Respiratory Infection and Inflammation in Cystic Fibrosis: A Dynamic Interplay among the Host, Microbes, and Environment for the Ages.

The interplay between airway inflammation and infection is now recognized as a major factor in the pathobiology in cystic fibrosis (CF). A proinflammatory environment is seen throughout the CF airway resulting in classic marked and enduring neutrophilic infiltrations, irreversibly damaging the lung. Although this is seen to occur early, independent of infection, respiratory microbes arising at different timepoints in life and the world environment perpetuate this hyperinflammatory state. Several selective pressures have allowed for the CF gene to persist until today despite an early mortality. Comprehensive care systems, which have been a cornerstone of therapy for the past few decades, are now revolutionized by CF transmembrane conductance regulator (CTFR) modulators. The effects of these small-molecule agents cannot be overstated and can be seen as early as in utero. For an understanding of the future, this review looks into CF studies spanning the historical and present period.

Survival of people with cystic fibrosis in Australia.

Survival statistics, estimated using data from national cystic fibrosis (CF) registries, inform the CF community and monitor disease progression. This study aimed to estimate survival among people with CF in Australia and to identify factors associated with survival. This population-based cohort study used prospectively collected data from 23 Australian CF centres participating in the Australian CF Data Registry (ACFDR) from 2005-2020. Period survival analysis was used to calculate median age of survival estimates for each 5-year window from 2005-2009 until 2016-2020. The overall median survival was estimated using the Kaplan-Meier method. Between 2005-2020 the ACFDR followed 4,601 people with CF, noting 516 (11.2%) deaths including 195 following lung transplantation. Out of the total sample, more than half (52.5%) were male and 395 (8.6%) had undergone lung transplantation. Two thirds of people with CF (66.1%) were diagnosed before six weeks of age or by newborn/prenatal screening. The overall median age of survival was estimated as 54.0 years (95% CI: 51.0-57.04). Estimated median survival increased from 48.9 years (95% CI: 44.7-53.5) for people with CF born in 2005-2009, to 56.3 years (95% CI: 51.2-60.4) for those born in 2016-2020. Factors independently associated with reduced survival include receiving a lung transplant, having low FEV1pp and BMI. Median survival estimates are increasing in CF in Australia. This likely reflects multiple factors, including newborn screening, improvement in diagnosis, refinements in CF management and centre-based multidisciplinary care.

Probiotic knowledge of adults with cystic fibrosis is limited but is associated with probiotic use: A cross-sectional survey study.

Background: Probiotics are used by people with cystic fibrosis (CF) and other chronic diseases to manage gastrointestinal symptoms. Aim: To describe probiotic knowledge; its relationship with probiotic use, probiotic information sources and factors influencing choice in adults with CF and a general population control group. Methods: A cross-sectional questionnaire study was conducted in adults with CF (n = 205) and Controls (n = 158). Probiotic knowledge was compared between CF and Controls using a knowledge score (maximum 5) based on predefined criteria: (1a) bacteria/microorganism; (1b) live; (2a) administered; (2b) adequate dose and (3) health benefit, using independent samples t-test. Two-way analysis of variance explored knowledge scores between CF and Control and between Ever User and Never User groups. Chi-square and Fisher's exact tests compared knowledge criterion, probiotic sources and influences on probiotic choice between groups. Thematic analysis of open-text responses explored probiotic-related knowledge and influences on probiotic decision making. Results: Knowledge scores (mean ± SD) did not differ between CF (1.70 ± 1.12) and Controls (1.89 ± 0.99), p = 0.13. Probiotic use was associated with knowledge score (p < 0.001). More CF Ever Users than Never Users correctly identified criteria 1a (65% vs. 38%), 1b (16% vs. 0%), 2a (45% vs. 22%) and 3 (73% vs. 42%) (all p < 0.005). CF participants considered 'dairy yoghurt' (69%), 'live cultures' (64%) and 'fermented foods' (37%) as 'all/mostly' probiotic sources. The internet was the commonest source of probiotic-related information. Conclusion: Probiotic knowledge and use were associated in adults with CF. Understanding of probiotic characteristics and sources were limited. Education is needed to help guide patient probiotic decision making.

Probiotic use in adults with cystic fibrosis is common and influenced by gastrointestinal health needs: A cross-sectional survey study.

BACKGROUND: Cystic fibrosis (CF) primarily affects the lung, however, gastrointestinal disorders and symptoms, including dysbiosis, also impact on morbidity and quality of life. There is interest in strategies to modulate the gastrointestinal microbiota, including probiotics, although the evidence remains inadequate to guide practice, and information on use is limited. The present study aimed to characterise probiotic use, beliefs and experiences of adults with CF. METHODS: A cross-sectional questionnaire study was conducted in adults with CF (n = 205) and a general population Control group (n = 158), recruited from Victoria, Australia. Participants were classified as probiotic 'Ever Users' or 'Never Users'. Outcomes included self-reported probiotic use and factors associated with probiotic use, which were analysed using logistic regression analysis. Open-ended questionnaire responses were thematically analysed. RESULTS: In total, 70% of adults with CF had ever used probiotics (supplements and/or foods), comparable to Controls (80%) (p = 0.03). Key reasons for CF probiotic use were gastrointestinal- and antibiotic-related (75%). Most CF Ever Users (73%) did not discuss probiotic use with CF clinicians and 33% were uncertain if probiotics had been helpful. Female gender (odds ratio [OR] = 2.82; 95% confidence interval [CI] = 1.36-5.87; p = 0.005), university-level education (OR = 2.73; 95% CI = 1.24-6.01; p = 0.01) and bloating on antibiotics (OR = 2.14; 95% CI = 1.04-4.40; p = 0.04) were independently associated with probiotic use in CF; as was female gender in Controls (OR = 2.84; 95% CI = 1.20-6.71; p = 0.02). CONCLUSIONS: Probiotics were used by adults with CF for gastrointestinal- and antibiotic-related reasons often without informing clinicians and despite uncertainty about perceived helpfulness. Further research investigating gastrointestinal outcomes of probiotics will inform practice recommendations guiding their use in CF and other chronic diseases.

The AWESCORE, a patient-reported outcome measure: development, feasibility, reliability, validity and responsiveness for adults with cystic fibrosis.

BACKGROUND: Quality of life has improved dramatically over the past two decades in people with cystic fibrosis (CF). Quantification has been enabled by patient-reported outcome measures (PROMs); however, many are lengthy and can be challenging to use in routine clinical practice. We propose a short-form PROM that correlates well with established quality-of-life measures. METHODS: We evaluated the utility of a 10-item score (AWESCORE) by measuring reliability, validity and responsiveness in adults with CF. The questions were developed by thematic analysis of survey questions to patients in a single adult CF centre. Each question was scored using a numerical rating scale 0 to 10. Total scores ranged from 0 to 100. Test-retest reliability was assessed over 24 h. To determine validity, comparisons were sought between stable subjects and those in pulmonary exacerbation, and between AWESCORE and Cystic Fibrosis Questionnaire - Revised (CFQ-R). Responsiveness to pulmonary exacerbation in individual subjects was evaluated. RESULTS: Five domains, each with two questions, were identified for respiratory, physical, nutritional, psychological and general health. A total of 246 consecutive adults attending the outpatient clinic completed the AWESCORE. Scores were higher during clinical stability compared to pulmonary exacerbation (mean± sd): 73±11 versus 48±11 (p<0.001). Each domain scored worse during an acute exacerbation (p<0.001). No differences in reliability were observed in scores on retesting using Bland-Altman comparison. The CFQ-R scores (mean±sd: 813±125) and AWESCORE (81±13) were moderately correlated (Pearson's r=0.649; p=0.002). CONCLUSIONS: The AWESCORE is valid, reliable and responsive to altered health status in CF.

Lumacaftor/ivacaftor-associated health stabilisation in adults with severe cystic fibrosis.

INTRODUCTION: Lumacaftor/ivacaftor (LUM/IVA) has been shown to improve clinical outcomes in cystic fibrosis (CF) patients homozygous for Phe508del with forced expiratory volume in 1 s (FEV1) % pred >40%. We assessed the clinical utility of LUM/IVA in all eligible adult CF patients with FEV1 % pred <40% treated for at least 1 year under a single-centre managed access programme. METHODS: Following clinical optimisation, eligible patients (n=40) with FEV1 % pred <40% were commenced on LUM/IVA and monitored for tolerance and clinical outcomes, including health service utilisation, pulmonary function, weight and body composition. 24 patients reached 1 year of treatment by the time of evaluation. Six patients discontinued due to adverse events (five for increased airways reactivity) and three underwent lung transplantation. RESULTS: In comparison with the year prior to LUM/IVA commencement, significant reductions (median per year) were observed in the treatment year in the number of pulmonary exacerbations requiring hospitalisation (from 3 to 1.5; p=0.0002), hospitalisation days (from 27 to 17; p=0.0002) and intravenous antibiotic (IVAB) usage days (from 45 to 27; p=0.0007). Mean±sd change in FEV1 % pred was -2.10±1.18% per year in the year prior, with the decline reversed in the year following (+1.45±1.13% per year; p=0.035), although there was significant heterogeneity in individual responses. Mean±sd weight gain at 1 year was 2.5±4.1 kg (p=0.0007), comprising mainly fat mass (mean 2.2 kg). The proportion of patients severely underweight (body mass index <18.5 kg·m-2) decreased from 33% at baseline to 13% at 1 year (p=0.003). CONCLUSION: This real-world evaluation study demonstrated benefits over several clinical domains (infective exacerbations requiring hospitalisation, IVABs, pulmonary function decline and nutritional parameters) in CF patients with severe lung disease.

Body composition and weight changes after ivacaftor treatment in adults with cystic fibrosis carrying the G551 D cystic fibrosis transmembrane conductance regulator mutation: A double-blind, placebo-controlled, randomized, crossover study with open-label extension.

OBJECTIVES: In patients with cystic fibrosis (CF) who carry the G551D mutation, treatment with ivacaftor improves lung function and weight; however, short- and long-term impacts on body composition have not been well studied. METHODS: Twenty adults with CF carrying the G551D mutation (mean ± standard deviation body mass index [BMI] 23.3 ± 4.3 kg/m2) were recruited for a single-center, double-blind, placebo-controlled, 28-d, crossover study of ivacaftor, followed by an open-label extension (OLE) for 5 mo. Eleven patients underwent measurements 2 y later. The study variables included weight, BMI, and body composition (including fat-free mass [FFM] and fat mass). RESULTS: After 28 d of treatment with ivacaftor, weight increased by 1.1 ± 1.3 kg, BMI by 0.4 ± 0.5 kg/m2, and FFM by 1.1 ± 1.2 kg (all P < .005) with no change in fat mass. Differences between 28-d changes on ivacaftor and placebo were not statistically significant. In the following 5 mo of the OLE, there were significant increases in weight (1.2 ± 1.9 kg; P < .05) and fat mass (1.5 ± 1.9 kg; P < .01), but not in FFM. Between baseline and the end of the OLE, the total weight gain was 2.5 ± 2.4 kg (P < .005), comprised of 0.9 ± 1.5 kg FFM (P < .05) and 1.6 ± 1.8 kg fat mass (P < .005). For the 11 participants who were followed for a further 2 y, no further changes in mean weight, BMI, or body composition parameters between 6 mo and 2 y later were observed. CONCLUSIONS: Small gains were seen in FFM in the first month of ivacaftor treatment. Weight, BMI, and fat-mass gains in the first 6 mo on ivacaftor plateaued by 2.5 y. The metabolic and clinical consequences of weight and fat-mass gains remain to be determined.

Integrated immune dynamics define correlates of COVID-19 severity and antibody responses.

SARS-CoV-2 causes a spectrum of COVID-19 disease, the immunological basis of which remains ill defined. We analyzed 85 SARS-CoV-2-infected individuals at acute and/or convalescent time points, up to 102 days after symptom onset, quantifying 184 immunological parameters. Acute COVID-19 presented with high levels of IL-6, IL-18, and IL-10 and broad activation marked by the upregulation of CD38 on innate and adaptive lymphocytes and myeloid cells. Importantly, activated CXCR3+cTFH1 cells in acute COVID-19 significantly correlate with and predict antibody levels and their avidity at convalescence as well as acute neutralization activity. Strikingly, intensive care unit (ICU) patients with severe COVID-19 display higher levels of soluble IL-6, IL-6R, and IL-18, and hyperactivation of innate, adaptive, and myeloid compartments than patients with moderate disease. Our analyses provide a comprehensive map of longitudinal immunological responses in COVID-19 patients and integrate key cellular pathways of complex immune networks underpinning severe COVID-19, providing important insights into potential biomarkers and immunotherapies.

Redesign of the Australian Cystic Fibrosis Data Registry: A multidisciplinary collaboration.

Clinical registries that monitor and review outcomes for patients with cystic fibrosis have existed internationally for many decades. However, their purpose continues to evolve and now includes the capability to support clinical effectiveness research, clinical trials and Phase IV studies, and international data comparisons and projects. To achieve this, registries must regularly update the information that they collect and ensure design that is adaptable and flexible to changing needs. The Australian Cystic Fibrosis Data Registry commenced in 1998, and in 2018-19 undertook a transformation to enable it to meet the needs of multiple stakeholders into the future. This included a comprehensive, multidisciplinary review of the registry's data elements, and a redesign and rebuild of the registry's database. The data element review comprised the processes of alignment, comparison, selection, consolidation, revision and definition of finalised data elements. The database redesign included attention to each of the registry functions of data collection, storage and management, and reporting. The revision of a national data collection system is a time-intensive process, and requires significant clinical and other expert engagement. The resulting database, while being continually refined, is now fit for purpose to support Australian clinicians and patients with CF to receive best practice care.

VO2max as an exercise tolerance endpoint in people with cystic fibrosis: Lessons from a lumacaftor/ivacaftor trial.

BACKGROUND: The impact of lumacaftor/ivacaftor on exercise tolerance in people with cystic fibrosis (CF) has not been thoroughly studied. METHODS: We conducted a multisite Phase 4 trial comparing the impact of lumacaftor/ivacaftor on exercise tolerance with that of placebo in participants ≥ 12 years of age with CF homozygous for F508del-CFTR. The primary endpoint was relative change from baseline in maximum oxygen consumption (VO2max) during cardiopulmonary exercise testing (CPET) at Week 24. The key secondary endpoint was relative change from baseline in exercise duration during CPET at Week 24. Other secondary endpoints included changes in other indices of exercise tolerance and changes in CF assessments; safety and tolerability were assessed as an endpoint. RESULTS: Seventy participants were randomized to receive lumacaftor/ivacaftor (n = 34) or placebo (n = 36). The least-squares mean difference for lumacaftor/ivacaftor versus placebo in relative change in VO2max from baseline at Week 24 was -3.2% (95% CI: -9.2, 2.9; P=0.3021); the least-squares mean difference in relative change from baseline in exercise duration at Week 24 was -3.2% (95% CI: -8.0, 1.6). Safety results were consistent with the known lumacaftor/ivacaftor safety profile. CONCLUSIONS: Definitive conclusions regarding the impact of lumacaftor/ivacaftor on exercise tolerance cannot be drawn from these results; however, multicenter studies using CPETs can be reliably performed with multiple time points and conventional methods, provided that calibration can be achieved. Future studies of exercise tolerance may benefit from lessons learned from this study. NCT02875366.

Lung function over the life course of paediatric and adult patients with cystic fibrosis from a large multi-centre registry.

A key measure of lung function in people with Cystic Fibrosis (CF) is Forced Expiratory Volume in the first second FEV1 percent predicted (FEV1pp). This study aimed to address challenges in identifying predictors of FEV1pp, specifically dealing with non-linearity and the censoring effect of death. Data was obtained from a large multi-centre Australian Cystic Fibrosis Data Registry (ACFDR). A linear mixed model was used to study FEV1pp as the endpoint. There were 3655 patients (52.4% male) included in our study. Restricted cubic splines were used to fit the non-linear relationship between age of visit and FEV1pp. The following predictors were found to be significant in the multivariate model: age of patient at visit, BMI z-score, age interaction with lung transplantation, insulin dependent diabetes, cirrhosis/portal hypertension, pancreatic insufficiency, Pseudomonas aeruginosa infection and baseline variability in FEV1pp. Those with P. aeruginosa infection had a lower mean difference in FEV1pp of 4.7 units, p < 0.001 compared to those who did not have the infection. Joint modelling with mortality outcome did not materially affect our findings. These models will prove useful for to study the impact of CFTR modulator therapies on rate of change of lung function among patients with CF.

A Shared TCR Bias toward an Immunogenic EBV Epitope Dominates in HLA-B*07:02-Expressing Individuals.

EBV is one of the most common viruses found in humans and is prototypic of a persistent viral infection characterized by periods of latency. Across many HLA class I molecules, the latent-specific CD8+ T cell response is focused on epitopes derived from the EBNA-3 protein family. In the case of HLA-B*07:02 restriction, a highly frequent class I allele, the T cell response is dominated by an epitope spanning residues 379-387 of EBNA-3 (RPPIFIRRL [EBVRPP]). However, little is known about either the TCR repertoire specific for this epitope or the molecular basis for this observed immunodominance. The EBVRPP CD8+ T cell response was common among both EBV-seropositive HLA-B*07:02+ healthy and immunocompromised individuals. Similar TCRs were identified in EBVRPP-specific CD8+ T cell repertoires across multiple HLA-B7+ individuals, indicating a shared Ag-driven bias in TCR usage. In particular, TRBV4-1 and TRAV38 usage was observed in five out of six individuals studied. In this study, we report the crystal structure of a TRBV4-1+ TCR-HLA-B*07:02/EBVRPP complex, which provides a molecular basis for the observed TRBV4-1 bias. These findings enhance our understanding of the CD8+ T cell response toward a common EBV determinant in HLA-B*07:02+ individuals.

Re-imagining cystic fibrosis care: next generation thinking.

Cystic fibrosis (CF) is a common multi-system genetically inherited condition, predominately found in individuals of Caucasian decent. Since the identification of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) gene in 1989, and the subsequent improvement in understanding of CF pathophysiology, significant increases in life-expectancy have followed. Initially this was related to improvements in the management and systems of care for treating the various affected organ systems. These cornerstone treatments are still essential for CF patients born today. However, over the last decade, the major advance has been in therapies that target the resultant genetic defect: the dysfunctional CFTR protein. Small molecule agents that target this dysfunctional protein via a variety of mechanisms have led to lung function improvements, reductions in pulmonary exacerbation rates and increases in weight and quality-of-life indices. As more patients receive these agents earlier and earlier in life, it is likely that general CF care will increasingly pivot around these specific therapies, although it is also likely that effects other than those identified in the initial trials will be discovered and need to be managed. Despite great excitement for modulator therapies, they are unlikely to be suitable or available for all; whether this is due to a lack of availability for specific CFTR mutations, drug-reactions or the health economic set-up in certain countries. Nevertheless, the CF community must be applauded for its ongoing focus on research and development for this life-limiting disease. With time, personalised individualised therapy would ideally be the mainstay of CF care.

CNS imaging studies in cystic fibrosis patients presenting with sudden neurological events.

Background: Acute neurological events may present as an extrapulmonary complication in patients with cystic fibrosis (CF). These events can be secondary to a range of different aetiologies. Methods: A retrospective analysis of 476 medical records of CF patients attending a large teaching hospital between 2000 and 2018 was performed. Patients presenting with acute neurological events who had MRI brain imaging were evaluated. Patients who had headaches without associated neurological symptoms were excluded from this analysis. Results: Acute neurological presentations, excluding headaches without associated neurological symptoms, were reported in 27 index patients out of the 476 patients. Of these, 16 patients had MRI brain imaging for review. Three patients suffered pathology secondary to vascular events, both ischaemic and haemorrhagic; four patients had evidence of ischaemia or infarction not consistent with a vascular territory stroke and the remaining patients experienced a range of different neurological events. The most common presentation among these patients was seizure activity, followed by a transient motor or sensory deficit. Conclusions: Neurological complications are recognised among individuals with CF. Although rare, they can be secondary to a range of different aetiologies, including dysfunctional cell energetics. Additional studies are required to further evaluate this association.

Smooth Muscle Phenotype in Idiopathic Pulmonary Hypertension: Hyper-Proliferative but not Cancerous.

Idiopathic pulmonary arterial hypertension (IPAH) is a complex disease associated with vascular remodeling and a proliferative disorder in pulmonary artery smooth muscle cells (PASMCs) that has been variably described as having neoplastic features. To decode the phenotype of PASMCs in IPAH, PASMCs from explanted lungs of patients with IPAH (IPAH-PASMCs) and from controls (C-PASMCs) were cultured. The IPAH-PASMCs grew faster than the controls; however, both growth curves plateaued, suggesting contact inhibition in IPAH cells. No proliferation was seen without stimulation with exogenous growth factors, suggesting that IPAH cells are incapable of self-sufficient growth. IPAH-PASMCs were more resistant to apoptosis than C-PASMCs, consistent with the increase in the Bcl2/Bax ratio. As cell replication is governed by telomere length, these parameters were assessed jointly. Compared to C-PASMCs, IPAH-PASMCs had longer telomeres, but a limited replicative capacity. Additionally, it was noted that IPAH-PASMCs had a shift in energy production from mitochondrial oxidative phosphorylation to aerobic glycolysis. As DNA damage and genomic instability are strongly implicated in IPAH development a comparative genomic hybridization was performed on genomic DNA from PASMCs which showed multiple break-points unaffected by IPAH severity. Activation of DNA damage/repair factors (γH2AX, p53, and GADD45) in response to cisplatin was measured. All proteins showed lower phosphorylation in IPAH samples than in controls, suggesting that the cells were resistant to DNA damage. Despite the cancer-like processes that are associated with end-stage IPAH-PASMCs, we identified no evidence of self-sufficient proliferation in these cells-the defining feature of neoplasia.

Characterization of Hypermutator Pseudomonas aeruginosa Isolates from Patients with Cystic Fibrosis in Australia.

Hypermutable Pseudomonas aeruginosa isolates (hypermutators) have been identified in patients with cystic fibrosis (CF) and are associated with reduced lung function. Hypermutators display a greatly increased mutation rate and an enhanced ability to become resistant to antibiotics during treatment. Their prevalence has been established among patients with CF, but it has not been determined for patients with CF in Australia. This study aimed to determine the prevalence of hypermutable P. aeruginosa isolates from adult patients with CF from a health care institution in Australia and to characterize the genetic diversity and antibiotic susceptibility of these isolates. A total of 59 P. aeruginosa clinical isolates from patients with CF were characterized. For all isolates, rifampin (RIF) mutation frequencies and susceptibility to a range of antibiotics were determined. Of the 59 isolates, 13 (22%) were hypermutable. Whole-genome sequences were determined for all hypermutable isolates. Core genome polymorphisms were used to assess genetic relatedness of the isolates, both to each other and to a sample of previously characterized P. aeruginosa strains. Phylogenetic analyses showed that the hypermutators were from divergent lineages and that hypermutator phenotype was mostly the result of mutations in mutL or, less commonly, in mutS Hypermutable isolates also contained a range of mutations that are likely associated with adaptation of P. aeruginosa to the CF lung environment. Multidrug resistance was more prevalent in hypermutable than nonhypermutable isolates (38% versus 22%). This study revealed that hypermutable P. aeruginosa strains are common among isolates from patients with CF in Australia and are implicated in the emergence of antibiotic resistance.

Subclinical Left Ventricular Dysfunction is Influenced by Genotype Severity in Patients with Cystic Fibrosis.

BACKGROUND AND OBJECTIVE: Over 2000 genotypes in the cystic fibrosis (CF) gene have been described. These genotypic differences result in variable clinical manifestations of CF, with severity of disease dependent on CF transmembrane conductance (CFTR) protein function. CFTR is widely distributed in nucleated cells, including cardiac myocytes, but the effect of genotype on cardiac function is not known. METHODS: This retrospective review of echocardiographic data is from a single adult CF centre between 2000 and 2015. Patients were cohorted based on the functional classification of genotype. 'Severe' patients had both CF genes from functional classification groups 1-3; 'mild' patients had one or no gene from these groups, or in the event of the second gene being unknown were pancreatic sufficient. RESULTS: Genotype and echocardiography were recorded during the inclusion period in 100 patients, 79 of whom were classified as having severe genotypes. Although the severe group were younger they had a lower fractional shortening (33.66 ± 6.6 vs 36.9 ± 6.3, P < .05), left atrial area (14.9 ± 3.6 versus 18.0 ± 4.2 cm2; P < .01) and volume (39.9 ± 18.7 versus 51.0 ± 18.7 mL; P < .05) and showed a trend to lower left ventricular ejection fraction. CONCLUSIONS: This study is the first to show that in CF, severity of genotype (functional classification) is associated with cardiac impairment. Patients with severe CF genotype and cardiac dysfunction should be identified to evaluate cardiac response to gene-modifying treatments prior to consideration for lung transplantation.

Mycobacterium abscessus complex: Natural history and treatment outcomes at a tertiary adult cystic fibrosis center.

Background: Mycobacterium abscessus complex (MAbsC) is a significant management dilemma when taking care of patients with cystic fibrosis (CF). Methods: We undertook a retrospective cohort analysis of all CF patients in whom MAbsC was isolated from 2005 to 2014. The natural history of MAbsC was determined and clinical factors examined in an attempt to predict transient compared to persistent colonization. Results: No correlation was found between recurrent MAbsC isolation and clinical factors such as body mass index, respiratory function, or age. Over two-thirds of our cohort cleared MAbsC colonization with no intervention and no consistent effect on lung function was identified. Four CF patients were initiated on treatment with only one successful outcome. Conclusion: This analysis demonstrates there are no clear predictors of those CF patients who will become persistently colonized with MAbsC and that a significant proportion will spontaneously clear carriage. As treatment success rate is poor, more work is urgently required in improving patient outcomes.

Clonally diverse CD38+HLA-DR+CD8+ T cells persist during fatal H7N9 disease.

Severe influenza A virus (IAV) infection is associated with immune dysfunction. Here, we show circulating CD8+ T-cell profiles from patients hospitalized with avian H7N9, seasonal IAV, and influenza vaccinees. Patient survival reflects an early, transient prevalence of highly activated CD38+HLA-DR+PD-1+ CD8+ T cells, whereas the prolonged persistence of this set is found in ultimately fatal cases. Single-cell T cell receptor (TCR)-αß analyses of activated CD38+HLA-DR+CD8+ T cells show similar TCRαß diversity but differential clonal expansion kinetics in surviving and fatal H7N9 patients. Delayed clonal expansion associated with an early dichotomy at a transcriptome level (as detected by single-cell RNAseq) is found in CD38+HLA-DR+CD8+ T cells from patients who succumbed to the disease, suggesting a divergent differentiation pathway of CD38+HLA-DR+CD8+ T cells from the outset during fatal disease. Our study proposes that effective expansion of cross-reactive influenza-specific TCRαß clonotypes with appropriate transcriptome signatures is needed for early protection against severe influenza disease.