Treatment of Pulmonary Exacerbations Improves Short But Not Long-Term Growth Trajectory in Children With Cystic Fibrosis

Although new inhaled antibiotics have profoundly improved respiratory diseases in cystic fibrosis (CF) patients, lung infections are still the leading cause of death. Inhaled antibiotics, i.e., colistin, tobramycin, aztreonam lysine and levofloxacin, are used as maintenance treatment for CF patients after the development of chronic Pseudomonas aeruginosa (P. aeruginosa) infection. Their use offers advantages over systemic therapy since a relatively high concentration of the drug is delivered directly to the lung, thus, enhancing the pharmacokinetic/pharmacodynamic parameters and decreasing toxicity. Notably, alternating treatment with inhaled antibiotics represents an important strategy for improving patient outcomes. The prevalence of CF patients receiving continuous inhaled antibiotic regimens with different combinations of the anti-P. aeruginosa antibiotic class has been increasing over time. Moreover, these antimicrobial agents are also used for preventing acute pulmonary exacerbations in CF. In this review, the efficacy and safety of the currently available inhaled antibiotics for lung infection treatment in CF patients are discussed, with a particular focus on strategies for eradicating P. aeruginosa and other pathogens. Moreover, the effects of long-term inhaled antibiotic therapy for chronic P. aeruginosa infection and for the prevention of pulmonary exacerbations is reviewed. Finally, how the mucus environment and microbial community richness can influence the efficacy of aerosolized antimicrobial agents is discussed.

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Prediction of Real-World Long-Term Outcomes of People with CF Homozygous for the F508del Mutation Treated with CFTR Modulators

Journal of Personalized Medicine ◽

10.3390/jpm11121376 ◽

2021 ◽

Vol 11 (12) ◽

pp. 1376

Author(s):

Danya Muilwijk ◽

Marlou Bierlaagh ◽

Peter van Mourik ◽

Jasmijn Kraaijkamp ◽

Renske van der Meer ◽

...

Keyword(s):

Cystic Fibrosis ◽

Real World ◽

Target Therapy ◽

Chloride Concentration ◽

Sweat Chloride ◽

Limited Effectiveness ◽

Pulmonary Exacerbations ◽

Cftr Modulators

The clinical response to cystic fibrosis transmembrane conductance regulator (CFTR) modulators is variable within people with cystic fibrosis (pwCF) homozygous for the F508del mutation. The prediction of clinical effect in individual patients would be useful to target therapy to those who would benefit from it. A multicenter observational cohort study was conducted including 97 pwCF (F508del/F508del), who started lumacaftor/ivacaftor (LUM/IVA) treatment before June 2018. In order to assess the associations of individual in vivo and in vitro biomarkers with clinical outcomes, we collected clinical data regarding sex, age, and sweat chloride concentration (SwCl) at baseline and after six months of LUM/IVA; the percent predicted forced expiratory volume in 1 s (ppFEV1) and the number of pulmonary exacerbations (PEx) during the three years before up to three years after modulator initiation; and the forskolin-induced swelling (FIS) responses to LUM/IVA, quantified in intestinal organoids. On a group level, the results showed an acute change in ppFEV1 after LUM/IVA initiation (2.34%, 95% CI 0.85–3.82, p = 0.003), but no significant change in annual ppFEV1 decline in the three years after LUM/IVA compared to the three years before (change: 0.11% per year, 95%CI: −1.94–2.19, p = 0.913). Neither of these two outcomes was associated with any of the candidate predictors on an individual level. The median number of pulmonary exacerbations (PEx) per patient year did not significantly change in the three years after LUM/IVA compared to the years before (median: 0.33/patient year, IQR: 0–0.67 before vs. median: 0/patient year, IQR: 0–0.67 after p = 0. 268). The PEx rate after modulator initiation was associated with the PEx rate before (IRR: 2.26, 95%CI: 1.67–3.08, p < 0.001), with sex (males vs. females IRR: 0.36, 95%CI: 0.21–0.63, p = 0.001) and with sweat chloride concentration (SwCl) at baseline (IRR: 0.96, 95%CI: 0.94–0.98, p = 0.001). The change in SwCl was also significant (−22.9 mmol/L (95%CI: −27.1–−18.8, p < 0.001) and was associated with SwCl at baseline (−0.64, 95%CI: −0.90–−0.37, p < 0.001) and with sex (males vs. females 8.32, 95%CI: 1.82–14.82, p = 0.013). In conclusion, ppFEV1 decline after CFTR modulator initiation remains difficult to predict in individual patients in a real-world setting, with limited effectiveness for double CFTR modulator therapies. The PEx rate prior to CFTR modulator treatment initiation, sex and SwCl at baseline could be potential predictors of long-term PEx rate and of changes in SwCl after modulator initiation.

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Effect of pulmonary exacerbations on long-term lung function decline in cystic fibrosis

European Respiratory Journal ◽

10.1183/09031936.00159111 ◽

2011 ◽

Vol 40 (1) ◽

pp. 61-66 ◽

Cited By ~ 127

Author(s):

Valerie Waters ◽

Sanja Stanojevic ◽

Eshetu G. Atenafu ◽

Annie Lu ◽

Yvonne Yau ◽

...

Keyword(s):

Cystic Fibrosis ◽

Lung Function ◽

Lung Function Decline ◽

Pulmonary Exacerbations

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Effect of Long-term, Low-Dose Erythromycin on Pulmonary Exacerbations Among Patients With Non–Cystic Fibrosis Bronchiectasis

JAMA ◽

10.1001/jama.2013.2290 ◽

2013 ◽

Vol 309 (12) ◽

pp. 1260 ◽

Cited By ~ 244

Author(s):

David J. Serisier ◽

Megan L. Martin ◽

Michael A. McGuckin ◽

Rohan Lourie ◽

Alice C. Chen ◽

...

Keyword(s):

Cystic Fibrosis ◽

Low Dose ◽

Pulmonary Exacerbations

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Pseudomonas aeruginosa PA80 is a cystic fibrosis isolate deficient in RhlRI quorum sensing

Scientific Reports ◽

10.1038/s41598-021-85100-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Syed A. K. Shifat Ahmed ◽

Michelle Rudden ◽

Sabrina M. Elias ◽

Thomas J. Smyth ◽

Roger Marchant ◽

...

Keyword(s):

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Quorum Sensing ◽

Virulence Factors ◽

Genomic Islands ◽

Clinical Strain ◽

Whole Genome ◽

Synonymous Mutations ◽

Wide Range

AbstractPseudomonas aeruginosa uses quorum sensing (QS) to modulate the expression of several virulence factors that enable it to establish severe infections. The QS system in P. aeruginosa is complex, intricate and is dominated by two main N-acyl-homoserine lactone circuits, LasRI and RhlRI. These two QS systems work in a hierarchical fashion with LasRI at the top, directly regulating RhlRI. Together these QS circuits regulate several virulence associated genes, metabolites, and enzymes in P. aeruginosa. Paradoxically, LasR mutants are frequently isolated from chronic P. aeruginosa infections, typically among cystic fibrosis (CF) patients. This suggests P. aeruginosa can undergo significant evolutionary pathoadaptation to persist in long term chronic infections. In contrast, mutations in the RhlRI system are less common. Here, we have isolated a clinical strain of P. aeruginosa from a CF patient that has deleted the transcriptional regulator RhlR entirely. Whole genome sequencing shows the rhlR locus is deleted in PA80 alongside a few non-synonymous mutations in virulence factors including protease lasA and rhamnolipid rhlA, rhlB, rhlC. Importantly we did not observe any mutations in the LasRI QS system. PA80 does not appear to have an accumulation of mutations typically associated with several hallmark pathoadaptive genes (i.e., mexT, mucA, algR, rpoN, exsS, ampR). Whole genome comparisons show that P. aeruginosa strain PA80 is closely related to the hypervirulent Liverpool epidemic strain (LES) LESB58. PA80 also contains several genomic islands (GI’s) encoding virulence and/or resistance determinants homologous to LESB58. To further understand the effect of these mutations in PA80 QS regulatory and virulence associated genes, we compared transcriptional expression of genes and phenotypic effects with isogenic mutants in the genetic reference strain PAO1. In PAO1, we show that deletion of rhlR has a much more significant impact on the expression of a wide range of virulence associated factors rather than deletion of lasR. In PA80, no QS regulatory genes were expressed, which we attribute to the inactivation of the RhlRI QS system by deletion of rhlR and mutation of rhlI. This study demonstrates that inactivation of the LasRI system does not impact RhlRI regulated virulence factors. PA80 has bypassed the common pathoadaptive mutations observed in LasR by targeting the RhlRI system. This suggests that RhlRI is a significant target for the long-term persistence of P. aeruginosa in chronic CF patients. This raises important questions in targeting QS systems for therapeutic interventions.

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Variation in treatment preferences of pulmonary exacerbations among Australian and New Zealand cystic fibrosis physicians

BMJ Open Respiratory Research ◽

10.1136/bmjresp-2021-000956 ◽

2021 ◽

Vol 8 (1) ◽

pp. e000956

Author(s):

Grace Currie ◽

Anna Tai ◽

Tom Snelling ◽

André Schultz

Keyword(s):

Cystic Fibrosis ◽

Clinical Trials ◽

New Zealand ◽

Treatment Options ◽

Early Response ◽

Treatment Preferences ◽

Dornase Alfa ◽

Clinical Scenarios ◽

Professional Opinion ◽

Pulmonary Exacerbations

BackgroundDespite advances in cystic fibrosis (CF) management and survival, the optimal treatment of pulmonary exacerbations remains unclear. Understanding the variability in treatment approaches among physicians might help prioritise clinical uncertainties to address through clinical trials.MethodsPhysicians from Australia and New Zealand who care for people with CF were invited to participate in a web survey of treatment preferences for CF pulmonary exacerbations. Six typical clinical scenarios were presented; three to paediatric and another three to adult physicians. For each scenario, physicians were asked to choose treatment options and provide reasons for their choices.ResultsForty-nine CF physicians (31 paediatric and 18 adult medicine) participated; more than half reported 10+ years of experience. There was considerable variation in primary antibiotic selection; none was preferred by more than half of respondents in any scenario. For secondary antibiotic therapy, respondents consistently preferred intravenous tobramycin and a third antibiotic was rarely prescribed, except in one scenario describing an adult patient. Hypertonic saline nebulisation and twice daily chest physiotherapy was preferred in most scenarios while dornase alfa use was more variable. Most CF physicians (>80%) preferred to change therapy if there was no early response. Professional opinion was the most common reason for antibiotic choice.ConclusionsVariation exists among CF physicians in their preferred choice of primary antibiotic and use of dornase alfa. These preferences are driven by professional opinion, possibly reflecting a lack of evidence to base policy recommendations. Evidence from high-quality clinical trials is needed to inform physician decision making.

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Long‐term benefits of nusinersen in a child affected by cystic fibrosis and spinal muscular atrophy type 1

Pediatric Pulmonology ◽

10.1002/ppul.25334 ◽

2021 ◽

Author(s):

Giorgia Bruno ◽

Bernadette Donnarumma ◽

Alessia Inverardi ◽

Paolo Buonpensiero ◽

Angela Sepe ◽

...

Keyword(s):

Cystic Fibrosis ◽

Spinal Muscular Atrophy ◽

Muscular Atrophy ◽

Spinal Muscular Atrophy Type

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