CFTR Modulators Therapy Efficacy in Reducing Cystic Fibrosis (CF) Exacerbation and Improving Selected Spirometry Parameters: A Real-Life Study in a Single-Centre Polish Population

Background/Objectives: Cystic fibrosis is a genetically determined disease that significantly influences and shortens life. Treatment with CFTR modulators (CFTR-T) is a new hope for patients. It can change the predictive values of a poor prognosis (e.g., exacerbation rate and FEV1 value). The aim of the study was to analyse exacerbation incidence and spirometry data before and after one year (+/- 2 weeks) of CFTR-T in 85 CF patients at the CF Centre in Poznań. To our knowledge, this is the first analysis of CFTR-T efficiency in the Central-Eastern Europe population. Methods: We retrospectively analysed the spirometry and exacerbation data of 85 CF adult patients (both men and women), who in the middle of 2022 began treatment with CFTR modulators. Results: The one-year ratio of hospitalisation caused by severe exacerbations lowered from 1.25 to 0.21 per patient per year. We also saw a 66% decline in ambulatory exacerbations. The median FEV1% increased by 9.60% in absolute values and by 460 mL. Even in the group with very severe obstruction (FEV1 < 35%), there was an increase in median FEV1% of 5.9 in absolute values. We also proved the increase in FVC% (median 17.10% in absolute value and 600 mL) in the study group. Conclusions: After one year of treatment, an impressive improvement was observed in two important predictive values of poor prognosis: exacerbation rate and FEV1 values. Further observation is needed to determine how long the improvement will be present and its influence on quality of life and life expectancy.

Home-spirometry exacerbation profiles in children with cystic fibrosis

BACKGROUND

Pulmonary exacerbations (PEx) are strong predictors of respiratory disease progression in children with cystic fibrosis (CwCF) and may be associated with persistent decreased lung function after acute management. Telemonitoring devices can be used for early detection and monitoring of PEx, but its utility is debated.

RESEARCH QUESTION

Which symptoms and telemonitoring spirometry characterics are related to outcome dynamics following initial PEx management?

METHODS

This retrospective study included CwCF followed at Bordeaux University Hospital, France. All severe PEx episodes treated with intravenous (IV) antibiotics (ATB) between 1 January 2017 and 31 December 2021 in CwCF using home telemonitoring were analyzed. Symptoms and home spirometry data were collected 45 days before and up to 60 days after each IV ATB course. We defined three response profiles based on terciles of baseline forced expiratory volume in 1 s (FEV1 ) recovery.

RESULTS

A total of 346 IV ATB courses for PEx were administered to 65 CwCF during the study period. The drop in FEV1 became significant 8 days before IV ATB initiation. Forty-one percent of IV ATB courses failed to restore baseline FEV1 . The magnitude of FEV1 drop and a greater delay in the initiation of treatment correlated with a low response level. On the 14th day of the IV treatment, a FEV1 recovery less than 94% of baseline was associated with a nonresponder profile.

INTERPRETATION

Home spirometry may facilitate the early recognition of PEx to implement earlier interventions. This study also provides an outcome lung function threshold which identifies low responders to IV ATB.

Application of gap time analysis with flexible hazards to pulmonary exacerbations in the EPIC observational study

Cystic fibrosis and other chronic lung disease clinical trials often use time to first pulmonary exacerbation (PEx) or total PEx count as endpoints. The use of these outcomes may fail to capture patterns or timing of multiple exacerbations and how covariates influence the risk of future exacerbations. Analysis of gap times between PEx provides a useful framework to understand risks of subsequent events, particularly to assess if there is a temporary increase in a hazard of a subsequent PEx following the occurrence of a PEx. This may be useful for estimating the amount of time needed to follow patients after a PEx and predicting which patients are more likely to have multiple PEx. We propose a smoothed hazard for gap times to account for elevated hazards after exacerbations. A simulation study was conducted to explore model performance and was able to appropriately estimate parameters in all situations with an underlying change point with independent or correlated recurrent events. Models with different change-point structures and trends are compared using Early Pseudomonas Infection Control (EPIC) observational study data, using a quasi-likelihood modification of the Akaike information criterion; a model with a change-point provided a better fit than a model without one. The analysis suggests that the change point may be 1.8 years (SE 0.09) after the end of a PEx. Models including covariates in the hazard function revealed that having one or two copies of the Δ $\Delta$ F508 mutation, female sex, and higher numbers of previous PEx were significantly associated with increased risk of another PEx.

The modified shuttle test as a predictor of risk for hospitalization in youths with cystic fibrosis: A two-year follow-up study: Modified shuttle test as a predictor of hospitalization

BACKGROUND

Patients with cystic fibrosis (CF) present exercise intolerance and episodes of pulmonary exacerbations. This study aimed to evaluate the association of the distance covered on the modified shuttle test (MST), as well as other clinical variables (anthropometry, chronic colonization by Pseudomonas aeruginosa, lung function), with the risk of hospitalization for pulmonary exacerbation.

METHODS

Cohort study including CF patients older than 6 years, from two specialized CF centers. All patients underwent a MST and a lung function test at the time of inclusion. Demographic, anthropometric and clinical data were collected. Free time until the first hospitalization, total days of hospitalization and use of antibiotics during the two years of follow-up were recorded.

RESULTS

Sixty-seven patients with a mean (SD) age of 12.4 (5.2) years and forced expiratory volume in the first second (FEV₁) of 78.7% (22.4) were included. The mean distance covered (m) in the MST was 775.6 (255.7) (73.4 ± 19.5% of predicted). The distance achieved (MST) was considered as the main independent variable to predict the risk of hospitalization (Cox HR 0.97, p = 0.029). Patients who walked a distance of less than 80% of predicted in the MST showed an increase of 3.9 (95%CI 1.0-15.3) in the relative risk for hospitalization and significantly higher total number of days of hospitalization (p = 0.022).

CONCLUSION

There is an association between the distance covered in the MST and the risk of hospitalization in youths with CF. Patients with reduced exercise capacity presented a 3.9 times increase in the relative risk for hospitalization due to pulmonary exacerbation.

Glycemic control and FEV1 recovery during pulmonary exacerbations in pediatric cystic fibrosis-related diabetes

RATIONALE

Whether short-term glucose control in cystic fibrosis-related diabetes (CFRD) is associated with FEV₁ recovery during acute pulmonary exacerbations is unclear.

METHODS

Data from all patients with CFRD ages 6-21 years hospitalized in 2010-2016 for pulmonary exacerbations at our CF Center were analyzed, including CFRD status at each encounter, all FEV₁ recorded during each exacerbation, and relevant clinical covariates. Glucose control was analyzed using meter blood glucose area under the curve (AUC) indices. The primary outcome was FEV₁ recovery.

RESULTS

Patients with CFRD who finished IV antibiotics at home were treated for longer than those fully treated in the hospital (22.2 vs. 13.8 days). In those who finished treatment at home, poor inpatient glycemic control was associated with lower lung function improvement: when comparing the 75th to the 25th percentile of each glycemic index (i.e., "poorer" vs. "better" glycemic control), FEV₁ recovery at discharge was 20.1% lower for glucose AUC (95%CI -0.4%, -39.9%); 20.9% lower for 48-h AUC (95%CI -2.7%, -39.1%); and 28.2% lower for AUC/day (95%CI -7.1%, -49.3%). Similar results were found at the end of IV antibiotics and at clinic follow-up. Likewise, patients with poor glycemic control had a lower slope of inpatient FEV₁ recovery. Analysis in patients with normal glucose tolerance was largely non-significant. No associations were found between hemoglobin A1c and FEV₁ recovery.

CONCLUSIONS

In patients with CFRD who complete IV antibiotic treatment at home, poor inpatient glycemic control is associated with worse FEV₁ recovery despite longer duration of treatment.

C-reactive protein levels in acute respiratory exacerbations of cystic fibrosis

C-reactive protein (CRP) levels increase in response to bacterial infection and have been used to guide the use of antibiotics. We assessed CRP levels in a cohort of patients with cystic fibrosis (CF) admitted to hospital with an exacerbation of their lung disease, requiring treatment with broad-spectrum antibiotics. In this group, most subjects had CRP levels of less than 20 mg/L, including patients who had pneumonia. The clinical utility of the CRP in guiding antibiotic use in exacerbations of CF is limited.

Application of multiple event analysis as an alternative approach to studying pulmonary exacerbations as an outcome measure

BACKGROUND

Pulmonary exacerbations (PEx) are important contributors to morbidity and mortality in cystic fibrosis (CF). Understanding risk factors for PEx is critical to improve treatment; pulmonary exacerbations also serve as an important outcome in CF clinical trials. Current risk estimates generally only evaluate time to the first PEx. Methods accounting for multiple exacerbations during the observation period could provide more power to detect significant risk factors.

METHODS

The Early Pseudomonas Infection Control (EPIC) Observational Study enrolled participants between 2004 and 2006 who were ≤ 12 years of age and negative for Pseudomonas aeruginosa. First and multiple event analyses were used to investigate risk factors for pulmonary exacerbations.

RESULTS

We evaluated a total of 5129 PEx from 1734 CF patients in the EPIC study. Multiple event analysis identified 2 more factors associated with occurrence of PEx compared to first event analysis. After adjusting for multiple factors, the following were associated with higher occurrence of PExs: female gender, older age at enrollment, household cigarette smoke exposure, increased cough at the most recent encounter, having used antibiotics since the previous encounter, a positive culture for any CF organism at the most recent encounter, and having had a PEx in the last 30 days.

CONCLUSIONS

Multiple event analyses use all PEx events and may identify more risk factors for PEx than analysis of time to first PEx. We have provided an example of how to apply this type of analysis and how to interpret estimates in the context of the EPIC study.

Antibiotic duration and changes in FEV1 are not associated with time until next exacerbation in adult cystic fibrosis: a single center study

Background

Pulmonary exacerbations (PEx) are a major driver of morbidity and mortality in cystic fibrosis and reducing their frequency by extending the time between them is an important therapeutic goal. Although treatment decisions for exacerbations are often made based on dynamic changes in lung function, it is not clear if these changes truly impact future exacerbation risk. We analyzed adults with chronic Pseudomonas aeruginosa infection to determine whether changes in FEV₁ or duration of intravenous antibiotic therapy were associated with time to the next pulmonary exacerbation.

Methods

Medical records and Cystic Fibrosis Foundation Patient Registry data were examined retrospectively to assess whether various patient-specific demographic factors and exacerbation-specific characteristics were associated with time until next exacerbation using the Andersen-Gill model in order to control for previous exacerbation frequency history.

Results

We examined 59 patients with 221 CF pulmonary exacerbations over a 3-year study period. Mean age was 28.2 years and mean baseline FEV₁ was 62% predicted. In our univariable model, fall in FEV₁ at onset of exacerbation (median absolute −3% predicted change), recovery of FEV₁ with treatment (median absolute +3% predicted change) and duration of IV antibiotics (median 16 days) were not associated with time to next exacerbation (median 93.5 days). Paradoxically each one-year increase in age was associated with a reduction in hazard of PEx by 3% (HR 0.97, P = 0.03, 95% CI 0.95–1.00).

Conclusions

FEV1 drop and recovery associated with onset and treatment of a CF pulmonary exacerbation or duration of intravenous antibiotics were not predictive of time until next exacerbation. Our finding that older age may be associated with decreased hazard of exacerbation is likely due to a healthy survivor effect and should be controlled for in clinical trials of pulmonary exacerbations.

Study design considerations for the Standardized Treatment of Pulmonary Exacerbations 2 (STOP2): A trial to compare intravenous antibiotic treatment durations in CF

BACKGROUND

Pulmonary exacerbations (PEx) in cystic fibrosis (CF) are common and contribute to morbidity and mortality. Duration of IV antibiotic therapy to treat PEx varies widely in the US, and there are few data to guide treatment decisions.

METHODS

We combined a survey of CF stakeholders with retrospective analyses of a recent observational study of CF PEx to design a multicenter, randomized, prospective study comparing the efficacy and safety of different durations of IV antibiotics for PEx to meet the needs of people with CF and their caregivers.

RESULTS

IV antibiotic duration was cited as the most important PEx research question by responding CF physicians and top concern among surveyed CF patients/caregivers. During PEx, forced expiratory volume in 1s (FEV₁% predicted) and symptom responses at 7-10days of IV antibiotics identified two distinct groups: early robust responders (ERR) who subsequently experienced greater FEV₁ improvements compared to non-ERR (NERR). In addition to greater FEV₁ and symptom responses, only 14% of ERR patients were treated with IV antibiotics for >15days, compared with 45% of NERR patients.

CONCLUSIONS

A divergent trial design that evaluates subjects' interim improvement in FEV₁ and symptoms to tailor randomization to IV treatment duration (10 vs. 14days for ERR, 14 vs. 21days for NERR) may alleviate physician and patient concerns about excess or inadequate treatment. Such a study has the potential to provide evidence necessary to standardize IV antibiotic duration in CF PEx care -a first step to conducting PEx research of other treatment features.

Fungal Pathogens in CF Airways: Leave or Treat?

Chronic airway infection plays an essential role in the progress of cystic fibrosis (CF) lung disease. In the past decades, mainly bacterial pathogens, such as Pseudomonas aeruginosa, have been the focus of researchers and clinicians. However, fungi are frequently detected in CF airways and there is an increasing body of evidence that fungal pathogens might play a role in CF lung disease. Several studies have shown an association of fungi, particularly Aspergillus fumigatus and Candida albicans, with the course of lung disease in CF patients. Mechanistically, in vitro and in vivo studies suggest that an impaired immune response to fungal pathogens in CF airways renders them more susceptible to fungi. However, it remains elusive whether fungi are actively involved in CF lung disease pathologies or whether they rather reflect a dysregulated airway colonization and act as microbial bystanders. A key issue for dissecting the role of fungi in CF lung disease is the distinction of dynamic fungal-host interaction entities, namely colonization, sensitization or infection. This review summarizes key findings on pathophysiological mechanisms and the clinical impact of fungi in CF lung disease.

Clinical utility of C-reactive protein to predict treatment response during cystic fibrosis pulmonary exacerbations

Rationale

C-reactive protein (CRP) is a systemic marker of inflammation that correlates with disease status in cystic fibrosis (CF). The clinical utility of CRP measurement to guide pulmonary exacerbation (PEx) treatment decisions remains uncertain.

Objectives

To determine whether monitoring CRP during PEx treatment can be used to predict treatment response. We hypothesized that early changes in CRP can be used to predict treatment response.

Methods

We reviewed all PEx events requiring hospitalization for intravenous (IV) antibiotics over 2 years at our institution. 83 PEx events met our eligibility criteria. CRP levels from admission to day 5 were evaluated to predict treatment non-response, using a modified version of a prior published composite definition. CRP was also evaluated to predict time until next exacerbation (TUNE).

Measurements and main results

53% of 83 PEx events were classified as treatment non-response. Paradoxically, 24% of PEx events were characterized by a ≥ 50% increase in CRP levels within the first five days of treatment. Absolute change in CRP from admission to day 5 was not associated with treatment non-response (p = 0.58). Adjusted for FEV₁% predicted, admission log₁₀ CRP was associated with treatment non-response (OR: 2.39; 95% CI: 1.14 to 5.91; p = 0.03) and shorter TUNE (HR: 1.60; 95% CI: 1.13 to 2.27; p = 0.008). The area under the receiver operating characteristics (ROC) curve of admission CRP to predict treatment non-response was 0.72 (95% CI 0.61–0.83; p<0.001). 23% of PEx events were characterized by an admission CRP of > 75 mg/L with a specificity of 90% for treatment non-response.

Conclusions

Admission CRP predicts treatment non-response and time until next exacerbation. A very elevated admission CRP (>75mg/L) is highly specific for treatment non-response and might be used to target high-risk patients for future interventional studies aimed at improving exacerbation outcomes.

Prevalence of Aspergillus sensitization and allergic bronchopulmonary aspergillosis in cystic fibrosis: systematic review and meta-analysis

BACKGROUND

The prevalence of Aspergillus sensitization (AS) and allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF) has been varyingly reported. The aim of this systematic review was to estimate the overall prevalence of AS/ABPA in CF.

METHODS

We searched the PubMed and EmBase databases for studies reporting the prevalence of AS/ABPA in CF. We calculated the proportion with 95% confidence interval (CI) to assess the prevalence of AS and ABPA in the individual studies and then pooled the results using a random effects model. Statistical heterogeneity was assessed using the I2 test while publication bias was assessed using both graphical and statistical methods.

RESULTS

Our search yielded 64 eligible studies. The pooled prevalence of AS was 39.1% (95% CI: 33.3-45.1) and was higher with skin test compared to specific IgE (43.8% vs. 32.8%, P = 0.002); however, the prevalence did not vary with the type of skin test used (intradermal or percutaneous). The prevalence of ABPA was 8.9% (95% CI: 7.4-10.7) and was higher in adults as compared to children (10.1% vs. 8.9%, P < 0.0001). There was a wide variation in the criteria used for diagnosing ABPA. Almost 50% (12/23) of the publications after 2004 used criteria other than the CF foundation criteria for diagnosing ABPA. There was significant statistical heterogeneity and evidence of publication bias.

CONCLUSIONS

There is a high prevalence of AS and ABPA in patients with CF. Despite six decades of research, there is still a need to adopt uniform methodology and criteria for the diagnosis of AS/ABPA.

Cystic Fibrosis Related Diabetes: a Unique Challenge in Diabetes Care

Cystic Fibrosis (CF) is a common autosomal recessive disease that affects multiple organs due to a defect in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). This transporter is present in various organs and tissues, including the airway epithelium, sinuses, pancreas, intestine, biliary tree, the vas deferens, and the sweat ducts, making CF a multi-system disease1. As CF patients are living longer, pancreatic function declines and diabetes emerges, further complicating the nutritional status and care of these patients.

C-Reactive Protein in Stable Cystic Fibrosis: An Additional Indicator of Clinical Disease Activity and Risk of Future Pulmonary Exacerbations

INTRODUCTION

In stable adult cystic fibrosis (CF) patients, we assessed the role of baseline high sensitivity C-reactive protein (hs-CRP) on CF clinical variables and frequency of intravenous (IV) treated pulmonary exacerbations (PExs) 1-year post-baseline.

METHODS

We recruited 51 clinically stable CF patients from our Adult CF Center. We incorporated collected parameters into Matouk CF clinical score and CF questionnaire-revised quality of life score (QOL). We used the clinical minus complications subscores as a clinical disease activity score (CDAS). We dichotomized our patients according to the cohort median baseline hs-CRP of 5.2 mg/L.

RESULTS

Patients in the high hs-CRP group (≥ 5.2 mg/L) demonstrated worse CDAS (r=0.67, p=0.0001) and QOL scores (r=0.57, p=0.0017) at a given FEV₁% predicted. In both hs-CRP groups, prior-year IV-treated PExs and baseline CDASs were significant predictors of future IV-treated PExs. Interestingly, the association between baseline CDAS and future PExs frequency was more robust in the high compared to the low hs-CRP group (r=-0.88, p<0.0001, r=-0.48, p=0.017, respectively) with a steeper regression slope (p=0.001). In addition, a significant interaction was demonstrated between elevated baseline hs-CRP levels and CDASs for the prediction of increased risk of future PExs (p=0.02). This interaction provided an additional indicator of clinical disease activity and added another dimension to the prior year PExs frequency phenotype to identify patients at increased risk for future PExs.

CONCLUSION

Stable CF patients with elevated baseline hs-CRP (≥ 5.2 mg/L) demonstrated worse clinical disease activity and QOL scores at a given level of disease severity (FEV₁% predicted). Elevated baseline hs-CRP values combined with clinical disease activity scores are associated with increased risk for future IV-treated PExs even in those with mild clinical disease activity scores.

Serum Iron Level Is Associated with Time to Antibiotics in Cystic Fibrosis

BACKGROUND

Serum levels of hepcidin-25, a peptide hormone that reduces blood iron content, are elevated when patients with cystic fibrosis (CF) develop pulmonary exacerbation (PEx). Because hepcidin-25 is unavailable as a clinical laboratory test, we questioned whether a one-time serum iron level was associated with the subsequent number of days until PEx, as defined by the need to receive systemic antibiotics (ABX) for health deterioration.

METHODS

Clinical, biochemical, and microbiological parameters were simultaneously checked in 54 adults with CF. Charts were reviewed to determine when they first experienced a PEx after these parameters were assessed. Time to ABX was compared in subgroups with and without specific attributes. Multivariate linear regression was used to identify parameters that significantly explained variation in time to ABX.

RESULTS

In univariate analyses, time to ABX was significantly shorter in subjects with Aspergillus-positive sputum cultures and CF-related diabetes. Multivariate linear regression models demonstrated that shorter time to ABX was associated with younger age, lower serum iron level, and Aspergillus sputum culture positivity.

CONCLUSIONS

Serum iron, age, and Aspergillus sputum culture positivity are factors associated with shorter time to subsequent PEx in CF adults.

IV-treated pulmonary exacerbations in the prior year: An important independent risk factor for future pulmonary exacerbation in cystic fibrosis

BACKGROUND

Single-center analyses have suggested that the number of CF pulmonary exacerbations (PEx) treated with intravenous antibiotics an individual has experienced in the prior year is significantly associated with their future PEx hazard.

METHODS

We studied Prior-year PEx association with future PEx hazard by Cox proportional hazards regression among CF Foundation Patient Registry patients who experienced PEx after Jan 1, 2010.

RESULTS

Among 13,579 patients, those with 1, 2, 3, or ≥4 Prior-year PEx treated with intravenous antibiotics were at 1.8, 2.9, 4.8, and 8.7 higher PEx hazard vs those without (P<.0001). Adjustment with significant demographic and clinical covariates (univariate P≤.0001) reduced Prior-year PEx hazard ratios to 1.6, 2.4, 3.6, and 6.0 (P<.0001). No other covariates had adjusted hazard ratios of >1.7.

CONCLUSIONS

Prior-year PEx strongly associate with future PEx hazard and should be accounted for in prospective trials where treatment-associated change in PEx hazard is an efficacy outcome.

Short-term and long-term response to pulmonary exacerbation treatment in cystic fibrosis

BACKGROUND

Treatment of pulmonary exacerbations (PEx) in cystic fibrosis (CF) varies widely with no consensus on management practices or best indicators of therapeutic success. To design trials evaluating PEx treatment factors, we characterise the heterogeneity of PEx care in adults and paediatrics, and correlate it with measures of clinical response including short-term and long-term lung function changes, change in symptom severity score and time to next intravenous antibiotic therapy.

METHODS

Data were used from a prospective observational study of patients with CF ≥10 years of age enrolled at six sites between 2007 and 2010. All were started on intravenous antibiotics for a clinically diagnosed PEx. Analysis of variance, logistic and Cox regression were used to examine the association of treatment factors with short-term and long-term clinical response.

RESULTS

Of 123 patients with CF (60% women, aged 23.1±10.2 years), 33% experienced <10% relative improvement in FEV1 during treatment, which was associated with failing to recover baseline lung function 3 months after treatment (OR=7.8, 95% CI 1.9 to 31.6, p=0.004) and a longer time to next intravenous antibiotic (HR=0.48, 95% CI 0.27 to 0.85, p=0.011). Symptom improvement was observed but was not associated with subsequent lung function or time to next antibiotic therapy, which had a median recurrence time of 143 days.

CONCLUSIONS

Immediate symptomatic or respiratory response to PEx treatment did not have a clear relationship with subsequent outcomes such as lung function or intravenous antibiotic-free interval. These results can inform future research of treatment regimens for PEx in terms of interventions and outcome measures.

TRIAL REGISTRATION

NCT00788359 (www.clinicaltrials.gov).

Reduction in Pseudomonas aeruginosa sputum density during a cystic fibrosis pulmonary exacerbation does not predict clinical response

Background

Pulmonary exacerbations (PEx) are critical events in cystic fibrosis (CF), responsible for reduced quality of life and permanent loss of lung function. Approximately 1/4 of PEx are associated with failure to recover lung function and/or resolve symptoms. Developing tools to optimize PEx treatment is of paramount importance.

Methods

We retrospectively audited all adults infected with Pseudomonas aeruginosa, experiencing PEx necessitating parenteral antibiotic therapy from 2006–2012 from our center. Quantitative analysis of sputum at admission, twice-weekly during hospitalization, and end of therapy were compared to baseline (most recent healthy) and follow-up (after PEx) samples. Change in P. aeruginosa burden from baseline was assessed for any and all morphotypes (ALL), as well as mucoid (MUC) and non-mucoid (NON) isolates specifically. PEx were identified as failures if >90% of baseline pulmonary function was not recovered.

Results

Forty-six patients meeting the above inclusion and exclusion criteria experienced 144 PEx during this time (median 3, IQR 2–6). Patients were treated for a median 14 days (IQR 13–16). No increase in ALL, MUC or NON were detected at PEx, nor was there an association between change in sputum density and magnitude of lung function decline. PEx failures were observed in 30% of events. Reductions of at least 1-log and 2 log P. aeruginosa sputum density was observed in 57% and 46% (ALL), 73% and 55% (MUC) and 58% and 46% (NON) of PEx, respectively. Factors associated with greater reduction of P. aeruginosa sputum density included choice of β-lactam antibiotic, antibiotics with in vitro predicted activity and treatment duration. PEx associated with reductions in P. aeruginosa sputum density were not associated with a reduced risk of PEx failure.

Conclusions

Enhanced killing of P. aeruginosa during PEx does not predict improved clinical outcomes. Studies accounting for the polymicrobial nature of CF respiratory disease and the heterogeneity of P. aeruginosa causing chronic infection may enable the identification of a more appropriate pathogen(s) based biomarker of PEx outcomes.

Treatment and demographic factors affecting time to next pulmonary exacerbation in cystic fibrosis

BACKGROUND

Pulmonary exacerbations (PEx) are important CF clinical events.

METHODS

We studied time to next PEx following intravenous (IV) antibiotic PEx treatment among Cleveland Ohio CF center patients occurring between January 2010 and September 2014. Patient demographics, clinical presentations, and treatments were modeled by Cox proportional hazards regression to identify covariates associated with time to next PEx.

RESULTS

193 patients were treated for PEx; 155 had a subsequent IV-treated PEx. Six covariates were associated with future PEx hazard: number of PEx in the prior year (hazard ratio 25.1 for ≥3 and 4.4 for 1-2 prior-year PEx versus none; P<.0001), IV treatment duration in weeks (1.2; P=.0004), percent hospital treatment (1.1; P=.0018), and chronic inhaled aminoglycosides (2.5; P<.0001), leukotriene modifiers (1.8; P=.0031), and high dose ibuprofen (0.52; P=.0006).

CONCLUSIONS

Time to next PEx was profoundly associated with prior-year PEx, suggestive of high-risk PEx phenotypes that warrant recognition and further study.

Management of pulmonary exacerbations in cystic fibrosis: still an unmet medical need in clinical practice

Pulmonary exacerbation (PEx) is a hallmark of cystic fibrosis. Although several criteria have been proposed for the definition of PEx, no consensus has yet been reached. Very often, many PEx cases go unreported. A standardized and validated definition is needed to reduce variability in clinical practice. The pathophysiology of recurrent episodes remains unclear, and both onset and risk are multifactorial. PEx leads to increased healthcare costs, impaired quality of life and a cycle in which PEx causes loss of lung function, which predisposes to further episodes. The number of episodes affects survival. Although early diagnosis and aggressive treatment are highly recommended, measures to prevent the emergence of new PEx are even more important. In particular, inhaled antibiotics administered under new treatment schedules could play a key role in preventing exacerbations and thus delay decline in lung function and reduce mortality. The primary objective is zero exacerbations.

Role of C-reactive protein as a biomarker for prediction of the severity of pulmonary exacerbations in patients with cystic fibrosis

Background

Pulmonary exacerbation is one of the main risk factors for death in patients with cystic fibrosis. Several biomarkers have proven useful in the diagnosis and treatment of pulmonary exacerbations, although none has been associated with severity. The objective of the present study was to investigate whether C-reactive protein (CRP) level was associated with the severity of pulmonary exacerbation requiring admission to hospital in patients with cystic fibrosis.

Methods

We designed a severity index for exacerbations based on 4 clinical parameters and determined whether there was an association between CRP levels and severity of the exacerbation. We also investigated the association between CRP and baseline functional and clinical variables.

Results

Twenty-seven patients with cystic fibrosis required 62 admissions to hospital. CRP levels were not significantly associated with the severity index, although they were associated with specific patient characteristics: colonization by Pseudomonas aeruginosa, allergic bronchopulmonary aspergillosis, treatment with oral corticosteroids, and number of severe exacerbations treated with intravenous antibiotics during the previous year.

Conclusions

CRP level is not associated with the severity of pulmonary exacerbations, but it is associated with specific clinical characteristics. This simple scoring system (severity index) could prove very useful for evaluating the severity of exacerbations.

Candidate markers associated with the probability of future pulmonary exacerbations in cystic fibrosis patients

Introduction

Pulmonary exacerbations (PEs) cause significant morbidity and can severely impact disease progression in cystic fibrosis (CF) lung disease, especially in patients who suffer from recurrent PEs. The assessments able to predict a future PE or a recurrent PE are limited. We hypothesized that combining clinical, molecular and patient reported data could identify patients who are at risk of PE.

Methods

We prospectively followed a cohort of 53 adult CF patients for 24 months. Baseline values for spirometry, clinical status using the Matouk Disease Score, quality of life (QOL), inflammatory markers (C-reactive protein (CRP), interleukins (IL)-1β, -6, -8, -10, macrophage inflammatory protein (MIP)-1β, tumor necrosis factor (TNF) and vascular endothelial growth factor (VEGF)), polyunsaturated fatty acids and lipid peroxidation in blood plasma were collected for all patients during periods of stable disease, and patients were monitored for PE requiring PO/IV antibiotic treatment. Additionally, we closely followed 13 patients during PEs collecting longitudinal data on changes in markers from baseline values. We assessed whether any markers were predictors of future PE at baseline and after antibiotic treatment.

Results

Out of 53 patients, 37 experienced PEs during our study period. At baseline, we found that low lung function, clinical scoring and QOL values were associated with increased risk of PE events. PEs were associated with increased inflammatory markers at Day 1, and these biomarkers improved with treatment. The imbalance in arachidonic acid and docosahexaenoic acid levels improved with treatment which coincided with reductions in lipid peroxidation. High levels of inflammatory markers CRP and IL-8 were associated with an early re-exacerbation.

Conclusion

Our results demonstrate that worse clinical and QOL assessments during stable disease are potential markers associated with a higher risk of future PEs, while higher levels of inflammatory markers at the end of antibiotic treatment may be associated with early re-exacerbation.

Systematic review of blood biomarkers in cystic fibrosis pulmonary exacerbations

BACKGROUND

Biomarkers reflective of disease activity in cystic fibrosis (CF) have the potential to improve patient care, particularly during CF pulmonary exacerbations (CFPEs). Although blood-based biomarkers have been studied in CFPE for nearly 3 decades, none have been integrated into routine clinical practice. To facilitate progress in this area, we performed a systematic review evaluating blood-based biomarkers during CFPE.

METHODS

MEDLINE, EMBASE, and CENTRAL were searched to identify relevant studies published from January 1995 to August 2012. We included all full-text studies examining systemic (blood-based) biomarkers to aid in the diagnosis of CFPE, predict outcomes of CFPE, and/or monitor the response to CFPE treatment.

RESULTS

Seventy-eight unique blood-based biomarkers have been studied to date, mainly inflammatory cytokines, acute phase reactants, and markers of oxidative stress. C-reactive protein (CRP) consistently correlated with disease activity, with a statistically significant increase from stable to exacerbation state in five of six studies, and changes in response to CFPE treatment, with a statistically significant decrease from the beginning to the end of CFPE treatment in 18 of 20 studies. Other promising biomarkers of CFPE disease activity include neutrophil elastase antiproteinase complex, IL-6, myeloperoxidase (MPO), lactoferrin, and calprotectin.

CONCLUSIONS

Although there are several blood-based biomarkers with evidence for application within the CFPE setting, CRP has been the most widely studied biomarker demonstrating the potential for clinical usefulness. Further validation studies and clinical trials are required to determine whether blood-based biomarkers can be used to ultimately improve health outcomes in the setting of a CFPE.