Proximal and Distal Bronchioles Contribute to the Pathogenesis of Non-Cystic Fibrosis Bronchiectasis.

Rationale: Non-cystic fibrosis bronchiectasis (NCFB) may originate in bronchiolar regions of the lung. Accordingly, there is a need to characterize the morphology and molecular characteristics of NCFB bronchioles. Objectives: Test the hypothesis that NCFB exhibits a major component of bronchiolar disease manifest by mucus plugging and ectasia. Methods: Morphologic criteria and region-specific epithelial gene expression, measured histologically and by RNA in situ hybridization and immunohistochemistry, identified proximal and distal bronchioles in excised NCFB lungs. RNA in situ hybridization and immunohistochemistry assessed bronchiolar mucus accumulation and mucin gene expression. CRISPR-Cas9-mediated IL-1R1 knockout in human bronchial epithelial cultures tested IL-1α and IL-1ß contributions to mucin production. Spatial transcriptional profiling characterized NCFB distal bronchiolar gene expression. Measurements and Main Results: Bronchiolar perimeters and lumen areas per section area were increased in proximal, but not distal, bronchioles in NCFB versus control lungs, suggesting proximal bronchiolectasis. In NCFB, mucus plugging was observed in ectatic proximal bronchioles and associated nonectatic distal bronchioles in sections with disease. MUC5AC and MUC5B mucins were upregulated in NCFB proximal bronchioles, whereas MUC5B was selectively upregulated in distal bronchioles. Bronchiolar mucus plugs were populated by IL-1ß-expressing macrophages. NCFB sterile sputum supernatants induced human bronchial epithelial MUC5B and MUC5AC expression that was >80% blocked by IL-1R1 ablation. Spatial transcriptional profiling identified upregulation of genes associated with secretory cells, hypoxia, interleukin pathways, and IL-1ß-producing macrophages in mucus plugs and downregulation of epithelial ciliogenesis genes. Conclusions: NCFB exhibits distinctive proximal and distal bronchiolar disease. Both bronchiolar regions exhibit bronchiolar secretory cell features and mucus plugging but differ in mucin gene regulation and ectasia.

Recessively Inherited Deficiency of Secreted WFDC2 (HE4) Causes Nasal Polyposis and Bronchiectasis.

Rationale: Bronchiectasis is a pathological dilatation of the bronchi in the respiratory airways associated with environmental or genetic causes (e.g., cystic fibrosis, primary ciliary dyskinesia, and primary immunodeficiency disorders), but most cases remain idiopathic. Objectives: To identify novel genetic defects in unsolved cases of bronchiectasis presenting with severe rhinosinusitis, nasal polyposis, and pulmonary Pseudomonas aeruginosa infection. Methods: DNA was analyzed by next-generation or targeted Sanger sequencing. RNA was analyzed by quantitative PCR and single-cell RNA sequencing. Patient-derived cells, cell cultures, and secretions (mucus, saliva, seminal fluid) were analyzed by Western blotting and immunofluorescence microscopy, and mucociliary activity was measured. Blood serum was analyzed by electrochemiluminescence immunoassay. Protein structure and proteomic analyses were used to assess the impact of a disease-causing founder variant. Measurements and Main Results: We identified biallelic pathogenic variants in WAP four-disulfide core domain 2 (WFDC2) in 11 individuals from 10 unrelated families originating from the United States, Europe, Asia, and Africa. Expression of WFDC2 was detected predominantly in secretory cells of control airway epithelium and also in submucosal glands. We demonstrate that WFDC2 is below the limit of detection in blood serum and hardly detectable in samples of saliva, seminal fluid, and airway surface liquid from WFDC2-deficient individuals. Computer simulations and deglycosylation assays indicate that the disease-causing founder variant p.Cys49Arg structurally hampers glycosylation and, thus, secretion of mature WFDC2. Conclusions: WFDC2 dysfunction defines a novel molecular etiology of bronchiectasis characterized by the deficiency of a secreted component of the airways. A commercially available blood test combined with genetic testing allows its diagnosis.

Airway Mucus Hyperconcentration in Non-Cystic Fibrosis Bronchiectasis.

Rationale: Non-cystic fibrosis bronchiectasis is characterized by airway mucus accumulation and sputum production, but the role of mucus concentration in the pathogenesis of these abnormalities has not been characterized.Objectives: This study was designed to: 1) measure mucus concentration and biophysical properties of bronchiectasis mucus; 2) identify the secreted mucins contained in bronchiectasis mucus; 3) relate mucus properties to airway epithelial mucin RNA/protein expression; and 4) explore relationships between mucus hyperconcentration and disease severity.Methods: Sputum samples were collected from subjects with bronchiectasis, with and without chronic erythromycin administration, and healthy control subjects. Sputum percent solid concentrations, total and individual mucin concentrations, osmotic pressures, rheological properties, and inflammatory mediators were measured. Intracellular mucins were measured in endobronchial biopsies by immunohistochemistry and gene expression. MUC5B (mucin 5B) polymorphisms were identified by quantitative PCR. In a replication bronchiectasis cohort, spontaneously expectorated and hypertonic saline-induced sputa were collected, and mucus/mucin concentrations were measured.Measurements and Main Results: Bronchiectasis sputum exhibited increased percent solids, total and individual (MUC5B and MUC5AC) mucin concentrations, osmotic pressure, and elastic and viscous moduli compared with healthy sputum. Within subjects with bronchiectasis, sputum percent solids correlated inversely with FEV1 and positively with bronchiectasis extent, as measured by high-resolution computed tomography, and inflammatory mediators. No difference was detected in MUC5B rs35705950 SNP allele frequency between bronchiectasis and healthy individuals. Hypertonic saline inhalation acutely reduced non-cystic fibrosis bronchiectasis mucus concentration by 5%.Conclusions: Hyperconcentrated airway mucus is characteristic of subjects with bronchiectasis, likely contributes to disease pathophysiology, and may be a target for pharmacotherapy.

Survival after lung transplantation of cystic fibrosis patients infected with Burkholderia dolosa (genomovar VI).

Cystic fibrosis (CF) with severe lung disease is a well-recognized indication for lung transplantation. Colonization with various organisms in CF patients may impact post-transplant morbidity and mortality. Burkholderia cepacia complex (BCC) is made up of distinct genomovars with significant morbidity and mortality associated with B. cenocepacia (genomovar III) following lung transplant. The outcomes of patients infected with genomovar B. dolosa (genomovar VI) have yet to be described in the literature. We performed a retrospective chart review of all cystic fibrosis patients colonized with B. dolosa from our center who underwent lung transplantation (n = 11) at various medical centers across the US between 2000 and 2014. Survival rates were 73%, 53%, and 30% for 1, 3, and 5 years, respectively. Median survival was 44 months (95% CI = 11.1-76.8). CF patients with B. dolosa that have undergone lung transplantation have decreased one-year survival when compared to all patients transplanted with cystic fibrosis. Conditional 5-year survival for B. dolosa-infected patients was 43% in patients that survived the first year post-transplant, suggesting that this first year is crucial in managing the infection. Importantly, the survival of the B. dolosa patients was higher than compared to previously reported survival rates of B. cenocepacia patients post-transplant.

Zebrafish Ciliopathy Screen Plus Human Mutational Analysis Identifies C21orf59 and CCDC65 Defects as Causing Primary Ciliary Dyskinesia.

Primary ciliary dyskinesia (PCD) is caused when defects of motile cilia lead to chronic airway infections, male infertility, and situs abnormalities. Multiple causative PCD mutations account for only 65% of cases, suggesting that many genes essential for cilia function remain to be discovered. By using zebrafish morpholino knockdown of PCD candidate genes as an in vivo screening platform, we identified c21orf59, ccdc65, and c15orf26 as critical for cilia motility. c21orf59 and c15orf26 knockdown in zebrafish and planaria blocked outer dynein arm assembly, and ccdc65 knockdown altered cilia beat pattern. Biochemical analysis in Chlamydomonas revealed that the C21orf59 ortholog FBB18 is a flagellar matrix protein that accumulates specifically when cilia motility is impaired. The Chlamydomonas ida6 mutant identifies CCDC65/FAP250 as an essential component of the nexin-dynein regulatory complex. Analysis of 295 individuals with PCD identified recessive truncating mutations of C21orf59 in four families and CCDC65 in two families. Similar to findings in zebrafish and planaria, mutations in C21orf59 caused loss of both outer and inner dynein arm components. Our results characterize two genes associated with PCD-causing mutations and elucidate two distinct mechanisms critical for motile cilia function: dynein arm assembly for C21orf59 and assembly of the nexin-dynein regulatory complex for CCDC65.

US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis.

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease such as cystic fibrosis (CF). Pulmonary disease caused by NTM has emerged as a major threat to the health of individuals with CF but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened an expert panel of specialists to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM pulmonary disease in individuals with CF. Nineteen experts were invited to participate in the recommendation development process. Population, Intervention, Comparison, Outcome (PICO) methodology and systematic literature reviews were employed to inform draft recommendations. An anonymous voting process was used by the committee to reach consensus. All committee members were asked to rate each statement on a scale of: 0, completely disagree, to 9, completely agree; with 80% or more of scores between 7 and 9 being considered 'good' agreement. Additionally, the committee solicited feedback from the CF communities in the USA and Europe and considered the feedback in the development of the final recommendation statements. Three rounds of voting were conducted to achieve 80% consensus for each recommendation statement. Through this process, we have generated a series of pragmatic, evidence-based recommendations for the screening, investigation, diagnosis and treatment of NTM infection in individuals with CF as an initial step in optimising management for this challenging condition.

US Cystic Fibrosis Foundation and European Cystic Fibrosis Society consensus recommendations for the management of non-tuberculous mycobacteria in individuals with cystic fibrosis: executive summary.

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that can cause chronic pulmonary infection, particularly in individuals with pre-existing inflammatory lung disease, such as cystic fibrosis (CF). Pulmonary disease (PD) caused by NTM has emerged as a major threat to the health of individuals with CF, but remains difficult to diagnose and problematic to treat. In response to this challenge, the US Cystic Fibrosis Foundation (CFF) and the European Cystic Fibrosis Society (ECFS) convened a panel of 19 experts to develop consensus recommendations for the screening, investigation, diagnosis and management of NTM-PD in individuals with CF. PICO (population, intervention, comparison, outcome) methodology and systematic literature reviews were employed to inform draft recommendations, which were then modified to achieve consensus and subsequently circulated for public consultation within the USA and European CF communities. We have thus generated a series of pragmatic, evidence-based recommendations as an initial step in optimising management for this challenging condition.

Primary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is an autosomal recessive disorder of cilia structure, function, and biogenesis leading to chronic infections of the respiratory tract, fertility problems, and disorders of organ laterality. The diagnosis can be challenging, using traditional tools such as characteristic clinical features, ciliary function, and ultrastructural defects and newer screening tools such as nasal nitric oxide levels and genetic testing add to the diagnostic algorithm. There are 32 known PCD-causing genes, and in the future, comprehensive genetic testing may screen young infants before developing symptoms, thus improving survival. Therapies include surveillance of pulmonary function and microbiology, in addition to airway clearance, antibiotics, and early referral to bronchiectasis centers. As with cystic fibrosis (CF), standardized care at specialized centers using a multidisciplinary approach likely improves outcomes. In conjunction with the CF foundation, the PCD foundation, with experienced investigators and clinicians, is developing a network of PCD clinical centers to coordinate the effort in North America and Europe. As the network grows, clinical care and knowledge will improve.

Mutations in RSPH1 cause primary ciliary dyskinesia with a unique clinical and ciliary phenotype.

RATIONALE: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder of motile cilia, but the genetic cause is not defined for all patients with PCD. OBJECTIVES: To identify disease-causing mutations in novel genes, we performed exome sequencing, follow-up characterization, mutation scanning, and genotype-phenotype studies in patients with PCD. METHODS: Whole-exome sequencing was performed using NimbleGen capture and Illumina HiSeq sequencing. Sanger-based sequencing was used for mutation scanning, validation, and segregation analysis. MEASUREMENTS AND MAIN RESULTS: We performed exome sequencing on an affected sib-pair with normal ultrastructure in more than 85% of cilia. A homozygous splice-site mutation was detected in RSPH1 in both siblings; parents were carriers. Screening RSPH1 in 413 unrelated probands, including 325 with PCD and 88 with idiopathic bronchiectasis, revealed biallelic loss-of-function mutations in nine additional probands. Five affected siblings of probands in RSPH1 families harbored the familial mutations. The 16 individuals with RSPH1 mutations had some features of PCD; however, nasal nitric oxide levels were higher than in patients with PCD with other gene mutations (98.3 vs. 20.7 nl/min; P < 0.0003). Additionally, individuals with RSPH1 mutations had a lower prevalence (8 of 16) of neonatal respiratory distress, and later onset of daily wet cough than typical for PCD, and better lung function (FEV1), compared with 75 age- and sex-matched PCD cases (73.0 vs. 61.8, FEV1 % predicted; P = 0.043). Cilia from individuals with RSPH1 mutations had normal beat frequency (6.1 ± Hz at 25°C), but an abnormal, circular beat pattern. CONCLUSIONS: The milder clinical disease and higher nasal nitric oxide in individuals with biallelic mutations in RSPH1 provides evidence of a unique genotype-phenotype relationship in PCD, and suggests that mutations in RSPH1 may be associated with residual ciliary function.

Sodium channel blockers for cystic fibrosis.

BACKGROUND: People with cystic fibrosis (CF) have increased transport of the salt, sodium across their airway lining. Over-absorption of sodium results in the dehydration of the liquid that lines the airway surface and (along with defective chloride secretion) is a primary defect in people with CF. OBJECTIVES: To determine whether the topical administration of drugs that block sodium transport improves the respiratory condition of people with CF. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. We contacted principal investigators known to work in the field, previous authors and pharmaceutical companies who manufacture ion transport agents for unpublished or follow-up data.Most recent search of the Group's register: 19 December 2013. SELECTION CRITERIA: Published or unpublished randomised controlled trials (RCTs) or quasi-randomised controlled trials of sodium channel blockers compared to placebo or another sodium channel blocker or the same sodium channel blocker at a different dosing regimen. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data. Meta-analysis was limited due to differing study designs. MAIN RESULTS: Five RCTs, with a total of 226 participants, examining the topical administration of the short-acting sodium channel blocker, amiloride, compared to placebo were identified as eligible for inclusion in the review. In three studies over six months, there was a significant difference found in the difference in relative change in FVC in favour of placebo (weighted mean difference 1.51% (95% confidence interval -2.77 to -0.25), although heterogeneity was evident. A two-week study demonstrated that hypertonic saline with amiloride pre-treatment did not result in a significant improvement in respiratory function or mucus clearance, in contrast to pre-treatment with placebo. There were no significant differences identified in other clinically relevant outcomes. AUTHORS' CONCLUSIONS: We found no evidence that the topical administration of a short-acting sodium channel blocker improves respiratory condition in people with cystic fibrosis and some limited evidence of deterioration in lung function.

Mutations in CCDC39 and CCDC40 are the major cause of primary ciliary dyskinesia with axonemal disorganization and absent inner dynein arms.

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder caused by cilia and sperm dysmotility. About 12% of cases show perturbed 9+2 microtubule cilia structure and inner dynein arm (IDA) loss, historically termed "radial spoke defect." We sequenced CCDC39 and CCDC40 in 54 "radial spoke defect" families, as these are the two genes identified so far to cause this defect. We discovered biallelic mutations in a remarkable 69% (37/54) of families, including identification of 25 (19 novel) mutant alleles (12 in CCDC39 and 13 in CCDC40). All the mutations were nonsense, splice, and frameshift predicting early protein truncation, which suggests this defect is caused by "null" alleles conferring complete protein loss. Most families (73%; 27/37) had homozygous mutations, including families from outbred populations. A major putative hotspot mutation was identified, CCDC40 c.248delC, as well as several other possible hotspot mutations. Together, these findings highlight the key role of CCDC39 and CCDC40 in PCD with axonemal disorganization and IDA loss, and these genes represent major candidates for genetic testing in families affected by this ciliary phenotype. We show that radial spoke structures are largely intact in these patients and propose this ciliary ultrastructural abnormality be referred to as "IDA and microtubular disorganisation defect," rather than "radial spoke defect."

Lung transplant outcomes in cystic fibrosis patients with pre-operative Mycobacterium abscessus respiratory infections.

BACKGROUND: Mycobacterium abscessus in cystic fibrosis (CF) patients is considered a contraindication to lung transplantation. We examine the post-transplant outcomes of CF patients with M. abscessus pre-transplant. METHODS: CF patients transplanted at the University of North Carolina from 1992 to 2012 were retrospectively examined. Patients with at least one respiratory sample positive for M. abscessus prior to transplantation were included. Data collected included age, FEV1, body mass index (BMI), systemic steroid use, diabetes mellitus, ventilatory assistance, co-existent CF pathogens, imaging, post-transplant complications, and survival. RESULTS (N = 13): At transplant, mean age was 24.6 yr, mean BMI was 18.1 kg/m(2), six had 3+ positive smears for M. abscessus, and three were ventilator dependent. All met American Thoracic Society microbiological criteria for disease pre-transplant. Three patients developed M. abscessus-related complications, with clearance of the organism following treatment. Survival post-transplant shows 77% alive at one yr, 64% at three yr, and 50% at five yr; none died of M. abscessus. The survival data showed no statistically significant difference (p = 0.8) compared with a contemporaneously transplanted population of CF patients without M. abscessus (n = 154). CONCLUSION: Lung transplantation, with favorable survival, is possible in CF patients with M. abscessus. Even if M. abscessus recurs, local control and clearance is possible.

Mutations in DNAH5 cause primary ciliary dyskinesia and randomization of left-right asymmetry.

Primary ciliary dyskinesia (PCD, MIM 242650) is characterized by recurrent infections of the respiratory tract due to reduced mucociliary clearance and by sperm immobility. Half of the affected offspring have situs inversus (reversed organs), which results from randomization of left-right (LR) asymmetry. We previously localized to chromosome 5p a PCD locus containing DNAH5, which encodes a protein highly similar to the Chlamydomonas gamma-dynein heavy chain. Here we characterize the full-length 14-kb transcript of DNAH5. Sequence analysis in individuals with PCD with randomization of LR asymmetry identified mutations resulting in non-functional DNAH5 proteins.

Sodium channel blockers for cystic fibrosis.

BACKGROUND: People with cystic fibrosis (CF) have increased transport of the salt, sodium across their airway lining. Over-absorption of sodium results in the dehydration of the liquid that lines the airway surface and is a primary defect in people with CF. OBJECTIVES: To determine whether the topical administration of drugs that block sodium transport improves the respiratory condition of people with CF. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. We contacted principal investigators known to work in the field, previous authors and pharmaceutical companies who manufacture ion transport agents for unpublished or follow-up data.Most recent search of the Group's register: 22nd August 2011. SELECTION CRITERIA: Published or unpublished randomised controlled trials (RCTs) or quasi-randomised controlled trials of sodium channel blockers compared to placebo or another sodium channel blocker or the same sodium channel blocker at a different dosing regimen. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data. Meta-analysis was limited due to differing study designs. MAIN RESULTS: Five RCTs, with a total of 226 participants, examining the topical administration of the short-acting sodium channel blocker, amiloride, compared to placebo were identified as eligible for inclusion in the review. In three studies over six months, there was a significant difference found in the difference in relative change in FVC in favour of placebo (weighted mean difference 1.51% (95% confidence interval -2.77 to -0.25), although heterogeneity was evident. A two-week study demonstrated that hypertonic saline with amiloride pre-treatment did not result in a significant improvement in respiratory function or mucus clearance, in contrast to pre-treatment with placebo. There were no significant differences identified in other clinically relevant outcomes. AUTHORS' CONCLUSIONS: We found no evidence that the topical administration of a short-acting sodium channel blocker improves respiratory condition in people with cystic fibrosis and some limited evidence of deterioration in lung function.

Chemical pleurodesis versus surgical intervention for persistent and recurrent pneumothoraces in cystic fibrosis.

BACKGROUND: Pneumothorax is a potentially life-threatening complication for people with cystic fibrosis. Spontaneous pneumothorax is the presence of air in the pleural space and can be subdivided into first episode and recurrent. The recurrence of pneumothorax is when it occurs on the same side seven days or more after initial resolution. A pneumothorax is persistent if the air leak lasts for more than five days (Schidlow 1993). Managing spontaneous pneumothoraces is controversial and there is no standard treatment. Medical and surgical intervention are the two main categories for the treatment of recurrent pneumothoraces in people with cystic fibrosis. While surgical interventions are felt to be more effective in people without cystic fibrosis, the complications directly related to the procedure, as well as the post-operative complications make surgical interventions riskier for people with cystic fibrosis. Additionally, these interventions have the potential to make people with cystic fibrosis ineligible for lung transplantation in the future. Therefore, the benefits and side effects or disadvantages for the medical and surgical treatment of recurrent pneumothoraces in people with cystic fibrosis need to be systematically reviewed. OBJECTIVES: To determine the clinical efficacy and safety of different treatment interventions for managing spontaneous persistent and recurrent pneumothoraces in people with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register which comprises references identified from comprehensive electronic database searches, handsearches of relevant journals and abstract books of conference proceedings.Date of the most recent search: 29 October 2012. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials which compared the use of chemical pleurodesis to surgical interventions for the treatment of persistent and recurrent pneumothoraces in CF. DATA COLLECTION AND ANALYSIS: No relevant trials were identified. MAIN RESULTS: No trials were included in this review AUTHORS' CONCLUSIONS: Pneumothorax is a potentially life-threatening complication for people with cystic fibrosis and the management of spontaneous pneumothoraces remains a topic of considerable controversy. Medical and surgical intervention are the two main categories for the treatment of recurrent pneumothoraces in this population. However, it is disappointing that neither intervention has been assessed by randomised controlled trials. This systematic review identifies the need for a multicentre randomised controlled trial assessing both efficacy and possible adverse effects of the use of chemical pleurodesis versus surgical interventions for the treatment of persistent and recurrent pneumothoraces in people with cystic fibrosis.

Pseudomonas aeruginosa associated with severity of non-cystic fibrosis bronchiectasis measured by the modified bronchiectasis severity score (BSI) and the FACED: The US bronchiectasis and NTM Research Registry (BRR) study.

RATIONALE: Non-cystic fibrosis bronchiectasis (NCFB) is characterized by dilated bronchi, poor mucus clearance and susceptibility to bacterial infection. Pseudomonas aeruginosa (PA) is one of the most frequently isolated pathogens in patients with NCFB. The purpose of this study was to evaluate the association between presence of PA and disease severity in patients within the US Bronchiectasis and Nontuberculous mycobacteria (NTM) Research Registry (BRR). METHODS: Baseline US BRR data from adult patients with NCFB collected between 2008 and 2018 was used for this study. The presence of PA was defined as one or more positive PA cultures within two years prior to enrollment. Modified Bronchiectasis Severity Index (m-BSI) and modified FACED (m-FACED) were computed to evaluate severity of bronchiectasis. Unadjusted and multivariable multinomial regression models were used to assess the association between presence of PA and severity of bronchiectasis. RESULTS: Average age of the study participants (n = 1831) was 63.7 years (SD = 14.1), 91.5% white, and 78.8% female. Presence of PA was identified in 25.4% of the patients. Patients with presence of PA had significantly lower mean pre-bronchodilator FEV1% predicted compared to those without PA (62.8% vs. 73.7%, p < .0001). In multivariate analyses, patients with presence of PA had significantly greater odds for having high (ORadj = 6.15 (95%CI:3.98-9.50) and intermediate (ORadj = 2.06 (95%CI:1.37-3.09) severity vs. low severity on m-BSI. CONCLUSION: The presence of PA is common in patients with NCFB within the Bronchiectasis and NTM Research Registry. Severity of bronchiectasis is significantly greater in patients with PA which emphasizes high burden of the disease.

Medical student imaging case files in the cloud.

BACKGROUND: Millennial digital learners value meaningful work, immediate feedback, collaborative communication and technology implementation. A student-produced digital imaging teaching case file-centric flipped curriculum offers these benefits. Our questions included: (i) is a cloud-based website platform supporting the online publication of student-selected and student-submitted teaching cases feasible; and (ii) what were the impressions of students of this educational intervention? METHODS: An open-source medical student-centric radiology website was created with limited-access cloud upload capability, with site analytics continuously recorded. Medical students submitted de-identified radiology cases on a topic of their choosing, for peer review and publication. By making the host site publicly accessible, we empowered students to list their publication(s) on resumes. Following six blocks of the 2018/19 academic year after implementation, an electronic survey was sent to the eligible medical student cohort who had were enrolled in a radiology elective in order to assess the effectiveness of the intervention (n = 107). RESULTS: The survey response rate was 52% (n = 56), of which 98% participated (n = 55) and 75% completed a teaching file (n = 42). The students assessed their ability to systematically review imaging, communicate pertinent clinical information, appropriately order imaging, correctly use the ACR Appropriateness Criteria® , consider procedure costs, consider procedure risks, consider procedure benefits, evaluate effectiveness and identify who to direct questions to regarding correct study. Students reported answers on a seven-point Likert scale. Data scores ranged from 5.28 (agree) to 6.71 (strongly agree) across all categories. CONCLUSIONS: Our successful student-developed teaching file takes advantage of digital radiology and the educational tools favoured by millennials. This activity meets core competencies in self-directed and lifelong learning.

Nutrition and Markers of Disease Severity in Patients With Bronchiectasis.

BACKGROUND: Increasing numbers of patients are being diagnosed with bronchiectasis, yet much remains to be elucidated about this heterogeneous patient population. We sought to determine the relationship between nutrition and health outcomes in non-cystic fibrosis (non-CF) bronchiectasis, using data from the U.S. Bronchiectasis Nontuberculous Mycobacterial Research Registry (U.S. BRR). METHODS: This was a retrospective, observational, longitudinal study using 5-year follow-up data from the BRR. Bronchiectasis was confirmed on computed tomography (CT). We stratified patients into nutrition categories using body mass index (BMI), and correlated BMI to markers of disease severity. RESULTS: Overall, n = 496 patients (mean age 64.6- ± 13 years; 83.3% female) were included. At baseline 12.3% (n = 61) were underweight (BMI < 18.5kg/m2), 63.9% (n = 317) had normal weight (BMI ≥ 18.5kg/m2 and <25.0kg/m2), 17.3% (n = 86) were overweight (BMI ≥ 25.0kg/m2 and < 30.0kg/m2), and 6.5% (n= 32) were obese (BMI ≥ 30kg/m2). Men were overrepresented in the overweight and obese groups (25.6% and 43.8% respectively, p < 0.0001). Underweight patients had lower lung function (forced expiratory volume in 1 second [FEV1] % predicted) than the other weight groups (64.5 ± 22, versus 73.5 ± 21, 68.5 ± 20, and 76.5 ± 21 in normal, overweight, and obese groups respectively, p = 0.02). No significant differences were noted between BMI groups for other markers of disease severity at baseline, including exacerbation frequency or hospitalization rates. No significant differences were noted in BMI distribution between patients with and without Pseudomonas, non-tuberculous mycobacteria, or by cause of bronchiectasis. The majority of patients demonstrated stable BMI over 5 years. CONCLUSIONS: Although underweight patients with bronchiectasis have lower lung function, lower BMI does not appear to relate to other markers of disease severity in this patient population.