Using bacterial biomarkers to identify early indicators of cystic fibrosis pulmonary exacerbation onset

Acute periods of pulmonary exacerbation are the single most important cause of morbidity in cystic fibrosis patients, and may be associated with a loss of lung function. Intervening prior to the onset of a substantially increased inflammatory response may limit the associated damage to the airways. While a number of biomarker assays based on inflammatory markers have been developed, providing useful and important measures of disease during these periods, such factors are typically only elevated once the process of exacerbation has been initiated. Identifying biomarkers that can predict the onset of pulmonary exacerbation at an early stage would provide an opportunity to intervene before the establishment of a substantial immune response, with major implications for the advancement of cystic fibrosis care. The precise triggers of pulmonary exacerbation remain to be determined; however, the majority of models relate to the activity of microbes present in the patient's lower airways of cystic fibrosis. Advances in diagnostic microbiology now allow for the examination of these complex systems at a level likely to identify factors on which biomarker assays can be based. In this article, we discuss key considerations in the design and testing of assays that could predict pulmonary exacerbations

Relationship between pulmonary exacerbations and daily physical activity in adults with cystic fibrosis

The aim of this study was to examine the relationship between pulmonary exacerbations and physical activity (PA) in adults with cystic fibrosis (CF)

Indicators of pulmonary exacerbation in cystic fibrosis: A Delphi survey of patients and health professionals

Background: There is uncertainty about the most important indicators of pulmonary exacerbations in CF. Methods: Two parallel Delphi surveys in 13 CF centres (UK and Ireland). Delphi 1: 31 adults with CF, ≥ one exacerbation over 12 months. Delphi 2: 38 CF health professionals. Rounds 1 and 2 participants rated their level of agreement with statements relating to indicators of exacerbation; Round 3 participants rated the importance of statements which were subsequently placed in rank order. Results: Objective measurements were of higher importance to health professionals. Feelings of increased debility were rated most important by adults with CF. Conclusions: There were clear differences in perspectives between the two groups as to the most important indicators of an exacerbation. This highlights that CF health professionals should take more cognisance of specific signs and symptoms reported by adults with CF, especially since these may be a precursor to an exacerbation

Cytomegalovirus-associated pulmonary exacerbation in patients with cystic fibrosis.

CMV is an unusual cause of pulmonary exacerbation in immunocompetent individuals with CF http://ow.ly/Rdds30hlnjV

Effects of propidium monoazide (PMA) treatment on mycobiome and bacteriome analysis of cystic fibrosis airways during exacerbation

Introduction and Purpose : Propidium monoazide (PMA)-pretreatment has increasingly been applied to remove the bias from dead or damaged cell artefacts, which could impact the microbiota analysis by high-throughput sequencing. Our study aimed to determine whether a PMA-pretreatment coupled with high-throughput sequencing analysis provides a different picture of the airway mycobiome and bacteriome. Results and Discussion : We compared deep-sequencing data of mycobiota and microbiota of 15 sputum samples from 5 cystic fibrosis (CF) patients with and without prior PMA-treatment of the DNA-extracts. PMA-pretreatment had no significant effect on the entire and abundant bacterial community (genera expressed as operational taxonomic units (OTUs) with a relative abundance greater than or equal to 1%), but caused a significant difference in the intermediate community (less than 1%) when analyzing the alpha biodiversity Simpson index (p = 0.03). Regarding PMA impact on the airway mycobiota evaluated for the first time here; no significant differences in alpha diversity indexes between PMA-treated and untreated samples were observed. Regarding beta diversity analysis, the intermediate communities also differed more dramatically than the total and abundant ones when studying both mycobiome and bacteriome. Our results showed that only the intermediate (or low abundance) population diversity is impacted by PMA-treatment, and therefore that abundant taxa are mostly viable during acute exacerbation in CF. Given such a cumbersome protocol (PMA-pretreatment coupled with high-throughput sequencing), we discuss its potential interest within the follow-up of CF patients. Further studies using PMA-pretreatment are warranted to improve our "omic" knowledge of the CF airways

Flexible semiparametric joint modeling: an application to estimate individual lung function decline and risk of pulmonary exacerbations in cystic fibrosis.

BACKGROUND: Epidemiologic surveillance of lung function is key to clinical care of individuals with cystic fibrosis, but lung function decline is nonlinear and often impacted by acute respiratory events known as pulmonary exacerbations. Statistical models are needed to simultaneously estimate lung function decline while providing risk estimates for the onset of pulmonary exacerbations, in order to identify relevant predictors of declining lung function and understand how these associations could be used to predict the onset of pulmonary exacerbations. METHODS: Using longitudinal lung function (FEV1) measurements and time-to-event data on pulmonary exacerbations from individuals in the United States Cystic Fibrosis Registry, we implemented a flexible semiparametric joint model consisting of a mixed-effects submodel with regression splines to fit repeated FEV1 measurements and a time-to-event submodel for possibly censored data on pulmonary exacerbations. We contrasted this approach with methods currently used in epidemiological studies and highlight clinical implications. RESULTS: The semiparametric joint model had the best fit of all models examined based on deviance information criterion. Higher starting FEV1 implied more rapid lung function decline in both separate and joint models; however, individualized risk estimates for pulmonary exacerbation differed depending upon model type. Based on shared parameter estimates from the joint model, which accounts for the nonlinear FEV1 trajectory, patients with more positive rates of change were less likely to experience a pulmonary exacerbation (HR per one standard deviation increase in FEV1 rate of change = 0.566, 95% CI 0.516-0.619), and having higher absolute FEV1 also corresponded to lower risk of having a pulmonary exacerbation (HR per one standard deviation increase in FEV1 = 0.856, 95% CI 0.781-0.937). At the population level, both submodels indicated significant effects of birth cohort, socioeconomic status and respiratory infections on FEV1 decline, as well as significant effects of gender, socioeconomic status and birth cohort on pulmonary exacerbation risk. CONCLUSIONS: Through a flexible joint-modeling approach, we provide a means to simultaneously estimate lung function trajectories and the risk of pulmonary exacerbations for individual patients; we demonstrate how this approach offers additional insights into the clinical course of cystic fibrosis that were not possible using conventional approaches

MRSA eradication of newly acquired lower respiratory tract infection in cystic fibrosis

UK cystic fibrosis (CF) guidelines recommend eradication of methicillin-resistant Staphylococcus aureus (MRSA) when cultured from respiratory samples. As there is no clear consensus as to which eradication regimen is most effective, we determined the efficacy of eradication regimens used in our CF centre and long-term clinical outcome. All new MRSA positive sputum cultures (n=37) that occurred between 2000 and 2014 were reviewed. Eradication regimen characteristics and clinical, microbiological and long-term outcome data were collected. Rifampicin plus fusidic acid was the most frequently used regimen (24 (65%) out of 37 patients), with an overall success rate of 79% (19 out of 24 patients). Eradication failure was more likely in patients with an additional MRSA-positive peripheral screening swab (p=0.03) and was associated with worse survival (p=0.04). Our results demonstrate the feasibility and clinical benefits of MRSA eradication. As peripheral colonisation was associated with lower eradication success, strategies combining systemic and topical treatments should be considered to optimise outcomes in CF patients

Weight gain during acute treatment of an initial pulmonary exacerbation is associated with a longer interval to the next exacerbation in adults with cystic fibrosis

Weight gain during treatment for a cystic fibrosis exacerbation http://ow.ly/f1zl30dU9AO

Risk factors leading to pulmonary exacerbation in patients with cystic fibrosis: A systematic review

Objective: To ascertain major risk factors associated with pulmonary exacerbation and pulmonary function decline in cystic fibrosis.Methods: The systematic review was conducted at Aga Khan University, Karachi, in September 2018, and comprised electronic search of PubMed, Ovid, Science Direct and Cumulative Index of Nursing and Allied Health Literature databases of studies conducted from January 1990 to September 2018 which were categorised into 3 sets; 1990-98, 1999-2007 and 2008-18. Studies included for review focussed on articles with pulmonary exacerbation as the health outcome indicator, and had diagnosis of cystic fibrosis as the inclusion criteria, while risk factors were the exposure terms used in the search process. References in bibliographies of the included studies were also systematically searched for relevant documents.Results: Of the 60 studies obtained, 31(51.7%) were selected; 2(6.45%) from 1990-98, 7(22.58%) from 1999-2007 and 22(70.96%) from 2008-18. Overall, 17(54.83%) were cohort studies, 7(22.5%) were cross-sectional studies, 3(9.6%) were case-control studies, 3(9.6%) were randomised controlled trials and 1(3.2%) was systematic review and meta-analysis. In terms of major risk factors, genetic mutations were cited by 4(12.9%) studies, infections and inflammatory biomarkers by 15(48.4%), nutritional deficiencies by 9(29%) and geographical and socioeconomic status by 3(9.6%) studies.Conclusions: Early identification and recognition of risk factors associated with pulmonary exacerbation can have an explicit impact on its management, leading to decreased morbidity and mortality burden in cystic fibrosis cases