 years. CF mortality rates decreased across sex, white race, non-Hispanic ethnicity, census regions, and urbanization status. Incongruent trends were reported in non-white races and Hispanic ethnicity. A lower median age of death was observed in women, non-white races, and Hispanic ethnicity. SARS-CoV-2 infection was the primary cause of death in 1.7% of CF decedents in 2020. The national CF-related mortality rates declined and the median age of death among CF decedents increased significantly indicating better survival in the recent years. The changes were relatively slow during the earlier period of the study, followed by a greater decline lately. We observed patterns of sex, ethnic, racial, and geographical disparities associated with the worsening of the gap between ethnicities, narrowing of the gap between races and rural vs. urban counties, and closing of the gap between sexes over the study period.

Drug Hypersensitivity Reactions in Patients with Cystic Fibrosis: Potential Value of the Lymphocyte Toxicity Assay to Assess Risk

BACKGROUND

Cystic fibrosis (CF) is a genetic disease characterized by multi-system dysfunction resulting in recurrent lung infections and progressive pulmonary disease. CF patients are at a higher risk for drug hypersensitivity reactions (DHRs) compared to the general population, which has been attributed to the recurrent need for antibiotics and the inflammation associated with CF disease. In vitro toxicity tests such as the lymphocyte toxicity assay (LTA) offer the potential for risk assessment for DHRs. In the current study, we investigated the utility of the LTA test for diagnosis of DHRs in a cohort of CF patients.

METHOD

Twenty CF patients with suspected DHRs to sulfamethoxazole, penicillins, cephalosporins, meropenem, vancomycin, rifampicin, and tobramycin were recruited to this study and tested using the LTA test along with 20 healthy control volunteers. Demographic data of the patients, including age, sex, and medical history, were obtained. Blood samples were withdrawn from patients and healthy volunteers, and the LTA test was performed on isolated peripheral blood monocytes (PBMCs) from those individuals.

RESULTS

Cells from CF patients with DHRs displayed a significant (p < 0.0001) concentration-dependent enhanced cell death upon incubation with the culprit drug compared to cells from healthy volunteers. The positivity rate of the LTA test was over 80% in patients with a medical history and clinical presentation consistent with DHRs.

CONCLUSION

This study is the first to evaluate the use of the LTA test for diagnosis of DHRs in CF patients. According to our results, the LTA test may be a useful tool for diagnosis and management of DHRs in CF patients. Identifying the culprit drug is essential for optimal healthcare for CF patients in the setting of a suspected DHR. The data also provide evidence that accumulation of toxic reactive metabolites could be an important component in the cascade of events leading to the development of DHRs in CF patients. A larger-scale study is needed to confirm the data.

Menopause in people with cystic fibrosis

This is the first study to examine the perimenopausal experiences of women with cystic fibrosis (CF) in the era of modulator therapy. As the life expectancy of people with CF continues to grow, CF care teams need to be able to address the perimenopausal needs of their female patients as well as the interactions between the menopausal transition and CF.

Objective

This study aimed to describe the menopause experience of people with cystic fibrosis (CF).

Methods

We conducted a computer-based cross-sectional survey of women with CF 25 years or older at 10 US CF centers exploring a range of sexual and reproductive health concerns, including menopause. We used descriptive statistics to analyze results.

Results

Of 460 participants, 5 (3%) were perimenopausal and 34 (7%) were postmenopausal. Of participants perimenopausal or menopausal (n = 39), 97% reported the following menopausal symptoms occurring at least once a week: most commonly early wake-up (83%); stiffness/soreness in joints, neck, or shoulders (65%); and night sweats (65%). Among menopausal participants, the median self-reported age at menopause was 48.5 years (interquartile range, 5.5 y). Thirty percent experienced worsened CF symptoms during menopause, and 42% experienced worsening CF symptoms after menopause. Twenty-four percent of menopausal participants were on estrogen therapy and 15% on estrogen and progesterone therapy. Three-fourths of participants using hormone therapy reported no change in their CF symptoms. One percent of the 460 survey participants reported discussing menopause with their CF provider, despite 19% wanting to discuss this topic with their CF team.

Conclusions

This is the first study to describe menopause symptoms of people with CF. People with CF experience a variety of menopausal symptoms and often report a worsening of their CF symptoms after menopause, suggesting an interplay between female sex hormones and CF. Larger studies are needed comparing the sexual and reproductive health experiences and care needs of people with CF in the menopause transition to the general population.

Cystic fibrosis: Infection prevention & control recommendations for universities, colleges and institutes of further and higher education - A practical guide

BACKGROUND

The avoidance of cross-infection remains of critical importance to prevent the transmission of cystic fibrosis (CF)-related microbial pathogens to persons/people with cystic fibrosis (PwCF). To date, there has been a paucity of infection prevention and control (IPC) guidance relating to infection risk at higher educational institutions. With improvements in treatments, more PwCF are now attending universities/colleges and educational institutions now seek CF-specific guidance on IPC from clinical CF teams/centres.

METHODS

Real world infection-related questions from university students, educators, university support staff and the CF multidisciplinary team were received and collated from various stakeholders, including individual consultations and focus group sessions with two local universities. Subsequently, evidence-based recommendations were compiled from existing peer-reviewed literature and from cystic fibrosis organisations. Glossaries were constructed relating to clinical, microbiological and educational/pedagogical terminology to aid with the understanding amongst these stakeholder groups.

RESULTS

This review addresses CF-related IPC recommendations across five areas of university/college life, including (i) on campus estate, (ii) teaching (lectures/tutorials/small study group work/group assignments), (iii) laboratory practicals, (iv) field trips/study visits/work placements and (v) residential accommodation and lists practical recommendations to help prevent the transmission of infections to PwCF students.

CONCLUSIONS

It is important that the educational institutional environment is safe permitting the PwCF student to enjoy their educational experience and journey through higher education, culminating in achievement of their educational goals, employment and independent living. The guidance presented in this review is intended to equip educational establishments in creating their own bespoke and robust IPC policies relating to PwCF students.

Toxoplasma gondii infection triggers ongoing inflammation mediated by increased intracellular Cl- concentration in airway epithelium

Toxoplasma gondii is a widespread parasitic protozoan causing toxoplasmosis including pulmonary toxoplasmosis. As the first line of host defense, airway epithelial cells play critical roles in orchestrating pulmonary innate immunity. However, the mechanism underlying the airway inflammation induced by the T. gondii infection remains largely unclear. This study demonstrated that after infection with T. gondii, the major anion channel located in the apical membranes of airway epithelial cells, cystic fibrosis transmembrane conductance regulator (CFTR), was degraded by the parasite-secreted cysteine proteases. The intracellular Cl^- concentration ([Cl^-]_i) was consequently elevated, leading to activation of nuclear factor-κB (NF-κB) signaling via serum/glucocorticoid regulated kinase 1. Furthermore, the heightened [Cl^-]_i and activated NF-κB signaling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP level through NF-κB-mediated up-regulation of phosphodiesterase 4. Conversely, the sulfur-containing compound allicin conferred anti-inflammatory effects on pulmonary toxoplasmosis by decreasing [Cl^-]_i via activation of CFTR. These results suggest that the intracellular Cl^- dynamically modulated by T. gondii mediates sustained airway inflammation, which provides a potential therapeutic target against pulmonary toxoplasmosis.

Effectiveness of Physical Exercise Interventions on Pulmonary Function and Physical Fitness in Children and Adults with Cystic Fibrosis: A Systematic Review with Meta-Analysis

Objective: Physical exercise is associated with several benefits in the treatment of cystic fibrosis (CF), associated with a reduction in patient mortality. The aim of this systematic review was to determine the effectiveness of exercise interventions on physical condition and lung function in children and adults with CF to establish the most appropriate type and dose of physical exercise used so far. Methods: The studies included were randomized controlled trials with physical exercise interventions performed with children or adults with CF, analyzing the effects on pulmonary function, cardiorespiratory capacity, and muscle strength. The variables analyzed in at least four studies in the same population (children or adults) with the same measuring test were included in the meta-analysis. Results:Pulmonary function: There were no changes in the forced expiratory volume 1 s, but mouth expiratory/inspiratory pressures were improved in some studies. Physical fitness: In children, the interventions did not manage to improve the VO2peak (SMD = 0.22; 95%CI: -0.25 to 0.68; p = 0.73) but improved muscle strength. In adults, physical exercise interventions based on high-intensity aerobic training showed positive results in the VO2peak, and in some muscle strength outcomes. Conclusions: Exercise interventions in children and adults with CF are effective in improving muscle strength, cardiovascular capacity, and respiratory muscle function. However, they do not achieve improvements in lung function. The most effective programs are those using strength training or cardiovascular high-intensity interval training, although to date there have been few such interventions.

Sexual and reproductive health experiences and care of adult women with cystic fibrosis

BACKGROUND

As survival and health improve in people with cystic fibrosis (CF), more women with CF (wwCF) are considering their sexual and reproductive health (SRH). This study compared SRH experiences, behaviors, and care utilization of wwCF to the general population and defined CF-impacted considerations and care preferences.

METHODS

We surveyed wwCF aged ≥25 years regarding SRH and compared results to the US National Survey of Family Growth (NSFG;n = 4357) and friend controls(n = 123). We used descriptive statistics and chi-squared/Fisher's exact testing and linear regression for comparisons.

RESULTS

A total of 460 wwCF (mean age 36.1 years) completed the survey. WwCF were less likely to report current contraceptive use (43%vs76% NSFG, p<0.001;60% friends, p = 0.005). Nearly 25% of wwCF reported worsened CF symptoms during their menstrual cycles, 50% experienced urinary incontinence, and 80% vulvovaginal candidiasis. WwCF were significantly less likely to be parents (46%vs62% friends, p = 0.015) and to have experienced pregnancy (37%vs78% NSFG, p<0.001;58% friends, p = 0.002). More wwCF required medical assistance to conceive (29%vs12% NSFG, p<0.001 and 5% friends, p<0.001). Eighty-four percent of wwCF view their CF doctor as their main physician and 41% report no primary care provider (vs19% friends; p<0.001). WwCF report suboptimal rates of contraceptive and preconception counseling/care and are less likely to have received HPV vaccination (42%vs55%friends, p = 0.02). Despite desiring SRH conversations with their CF team, <50% report discussing SRH topics.

CONCLUSION

WwCF have significantly different SRH experiences than non-CF peers. They report suboptimal SRH care compared to their preferences highlighting an urgent need to encourage SRH counseling/care in the CF model.

Is the ENaC Dysregulation in CF an Effect of Protein-Lipid Interaction in the Membranes?

While approximately 2000 mutations have been discovered in the gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR), only a small amount (about 10%) is associated with clinical cystic fibrosis (CF) disease. The discovery of the association between CFTR and the hyperactive epithelial sodium channel (ENaC) has raised the question of the influence of ENaC on the clinical CF phenotype. ENaC disturbance contributes to the pathological secretion, and overexpression of one ENaC subunit, the β-unit, can give a CF-like phenotype in mice with normal acting CFTR. The development of ENaC channel modulators is now in progress. Both CFTR and ENaC are located in the cell membrane and are influenced by its lipid configuration. Recent studies have emphasized the importance of the interaction of lipids and these proteins in the membranes. Linoleic acid deficiency is the most prevailing lipid abnormality in CF, and linoleic acid is an important constituent of membranes. The influence on sodium excretion by linoleic acid supplementation indicates that lipid-protein interaction is of importance for the clinical pathophysiology in CF. Further studies of this association can imply a simple clinical adjuvant in CF therapy.