Daily variability of Pseudomonas aeruginosa density in cystic fibrosis sputum.

Treatment-associated differences in Pseudomonas aeruginosa (Pa) density in sputum have been used as a response biomarker in clinical trials of cystic fibrosis (CF) therapies. Although most studies have included placebo-treated groups as comparators, variability of Pa density in untreated individuals has rarely been reported. We measured day-to-day differences in Pa density in 267 sputum sample pairs collected from 13 adults with CF during days in which no changes in antibiotic therapy occurred.

ECFS standards of care on CFTR-related disorders: Identification and care of the disorders.

This is the third paper in the series providing updated information and recommendations for people with cystic fibrosis transmembrane conductance regulator (CFTR)-related disorder (CFTR-RD). This paper covers the individual disorders, including the established conditions - congenital absence of the vas deferens (CAVD), diffuse bronchiectasis and chronic or acute recurrent pancreatitis - and also other conditions which might be considered a CFTR-RD, including allergic bronchopulmonary aspergillosis, chronic rhinosinusitis, primary sclerosing cholangitis and aquagenic wrinkling. The CFTR functional and genetic evidence in support of the condition being a CFTR-RD are discussed and guidance for reaching the diagnosis, including alternative conditions to consider and management recommendations, is provided.

Creation of a CF-specific antibiotic spectrum index (ASI) as an antimicrobial stewardship initiative.

Antibiotics are frequently utilized for cystic fibrosis (CF)-related pulmonary exacerbation treatment. The antibiotic spectrum index (ASI) is an antimicrobial stewardship tool developed to compare the relative breadth of individual antibiotics. This study aimed to create two expanded CF-specific ASI scoring indices for use in antimicrobial stewardship research and clinical care.

Heterogeneity of CFTR modulator-induced sweat chloride concentrations in people with cystic fibrosis.

Background: Sweat chloride (SC) concentrations in people with cystic fibrosis (PwCF) reflect relative CF transmembrane conductance regulator (CFTR) protein function, the primary CF defect. Populations with greater SC concentrations tend to have lesser CFTR function and more severe disease courses. CFTR modulator treatment can improve CFTR function within specific CF genotypes and is commonly associated with reduced SC concentration.

Adjunctive Systemic Corticosteroids for Pulmonary Exacerbations of Cystic Fibrosis.

Pulmonary exacerbations (PEx) remain the most common cause of morbidity, recurrent hospitalization, and diminished survival in people with cystic fibrosis (PWCF) and are characterized by excess inflammation. Corticosteroids are potent, widely available antiinflammatory drugs. However, corticosteroid efficacy data from randomized controlled trials in PWCF are limited.

Prevalence and Clinical Impact of Respiratory Viral Infections from the STOP2 Study of Cystic Fibrosis Pulmonary Exacerbations.

Rates of viral respiratory infection (VRI) are similar in people with cystic fibrosis (CF) and the general population; however, the associations between VRI and CF pulmonary exacerbations (PEx) require further elucidation. To determine VRI prevalence during CF PEx and evaluate associations between VRI, clinical presentation, and treatment response. The STOP2 (Standardized Treatment of Pulmonary Exacerbations II) study was a multicenter randomized trial to evaluate different durations of intravenous antibiotic therapy for PEx.

Longitudinal bacterial prevalence in cystic fibrosis airways: Fact and artifact.

Background: Opportunistic bacterial infection is a hallmark of cystic fibrosis (CF) lung disease and early mortality. Poorly characterized prevalence changes have accompanied two decades of health improvements, with CFTR modulators likely to further affect infection epidemiology.

Methods: Bacterial prevalence change trends across birth cohorts were assessed with linear regression using 2001-2019 US CF Foundation Patient Registry data.

Impact of lumacaftor/ivacaftor and tezacaftor/ivacaftor on treatment response in pulmonary exacerbations of F508del/F508del cystic fibrosis.

Background: Pulmonary exacerbations (PEx) remain a major cause of morbidity and mortality in people with cystic fibrosis (PWCF). Although the combination cystic fibrosis transmembrane conductance regulator (CFTR) modulators lumacaftor/ivacaftor and tezacaftor/ivacaftor have been shown to reduce PEx frequency, their influence on clinical and biochemical responses to acute PEx treatment is unknown.

Methods: We performed a secondary analysis of STOP2, a large multicenter randomized controlled trial of antimicrobial treatment durations for adult PWCF presenting with PEx.

Willingness of people with cystic fibrosis receiving elexacaftor/tezacaftor/ivacaftor (ETI) to participate in randomized modulator and inhaled antimicrobial clinical trials.

Objective: To assess the feasibility of enrolling people with CF (pwCF) taking the CFTR modulator elexacaftor/tezacaftor/ivacaftor (ETI) in clinical trials of a new modulator.

Methods: PwCF receiving ETI at CHEC-SC study (NCT03350828) enrollment were surveyed for interest in 2-week to 6-month placebo- (PC) and active-comparator (AC) modulator studies. Those taking inhaled antimicrobials (inhABX) were surveyed for interest in PC inhABX studies.

Standards of care for CFTR variant-specific therapy (including modulators) for people with cystic fibrosis.

Cystic fibrosis (CF) has entered the era of variant-specific therapy, tailored to the genetic variants in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. CFTR modulators, the first variant-specific therapy available, have transformed the management of CF. The latest standards of care from the European CF Society (2018) did not include guidance on variant-specific therapy, as CFTR modulators were becoming established as a novel therapy.

Re-examining baseline lung function recovery following IV-treated pulmonary exacerbations.

CF registry pulmonary exacerbation (PEx) analyses have employed "before and after" spirometry recovery, where the best percent predicted forced expiratory volume in 1 s (ppFEV) prior to PEx ("baseline") is compared to the best ppFEV <3 months post-PEx. This methodology lacks comparators and ascribes recovery failure to PEx. Herein, we describe 2014 CF Foundation Patient Registry PEx analyses including a comparator: recovery around nonPEx events, birthdays.

The Elusive Role of Airway Infection in Cystic Fibrosis Exacerbation.

Cystic fibrosis (CF) pulmonary exacerbations (PEx) are clinical events that commonly result in increased treatment burden, decreased quality of life, and accelerated lung disease progression. CF PEx have historically been approached as though dealing with acute infections, and antibiotic treatments have been associated with improved outcomes. In this review, we discuss data supporting a causal role of CF airway infection in PEx as well studies that highlight our knowledge gaps in regard to PEx definitions, pathophysiology, and optimal treatment approaches.

Characterizing CFTR modulated sweat chloride response across the cf population: Initial results from the CHEC-SC study.

Background: CHEC-SC is an ongoing epidemiologic study characterizing modulator-induced sweat chloride (SC) responses across the CF population, with interim results available prior to the availability of triple combination modulator therapy.

Methods: Eligible participants had been prescribed a modulator for ≥90 days with re-enrollment allowed upon establishment of a new modulator. Pre-modulator SC values were obtained from chart review; post-modulator sweat was collected and analyzed locally.

Changes in airway bacterial communities occur soon after initiation of antibiotic treatment of pulmonary exacerbations in cystic fibrosis.

Chronic polymicrobial airway infections are a hallmark of cystic fibrosis (CF) lung disease. Antibiotic therapy is a primary treatment of CF pulmonary exacerbations (PEx); however, the impact of episodic antibiotic treatment on airway bacterial communities has not been well described. We analyzed sputum samples from adults with CF obtained immediately before and during antibiotic treatment of PEx.

Antipseudomonal treatment decisions during CF exacerbation management.

Background: Cystic fibrosis (CF) pulmonary exacerbation (PEx) treatment guidelines suggest that Pseudomonas aeruginosa (Pa) airway infection be treated with two antipseudomonal agents.

Methods: We retrospectively studied treatment responses for STOP2 PEx treatment trial (NCT02781610) participants with a history of Pa infection. Mean lung function and symptom changes from intravenous (IV) antimicrobial treatment start to Visit 2 (7 to 10 days later) were compared between those receiving one, two, and three+ antipseudomonal classes before Visit 2 by ANCOVA.

Health care costs in a randomized trial of antimicrobial duration among cystic fibrosis patients with pulmonary exacerbations.

Background: The purpose of these analyses was to determine whether overall costs were reduced in cystic fibrosis (CF) patients experiencing pulmonary exacerbation (PEx) who received shorter versus longer durations of treatment.

Methods: Among people with CF experiencing PEx, we calculated 30-day inpatient, outpatient, emergency room, and medication costs and summed these to derive total costs in 2020 USD. Using the Kaplan-Meier sample average (KMSA) method, we calculated adjusted costs and differences in costs within two pairs of randomized groups: early robust responders (ERR) randomized to receive treatment for 10 days (ERR-10 days) or 14 days (ERR-14 days), and non-early robust responders (NERR) randomized to receive treatment for 14 days (NERR-14 days) or 21 days (NERR-21 days).

C-reactive protein (CRP) as a biomarker of pulmonary exacerbation presentation and treatment response.

Background: C-reactive protein (CRP) has been proposed as a biomarker for pulmonary exacerbation (PEx) diagnosis and treatment response. CRP >75mg/L has been associated with increased risk of PEx treatment failure. We have analyzed CRP measures as biomarkers for clinical response during the STOP2 PEx study (NCT02781610).

Association of site of treatment with clinical outcomes following intravenous antimicrobial treatment of a pulmonary exacerbation.

Background: In the STOP2 (Standardized Treatment of Pulmonary Exacerbations-2) study, intravenous (IV) antimicrobial treatment duration for adults with cystic fibrosis (CF) experiencing pulmonary exacerbations (PEx) was determined based on initial treatment response. The impact of home vs hospital care remains an important clinical question in CF. Our hypothesis was that STOP2 participants treated at home would have less improvement in lung function compared to those treated in the hospital.

A Randomized Clinical Trial of Antimicrobial Duration for Cystic Fibrosis Pulmonary Exacerbation Treatment.

People with cystic fibrosis (CF) experience acute worsening of respiratory symptoms and lung function known as pulmonary exacerbations. Treatment with intravenous antimicrobials is common; however, there is scant evidence to support a standard treatment duration. To test differing durations of intravenous antimicrobials for CF exacerbations.

Measuring the impact of CFTR modulation on sweat chloride in cystic fibrosis: Rationale and design of the CHEC-SC study.

Background: The Characterizing CFTR Modulated Changes in Sweat Chloride and their Association with Clinical Outcomes (CHEC-SC) study is a large epidemiologic study designed to determine the relationship between sweat chloride response and clinical outcomes in people with cystic fibrosis (CF) on commercially approved CFTR modulators. A challenge to study feasibility was capturing sweat chloride measurements before modulator initiation. We tested the hypothesis that historic sweat chloride approximated contemporary pre-modulator values to estimate CFTR modulator-induced changes, allowing a single-visit study design.