The pathophysiology of bronchiectasis

Factors associated with bronchiectasis in patients with moderate-severe chronic obstructive pulmonary disease

A high prevalence of bronchiectasis was found by chest computed tomography (CT) in patients with moderate-severe chronic obstructive pulmonary disease (COPD), and it was shown to be associated with more severe symptoms, higher frequency of exacerbations and mortality. The risk factors for bronchiectasis in COPD are not yet clarified.High-resolution computed tomography (HRCT) of chest was performed in patients with moderate-severe COPD, and the presence and the extent of bronchiectasis were evaluated by two radiologists. Demographic data, respiratory symptoms, lung function, previous pulmonary tuberculosis, serum inflammatory markers, serum total immunoglobulin E (T-IgE), and sputum culture of Pseudomonas aeruginosa were compared between those with and without bronchiectasis. Multivariate logistic regression analysis was used to determine the independent factors associated with bronchiectasis.We enrolled 190 patients with stable COPD, of which 87 (87/190, 45.8%) had bronchiectasis on HRCT. Compared with those without bronchiectasis, COPD patients with bronchiectasis were more likely to be males (P = 0.021), had a lower body mass index (BMI) (P = 0.019), a higher prevalence of previous tuberculosis (P = 0.005), longer history of dyspnea (P < 0.001), more severe dyspnea (P = 0.041), higher frequency of acute exacerbation (P = 0.002), higher serum concentrations of C-reactive protein (CRP) (P = 0.017), fibrinogen (P = 0.016), and T-IgE [P = 0.004; for log10(T-IgE), P <0.001]. COPD patients with bronchiectasis also showed poorer lung function (for FEV1/FVC, P = 0.013; for FEV1%predicted, P = 0.012; for global initiative for chronic obstructive lung disease (GOLD) grades, P = 0.035), and a higher positive rate of sputum P aeruginosa (P = 0.020). Logistic regression analysis demonstrated that male gender (P = 0.021), previous tuberculosis (P = 0.021), and increased level of serum T-IgE [for log10(T-IgE), P < 0.001] were risk factors for coexistent bronchiectasis. More notably, the level of serum T-IgE [log10(T-IgE)] was positively correlated with the extent of bronchiectasis in COPD patients (r = 0.208, P = 0.05).Higher serum T-IgE, male gender, and previous tuberculosis are independent risk factors for coexistent bronchiectasis in COPD. The association of T-IgE with the extent of bronchiectasis also suggests that further investigations are needed to explore the potential role of IgE in the pathogenesis of bronchiectasis in COPD.

Neutrophilic Bronchial Inflammation Correlates with Clinical and Functional Findings in Patients with Noncystic Fibrosis Bronchiectasis

Background. Neutrophilic bronchial inflammation is a main feature of bronchiectasis, but not much is known about its relationship with other disease features. Aim. To compare airway inflammatory markers with clinical and functional findings in subjects with stable noncystic fibrosis bronchiectasis (NCFB). Methods. 152 NFCB patients (62.6 years; females: 57.2%) underwent clinical and functional cross-sectional evaluation, including microbiologic and inflammatory cell profile in sputum, and exhaled breath condensate malondialdehyde (EBC-MDA). NFCB severity was assessed using BSI and FACED criteria. Results. Sputum neutrophil percentages inversely correlated with FEV1 (P < 0.0001; rho = -0.428), weakly with Leicester Cough Questionnaire score (P = 0.068; rho = -0.58), and directly with duration of the disease (P = 0.004; rho = 0.3) and BSI severity score (P = 0.005; rho = 0.37), but not with FACED. Sputum neutrophilia was higher in colonized subjects, P. aeruginosa colonized subjects showing greater sputum neutrophilia and lower FEV1. Patients with ≥3 exacerbations in the last year showed a significantly greater EBC-MDA than the remaining patients. Conclusions. Sputum neutrophilic inflammation and biomarkers of oxidative stress in EBC can be considered good biomarkers of disease severity in NCFB patients, as confirmed by pulmonary function, disease duration, bacterial colonization, BSI score, and exacerbation rate.

Prolonged antibiotics for non-cystic fibrosis bronchiectasis in children and adults

BACKGROUND

The vicious cycle hypothesis for bronchiectasis predicts that bacterial colonisation of the respiratory tract perpetuates inflammatory change. This damages the mucociliary escalator, preventing bacterial clearance and allowing persistence of pro-inflammatory mediators. Conventional treatment with physiotherapy and intermittent antibiotics is believed to improve the condition of people with bronchiectasis, although no conclusive data show that these interventions influence the natural history of the condition. Various strategies have been tried to interrupt this cycle of infection and inflammation, including prolonging antibiotic treatment with the goal of allowing the airway mucosa to heal.

OBJECTIVES

To determine the benefits of prolonged antibiotic therapy in the treatment of patients with bronchiectasis.

SEARCH METHODS

We searched the Cochrane Airways Group Trials Register and reference lists of identified articles. Searches were current as of February 2014.

SELECTION CRITERIA

Randomised trials examining the use of prolonged antibiotic therapy (for four or more weeks) in the treatment of bronchiectasis compared with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors to ask for missing information.

MAIN RESULTS

Eighteen trials met the inclusion criteria, randomly assigning a total of 1157 participants. Antibiotics were given for between four weeks and 83 weeks. Limited meta-analysis was possible because of the diversity of outcomes reported in these trials. Based on the number of participants with at least one exacerbation, the meta-analysis showed significant effects in favour of the intervention (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.19 to 0.52; P value < 0.00001), with events occurring in 271 per 1000 people in the intervention arm (95% CI 126 to 385) and in 546 per 1000 in the control population, based on evidence of moderate quality. A non-statistically significant reduction in hospitalisation favoured the use of prolonged antibiotics with a moderate quality grade of supporting evidence (37 per 1000 in the intervention arm (95% CI 13 to 96) and 87 per 1000 in control (OR 0.40, 95% CI 0.14 to 1.11; P value = 0.08). Drug resistance developed in 36 of 220 participants taking antibiotics compared with 10 of 211 participants given placebo or standard therapy (OR 3.48, 95% CI 1.20 to 10.07; P value = 0.02), translating to natural frequencies of 155 per 1000 in the intervention arm (95% CI 59 to 346) and 50 per 1000 in the control arm. The intervention was well tolerated with no overall significant difference in withdrawal between treatment and placebo groups (OR 0.91, 95% CI 0.56 to 1.49). Diarrhoea was commonly reported as an adverse event, particularly with an oral intervention.

AUTHORS' CONCLUSIONS

Available evidence shows benefit associated with use of prolonged antibiotics in the treatment of patients with bronchiectasis, at least halving the odds of exacerbation (with 275 fewer exacerbations per every 1000 people treated in the antibiotic arm compared with the control arm) and hospitalisation (50 fewer hospitalisations per 1000 people in the antibiotic arm compared with the control arm). However, the risk of emerging drug resistance is increased more than threefold. This review is limited by diversity of trials and by evidence of moderate to low quality. Further randomised controlled trials with adequate power and standardised end points are required.

Bronchiectasis: Mechanisms and Imaging Clues of Associated Common and Uncommon Diseases

Bronchiectasis is permanent irreversible dilatation of the airways and occurs in a variety of pathologic processes. Recurrent infection and inflammation and the resulting chemical and cellular cascade lead to permanent architectural changes in the airways. Bronchiectasis can confer substantial potential morbidity, usually secondary to recurrent infection. In severe cases of bronchiectasis, massive hemoptysis can lead to death. Thin-section computed tomography is the most sensitive imaging modality for the detection of bronchiectasis; findings include bronchial diameter exceeding that of the adjacent pulmonary artery and lack of normal tapering of terminal bronchioles as they course toward the lung periphery. The authors will review various causes of bronchiectasis, including common causes, such as recurrent infection or aspiration, and uncommon causes, such as congenital immunodeficiencies and disorders of cartilage development. The authors will also present an approach emphasizing the distribution (apical versus basal and central versus peripheral) and concomitant findings, such as nodules, cavities, and/or lymphadenopathy, that can assist in narrowing the differential diagnosis. Although an adequate understanding of these underlying causes in conjunction with their specific imaging appearances will allow radiologists to more confidently determine the process causing this common radiologic finding, clinical history and patient demographic characteristics play an integral role in determining a pertinent and concise differential diagnosis.

Effect of low-dose, long-term roxithromycin on airway inflammation and remodeling of stable noncystic fibrosis bronchiectasis

Background. Noncystic fibrosis bronchiectasis (NCFB) is characterized by airway expansion and recurrent acute exacerbations. Macrolide has been shown to exhibit anti-inflammatory effects in some chronic airway diseases. Objective. To assess the efficacy of roxithromycin on airway inflammation and remodeling in patients with NCFB under steady state. Methods. The study involved an open-label design in 52 eligible Chinese patients with NCFB, who were assigned to control (receiving no treatment) and roxithromycin (receiving 150 mg/day for 6 months) groups. At baseline and 6 months, the inflammatory markers such as interleukin- (IL-)8, neutrophil elastase (NE), matrix metalloproteinase- (MMP)9, hyaluronidase (HA), and type IV collagen in sputum were measured, along with the detection of dilated bronchus by throat computed tomography scan, and assessed the exacerbation. Results. Forty-three patients completed the study. The neutrophil in the sputum was decreased in roxithromycin group compared with control (P < 0.05). IL-8, NE, MMP-9, HA, and type IV collagen in sputum were also decreased in roxithromycin group compared with the control group (all P < 0.01). Airway thickness of dilated bronchus and exacerbation were reduced in roxithromycin group compared with the control (all P < 0.05). Conclusions. Roxithromycin can reduce airway inflammation and airway thickness of dilated bronchus in patients with NCFB.

Clinical-radiological, histological and genetic analyses in a lung transplant recipient with Mounier-Kuhn syndrome and end-stage chronic obstructive pulmonary disease

BACKGROUND AND AIMS

The Mounier-Kuhn syndrome (MKS) is a rare disease characterized by a pathological dilation of the trachea and the bronchial system. The etiology of the disorder remains elusive, but genetic alterations and degradation of elastic fibers are thought to be involved in the pathogenesis. No causative treatment is available although transplantation is an option for end-stage disease. Here, we describe a patient suffering from MKS who received a double lung transplant at our department.

METHODS

Since a familial clustering of MKS is discussed in the literature, we performed a chromosomal analysis and an array-comparative genomic hybridization (CGH) to search for genetic abnormalities. At the time of transplantation, we collected samples from the bronchi and performed hematoxylin and eosin (HE), Elastic von-Gieson (EVG) and immunohistochemical stains of the explanted MKS bronchus, a control bronchus and of the inflammatory infiltrates. Specimens of main bronchi from the donor lung harvested for transplant served as control. Bronchial smears were taken from both main bronchi of the recipient for microbiological cultures.

RESULTS

No genetic alterations could be found in chromosomal analysis and in array-CGH. Histological analysis revealed a strong reduction of elastic fibers in the submucosal connective tissue and a diffuse inflammatory infiltrate, mainly comprised of CD4+ cells. In addition, immunohistochemistry showed increased matrix metalloproteinases (MMPs) protein expression of MMP-1, 2, 3 and 9.

CONCLUSIONS

Based on our findings, we hypothesize that MKS is a chronic inflammatory disease characterized by an MMP-mediated degradation of submucosal elastic fibers.

Bronchiectasis in older patients with chronic obstructive pulmonary disease : prevalence, diagnosis and therapeutic management

The prevalence of chronic obstructive pulmonary disease (COPD) increases with age. Recent evidence suggests that the finding of co-existent bronchiectasis is becoming increasingly common, possibly because of increased use of high-resolution CT scanning in the assessment of patients with COPD. This may represent a distinct phenotype of COPD, but, nevertheless, it is likely to pose an increased burden to health services and challenges in determining the correct management of these patients. Here, we review the factors associated with bronchiectasis in older patients with COPD and the evidence for many of the therapies currently used in the treatment of patients, providing a rational approach to their management.

Mucociliary clearance: pathophysiological aspects

Mucociliary clearance has long been known to be a significant innate defence mechanism against inhaled microbes and irritants. Important knowledge has been gathered regarding the anatomy and physiology of this system, and in recent years, extensive studies of the pathophysiology related to lung diseases characterized by defective mucus clearance have resulted in a variety of therapies, which might be able to enhance clearance from the lungs. In addition, ways to study in vivo mucociliary clearance in humans have been developed. This can be used as a means to assess the effect of different pharmacological interventions on clearance rate, to study the importance of defective mucus clearance in different lung diseases or as a diagnostic tool in the work-up of patients with recurrent airway diseases. The aim of this review is to provide an overview of the anatomy, physiology, pathophysiology, and clinical aspects of mucociliary clearance and to present a clinically applicable test that can be used for in vivo assessment of mucociliary clearance in patients. In addition, the reader will be presented with a protocol for this test, which has been validated and used as a diagnostic routine tool in the work-up of patients suspected for primary ciliary dyskinesia at Rigshospitalet, Denmark for over a decade.

Bronchiectasis-associated hospitalizations in Germany, 2005-2011: a population-based study of disease burden and trends

Background

Representative population-based data on the epidemiology of bronchiectasis in Europe are limited. The aim of the present study was to investigate the current burden and the trends of bronchiectasis-associated hospitalizations and associated conditions in Germany in order to inform focused patient care and to facilitate the allocation of healthcare resources.

Methods

The nationwide diagnosis-related groups hospital statistics for the years 2005–2011 were used in order to identify hospitalizations with bronchiectasis as any hospital discharge diagnosis according to the International Classification of Diseases, 10th revision, code J47, (acquired) bronchiectasis. Poisson log-linear regression analysis was used to assess the significance of trends. In addition, the overall length of hospital stay (LOS) and the in-hospital mortality in comparison to the nationwide overall mortality due to bronchiectasis as the primary diagnosis was assessed.

Results

Overall, 61,838 records with bronchiectasis were extracted from more than 125 million hospitalizations. The average annual age-adjusted rate for bronchiectasis as any diagnosis was 9.4 hospitalizations per 100,000 population. Hospitalization rates increased significantly during the study period, with the highest rate of 39.4 hospitalizations per 100,000 population among men aged 75–84 years and the most pronounced average annual increases among females. Besides numerous bronchiectasis-associated conditions, chronic obstructive pulmonary disease (COPD) was most frequently found in up to 39.2% of hospitalizations with bronchiectasis as the primary diagnosis. The mean LOS was comparable to that for COPD. Overall, only 40% of bronchiectasis-associated deaths occurred inside the hospital.

Conclusions

The present study provides evidence of a changing epidemiology and a steadily increasing prevalence of bronchiectasis-associated hospitalizations. Moreover, it confirms the diversity of bronchiectasis-associated conditions and the possible association between bronchiectasis and COPD. As the major burden of disease may be managed out-of-hospital, prospective patient registries are needed to establish the exact prevalence of bronchiectasis according to the specific underlying condition.

The challenge of chronic lung disease in HIV-infected children and adolescents

Until recently, little attention has been given to chronic lung disease (CLD) in HIV-infected children. As the HIV epidemic matures in sub-Saharan Africa, adolescents who acquired HIV by vertical transmission are presenting to health services with chronic diseases. The most common is CLD, which is often debilitating. This review summarizes the limited data available on the epidemiology, pathophysiology, clinical picture, special investigations and management of CLD in HIV-infected adolescents. A number of associated conditions: lymphocytic interstitial pneumonitis, tuberculosis and bronchiectasis are well described. Other pathologies such as HIV-associated bronchiolitis obliterans resulting in non-reversible airway obstruction, has only recently been described. In this field, there are many areas of uncertainty needing urgent research. These areas include the definition of CLD, pathophysiological mechanisms and common pathologies responsible. Very limited data are available to formulate an effective plan of investigation and management.

Efficacy of inhaled ciprofloxacin in the management of non-cystic fibrosis bronchiectasis

Non-cystic fibrosis bronchiectasis (NCFBE), a historically under-recognized chronic respiratory condition, is a significant diagnosis currently experiencing a resurgence of interest in its clinical management. Ciprofloxacin is part of the current armamentarium used in the treatment of the recurrent respiratory tract infections seen in NCFBE. Inhaled ciprofloxacin, a novel method of drug delivery for the fluoroquinolone class, is being actively investigated. The inhaled formulation is designed to enhance drug delivery to the site of infection in the lung while minimizing the risk of systemic toxicity. This review summarizes the pharmacology and pharmacokinetics of ciprofloxacin and the rationale for the development of an inhaled formulation for NCFBE. Preclinical and clinical data regarding current development of inhaled ciprofloxacin formulations is also evaluated. Lastly, the anticipated role of inhaled ciprofloxacin in the management of NCFBE is discussed, including future considerations and potential limitations of therapy.

Could vitamin d have a potential anti-inflammatory and anti-infective role in bronchiectasis?

Bronchiectasis is a chronic infective and inflammatory respiratory disease that causes significant morbidity and mortality. Patients with non-cystic-fibrosis bronchiectasis are frequently vitamin D deficient, and vitamin D levels correlate with disease severity. Infection-specific actions of vitamin D include the enhancement of innate immunity and the moderation of inflammation caused by the adaptive immune response. Potentially, vitamin D could influence the processes that lead to bronchiectasis and the frequency and severity of acute exacerbations. Randomized trials of vitamin D supplementation have shown effects that are likely to be protective against the development of bronchiectasis. Several issues need to be clarified before the development of clinical trials to investigate the role of vitamin D in bronchiectasis. These include an optimal vitamin D supplementation dose and appropriate and sensitive outcome measures that include assessment of exacerbation frequency and severity, lung function, and health-related quality of life.

Efficacy of Halotherapy for Improvement of Pulmonary function Tests and Quality of Life of Non-Cystic Fibrosis Bronchiectatic Patients

BACKGROUND

Halotherapy is a treatment modality suggested for patients with chronic pulmonary diseases. In this technique, inhalation of crystal salt stones extracted from mines improves patients' pulmonary function tests and symptoms by facilitating the secretion or expulsion of phlegm and mucus and reducing the risk of bacterial infections. Bronchiectasis is chronic disease of the airways characterized by irreversible dilation of airways. It has a progressive course and despite the available treatments, many of these patients eventually enter the advanced phase of disease. The aim of this study was to evaluate the effect of halotherapy on pulmonary function tests and quality of life of non-CF bronchiectatic patients.

MATERIALS AND METHODS

This clinical trial evaluated the results of spirometry and 6-minute walk test as well as the quality of life (according to SF-36 questionnaire) of stable non-CF bronchiectatic patients presenting to the pulmonary clinic before and after the use of salt spray for 2 months.

RESULTS

Of 40 study patients, 20 were excluded due to various reasons and 20 were evaluated. The mean age of patients was 35±11 years and the underlying cause of disease was chronic pulmonary infection in 65% of cases. Comparison of the results of pulmonary function tests and 6-minute walk test and quality of life indices in SF-36 questionnaire before and after the intervention showed no significant difference (P > 0.05). However, 65% of patients were satisfied with halotherapy and requested to receive the medication again.

CONCLUSION

Our study results indicated that 2-month halotherapy with Salitair inhaler containing salt crystals extracted from the Klodawa mine in Poland could not improve the pulmonary function tests or quality of life of non-CF bronchiectatic patients. No significant side effects were noted in understudy patients. Future studies with larger sample size and longer duration of treatment are recommended to better determine the efficacy of this treatment modality.

Chronic arsenic exposure in nanomolar concentrations compromises wound response and intercellular signaling in airway epithelial cells

Paracrine ATP signaling in the lung epithelium participates in a variety of innate immune functions, including mucociliary clearance, bactericide production, and as an initiating signal in wound repair. We evaluated the effects of chronic low-dose arsenic relevant to U.S. drinking water standards (i.e., 10 ppb [130nM]) on airway epithelial cells. Immortalized human bronchial epithelial cells (16HBE14o-) were exposed to 0, 130, or 330nM arsenic (as Na-arsenite) for 4-5 weeks and examined for wound repair efficiency and ATP-mediated Ca(2+) signaling. We found that chronic arsenic exposure at these low doses slows wound repair and reduces ATP-mediated Ca(2+) signaling. We further show that arsenic compromises ATP-mediated Ca(2+) signaling by altering both Ca(2+) release from intracellular stores (via metabotropic P2Y receptors) and Ca(2+) influx mechanisms (via ionotropic P2X receptors). To better model the effects of arsenic on ATP-mediated Ca(2+) signaling under conditions of natural exposure, we cultured tracheal epithelial cells obtained from mice exposed to control or 50 ppb Na-arsenite supplemented drinking water for 4 weeks. Tracheal epithelial cells from arsenic-exposed mice displayed reduced ATP-mediated Ca(2+) signaling dynamics similar to our in vitro chronic exposure. Our findings demonstrate that chronic arsenic exposure at levels that are commonly found in drinking water (i.e., 10-50 ppb) alters cellular mechanisms critical to airway innate immunity.

Airway disease: similarities and differences between asthma, COPD and bronchiectasis

Airway diseases are highly prevalent worldwide; however, the prevalence of these diseases is underestimated. Although these diseases present several common characteristics, they have different clinical outcomes. The differentiation between asthma, chronic obstructive pulmonary disease and bronchiectasis in the early stage of disease is extremely important for the adoption of appropriate therapeutic measures. However, because of the high prevalence of these diseases and the common pathophysiological pathways, some patients with different diseases may present with similar symptoms. The objective of this review is to highlight the similarities and differences between these diseases in terms of the risk factors, pathophysiology, symptoms, diagnosis and treatment.

The immune response and its therapeutic modulation in bronchiectasis

Bronchiectasis (BC) is a chronic pulmonary disease with tremendous morbidity and significant mortality. As pathogen infection has been advocated as a triggering insult in the development of BC, a central role for the immune response in this process seems obvious. Inflammatory cells are present in both the airways as well as the lung parenchyma, and multiple mediators of immune cells including proteases and cytokines or their humoral products are increased locally or in the periphery. Interestingly, a defect in the immune system or suppression of immune response during conditions such as immunodeficiency may well predispose one to the devastating effects of BC. Thus, the outcome of an active immune response as detrimental or protective in the pathogenesis of BC may be dependent on the state of the patient's immunity, the severity of infection, and the magnitude of immune response. Here we reassess the function of the innate and acquired immunity in BC, the major sites of immune response, and the nature of the bioactive mediators. Furthermore, the potential link(s) between an ongoing immune response and structural alterations accompanying the disease and the success of therapies that can modulate the nature and extent of immune response in BC are elaborated upon.

Ciprofloxacin dry powder for inhalation in non-cystic fibrosis bronchiectasis: a phase II randomised study

This phase II, randomised, double-blind, multicentre study (NCT00930982) investigated the safety and efficacy of ciprofloxacin dry powder for inhalation (DPI) in patients with non-cystic fibrosis bronchiectasis.

Adults who were culture positive for pre-defined potential respiratory pathogens (including Pseudomonas aeruginosa and Haemophilus influenzae) were randomised to ciprofloxacin DPI 32.5 mg or placebo administered twice daily for 28 days (with 56 days of follow-up). Bacterial density in sputum (primary end-point), pulmonary function tests, health-related quality of life and safety were monitored throughout the study.

60 subjects received ciprofloxacin DPI 32.5 mg and 64 received placebo. Subjects on ciprofloxacin DPI had a significant reduction (p<0.001) in total sputum bacterial load at the end of treatment (-3.62 log₁₀ CFU·g⁻¹ (range -9.78–5.02 log₁₀ CFU·g⁻¹)) compared with placebo (-0.27 log₁₀ CFU·g⁻¹ (range -7.96–5.25 log₁₀ CFU·g⁻¹)); the counts increased thereafter. In the ciprofloxacin DPI group, 14 (35%) out of 40 subjects reported pathogen eradication at end of treatment versus four (8%) out of 49 in the placebo group (p=0.001). No abnormal safety results were reported and rates of bronchospasm were low.

Ciprofloxacin DPI 32.5 mg twice daily for 28 days was well tolerated and achieved significant reductions in total bacterial load compared with placebo in subjects with non-cystic fibrosis bronchiectasis.

Pulmonary bacterial communities in surgically resected noncystic fibrosis bronchiectasis lungs are similar to those in cystic fibrosis

Background. Recurrent bacterial infections play a key role in the pathogenesis of bronchiectasis, but conventional microbiologic methods may fail to identify pathogens in many cases. We characterized and compared the pulmonary bacterial communities of cystic fibrosis (CF) and non-CF bronchiectasis patients using a culture-independent molecular approach. Methods. Bacterial 16S rRNA gene libraries were constructed from lung tissue of 10 non-CF bronchiectasis and 21 CF patients, followed by DNA sequencing of isolates from each library. Community characteristics were analyzed and compared between the two groups. Results. A wide range of bacterial diversity was detected in both groups, with between 1 and 21 bacterial taxa found in each patient. Pseudomonas was the most common genus in both groups, comprising 49% of sequences detected and dominating numerically in 13 patients. Although Pseudomonas appeared to be dominant more often in CF patients than in non-CF patients, analysis of entire bacterial communities did not identify significant differences between these two groups. Conclusions. Our data indicate significant diversity in the pulmonary bacterial community of both CF and non-CF bronchiectasis patients and suggest that this community is similar in surgically resected lungs of CF and non-CF bronchiectasis patients.

Bronchiectasis: new approaches to diagnosis and management

Non-cystic fibrosis (CF) bronchiectasis is a common, potentially serious, condition. Further investigations should be performed in an attempt to identify the underlying cause because it may lead to a change in therapy and have significant prognostic implications. MRI is being investigated as a radiation free alternative to high-resolution CT scan of the chest. Many of the treatment recommendations for non-CF bronchiectasis have not been studied in randomized controlled trials but have been extrapolated from the management recommendations for CF. Studies are beginning to inform decisions regarding the management of non-CF bronchiectasis, and an understanding of the best treatment options is beginning to emerge.

Noninvasive assessment of bleomycin-induced lung injury and the effects of short-term glucocorticosteroid treatment in rats using MRI

PURPOSE

To demonstrate the feasibility of proton MRI to noninvasively quantify bleomycin-induced injury and the effects of glucocorticosteroids in a rat model of lung fibrosis.

MATERIALS AND METHODS

Sprague-Dawley rats received bleomycin intra-tracheally and underwent MRI up to day 70 following injury onset. A subgroup of animals was treated with budesonide.

RESULTS

The response in the first 2 weeks post-bleomycin, characterized by diffuse MRI signals, was related primarily to inflammation as confirmed by histology. Later, increased signals reflected principally tissue remodeling involved in fibrosis development, as suggested by histological analysis revealing collagen deposition in the same areas where MRI signals had been detected. Budesonide administration at days 6 and 13 after bleomycin resulted in decreased MRI signals 24 h after each corticosteroid application. However, no complete signal resolution was observed. Histology showed that budesonide affected inflammation but not fibrosis.

CONCLUSION

The ability of MRI to noninvasively quantify lung injury in bleomycin-treated rats will facilitate in vivo pharmacological studies in this model of pulmonary fibrosis. Repetitive measurements open new avenues in testing compounds as the responses at several time points during the course of treatment can be easily compared. Specifically, studies at the chronic phase, when fibrosis is already established, become amenable.