Telemedicine of patients with cystic fibrosis during the COVID-19 pandemic.

OBJECTIVE: To describe then experience of implementing routine teleconsultations in respiratory physiotherapy at a reference center for Cystic Fibrosis (CF) in Rio de Janeiro / Brazil, during the COVID-19 pandemic. METHODS: Cross-sectional, descriptive, study with children and adolescents with CF. The sample was divided between participants and those who did not participate in the teleconsultations. The teleconsultations were multidisciplinary and carried out by videoconference or telephone, depending on the patient's availability. The sequence of care provided by the team was organized together with the professionals, so that everyone could carry out individual and sequential teleconsultations. Physiotherapy appointments were divided into two segments: teleconsultation and telemonitoring. Demographic and clinical data were collected. RESULTS: Among the 184 patients assisted in the center, 153 (83.2%) participated in the teleservices and, of these, 33 (21.6%) required telemonitoring; 31 (16.8%) patients did not participate in the teleconsultations for not answering the calls. There was no statistical difference between the group that participated or not in teleservices, nor among those who participated in teleconsultations and telemonitoring. The mean age of the studied population was 7.0±0.4 years. Regarding the CFTR gene mutation, 64.7% had at least one F508del allele and 30.9% of the sample had no pathogens in the sputum test. CONCLUSIONS: Most participants with CF participated in teleconsultations, highlighting the importance of remote assistance activities during the COVID-19 pandemic period. This strategy was considered as positive, and it may become permanent in the care of patients with CF.

Chronic airway epithelial hypoxia exacerbates injury in muco-obstructive lung disease through mucus hyperconcentration.

Unlike solid organs, human airway epithelia derive their oxygen from inspired air rather than the vasculature. Many pulmonary diseases are associated with intraluminal airway obstruction caused by aspirated foreign bodies, virus infection, tumors, or mucus plugs intrinsic to airway disease, including cystic fibrosis (CF). Consistent with requirements for luminal O2, airway epithelia surrounding mucus plugs in chronic obstructive pulmonary disease (COPD) lungs are hypoxic. Despite these observations, the effects of chronic hypoxia (CH) on airway epithelial host defense functions relevant to pulmonary disease have not been investigated. Molecular characterization of resected human lungs from individuals with a spectrum of muco-obstructive lung diseases (MOLDs) or COVID-19 identified molecular features of chronic hypoxia, including increased EGLN3 expression, in epithelia lining mucus-obstructed airways. In vitro experiments using cultured chronically hypoxic airway epithelia revealed conversion to a glycolytic metabolic state with maintenance of cellular architecture. Chronically hypoxic airway epithelia unexpectedly exhibited increased MUC5B mucin production and increased transepithelial Na+ and fluid absorption mediated by HIF1α/HIF2α-dependent up-regulation of ß and γENaC (epithelial Na+ channel) subunit expression. The combination of increased Na+ absorption and MUC5B production generated hyperconcentrated mucus predicted to perpetuate obstruction. Single-cell and bulk RNA sequencing analyses of chronically hypoxic cultured airway epithelia revealed transcriptional changes involved in airway wall remodeling, destruction, and angiogenesis. These results were confirmed by RNA-in situ hybridization studies of lungs from individuals with MOLD. Our data suggest that chronic airway epithelial hypoxia may be central to the pathogenesis of persistent mucus accumulation in MOLDs and associated airway wall damage.

Factors associated with receiving CF care and use of telehealth in 2020 among persons with Cystic Fibrosis in the United States.

BACKGROUND: The COVID-19 pandemic resulted in the use of telehealth to deliver the cystic fibrosis (CF) care model, which recommends routine follow-up for monitoring of nutritional status, bacterial culture surveillance, pulmonary function testing, and screening for CF-related complications such as diabetes or osteoporosis. METHODS: The objective of this study was to use Cystic Fibrosis Foundation Patient Registry (CFFPR) data to quantify the extent to which persons with CF received the recommended components of the care model in 2019 versus 2020. A risk factor analysis was implemented to identify patient characteristics associated with attaining the recommended CF care and use of any telehealth using multivariable logistic regression. RESULTS: A total of 28,132 CFFPR participants were included in the study. The proportion of individuals meeting the recommendations for CF care was lower in 2020 for every indicator, and lower in adults compared to children. In adults, demographic, socioeconomic and CF-related disease covariates were significantly associated with both achieving an aggregate level of care and use of telehealth. In the pediatric population, minority race/ethnicity and markers of lower socioeconomic status were associated with a lower odds of telehealth use. In all analyses, having received the recommended level of care in 2019 was associated with a higher odds of both reported telehealth use and achieving the recommended elements of the CF care model in 2020. CONCLUSION: Fewer participants met recommendations for care in 2020 despite widespread use of telehealth, and use of telehealth did not equate to adherence to all aspects of CF care.

Humoral and cell-mediated immune responses to BNT162b2 vaccine against SARS-CoV-2 in people with cystic fibrosis.

People with cystic fibrosis (pwCF) were considered to be clinically vulnerable to COVID-19 and were therefore given priority in the vaccination campaign. Vaccines induced a humoral response in these patients that was comparable to the response observed among the general population. However, the role of the cell-mediated immune response in providing long-term protection against SARS-CoV-2 in pwCF has not yet been defined. In this study, humoral (antibody titre) and cell-mediated immune responses (interferon-γ release) to the BNT162b2 vaccine were measured at different time points, from around 6-8 months after the 2nd dose and up to 8 months after the 3rd dose, in 118 CF patients and 26 non-CF subjects. Subjects were sampled between November 2021 and September 2022 and followed-up for breakthrough infection through October 2022. pwCF mounted a cell-mediated response that was similar to that observed in non-CF subjects. Low antibody titres (<1st quartile) were associated with a higher risk of breakthrough infection (HR: 2.39, 95 % CI: 1.17-4.88), while there was no significant association with low INF-γ levels (<0.3 IU/mL) (HR: 1.38, 95 % CI: 0.64-2.99). Further studies are needed in subgroup of pwCF receiving immunosuppressive therapy, such as organ transplant recipients. This data is important for tailoring vaccination strategies for this clinically vulnerable population.

Pilot of a therapist-guided digital mental health intervention (eHealth CF-CBT) for adults with cystic fibrosis.

BACKGROUND: eHealth CF-CBT is the first digital mental health intervention for depression/anxiety in adults with cystic fibrosis (awCF); an 8-session therapist-guided internet-delivered program that was developed in English and Dutch with stakeholder input and evaluation indicating high acceptability and usability. METHODS: Dutch eHealth CF-CBT was piloted in awCF with mild-moderate symptoms of depression and/or anxiety. Feasibility, usability, acceptability, and preliminary efficacy were assessed, measuring pre-post changes in depression (PHQ-9), anxiety (GAD-7), perceived stress (PSS), and health-related quality of life (CFQ-R). RESULTS: All participants (n = 10, seven female, mean age 29 [range 21-43], mean FEV1 71%pred [range 31-115]) completed all sessions. Patient-rated feasibility, usability, and acceptability of eHealth CF-CBT were positive on validated scales, as were qualitative assessments of content and format. GAD-7 improved in 90% of participants; in 50% by ≥the minimally important difference (MID) of four points. PHQ-9 improved in 90%; 40% by ≥the MID of 5. PSS improved in 80%. CFQ-R improved in the domain health perceptions (70%). CONCLUSIONS: eHealth CF-CBT demonstrated feasibility, usability, acceptability, and promising preliminary efficacy in this pilot trial with Dutch awCF with mild to moderate symptoms of depression and anxiety.

Telemedicine and remote monitoring in cystic fibrosis.

PURPOSE OF REVIEW: Guidelines for cystic fibrosis (CF) care recommend multidisciplinary teams see patients at least quarterly with frequent measurement of spirometry and collection of respiratory cultures. This can be burdensome for people with CF, particularly if they live far from a specialized care center. This has led to an interest in telehealth coupled with remote monitoring. We review the recent literature on these topics for people with CF. RECENT FINDINGS: The COVID-19 pandemic accelerated a move toward remote delivery of CF care and multiple recent publications have reported on the feasibility of telehealth, remote spirometry, remote collection of respiratory cultures, adherence monitoring, cough assessment, symptom monitoring and activity tracking. Useful data can be obtained and both clinicians and patients have favorable opinions about remote delivery of healthcare, though the impact on clinical outcomes is not yet known. SUMMARY: Telehealth and remote monitoring for people with CF is feasible and has grown in use, though it is too early to know how prominently these approaches will fit into routine care for CF.

Furin as a therapeutic target in cystic fibrosis airways disease.

Clinical management of cystic fibrosis (CF) has been greatly improved by the development of small molecule modulators of the CF transmembrane conductance regulator (CFTR). These drugs help to address some of the basic genetic defects of CFTR; however, no suitable CFTR modulators exist for 10% of people with CF (PWCF). An alternative, mutation-agnostic therapeutic approach is therefore still required. In CF airways, elevated levels of the proprotein convertase furin contribute to the dysregulation of key processes that drive disease pathogenesis. Furin plays a critical role in the proteolytic activation of the epithelial sodium channel; hyperactivity of which causes airways dehydration and loss of effective mucociliary clearance. Furin is also responsible for the processing of transforming growth factor-ß, which is increased in bronchoalveolar lavage fluid from PWCF and is associated with neutrophilic inflammation and reduced pulmonary function. Pathogenic substrates of furin include Pseudomonas exotoxin A, a major toxic product associated with Pseudomonas aeruginosa infection and the spike glycoprotein of severe acute respiratory syndrome coronavirus 2, the causative pathogen for coronavirus disease 2019. In this review we discuss the importance of furin substrates in the progression of CF airways disease and highlight selective furin inhibition as a therapeutic strategy to provide clinical benefit to all PWCF.

Neutrophil elastase decreases SARS-CoV-2 spike protein binding to human bronchial epithelia by clipping ACE-2 ectodomain from the epithelial surface.

Patients with cystic fibrosis (CF) have decreased severity of severe acute respiratory syndrome-like coronavirus-2 (SARS-CoV-2) infections, but the underlying cause is unknown. Patients with CF have high levels of neutrophil elastase (NE) in the airway. We examined whether respiratory epithelial angiotensin-converting enzyme 2 (ACE-2), the receptor for the SARS-CoV-2 spike protein, is a proteolytic target of NE. Soluble ACE-2 levels were quantified by ELISA in airway secretions and serum from patients with and without CF, the association between soluble ACE-2 and NE activity levels was evaluated in CF sputum. We determined that NE activity was directly correlated with increased ACE-2 in CF sputum. Additionally, primary human bronchial epithelial (HBE) cells, exposed to NE or control vehicle, were evaluated by Western analysis for the release of cleaved ACE-2 ectodomain fragment into conditioned media, flow cytometry for the loss of cell surface ACE-2, its impact on SARS-CoV-2 spike protein binding. We found that NE treatment released ACE-2 ectodomain fragment from HBE and decreased spike protein binding to HBE. Furthermore, we performed NE treatment of recombinant ACE-2-Fc-tagged protein in vitro to assess whether NE was sufficient to cleave recombinant ACE-2-Fc protein. Proteomic analysis identified specific NE cleavage sites in the ACE-2 ectodomain that would result in loss of the putative N-terminal spike-binding domain. Collectively, data support that NE plays a disruptive role in SARS-CoV-2 infection by catalyzing ACE-2 ectodomain shedding from the airway epithelia. This mechanism may reduce SARS-CoV-2 virus binding to respiratory epithelial cells and decrease the severity of COVID19 infection.

Impact of elexacaftor/tezacaftor/ivacaftor on depression and anxiety in cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is associated with worsening of depression and anxiety symptoms. Elexacaftor/tezacaftor/ivacaftor (Trikafta®), a cystic fibrosis transmembrane regulator (CFTR) modulator approved in 2019, significantly improves lung function, decreases pulmonary exacerbations, and improves quality of life. Studies are needed to evaluate the effects of Trikafta on symptoms of anxiety and depression. RESEARCH QUESTION: Do adults with CF report a change in depression and anxiety symptoms after Trikafta initiation? STUDY DESIGN AND METHODS: A retrospective chart review was conducted of patients with CF (n = 127) receiving care from January 2015 through February 2022. Data collected included demographics, annual PHQ-9 and GAD-7 scores, FEV1 percent predicted at each visit, BMI, consistency and timeline of Trikafta use, mental health diagnoses, counseling/psychotherapy use, psychiatric medication use, prescriber of psychiatric medications, number of psychiatric emergency department visits and psychiatric hospital admissions, and sleep disturbances. RESULTS: Of the 127 patients screened for eligibility, 100 patients were included. Data collected yielded 563 PHQ-9, 563 GAD-7, and 560 ppFEV1 data points. No significant changes in average PHQ-9 or GAD-7 scores were found after Trikafta initiation or due to the COVID-19 pandemic. However, 22% of patients initiated or had a change in psychiatric medications, and patients with changes in psychiatric medications had significantly higher PHQ-9 and GAD-7 scores than patients not prescribed psychiatric medications. Trikafta use improved lung function by an average of 5.23% (p = 8.56e-08). Around a quarter (23%) of all patients reported sleep issues after initiating Trikafta. INTERPRETATION: No significant changes in average PHQ-9 and GAD-7 scores were found after Trikafta initiation. A quarter of patients required a change in psychiatric medications, and significant differences in depression and anxiety scores were found between patients with a change in psychiatric medications and those not prescribed medication. Twenty-three percent of patients reported a prevalence of sleep issues after Trikafta initiation.

Depression, anxiety, and resilience during COVID-19 in Dutch patients with cystic fibrosis or primary ciliary dyskinesia and their caregivers.

BACKGROUND: The COVID-19 pandemic has spread across the world, leading to government measures associated with a negative impact on mental health. The aim of this study was to evaluate the impact of the pandemic on depression, anxiety and resilience in Dutch people with cystic fibrosis (PwCF) or primary ciliary dyskinesia (PwPCD) and their caregivers. METHODS: Adolescents (12-17 years) and caregivers of children (0-17 years) with CF, and adolescents, adults and caregivers of children with PCD completed questionnaires on depression, anxiety and resilience between September 2020 and February 2021. The psychosocial impact of COVID-19 was measured by the Exposure and Family Impact Survey (CEFIS) Part 2. Mixed model analyses compared depression and anxiety results to participants' prepandemic scores. RESULTS: One hundred ten participants (10 PwCF, 31 PwPCD, 52 CF caregivers, 17 PCD caregivers) completed questionnaires during the pandemic. Prepandemic outcomes were available for 87 participants. The prevalence of symptoms of depression and anxiety (PHQ-9 or GAD-7 scores ≥5) in PwCF and PwPCD and their caregivers before and during the pandemic was high, with an increase in depression in PwCF (2.75; 95% confidence interval: 0.82-4.68) and increase in anxiety in CF caregivers (1.03; 0.09-1.96) during the pandemic. Resilience was within the normal range for all groups, CEFIS scores corresponded to a low to normal impact. CONCLUSION: PwCF and PwPCD and their caregivers were at risk of elevated depression and anxiety symptoms both before and during the pandemic, which emphasizes the importance of mental health screening and psychological care in CF and PCD.

Disruptions in the Cystic Fibrosis Community's Experiences and Concerns During the COVID-19 Pandemic: Topic Modeling and Time Series Analysis of Reddit Comments.

BACKGROUND: The COVID-19 pandemic disrupted the needs and concerns of the cystic fibrosis community. Patients with cystic fibrosis were particularly vulnerable during the pandemic due to overlapping symptoms in addition to the challenges patients with rare diseases face, such as the need for constant medical aid and limited information regarding their disease or treatments. Even before the pandemic, patients vocalized these concerns on social media platforms like Reddit and formed communities and networks to share insight and information. This data can be used as a quick and efficient source of information about the experiences and concerns of patients with cystic fibrosis in contrast to traditional survey- or clinical-based methods. OBJECTIVE: This study applies topic modeling and time series analysis to identify the disruption caused by the COVID-19 pandemic and its impact on the cystic fibrosis community's experiences and concerns. This study illustrates the utility of social media data in gaining insight into the experiences and concerns of patients with rare diseases. METHODS: We collected comments from the subreddit r/CysticFibrosis to represent the experiences and concerns of the cystic fibrosis community. The comments were preprocessed before being used to train the BERTopic model to assign each comment to a topic. The number of comments and active users for each data set was aggregated monthly per topic and then fitted with an autoregressive integrated moving average (ARIMA) model to study the trends in activity. To verify the disruption in trends during the COVID-19 pandemic, we assigned a dummy variable in the model where a value of "1" was assigned to months in 2020 and "0" otherwise and tested for its statistical significance. RESULTS: A total of 120,738 comments from 5827 users were collected from March 24, 2011, until August 31, 2022. We found 22 topics representing the cystic fibrosis community's experiences and concerns. Our time series analysis showed that for 9 topics, the COVID-19 pandemic was a statistically significant event that disrupted the trends in user activity. Of the 9 topics, only 1 showed significantly increased activity during this period, while the other 8 showed decreased activity. This mixture of increased and decreased activity for these topics indicates a shift in attention or focus on discussion topics during this period. CONCLUSIONS: There was a disruption in the experiences and concerns the cystic fibrosis community faced during the COVID-19 pandemic. By studying social media data, we were able to quickly and efficiently study the impact on the lived experiences and daily struggles of patients with cystic fibrosis. This study shows how social media data can be used as an alternative source of information to gain insight into the needs of patients with rare diseases and how external factors disrupt them.

Survey of exercise testing and training in cystic fibrosis clinics in the UK: a decade of progress.

OBJECTIVES: Regular exercise testing is recommended for people with cystic fibrosis (pwCF), as is the provision and regular review of exercise training programmes. A previous survey on exercise testing and training for pwCF in the UK was conducted over a decade ago. With the landscape of CF changing considerably during this time, this survey aimed to evaluate UK-based exercise testing and training practices for pwCF a decade on. DESIGN: Cross-sectional, online survey. PARTICIPANTS: A survey was distributed electronically to UK CF clinics and completed by the individual primarily responsible for exercise services. Descriptive statistics and qualitative analyses were undertaken. RESULTS: In total, 31 CF centres participated, representing ~50% of UK specialist clinics. Of these, 94% reported using exercise testing, 48% of which primarily use cardiopulmonary exercise testing. Exercise testing mostly occurs at annual review (93%) and is most often conducted by physiotherapists (62%). A wide variation in protocols, exercise modalities, normative reference values and cut-offs for exercise-induced desaturation are currently used. All centres reportedly discuss exercise training with pwCF; 94% at every clinic appointment. However, only 52% of centres reportedly use exercise testing to inform individualised exercise training. Physiotherapists typically lead discussions around exercise training (74%). CONCLUSIONS: These data demonstrate that the majority of respondent centres in the UK now offer some exercise testing and training advice for pwCF, representing a marked improvement over the past decade. However, continued efforts are now needed to standardise exercise practices, particularly regarding field testing practices and the translation of test results into personalised training programmes for pwCF.

Experiences and perceptions of receiving and prescribing rehabilitation in adults with cystic fibrosis undergoing lung transplantation.

BACKGROUND: Rehabilitation is prescribed to optimize fitness before lung transplantation (LTx) and facilitate post-transplant recovery. Individuals with cystic fibrosis (CF) may experience unique health issues that impact participation. METHODS: Patient and healthcare provider semi-structured interviews were administered to explore perceptions and experiences of rehabilitation before and after LTx in adults with CF. Interviews were analyzed via inductive thematic analysis. RESULTS: Eleven participants were interviewed between February and October 2021 (five patients, median 28 (IQR 27-29) years, one awaiting re-LTx, four following first or second LTx) and six healthcare providers. Rehabilitation was delivered both in-person and virtually using a remote monitoring App. Six key themes emerged: (i) structured exercise benefits both physical and mental health, (ii) CF-specific physiological impairments were a large barrier, (iii) supportive in-person or virtual relationships facilitated participation, (iv) CF-specific evidence and resources are needed, (v) tele-rehabilitation experiences during the COVID-19 pandemic resulted in preferences for a hybrid model and (vi) virtual platforms and clinical workflows require further optimization. There was good engagement with remote data entry alongside satisfaction with virtual support. CONCLUSIONS: Structured rehabilitation provided multiple benefits and a hybrid model was preferred going forward. Future optimization of tele-rehabilitation processes and increased evidence to support exercise along the continuum of CF care are needed.

The outcome of COVID-19 in children with chronic lung disease: Systematic review and meta-analyses.

BACKGROUND: Few studies have examined the impact of Coronavirus disease 2019 (COVID-19) infection on children with chronic lung disease (CLD). OBJECTIVE: To perform a systematic review and meta-analysis to determine the prevalence, risk factors for contracting COVID-19, and complications of COVID-19, in children with CLD. METHODS: This systematic review was based on articles published between January 1, 2020 and July 25, 2022. Children under 18 years old, with any CLD and infected with COVID-19 were included. RESULTS: Ten articles involving children with asthma and four involving children with cystic fibrosis (CF) were included in the analyses. The prevalence of COVID-19 in children with asthma varied between 0.14% and 19.1%. The use of inhaled corticosteroids (ICS) was associated with reduced risk for COVID-19 (risk ratio [RR]: 0.60, 95% confidence interval [CI]: 0.40-0.90). Uncontrolled asthma, younger age, AND moderate-severe asthma were not significant risk factors for contracting COVID-19. Children with asthma had an increased risk for hospitalization (RR: 1.62, 95% CI: 1.07-2.45) but were not more likely to require assisted ventilation (RR: 0.51, 95% CI: 0.14-1.90). The risk of COVID-19 infection among children with CF was <1%. Posttransplant and cystic fibrosis-related diabetes mellitus (CFRDM) patients were at an increased risk for hospitalization and intensive care treatment. CONCLUSION: Hospitalizations were higher in children with asthma with COVID-19 infection. However, using ICS reduced the risk of COVID-19 infection. As for CF, postlung transplantation and CFRDM were risk factors for severe disease.

A survey assessing the impact of COVID-19 and elexacaftor/tezacaftor/ifavacaftor on both physical and mental health in adults with cystic fibrosis.

In this letter to the editor, we report 82 persons with CF (PwCF) self-reported changes in mental and physical health and potential attribution with either the COVID-19 pandemic and the initiation elexacaftor/tezacaftor/ivacaftor (ETI). Emerging evidence has shown an association with ETI and mental health adverse events. The close proximity of ETI FDA approval and prescribing in PwCF and the COVID-19 pandemic present a challenge in determining the cause of mental health decline. We report 33 (40%) of respondents felt that COVID-19 contributed to a worsening of either their anxiety, depression, or both and 7 (9%) of respondents felt that ETI contributed to a worsening in their anxiety, depression, or both. Eighteen (23%) of respondents felt that ETI had contributed to improvement their mental health. This letter highlights multiple factors that could be impacting mental health beyond ETI. As the COVID-19 pandemic is moving toward an endemic phase, future studies may have more success in deciphering ETI effects on mental health.

Impact of Digital Technologies on Clinical Care for Adults with Cystic Fibrosis.

The coronavirus disease 2019 pandemic accelerated the implementation of digital technologies, which have now become embedded as essential tools for the management of chronic disease, including cystic fibrosis (CF). Despite subsequent easing of restrictions and because of improved clinical stability resulting from the introduction of highly effective modulator therapy, digital technologies including video and telephone consultations and remote monitoring are likely to remain integral to the future delivery of CF health care. In this article, we explore some of the key developments in digital technologies, barriers to their adoption, and how the CF community is likely to embrace lessons learned from the recent pandemic to help modernize and reshape the future of CF care.

Modeling of Respiratory Diseases Evolving with Fibrosis from Organoids Derived from Human Pluripotent Stem Cells.

Respiratory disease is one of the leading causes of morbidity and mortality worldwide. There is no cure for most diseases, which are treated symptomatically. Hence, new strategies are required to deepen the understanding of the disease and development of therapeutic strategies. The advent of stem cell and organoid technology has enabled the development of human pluripotent stem cell lines and adequate differentiation protocols for developing both airways and lung organoids in different formats. These novel human-pluripotent-stem-cell-derived organoids have enabled relatively accurate disease modeling. Idiopathic pulmonary fibrosis is a fatal and debilitating disease that exhibits prototypical fibrotic features that may be, to some extent, extrapolated to other conditions. Thus, respiratory diseases such as cystic fibrosis, chronic obstructive pulmonary disease, or the one caused by SARS-CoV-2 may reflect some fibrotic aspects reminiscent of those present in idiopathic pulmonary fibrosis. Modeling of fibrosis of the airways and the lung is a real challenge due to the large number of epithelial cells involved and interaction with other cell types of mesenchymal origin. This review will focus on the status of respiratory disease modeling from human-pluripotent-stem-cell-derived organoids, which are being used to model several representative respiratory diseases, such as idiopathic pulmonary fibrosis, cystic fibrosis, chronic obstructive pulmonary disease, and COVID-19.

Respiratory Viruses and Cystic Fibrosis.

The threat of respiratory virus infection to human health and well-being has been clearly highlighted by the coronavirus disease 2019 (COVID-19) pandemic. For people with cystic fibrosis (CF), the clinical significance of viral infections long predated the emergence of severe acute respiratory syndrome coronavirus 2. This article reviews the epidemiology, diagnosis, and treatment of respiratory virus infection in the context of CF as well as the current understanding of interactions between viruses and other microorganisms in the CF lung. The incidence of respiratory virus infection in CF varies by age with young children typically experiencing more frequent episodes than adolescents and adults. At all ages, respiratory viruses are very common in CF and are associated with pulmonary exacerbations. Respiratory viruses are identified at up to 69% of exacerbations, while viruses are also frequently detected during clinical stability. The full impact of COVID-19 in CF is yet to be established. Early studies found that rates of COVID-19 were lower in CF cohorts than in the general population. The reasons for this are unclear but may be related to the effects of shielding, infection control practices, maintenance CF therapies, or the inflammatory milieu in the CF lung. Observational studies have consistently identified that prior solid organ transplantation is a key risk factor for poor outcomes from COVID-19 in CF. Several key priorities for future research are highlighted. First, the impact of highly effective CFTR modulator therapy on the epidemiology and pathophysiology of viral infections in CF requires investigation. Second, the impact of respiratory viruses on the development and dynamics of the CF lung microbiota is poorly understood and viral infection may have important interactions with bacteria and fungi in the airway. Finally, bacteriophages represent a key focus of future investigation both for their role in transmission of antimicrobial resistance and as a promising treatment modality for multiresistant pathogens.