Cystic Fibrosis Pulmonary Exacerbations Research Articles

590 Changing face of pediatric pulmonary exacerbations in cystic fibrosis

590 Changing face of pediatric pulmonary exacerbations in cystic fibrosis

104 Effect of acute systemic corticosteroids on clinical outcomes in cystic fibrosis pulmonary exacerbations

104 Effect of acute systemic corticosteroids on clinical outcomes in cystic fibrosis pulmonary exacerbations

143 High-dose vitamin D treatment of cystic fibrosis pulmonary exacerbations modulates the correlation profile of plasma immune mediators

143 High-dose vitamin D treatment of cystic fibrosis pulmonary exacerbations modulates the correlation profile of plasma immune mediators

Breath of fresh insight: unraveling the evolution of our understanding of cystic fibrosis pulmonary exacerbations.

Pulmonary exacerbations are critical events with significant negative impacts in persons with cystic fibrosis, but their diagnosis and management are highly variable. Highly effective modulator therapies have greatly improved health and reduced exacerbation events, but have also reshaped how they present. This review discusses the complexities of the diagnosis and management of pulmonary exacerbations as well as the emerging work and evidence in this area. The shifting epidemiology and our understanding of risk factors for pulmonary exacerbations are discussed. As symptoms may be more subtle in the modulator context, novel technologies including studies of remote monitoring are presented. The continued relevance of pulmonary exacerbations, the heterogeneity in their management, as well as current and forthcoming clinical trials to optimize treatment approaches are detailed. In spite of the dramatic reductions in pulmonary exacerbations, airway infections persist, a proportion of persons with cystic fibrosis either on or off modulator therapies continue to experience exacerbation events, and long-term data is lacking. Innovative approaches and studies will be crucial to enable standardized and generalizable strategies to improve outcomes in persons with cystic fibrosis.

Factors associated with lung function response with oral antibiotic treatment of pulmonary exacerbations in cystic fibrosis

Pulmonary exacerbations treated with oral antibiotics (oPEx) have a significant effect on lung function decline in people with cystic fibrosis (CF). However, factors associated with lung function response with oPExs are not well defined.We performed a retrospective cohort study of pediatric and adult patients with CF followed in the Toronto CF Database. Lung function response was measured both as the change in forced expiratory volume in 1 second (FEV1) from Day 0 of antibiotic therapy to end of treatment as well as from baseline to end of treatment. Drop from baseline to Day 0 FEV1 was strongly associated with lung function response (p<0.001). Greater FEV1 improvements were associated with longer antibiotic treatment durations. Older, female patients had less improvements in FEV1 at end of treatment compared to younger, male patients.

Ceftolozane/tazobactam heteroresistance in cystic fibrosis-related Pseudomonas aeruginosa infections.

Cystic fibrosis (CF) patients are often colonized with Pseudomonas aeruginosa. During treatment, P. aeruginosa can develop subpopulations exhibiting variable in vitro antimicrobial (ABX) susceptibility patterns. Heteroresistance (HR) may underlie reported discrepancies between in vitro susceptibility results and clinical responses to various ABXs. Here, we sought to examine the presence and nature of P. aeruginosa polyclonal HR (PHR) and monoclonal HR (MHR) to ceftolozane/tazobactam in isolates originating from CF pulmonary exacerbations. This was a single-centre, non-controlled study. Two hundred and forty-six P. aeruginosa isolates from 26 adult CF patients were included. PHR was defined as the presence of different ceftolozane/tazobactam minimum inhibitory concentration (MIC) values among P. aeruginosa isolates originating from a single patient specimen. Population analysis profiles (PAPs) were performed to assess the presence of MHR, defined as ≥4-fold change in the ceftolozane/tazobactam MIC from a single P. aeruginosa colony. Sixteen of 26 patient specimens (62%) contained PHR P. aeruginosa populations. Of these 16 patients, 6 (23%) had specimens in which PHR P. aeruginosa isolates exhibited ceftolozane/tazobactam MICs with categorical differences (i.e. susceptible versus resistant) compared to results reported as part of routine care. One isolate, PSA 1311, demonstrated MHR. Canonical ceftolozane/tazobactam resistance genes were not found in the MHR isolates (MHR PSA 1311 or PHR PSA 6130). Ceftolozane/tazobactam PHR exists among P. aeruginosa isolates in this work, and approximately a quarter of these populations contained isolates with ceftolozane/tazobactam susceptibiilty interpretations different from what was reported clinically, supporting concerns surrounding the utility of traditional susceptibility testing methodology in the setting of CF specimens. Genome sequencing of isolates with acquired MHR to ceftolozane/tazobactam revealed variants of unknown significance. Future work will be centred on determining the significance of these mutations to better understand these data in clinical context.

How Does the Corrected Exhalyzer Software Change the Predictive Value of LCI in Pulmonary Exacerbations in Children with Cystic Fibrosis?

Aim: Recently, the most commonly used for multiple breath washout device, the Exhalyzer D, has been shown to overestimate lung clearance index (LCI) results due to a software error. Our study aimed to compare the predictive values of LCI in the CF pulmonary exacerbations (PE) calculated with the updated (3.3.1) and the previous (3.2.1) version of the Spiroware software. Materials and Methods: The measurements were performed during 259 visits in CF pediatric patients. We used 39ΔPE pairs (PE preceded by stable visit) and 138ΔS pairs (stable visit preceded by stable visit) to compare the LCI changes during PE. The areas under the receiver operating curves (AUCROC) and odds ratios were calculated based on the differences between ΔPEs and ΔSs. The exacerbation risk was estimated using a logistic regression model with generalized estimating equations (GEE). Results: There were statistically significant differences in LCI 2.5% median values measured using the two versions of the software in the stable condition but not during PE. The AUCROC for changes between the two consecutive visits for LCI did not change significantly using the updated Spiroware software. Conclusions: Despite the lower median values, using the recalculated LCI values does not influence the diagnostic accuracy of this parameter in CF PE.

Longitudinal effects of elexacaftor/tezacaftor/ivacaftor on sputum viscoelastic properties, airway infection and inflammation in patients with cystic fibrosis.

Recent studies demonstrated that the triple combination cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy elexacaftor/tezacaftor/ivacaftor (ETI) improves lung function and reduces pulmonary exacerbations in cystic fibrosis (CF) patients with at least one F508del allele. However, effects of ETI on downstream consequences of CFTR dysfunction, i.e. abnormal viscoelastic properties of airway mucus, chronic airway infection and inflammation have not been studied. The aim of this study was to determine the longitudinal effects of ETI on airway mucus rheology, microbiome and inflammation in CF patients with one or two F508del alleles aged ≥12 years throughout the first 12 months of therapy. In this prospective observational study, we assessed sputum rheology, the microbiome, inflammation markers and proteome before and 1, 3 and 12 months after initiation of ETI. In total, 79 patients with CF and at least one F508del allele and 10 healthy controls were enrolled in this study. ETI improved the elastic modulus and viscous modulus of CF sputum at 3 and 12 months after initiation (all p<0.01). Furthermore, ETI decreased the relative abundance of Pseudomonas aeruginosa in CF sputum at 3 months and increased the microbiome α-diversity at all time points. In addition, ETI reduced interleukin-8 at 3 months (p<0.05) and free neutrophil elastase activity at all time points (all p<0.001), and shifted the CF sputum proteome towards healthy. Our data demonstrate that restoration of CFTR function by ETI improves sputum viscoelastic properties, chronic airway infection and inflammation in CF patients with at least one F508del allele over the first 12 months of therapy; however, levels close to healthy were not reached.

Role of hyperglycemia in cystic fibrosis pulmonary exacerbations

BackgroundHyperglycemia could affect treatment response during cystic fibrosis (CF) exacerbations. We aimed to evaluate the prevalence and associations of hyperglycemia with exacerbation outcomes. We also evaluated feasibility of continuous glucose monitoring (CGM) during exacerbations. MethodsThe STOP2 study assessed efficacy and safety of different durations of intravenous antibiotics for CF exacerbations. We conducted a secondary data analysis of random glucose levels measured as part of clinical care during exacerbations. A small subset of participants also underwent CGM per research protocol. The associations between hyperglycemia, defined as random glucose ≥140 mg/dL, and changes in weight and lung function with exacerbation treatment were evaluated with linear regression after adjustment for confounding variables. ResultsGlucose levels were available for 182 STOP2 participants of mean (SD) age 31.6 (10.8) years, baseline percent predicted (pp) FEV1 53.6 (22.5); 37% had CF related diabetes and 27% were on insulin. Hyperglycemia was detected in 44% of participants. Adjusted mean difference (95% CI) was 1.34% (-1.39, 4.08) (p = 0.336) for change in ppFEV1 and 0.33 kg (-0.11, 0.78) (p = 0.145) for change in weight between hyperglycemic and non-hyperglycemic groups. Ten participants not on antidiabetic agents in the 4 weeks prior to enrollment underwent CGM; mean (SD) time spent >140 mg/dL was 24.6% (12.5) with 9/10 participants spending >4.5% time >140 mg/dL. ConclusionsHyperglycemia identified with random glucose is prevalent during CF exacerbations but not associated with changes in lung function or weight with exacerbation treatment. CGM is feasible and may provide a useful tool for hyperglycemia monitoring during exacerbations.

Changes in bone turnover after high-dose vitamin D supplementation during acute pulmonary exacerbation in cystic fibrosis

In people with cystic fibrosis (CF), chronic inflammation and infection increase the risk for low bone mineral density and CF-related bone disease. During acute pulmonary exacerbations (APE), people with CF have increases in markers of bone resorption. Vitamin D has been proposed as a potential nutrient to lower inflammation. In this ancillary analysis of the Vitamin D for the Immune System in CF study, we hypothesized that vitamin D administered at the time of APE would have favorable changes on bone turnover markers compared to placebo. Participants with CF were randomized to receive a single dose of 250,000 IU of vitamin D or placebo during an APE and followed for 1 year for the primary outcome of APE or death after randomization. Bone turnover markers: C-terminal telopeptide (CTX-1) and procollagen type 1 intact N-terminal propetide (P1NP) were assessed at randomization (during APE) and after recovery from the APE in 45 participants. Participants randomized to vitamin D had significant decreases in markers of bone turnover; participants who received placebo had non-significant increases in markers of bone turnover. Vitamin D supplementation during an APE may help reduce the risk for CF-related bone disease.

P185 Prospective randomized observational study validating biomarkers for association with future pulmonary exacerbations in people with cystic fibrosis

Airway inflammation underlies pulmonary exacerbations in cystic fibrosis (CF). We tested multiple inflammatory molecules previously studied to validate specific biomarkers and pathways as potential causes of CF pulmonary exacerbations.

P250 Minimum inhibitory concentration targeted antibiotic dose optimization in patients with cystic fibrosis

Frequent pulmonary exacerbations of Cystic Fibrosis (CF) reduce survival and quality of life even among patients receiving highly effective modulator therapy suggesting the need for better treatments. Our primary objective was to discern whether antibiotics matched with bacterial culture susceptibilities and meeting minimum inhibitory concentration (MIC)-based target serum levels improve pulmonary exacerbation treatment outcomes. MIC directed antibiotic dose selection and optimization therapy is standard practice at our center.

P096 Effect of acute systemic corticosteroids on clinical outcomes in cystic fibrosis pulmonary exacerbations

P096 Effect of acute systemic corticosteroids on clinical outcomes in cystic fibrosis pulmonary exacerbations

P186 Airway clearance in the STOP PEDS pilot study of oral antibiotic treatment strategies for paediatric cystic fibrosis pulmonary exacerbations

Increased frequency of airway clearance therapy (ACT) is a key component of pulmonary exacerbation (PEx) treatment. STOP PEDS (Streamlined Treatment of Pulmonary exacerbations in Pediatrics) was a multicenter, prospective, open-label feasibility study in which oral antibiotic treatment for a mild outpatient pulmonary exacerbation was assigned randomly to either “immediate oral antibiotics” or “tailored therapy” (oral antibiotics started only for pre-specified criteria). Here we report the self-reported frequency of ACT among participants in both arms.

Measuring energy requirements during pulmonary exacerbations of cystic fibrosis using indirect calorimetry

ObjectiveThe energy demands of individuals with cystic fibrosis (CF) vary depending on pancreatic function, body composition, lung function, and clinical status. In clinical practice, predictive equations are used to determine energy requirements yet do not reliably account for these factors. Research regarding energy requirements during CF pulmonary exacerbation (CFPEx) and clinical stability is conflicting. The aim of this study was to investigate potential within-individual changes in measured resting energy expenditure (mREE) using indirect calorimetry (IC) at the commencement and completion of intravenous antibiotic treatment (IVABx) for CFPEx and during clinical stability. Secondary aims were to investigate potential differences between predicted resting energy expenditure (pREE) using Schofield equation and correlations between clinical factors with mREE. MethodsBody composition using bioimpedance analysis and mREE were conducted at three time points: commencement of IVABx; completion of IVABx; and clinically stable period thereafter. ResultsTwenty-eight adults with CF completed at least one valid IC measurement. No significant within-person changes in mREE and body composition parameters were observed across time points. The mREE was positively correlated with fat-free mass (kg; r = 0.6; P = 0.008). The mREE was significantly higher than pREE at all time points with the mREE/pREE ratio elevated at time point 1:118% ± 19.5%; time point 2: 112% ± 13.2%; and time point 3: 122 ± 14.3%. ConclusionThe mREE remained stable during CFPEx and clinical stability. The pREE underestimated mREE and application of injury factor adjustment of 110% to 130% could potentially account for this discrepancy. The potential role of IC and body composition in individualizing CF nutritional assessment and prescription requires further exploration.

Evaluation of serum VIP and aCGRP during pulmonary exacerbation in cystic fibrosis: A longitudinal pilot study of patients undergoing antibiotic therapy.

Objective monitoring of improvement during treatment of pulmonary exacerbation can be difficulty in children when pulmonary function testing cannot be obtained. Thus, the identification of predictive biomarkers to determine the efficacy of drug treatments is of high priority. The major aim of the current study was to investigate the serum levels of vasoactive intestinal peptide (VIP) and alpha calcitonin gene related peptide (aCGRP) of cystic fibrosis pediatric patients during pulmonary exacerbation and post-antibiotic therapy, and possible associations of their levels with different clinicopathological parameters. 21 patients with cystic fibrosis were recruited at onset of pulmonary exacerbation. Serum was collected at time of admission, three days post-antibiotic therapy, and two weeks post-antibiotic therapy (end of antibiotic therapy). Serum VIP and aCGRP levels were measured using ELISA. Overall least square means of serum aCGRP level but not VIP changed from time of exacerbation to completion of antibiotic therapy (p = 0.005). Serum VIP was significantly associated with the presence of diabetes mellitus (p = 0.026) and other comorbidities (p = 0.013), and with type of antibiotic therapy (p = 0.019). Serum aCGRP level was significantly associated with type of antibiotic therapy (p = 0.012) and positive Staphylococcus aureus microbiology test (p = 0.046). This study could only show significant changes in serum aCGRP levels following treatment of pulmonary exacerbations. Future studies with larger sample size are required to investigate the clinical importance of VIP and aCGRP in cystic fibrosis patients.

Digital technology for early identification of exacerbations in people with cystic fibrosis.

Cystic fibrosis (CF) is a life-limiting genetic condition affecting various organ systems including the gastrointestinal tract, endocrine system and especially the respiratory tract. Pulmonary exacerbations in CF result in increased symptoms, an acceleration in the rate of lung decline and an increased need for treatment. Early detection of infections or clinical worsening provides an opportunity for proactive treatment that may affect clinical outcomes. To evaluate whether digital technology can effectively predict pulmonary exacerbations to allow earlier intervention and improved health outcomes without increasing the burden of treatment in people with CF. We used standard, extensive Cochrane search methods. We searched the Cochrane Cystic Fibrosis Trials Register and the reference lists of relevant articles and reviews on 13 October 2022. We searched Embase and the clinical trial registries on 3 January 2023. We included randomised controlled trials (RCTs) or quasi-RCTs in people with CF looking at whether digital technology can effectively predict pulmonary exacerbations to allow earlier intervention and improved health outcomes without increasing the burden of treatment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. pulmonary exacerbations and 2. quality of life (QoL). Our secondary outcomes were 3. lung function, 4. hospitalisations, 5. intravenous (IV) antibiotics, 6. microbiology, 7. cost-effectiveness and 8. We used GRADE to assess certainty of evidence. We included three studies (415 participants) in people with CF aged 15 to 41 years over a 12-month period. One was a multicentre RCT, whilst two were single-centre RCTs. The three studies were mostly similar in their risk of bias, having low or unclear risk of selection bias but a high risk of detection bias, due to the unblinded design of these studies. The studies used a variety of digital technologies to monitor symptoms such as a digital symptom diary either with or without home spirometry monitoring. As the trials only included adults and older children, we are not certain that the results would apply to younger children. One of our primary outcomes was to assess time to detection of pulmonary exacerbation and number of pulmonary exacerbations identified between the intervention and routine care groups. We were largely unable to pool results in a meta-analysis due to the variety of methodologies and ways of reporting data. Two studies noted a shorter time to detection of exacerbations in the intervention group and one of these also reported that the intervention group had a shorter time to first exacerbation (hazard ratio for time to first exacerbation 1.45, 95% confidence interval (CI) 1.09 to 1.93), whilst a further study reported a shorter time to detection of exacerbations in the intervention group requiring oral or IV antibiotics compared to the control group (median: 70 (interquartile range (IQR) 123) days with intervention versus 141 (IQR 140) days with control; P = 0.02). However, all three studies were concordant in finding no probable effect on spirometry in the intervention groups when compared with their routine care groups over a 12-month period. We found that there is probably no difference between groups with regard to QoL scores across most domains except for Weight and Body Image, which favoured the usual care group. There is also probably no difference in the number of days of additional IV antibiotics needed or newly detected pathogens. No studies reported serious adverse events directly linked to the intervention and one study reported their smartphone application was generally well received. Pulmonary exacerbations are universally accepted to be detrimental to progression of CF-related lung disease, therefore, it is intuitive that early detection and intervention would help to improve outcomes. Digital technology provides an opportunity to detect physiological and symptomatic changes to identify exacerbations early. Our review found that digital technologies based on recording physiological change (spirometry) and symptoms probably allow earlier identification of exacerbations as a group. However, this may not reduce the number of exacerbations warranting IV antibiotics and there is probably no effect on lung function. This may be partly due to inconsistent definitions of pulmonary exacerbations and discrepancy in the management strategies for pulmonary exacerbations. Overall, the intervention may make little or no difference to QoL scores. The adherence to and uptake of digital technologies, especially those which include physiological measurements, are not well sustained and the costs of these need to be balanced against the clinical efficacy.

Chinese experts consensus statement: diagnosis and treatment of cystic fibrosis (2023)

Chinese experts consensus statement: diagnosis and treatment of cystic fibrosis (2023)

Therapeutic drug monitoring in cystic fibrosis and associations with pulmonary exacerbations and lung function

BackgroundCystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy have resulted in longer life expectancies, yet pulmonary exacerbations remain a leading cause of morbidity. Intravenous antibiotics is the mainstay treatment, however achieving adequate concentrations remains challenging. The effect of therapeutic drug monitoring (TDM) of beta-lactams on exacerbations and lung function has not been studied. MethodsPatient demographics, antibiotic regimens, forced expiratory volume 1 s (FEV1), and exacerbation history was obtained from 32 patients with cystic fibrosis admitted for exacerbations. All patients were colonized with Pseudomonas aeruginosa, received CFTR therapy for at least one year, and had 3-month interval follow ups. Plasma concentrations, FEV1, and exacerbation history was obtained before and after therapeutic drug monitoring. This included peak and trough plasma concentrations of piperacillin-tazobactam and cefepime using liquid chromatography with mass spectrometry. T-test and Mann-Whitney U test were used to compare medians/means of FEV1 and pulmonary exacerbations pre and post-TDM as well as free trough-to-minimum inhibitory concentration ratio (fCmin/MIC) ≥1 and ≥ 4. ResultsTDM was associated with decreased exacerbations/year from 1.91 to 1.31 (p = 0.04) and among the cohort with >/ = 2 exacerbations per year, there was a longer exacerbation free interval after TDM (196.2 vs 103.7 days, p = 0.02). The decline in FEV1% predicted after therapeutic drug monitoring to the first exacerbation was −4.9 compared to −9.7 prior (p = 0.03). ConclusionsTDM for cystic fibrosis pulmonary exacerbations results in decreased pulmonary exacerbations, longer intervals to pulmonary exacerbation, and lower decline in FEV1% predicted.

Ventilatory Threshold and Risk of Pulmonary Exacerbations in Cystic Fibrosis.

Whereas pulmonary exacerbations and aerobic fitness play a key role in the prognosis of cystic fibrosis (CF), the use of ventilatory threshold data as markers of exacerbation risk has been scarcely addressed. This study sought to examine the association between aerobic fitness, assessed through ventilatory threshold variables recorded during cardiopulmonary exercise testing (CPET), and the risk of exacerbations in individuals with CF. Participants of this retrospective cohort study were subjects from 6 y of age. Over a 4-y period, the following data were recorded: lung function indicators, CPET variables, time to first exacerbation and antibiotic use, along with demographic, clinical, and anthropometric data. The mean age of 20 subjects included was 16 ± 5.4 y. Univariate regression analysis revealed that lung function (FEV1: Cox hazard ratio [HR] 0.97, P = .03; and forced expiratory flow between 25-75% of vital capacity [FEF25-75]: Cox HR 0.98, P = .036) and aerobic fitness (oxygen consumption [V̇O2 ] at ventilatory threshold: Cox HR 0.94, P = .01; and ventilatory equivalent for carbon dioxide [V̇E/V̇CO2 ] at ventilatory threshold: Cox HR 1.13, P = .049) were associated with exacerbation risk, whereas in the multivariate model, only V̇O2 at the ventilatory threshold (%max) (Cox HR 0.92, P = .01) had a significant impact on this risk. Consistently, individuals experiencing exacerbation had significantly lower V̇O2 values (%max) at the ventilatory threshold (P = .050) and higher ventilatory equivalent for oxygen consumption (V̇E/V̇O2 ) (P = .040) and V̇E/V̇O2 (P = .037) values at the ventilatory threshold. Time to exacerbation was significantly correlated with V̇O2 at the ventilatory threshold (r = 0.50, P = .02), V̇E/V̇O2 (r = -0.48, P = .02), and V̇E/V̇CO2 (r = -0.50, P = .02). Our results suggest an association between CPET variables at the ventilatory threshold and exacerbations. Percentage V̇O2 at the ventilatory threshold could serve as a complementary variable to monitor exacerbations in people with CF.