Our objectives were to characterise the microbiota in cystic fibrosis (CF) bronchoalveolar lavage fluid (BALF), and determine its relationship to inflammation and disease status.BALF from paediatric and adult CF patients and paediatric disease controls undergoing clinically indicated bronchoscopy was analysed for total bacterial load and for microbiota by 16S rDNA sequencing.We examined 191 BALF samples (146 CF and 45 disease controls) from 13 CF centres. In CF patients aged <2 years, nontraditional taxa (e.g.Streptococcus,PrevotellaandVeillonella) constituted ∼50% of the microbiota, whereas in CF patients aged ≥6 years, traditional CF taxa (e.g.Pseudomonas,StaphylococcusandStenotrophomonas) predominated. Sequencing detected a dominant taxon not traditionally associated with CF (e.g.StreptococcusorPrevotella) in 20% of CF BALF and identified bacteria in 24% of culture-negative BALF. Microbial diversity and relative abundance ofStreptococcus,PrevotellaandVeillonellawere inversely associated with airway inflammation. Microbiota communities were distinct in CF compared with disease controls, but did not differ based on pulmonary exacerbation status in CF.The CF microbiota detected in BALF differs with age. In CF patients aged <2 years,Streptococcuspredominates, whereas classic CF pathogens predominate in most older children and adults.

Background Pulmonary exacerbations (PEx), frequently associated with airway infection and inflammation, are the leading cause of morbidity in cystic fibrosis (CF). Molecular microbiologic approaches detect complex microbiota from CF airway samples taken during PEx. The relationship between airway microbiota, inflammation, and lung function during CF PEx is not well understood. Objective To determine the relationships between airway microbiota, inflammation, and lung function in CF subjects treated for PEx. Methods Expectorated sputum and blood were collected and lung function testing performed in CF subjects during early (0–3d.) and late treatment (>7d.) for PEx. Sputum was analyzed by culture, pyrosequencing of 16S rRNA amplicons, and quantitative PCR for total and specific bacteria. Sputum IL-8 and neutrophil elastase (NE); and circulating C-reactive protein (CRP) were measured. Results Thirty-seven sputum samples were collected from 21 CF subjects. At early treatment, lower diversity was associated with high relative abundance (RA) of Pseudomonas (r = −0.67, p<0.001), decreased FEV 1% predicted (r = 0.49, p = 0.03) and increased CRP (r = −0.58, p = 0.01). In contrast to Pseudomonas , obligate and facultative anaerobic genera were associated with less inflammation and higher FEV 1 . With treatment, Pseudomonas RA and P. aeruginosa by qPCR decreased while anaerobic genera showed marked variability in response. Change in RA of Prevotella was associated with more variability in FEV 1 response to treatment than Pseudomonas or Staphylococcus . Conclusions Anaerobes identified from sputum by sequencing are associated with less inflammation and higher lung function compared to Pseudomonas at early exacerbation. CF PEx treatment results in variable changes of anaerobic genera suggesting the need for larger studies particularly of patients without traditional CF pathogens.

Objective To determine whether the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is involved in human insulin secretion by assessing the metabolic impact of the new CFTR corrector—ivacaftor. Methods This open‐label pilot study was conducted in CF patients with the G551D mutation given new prescriptions for ivacaftor. At baseline and 4 wk after daily ivacaftor therapy, intravenous glucose tolerance tests (IVGTT) and oral glucose tolerance tests (OGTT) were performed. Results Five patients aged 6–52 were studied. After 1 month on ivacaftor, the insulin response to oral glucose improved by 66–178% in all subjects except one with long‐standing diabetes. OGTT glucose levels were not lower in the two individuals with diabetes or the two with normal glucose tolerance (NGT), but the glucose tolerance category in the subject with impaired glucose tolerance (IGT) improved to NGT after treatment. In response to intravenous glucose, the only patient whose acute insulin secretion did not improve had newly diagnosed, untreated CFRD. The others improved by 51–346%. Acute insulin secretion was partially restored in two subjects with no measurable acute insulin response at baseline, including the one with IGT and the one with long‐standing diabetes. Conclusions This small pilot study suggests there is a direct role of CFTR in human insulin secretion. Larger, long‐term longitudinal studies are necessary to determine whether early initiation of CFTR correction, particularly in young children with CF who have not yet lost considerable β‐cell mass, will delay or prevent development of diabetes in this high‐risk population.

Ode KL, Frohnert B, Laguna T, Phillips J, Holme B, Regelmann W, Thomas W, Moran A. Oral glucose tolerance testing in children with cystic fibrosis. Background: Cystic fibrosis (CF) related diabetes is the most common comorbidity in persons with CF. International Society for Pediatric and Adolescent Diabetes (ISPAD) guidelines recommend annual oral glucose tolerance testing (OGTT) screening starting at age 10. The OGTT might be recommended in younger children if, as in adults, it provided clinically relevant prognostic information. A database review was performed to determine whether OGTT findings in children with CF predict subsequent clinical course. Methods: A retrospective matched‐pair cohort study was based on OGTTs performed during 1998–2003. Children aged 6–9 were classified as having normal glucose tolerance (NGT) or abnormal glucose tolerance (AGT). Children with AGT were matched by age and gender to those with NGT. Clinical status was assessed at baseline and 5 yr later. In a separate investigation, diabetes and prior AGT status of children aged 10–18 were used to assess predictions derived from the cohort study. Results: In 1998–2003, 39 of 94 children had AGT. Of these, 31 had sufficient follow‐up data to be included. Both at baseline and 5 yr later there was no significant difference in height, weight, body mass index (BMI) or lung function between AGT and NGT. Diabetes developed in 13 AGT (42%) and one NGT (3%) [odds ratio (OR) 11, p = 0.0009]. Age of diabetes onset was 12 ± 1 yr in boys and 11 ± 1 yr in girls, compared to approximately 23 yr in the general CF population. Fifteen current children age 10–18 who had AGT before age 10 have diabetes, close to the prediction of 19. Conclusions: AGT in children with CF age 6–9 yr identifies those at high risk for progression to early onset diabetes.

The emerging scientific field of proteomics encompasses the identification, characterization, and quantification of the protein content or proteome of whole cells, tissues, or body fluids. The potential for proteomic technologies to identify and quantify novel proteins in the plasma that can function as biomarkers of the presence or severity of clinical disease states holds great promise for clinical use. However, there are many challenges in translating plasma proteomics from bench to bedside, and relatively few plasma biomarkers have successfully transitioned from proteomic discovery to routine clinical use. Key barriers to this translation include the need for “orthogonal” biomarkers (i.e., uncorrelated with existing markers), the complexity of the proteome in biological samples, the presence of high abundance proteins such as albumin in biological samples that hinder detection of low abundance proteins, false positive associations that occur with analysis of high dimensional datasets, and the limited understanding of the effects of growth, development, and age on the normal plasma proteome. Strategies to overcome these challenges are discussed.

Upper airway cultures guide the identification and treatment of lung pathogens in infants with cystic fibrosis (CF); however, this may not fully reflect the spectrum of bacteria present in the lower airway. Our objectives were to characterize the airway microbiota using bronchoalveolar lavage fluid (BALF) from asymptomatic CF infants during the first year of life and to investigate the relationship between BALF microbiota, standard culture and clinical characteristics. BALF, nasopharyngeal (NP) culture and infant pulmonary function testing data were collected at 6 months and one year of age during periods of clinical stability from infants diagnosed with CF by newborn screening. BALF was analyzed for total bacterial load by qPCR and for bacterial community composition by 16S ribosomal RNA sequencing. Clinical characteristics and standard BALF and NP culture results were recorded over five years of longitudinal follow-up. 12 BALF samples were collected from 8 infants with CF. Streptococcus, Burkholderia, Prevotella, Haemophilus, Porphyromonas, and Veillonella had the highest median relative abundance in infant CF BALF. Two of the 3 infants with repeat BALF had changes in their microbial communities over six months (Morisita-Horn diversity index 0.36, 0.38). Although there was excellent percent agreement between standard NP and BALF cultures, these techniques did not routinely detect all bacteria identified by sequencing. BALF in asymptomatic CF infants contains complex microbiota, often missed by traditional culture of airway secretions. Anaerobic bacteria are commonly found in the lower airways of CF infants.