Prevalence of allergic bronchopulmonary aspergillosis in cystic fibrosis in an area with a high frequency of atopy

Pulmonary Aspergillosis in People with Cystic Fibrosis

In the last decade, fungal respiratory diseases have been increasingly investigated for their impact on the clinical course of people with cystic fibrosis (CF), with a particular focus on infections caused by Aspergillus spp. The most common organisms from this genus detected from respiratory cultures are Aspergillus fumigatus and Aspergillus terreus, followed by Aspergillus flavus, Aspergillus niger, and Aspergillus nidulans. These species have been identified to be both chronic colonizers and sources of active infection and may negatively impact lung function in people with CF. This review article discusses definitions of aspergillosis, challenges in clinical practice, and current literature available for laboratory findings, clinical diagnosis, and treatment options for pulmonary diseases caused by Aspergillus spp. in people with CF.

A cooperativity between virus and bacteria during respiratory infections

Respiratory tract infections remain the leading cause of morbidity and mortality worldwide. The burden is further increased by polymicrobial infection or viral and bacterial co-infection, often exacerbating the existing condition. Way back in 1918, high morbidity due to secondary pneumonia caused by bacterial infection was known, and a similar phenomenon was observed during the recent COVID-19 pandemic in which secondary bacterial infection worsens the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) condition. It has been observed that viruses paved the way for subsequent bacterial infection; similarly, bacteria have also been found to aid in viral infection. Viruses elevate bacterial infection by impairing the host's immune response, disrupting epithelial barrier integrity, expression of surface receptors and adhesion proteins, direct binding of virus to bacteria, altering nutritional immunity, and effecting the bacterial biofilm. Similarly, the bacteria enhance viral infection by altering the host's immune response, up-regulation of adhesion proteins, and activation of viral proteins. During co-infection, respiratory bacterial and viral pathogens were found to adapt and co-exist in the airways of their survival and to benefit from each other, i.e., there is a cooperative existence between the two. This review comprehensively reviews the mechanisms involved in the synergistic/cooperativity relationship between viruses and bacteria and their interaction in clinically relevant respiratory infections.

Aspergillus-related lung disease in people with cystic fibrosis: can imaging help us to diagnose disease?

In people with cystic fibrosis (PwCF), viscous sputum and dysfunction of the mucociliary escalator leads to early and chronic infections. The prevalence of Aspergillus fumigatus in sputum is high in PwCF and the contribution of A. fumigatus to the progression of structural lung disease has been reported. However, overall, relatively little is known about the contribution of A. fumigatus to CF lung disease. More knowledge is needed to aid clinical decisions on whether to start antifungal treatment. In this review, we give an overview of A. fumigatus colonisation and infection in PwCF and the different types of pulmonary disease caused by it. Furthermore, we discuss the current evidence for structural lung damage associated with A. fumigatus in PwCF on chest computed tomography and magnetic resonance imaging. We conclude that radiological outcomes to identify disease caused by A. fumigatus can be important for clinical studies and management.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 09 September 2021. We searched two ongoing trial registries (Clinicaltrials.gov and the WHO trials platform). Date of latest search: 16 August 2021.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager.

MAIN RESULTS

Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

State of the art in cystic fibrosis pharmacology optimization of antimicrobials in the treatment of cystic fibrosis pulmonary exacerbations: III. Executive summary

Acute pulmonary exacerbations are complications of cystic fibrosis (CF) and are associated with increased morbidity and mortality. Methicillin-resistant Staphylococcus aureus (MRSA) and Aspergillus fumigatus are organisms that have been detected in the lungs of CF patients. The focus of this review is to provide an overview of the classes of antimicrobials used for MRSA and allergic bronchopulmonary aspergillosis (ABPA), a hypersensitivity reaction caused by A. fumigatus. The current anti-MRSA antibiotics and medications for ABPA dosing recommendations are discussed. This article also reviews the findings from the MRSA utilization surveys and the pharmacokinetic and pharmacodynamic differences between CF and non-CF patients. Antimethicillin S. aureus antibiotics include ceftaroline, clindamycin, fluoroquinolone derivatives (ciprofloxacin, levofloxacin), glycopeptide derivatives (telavancin, vancomycin), linezolid, rifampin, sulfamethoxazole/trimethoprim, and tetracycline derivatives (doxycycline, minocycline, tigecycline). Medications used for ABPA include corticosteroids, amphotericin B, azole antifungals (isavuconazole, itraconazole, posaconazole, voriconazole), and a monoclonal antibody, omalizumab.

Optimization of antimicrobials in the treatment of cystic fibrosis pulmonary exacerbations: II. Therapies for allergic bronchopulmonary aspergillosis

This review is the second article in the State-of-the-Art series and aims to evaluate medications used in the treatment of allergic bronchopulmonary aspergillosis (ABPA) in pediatric and adult patients with cystic fibrosis (CF). ABPA is one of several organisms that are found in the airways of CF patients. This review provides an evidence-based summary of pharmacokinetic (PK)/pharmacodynamic (PD), tolerability, and efficacy studies of medications including corticosteroids, amphotericin B, azole antifungals (isavuconazole, itraconazole, posaconazole, and voriconazole), and a monoclonal antibody omalizumab in the treatment of ABPA and identifies areas where further study is warranted.

Coinfection with Pseudomonas aeruginosa and Aspergillus fumigatus in cystic fibrosis

OBJECTIVES

Cystic fibrosis (CF) lung disease is characterised by mucus stasis, chronic infection and inflammation, causing progressive structural lung disease and eventual respiratory failure. CF airways are inhabited by an ecologically diverse polymicrobial environment with vast potential for interspecies interactions, which may be a contributing factor to disease progression. Pseudomonas aeruginosa and Aspergillus fumigatus are the most common bacterial and fungal species present in CF airways respectively and coinfection results in a worse disease phenotype.

METHODS

In this review we examine existing expert knowledge of chronic co-infection with P. aeruginosa and A. fumigatus in CF patients. We summarise the mechanisms of interaction and evaluate the clinical and inflammatory impacts of this co-infection.

RESULTS

P. aeruginosa inhibits A. fumigatus through multiple mechanisms: phenazine secretion, iron competition, quorum sensing and through diffusible small molecules. A. fumigatus reciprocates inhibition through gliotoxin release and phenotypic adaptations enabling evasion of P. aeruginosa inhibition. Volatile organic compounds secreted by P. aeruginosa stimulate A. fumigatus growth, while A. fumigatus stimulates P. aeruginosa production of cytotoxic elastase.

CONCLUSION

A complex bi-directional relationship exists between P. aeruginosa and A. fumigatus, exhibiting both mutually antagonistic and cooperative facets. Cross-sectional data indicate a worsened disease state in coinfected patients; however, robust longitudinal studies are required to derive causality and to determine whether interspecies interaction contributes to disease progression.

Elevated serum βglucan levels in cavitary pulmonary nocardiosis

An 86-year-old woman with Borrmann type III colorectal cancer (Union for International Cancer Control pT4aN2bM1c, pStage IVc) had received dexamethasone for the last 6 months as palliative care. She presented with a low-grade fever, chest pain and cough. Chest radiography on admission showed cavities and consolidations bilaterally in the upper lobes. A blood examination on admission revealed highly elevated serum β-d-glucan levels. The diagnosis by bronchoscopy was pulmonary nocardiosis. With trimethoprim/sulfamethoxazole and imipenem/cilastatin, the β-d-glucan levels were decreased, and chest X-ray showed improvement after 1 month. β-d-glucan is known to be a biomarker of fungal infection. It is possible that β-d-glucan levels also indicate a pulmonary infection by Nocardia.

Aspergillus colonization and antifungal immunity in cystic fibrosis patients

Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, is the most common inherited life-limiting disease in North European people affecting 90,000 people worldwide. Progressive lung damage caused by recurrent infection and chronic airway inflammation is the major determinant of survival with a median age at death of 29 years. Approximately 60% of CF patients are infected with Aspergillus fumigatus, a ubiquitous environmental fungus, and its presence has been associated with accelerated lung function decline. Half of the patients infected with Aspergillus are <18 years of age. Yet time of acquisition of this fungus and determinants of CF-related Aspergillus disease severity and progression are not known. CFTR expression has been demonstrated in cells of the innate and adaptive immune system and has shown to be critical for normal function. Research delineating the role of CFTR-deficient phagocytes in Aspergillus persistence and infection in the CF lung, has only recently received attention. In this concise review we aim to present the current understanding with respect to when people with CF acquire infection with A. fumigatus and antifungal immune responses by CF immune cells.

Interaction between Pseudomonas aeruginosa and Aspergillus fumigatus in cystic fibrosis

Background

Cystic fibrosis (CF) is a disease characterized by chronic airway infection with a high incidence and poor prognosis. Pseudomonas aeruginosa and Aspergillus fumigatus are pathogens commonly found in CF patients. Clinically, these two microorganisms often coexist in the airway of CF patients. Combined infection with P. aeruginosa and A. fumigatus results in worsening lung function and clinical condition.

Methods

In this review, we focus on the mutual inhibition and promotion mechanisms of P. aeruginosa and A. fumigatus in CF patients. We also summarized the mechanisms of the interaction between these pathogenic microorganisms.

Results

P. aeruginosa inhibits A. fumigatus growth through the effects of phenazines, the quorum sensing system, iron competition, bacteriophages, and small colony variants. P. aeruginosa induces A. fumigatus growth through volatile organic compounds and subbacteriostatic concentrations of phenazines. A. fumigatus interferes with P. aeruginosa, affecting its metabolic growth via phenazine metabolic transformation, gliotoxin production, and reduced antibiotic sensitivity.

Discussion

Coexistence of P. aeruginosa and A. fumigatus can lead to both mutual inhibition and promotion. In different stages of CF disease, the interaction between these two pathogenic microorganisms may shift between promotion and inhibition. A discussion of the mechanisms of P. aeruginosa and A. fumigatus interaction can be beneficial for further treatment of CF patients and for improving the prognosis of the disease.

Seasonal fluctuation of lung function in cystic fibrosis: A national register-based study in two northern European populations

Background

Many risk factors for lung disease in cystic fibrosis (CF) display a seasonal pattern yet it is unclear whether this is reflected in seasonal fluctuations in lung function.

Methods

We conducted a longitudinal study using CF registries in Denmark and the UK. 471 individuals with a median of 104 FEV₁ measurements per person and 7586 individuals with a median of nine FEV₁ measures per person were included from Denmark and the UK respectively. We estimated the effect of seasonality on percent predicted FEV₁ trajectories using mixed effects models whilst adjusting for clinically important covariates.

Results

We found no significant cyclical seasonal variation in lung function in either country. The maximum variation in percent predicted FEV₁ around the yearly average was estimated to be 0.1 percentage points (95%CI 0 to 0.21) and 0.14 percentage points (95%CI 0 to 0.29) in Denmark and the UK, respectively. When considering possible step-like changes between the four seasons, we found that lung function was higher in spring compared to winter in the UK (0.34 percentage points, 95%CI 0.1 to 0.59) though the difference was not of clinical significance.

Conclusion

In both the UK and Denmark there may be small seasonal changes in lung function but this effect is not of clinical importance.

•

It is not well understood how the four seasons affect lung function in CF.

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We performed a longitudinal analysis in the UK and Danish CF populations.

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Forty years of data were included in a comprehensive mixed effects models.

•

The seasonal variation was small and not clinically important.

The co-colonization prevalence of Pseudomonas aeruginosa and Aspergillus fumigatus in cystic fibrosis: A systematic review and meta-analysis

PURPOSE

The co-colonization prevalence of P. aeruginosa and A. fumigatus in cystic fibrosis (CF) has been inconsistently reported. The purpose of this systematic review and meta-analysis was to estimate the overall co-colonization prevalence of P. aeruginosa and A. fumigatus in CF.

METHODS

The Embase, PubMed and Web of Science databases were systematically searched for studies reporting the co-colonization prevalence of P. aeruginosa and A. fumigatus in CF. The co-colonization prevalence of two pathogenic microorganisms in the individual studies was assessed by calculating the proportion and 95% confidence interval (CI). The random effects model was used to calculate the pooled prevalence. The I² test was used to assess statistical heterogeneity. The funnel plot and two statistical methods were used to assess publication bias.

RESULTS

Twenty-three eligible studies were included in this analysis. The pooled co-colonization prevalence of P. aeruginosa and A. fumigatus in CF patients was 15.8% (95% CI: 9.9-21.8). The co-colonization prevalence of P. aeruginosa and A. fumigatus chronic colonization was lower than that of intermittent colonization, higher in sputum cultures than in bronchoalveolar lavage (BAL) cultures, and lower in children than in adults. There was a statistically significant difference in co-colonization prevalence among studies from different decades, but the prevalence was similar in different geographical regions and with different study types.

CONCLUSIONS

The co-colonization prevalence of P. aeruginosa and A. fumigatus in the lower respiratory tract of CF patients was high. The anti-infective treatment in exacerbation of CF should be considered to cover the two pathogenic microorganisms simultaneously. Large-scale research is still needed to obtain more accurate co-colonization data.

Omalizumab in allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

Background

Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterized by a Th2 response, serum eosinophilia, and increased total serum IgE to Aspergillus fumigatus. ABPA occurs in cystic fibrosis (CF) and asthma. Omalizumab is a humanized recombinant monoclonal antibody against IgE. Previous studies reported borderline results when treating ABPA with omalizumab.

Methods

A retrospective study to investigate the efficacy of omalizumab in the treatment of ABPA in CF patients was conducted at 3 CF centers in Israel and Belgium. Data were obtained from the digital archive. We measured 4 outcome parameters: forced expiratory volume in 1 second, body mass index, pulmonary exacerbations, and steroid sparing.

Results

The database was composed on the records of 9 patients. None of the outcome parameters showed any improvement. A favorable outcome was observed in patients with higher levels of posttreatment total IgE than those with lower levels. CF-related diabetes and male gender showed trends for poorer outcomes.

Conclusion

No benefits were detected on treating ABPA in CF with omlaizumb. Monitoring the total IgE was not helpful. A prospective randomized double-blind study is needed.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 29 September 2017.We searched two ongoing trial registries (Clinicaltrials.gov and the WHO trials platform). Date of latest search: 24 January 2018.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager.

MAIN RESULTS

Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Childhood allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disease caused by Aspergillus induced hypersensitivity. It usually occurs in immunocompetent but susceptible patients with bronchial asthma and cystic fibrosis. If ABPA goes undiagnosed and untreated, it may progress to bronchiectasis and/or pulmonary fibrosis with significant morbidity and mortality. ABPA is a well-recognized entity in adults; however, there is lack of literature in children. The aim of the present review is to summarize pathophysiology, diagnostic criteria, clinical features, and treatment of ABPA with emphasis on the pediatric population. A literature search was undertaken through PubMed till April 30, 2018, with keywords “ABPA or allergic bronchopulmonary aspergillosis” with limitation to “title.” The relevant published articles related to ABPA in pediatric population were included for the review. The ABPA is very well studied in adults. Recently, it is increasingly being recognized in children. There is lack of separate diagnostic criteria of ABPA for children. Although there are no trials regarding treatment of ABPA in children, steroids and itraconazole are the mainstay of therapy based on studies in adults and observational studies in children. Omalizumab is upcoming therapy, especially in refractory ABPA cases. There is a need to develop the pediatric-specific cutoffs for diagnostic criteria in ABPA. Well-designed trials are required to determine appropriate treatment regimen in children.

Co-colonisation with Aspergillus fumigatus and Pseudomonas aeruginosa is associated with poorer health in cystic fibrosis patients: an Irish registry analysis

BACKGROUND

Pulmonary infection is the main cause of death in cystic fibrosis (CF). Aspergillus fumigatus (AF) and Pseudomonas aeruginosa (PA) are the most prevalent fungal and bacterial pathogens isolated from the CF airway, respectively. Our aim was to determine the effect of different colonisation profiles of AF and PA on the clinical status of patients with CF.

METHODS

A retrospective analysis of data from the Cystic Fibrosis Registry of Ireland from 2013 was performed to determine the effect of intermittent and persistent colonisation with AF or PA or co-colonisation with both microorganisms on clinical outcome measures in patients with CF. Key outcomes measured included forced expiratory volume in one second (FEV₁), number of hospitalisations, respiratory exacerbations and antimicrobials prescribed, and complications of CF, including CF related diabetes (CFRD) and allergic bronchopulmonary aspergillosis (ABPA).

RESULTS

The prevalence of AF and PA colonisation were 11% (5% persistent, 6% intermittent) and 31% (19% persistent, 12% intermittent) in the Irish CF population, respectively. Co-colonisation with both pathogens was associated with a 13.8% reduction in FEV₁ (p = 0.016), higher levels of exacerbations (p = 0.042), hospitalisations (p = 0.023) and antimicrobial usage (p = 0.014) compared to non-colonised patients and these clinical outcomes were comparable to those persistently colonised with PA. Intermittent and persistent AF colonisation were not associated with poorer clinical outcomes or ABPA. Patients with persistent PA had a higher prevalence of CFRD diagnosis (p = 0.012).

CONCLUSIONS

CF patients co-colonised with AF and PA had poor clinical outcomes comparable to patients persistently colonised with PA, emphasising the clinical significance of co-colonisation with these microorganisms.

Allergic bronchopulmonary aspergillosis in patients with cystic fibrosis

Allergic bronchopulmonary aspergillosis (ABPA) is a pulmonary disorder that often occurs in patients with asthma or cystic fibrosis (CF) and is characterized by a hypersensitivity response to the allergens of the fungus Aspergillus fumigatus. In patients with CF, growth of A. fumigatus hyphae within the bronchial lumen triggers an immunoglobulin E (IgE)-mediated hypersensitivity response that results in airway inflammation, bronchospasm, and bronchiectasis. In most published studies, the prevalence of ABPA is about 8.9% in patients with CF. Since the clinical features of this condition overlap significantly with that of CF, ABPA is challenging to diagnose and remains underdiagnosed in many patients. Diagnosis of ABPA in CF patients should be sought in those with evidence of clinical and radiologic deterioration that is not attributable to another etiology, a markedly elevated total serum IgE level (while off steroid therapy) and evidence of A. fumigatus sensitization. Management of ABPA involves the use of systemic steroids to reduce inflammation and modulate the immune response. In patients who do not respond to steroids or cannot tolerate them, antifungal agents should be used to reduce the burden of A. fumigatus allergens. Recent studies suggest that omalizumab may be an effective option to reduce the frequency of ABPA exacerbations in patients with CF. Further randomized controlled trials are needed to better establish the efficacy of omalizumab in managing patients with CF and ABPA.

Prevalence of Aspergillus sensitization and allergic bronchopulmonary aspergillosis in cystic fibrosis: systematic review and meta-analysis

BACKGROUND

The prevalence of Aspergillus sensitization (AS) and allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF) has been varyingly reported. The aim of this systematic review was to estimate the overall prevalence of AS/ABPA in CF.

METHODS

We searched the PubMed and EmBase databases for studies reporting the prevalence of AS/ABPA in CF. We calculated the proportion with 95% confidence interval (CI) to assess the prevalence of AS and ABPA in the individual studies and then pooled the results using a random effects model. Statistical heterogeneity was assessed using the I2 test while publication bias was assessed using both graphical and statistical methods.

RESULTS

Our search yielded 64 eligible studies. The pooled prevalence of AS was 39.1% (95% CI: 33.3-45.1) and was higher with skin test compared to specific IgE (43.8% vs. 32.8%, P = 0.002); however, the prevalence did not vary with the type of skin test used (intradermal or percutaneous). The prevalence of ABPA was 8.9% (95% CI: 7.4-10.7) and was higher in adults as compared to children (10.1% vs. 8.9%, P < 0.0001). There was a wide variation in the criteria used for diagnosing ABPA. Almost 50% (12/23) of the publications after 2004 used criteria other than the CF foundation criteria for diagnosing ABPA. There was significant statistical heterogeneity and evidence of publication bias.

CONCLUSIONS

There is a high prevalence of AS and ABPA in patients with CF. Despite six decades of research, there is still a need to adopt uniform methodology and criteria for the diagnosis of AS/ABPA.

Fungal spores and pollen in particulate matter collected during agricultural activities in the Po Valley (Italy)

Airborne particulate matter (PM) containing fungal spores and pollen grains was sampled within a monitoring campaign of wheat threshing, plowing and sowing agricultural operations. Fungal spores and pollen grains were detected and identified on morphological basis. No studies were previously available about fungal spore and pollen content in agricultural PM in the Po Valley. Sampling was conducted in a Po Valley farmland in Mezzano (Ferrara, Italy). The organic particles collected were examined by scanning electron microscopy with energy dispersive X-ray spectrometer. Fungal spores and pollen grains were identified when possible at the level of species. The most frequent components of the organic particles sampled were spores of Aspergillus sp., which could represent a risk of developing allergies and aspergillosis for crop farmers.

Detection of Airway Colonization by Aspergillus fumigatus by Use of Electronic Nose Technology in Patients with Cystic Fibrosis

Currently, there is no noninvasive test that can reliably diagnose early invasive pulmonary aspergillosis (IA). An electronic nose (eNose) can discriminate various lung diseases through an analysis of exhaled volatile organic compounds. We recently published a proof-of-principle study showing that patients with prolonged chemotherapy-induced neutropenia and IA have a distinct exhaled breath profile (or breathprint) that can be discriminated with an eNose. An eNose is cheap and noninvasive, and it yields results within minutes. We determined whether Aspergillus fumigatus colonization may also be detected with an eNose in cystic fibrosis (CF) patients. Exhaled breath samples of 27 CF patients were analyzed with a Cyranose 320. Culture of sputum samples defined the A. fumigatus colonization status. eNose data were classified using canonical discriminant analysis after principal component reduction. Our primary outcome was cross-validated accuracy, defined as the percentage of correctly classified subjects using the leave-one-out method. The P value was calculated by the generation of 100,000 random alternative classifications. Nine of the 27 subjects were colonized by A. fumigatus. In total, 3 subjects were misclassified, resulting in a cross-validated accuracy of the Cyranose detecting IA of 89% (P = 0.004; sensitivity, 78%; specificity, 94%). Receiver operating characteristic (ROC) curve analysis showed an area under the curve (AUC) of 0.89. The results indicate that A. fumigatus colonization leads to a distinctive breathprint in CF patients. The present proof-of-concept data merit external validation and monitoring studies.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 27 July 2015.We searched the ongoing trial registry clinicaltrials.gov for any ongoing trials. Latest search for clinicaltrials.gov: 23 October 2015.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager.

MAIN RESULTS

Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Aspergillus fumigatus chronic colonization and lung function decline in cystic fibrosis may have a two-way relationship

Aspergillus fumigatus is commonly found in cystic fibrosis (CF) airways. Our aim was to assess the relationship between A. fumigatus chronic colonization and lung function in CF patients. A case-control study of CF patients born from 1989 to 2002 was performed. Medical records were reviewed from the time of initial diagnosis until December 2013. Chronic colonization was defined as two or more positive sputum cultures in a given year. Each patient chronically colonized with A. fumigatus was matched with three control patients (never colonized by A. fumigatus) for age, sex, and year of birth (±3 years). A number of parameters were recorded and analyzed prospectively. The primary outcome measure was the difference in forced expiratory volume in 1 s (FEV1) in percent predicted between groups. Linear mixed models were used for longitudinal analyses to evaluate the relationship between A. fumigatus chronic colonization and lung function during a 7-year period and study the lung function 4 years before the time of enrollment (t0). Twenty patients had chronic colonization and were matched with 60 controls. A significant difference in lung function was detected throughout the 7-year period after adjustment for confounders (est = 8.66, p = 0.020). Four years before t0, FEV1 baseline was the only factor associated with the course of lung function (est = 0.64, p < 0.001) and was significantly different between groups (p = 0.001). In conclusion, a decreased FEV1 baseline appears to be a risk factor for chronic colonization by A. fumigatus, which, in turn, may cause a faster deterioration of lung function.

Evolution of the Immune Response to Chronic Airway Colonization with Aspergillus fumigatus Hyphae

Airway colonization by the mold Aspergillus fumigatus is common in patients with underlying lung disease and is associated with chronic airway inflammation. Studies probing the inflammatory response to colonization with A. fumigatus hyphae have been hampered by the lack of a model of chronic colonization in immunocompetent mice. By infecting mice intratracheally with conidia embedded in agar beads (Af beads), we have established an in vivo model to study the natural history of airway colonization with live A. fumigatus hyphae. Histopathological examination and galactomannan assay of lung homogenates demonstrated that hyphae exited beads and persisted in the lungs of mice up to 28 days postinfection without invasive disease. Fungal lesions within the airways were surrounded by a robust neutrophilic inflammatory reaction and peribronchial infiltration of lymphocytes. Whole-lung cytokine analysis from Af bead-infected mice revealed an increase in proinflammatory cytokines and chemokines early in infection. Evidence of a Th2 type response was observed only early in the course of colonization, including increased levels of interleukin-4 (IL-4), elevated IgE levels in serum, and a mild increase in airway responsiveness. Pulmonary T cell subset analysis during infection mirrored these results with an initial transient increase in IL-4-producing CD4(+) T cells, followed by a rise in IL-17 and Foxp3(+) cells by day 14. These results provide the first report of the evolution of the immune response to A. fumigatus hyphal colonization.

Domestic exposure to fungal allergenic particles determined by halogen immunoassay using subject's serum versus particles carrying three non-fungal allergens determined by allergen-specific HIA

Studies that estimate indoor aeroallergen exposure typically measure a pre-selected limited range of allergens. In this study, inhalable aeroallergen particles were quantified using the halogen immunoassay (HIA) to determine the contribution of fungal and non-fungal aeroallergens to total allergen exposure. Bioaerosols from 39 homes of fungal-allergic subjects were sampled using inhalable fraction samplers and immunostained by HIA using resident subject's immunoglobulin E (IgE) to detect allergen-laden particles. Fungal aerosols as well as particles carrying mite, cat, and cockroach allergens were identified and enumerated by HIA. Reservoir dust-mite (Der p 1), cat (Fel d 1), and cockroach (Bla g 1) allergen concentrations were quantified by ELISA. Fungal particles that bound subject's IgE in the HIA were 1.7 (bedroom)- and 1.4 (living room)-fold more concentrated than Der p 1, Fel d 1, and Bla g 1 allergen particles combined. Predominant fungal conidia that bound IgE were derived from common environmental genera including Cladosporium and other fungi that produce amerospores. Airborne mite, cat, and cockroach allergen particle counts were not associated with reservoir concentrations determined by ELISA. This study demonstrates that inhalable fungal aerosols are the predominant aeroallergen sources in Sydney homes and should be considered in future exposure assessments.

PRACTICAL IMPLICATIONS

Indoor allergen exposure assessment studies have primarily focused on a limited range of allergen sources in samples derived from reservoir dust samples. Using an innovative immunodiagnostic approach, this study demonstrates that fungal bioaerosols are the dominant source of aeroallergen exposure in the domestic environment, providing unique insight into domestic aeroallergen exposure.

Inhaled corticosteroids and Aspergillus fumigatus isolation in cystic fibrosis

Aspergillus fumigatus isolation in cultures from respiratory specimens of patients with cystic fibrosis (CF) is quite common; however, the role of A. fumigatus as a pathogen and whether its presence is associated with progression of pulmonary disease remain unclear. We investigated the association between inhaled corticosteroids and the recovery of A. fumigatus by performing a retrospective cohort study of CF patients born between 1988 and 1996. The patients' medical records from their first visit to the CF Center until December 2010 were reviewed. Outcomes were the occurrence of A. fumigatus first isolation, chronic colonization, or the last visit at the CF Center. A number of possible confounders were included in the multivariate logistic regression analysis in order to identify an independent association between inhaled corticosteroids and colonization status. A total of 121 patients were included in the study. Thirty-nine patients (32.2%) had at least one positive culture and 14 (11.6%) developed chronic colonization. Multivariate logistic regression analysis was used to determine the independent effect of inhaled corticosteroids on the odds of first isolation (odds ratio [OR], 1.165; 95% confidence interval [CI], 1.015-1.337; P = 0.029) and chronic colonization (OR, 1.180; 95% CI, 1.029-1.353; P = 0.018). In conclusion, A. fumigatus first isolation and chronic colonization are associated with the duration of inhaled corticosteroid treatment.

Aspergillus sensitization or carriage in cystic fibrosis patients

BACKGROUND

Aspergillus fumigatus (Af) sensitization and persistent carriage are deleterious to lung function, but no consensus has been reached defining these medical entities. This work aimed to identify possible predictive factors for patients who become sensitized to Af, compared with a control group of non-sensitized Af carriers.

METHODS

Between 1995 and 2007, 117 pediatric patients were evaluated. Demographic data, CFTR gene mutations, body mass index and FEV1 were recorded. The presence of Af in sputum, the levels of Af-precipitin, total IgE (t-IgE) and specific IgE to Af (Af-IgE) were determined. Patients were divided into 2 groups: (1) "sensitization": level of Af-IgE > 0.35 IU/mL with t-IgE level < 500 IU/mL and (2) "persistent or transient carriage": Af-IgE level ≤ 0.35 IU/mL with either an Af transient or persistent positive culture. A survival analysis was performed with the appearance of Af-IgE in serum as an outcome variable.

RESULTS

Severe mutation (hazard ratio = 3.2), FEV1 baseline over 70% of theoretical value (hazard ratio = 4.9), absence of Pa colonization, catalase activity and previous azithromycin administration (hazard ratio = 9.8, 4.1 and 1.9, respectively) were predictive factors for sensitization. We propose a timeline of the biological events and a tree diagram for risk calculation.

CONCLUSIONS

Two profiles of cystic fibrosis patients can be envisaged: (1) patients with nonsevere mutation but low FEV1 baselines are becoming colonized with Af or (2) patients with high FEV1 baselines who present with severe mutation are more susceptible to the Af sensitization and then to the presentation of an allergic bronchopulmonary aspergillosis event.

Multi-country estimate of different manifestations of aspergillosis in cystic fibrosis

Aspergillus spp. can lead to allergic bronchopulmonary aspergillosis (ABPA), Aspergillus sensitisation and Aspergillus bronchitis in CF. The relative frequencies of these entities have recently been ascertained in a large UK adult CF cohort. We have used this data to estimate the burden of aspergillosis and ABPA cases in adult CF patients in 30 countries reporting CF. National and international CF registry data was accessed and assessed for completeness and age distribution. Published proportions of ABPA (17.7%), Aspergillus sensitisation (14.6%) and Aspergillus bronchitis (30%) in CF were applied to those >18 years and compared with notified ABPA cases. Of the 76,201 estimated CF patients worldwide (not including India), 37,714 were >18 years. The proportion of adults to children varied from 63% in Norway to 20% in Brazil. ABPA caseload in adults is anticipated to be 6,675 cases of which only 2,221 cases (33%) are currently recorded, indicating substantial underdiagnosis. The ABPA diagnosis rate compared with estimated rates varies by country from 101% (France) to 14.5% (Greece), although genetic variation could account for genuine differences compared with the UK. Aspergillus bronchitis is not currently recognised or recorded in CF registries but there are an anticipated 10,988 adult cases. Aspergillus sensitisation, associated with increased bronchiectasis and reduced FEV1, affects an anticipated 5,506 patients without ABPA or Aspergillus bronchitis. Together ABPA and Aspergillus bronchitis are estimated to affect 17,989 adults, 47.7% of the adult CF population. ABPA also occurs in children and teenagers and 984 cases were documented in registries. Diagnosed ABPA rates by age were available for the ECFS registry, USA, UK, Ireland, Belgium and Netherlands. The rate was <1% under 4 years, and increased throughout childhood and adolescence, with marked variation between countries. Newly published diagnostic criteria and methods should facilitate better recognition of aspergillosis in CF, allowing better CF disease control.

Anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis

BACKGROUND

Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

OBJECTIVES

To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 21 January 2013.We searched the ongoing trial registry clinicaltrials.gov for any ongoing trials. Latest search for clinicaltrials.gov: 22 February 2013.

SELECTION CRITERIA

Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager 5.1.

MAIN RESULTS

Only one trial enrolling 14 patients was eligible for inclusion in the review. The study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit patients into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) patients in omalizumab group and placebo group respectively.

AUTHORS' CONCLUSIONS

There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in patients with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled trials of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

Effects of Aspergillus fumigatus colonization on lung function in cystic fibrosis

PURPOSE OF REVIEW

Aspergillus fumigatus is frequently isolated from cystic fibrosis (CF) patients and is notorious for its role in the debilitating condition of allergic bronchopulmonary aspergillosis (ABPA). Although CF patients suffer from perpetual microorganism-related lung disease, it is unclear whether A. fumigatus colonization has a role in causing accelerated lung function decline and whether intervention is necessary.

RECENT FINDINGS

A. fumigatus morbidity appears to be related to cystic fibrosis transmembrane conductance regulator-dependant function of the innate immune system. A. fumigatus-colonized patients have a lower lung capacity, more frequent hospitalizations and more prominent radiological abnormalities than noncolonized patients. Treatment with antifungal agents can be of value but has several drawbacks and a direct effect on lung function is yet to be shown.

SUMMARY

A. fumigatus appears to have an important role in CF lung disease, not exclusive to the context of ABPA. However, a causal relationship still needs to be confirmed. Study observations and trends indicate a need to further elucidate the mechanisms of A. fumigatus interactions with the host innate immune system and its role in CF lung morbidity.

Treatment of Aspergillus fumigatus in patients with cystic fibrosis: a randomized, placebo-controlled pilot study

Background

Many patients with cystic fibrosis develop persistent airway infection/colonization with Aspergillus fumigatus, however the impact of A. fumigatus on clinical outcomes remains unclear. The objective of this study was to determine whether treatment directed against Aspergillus fumigatus improves pulmonary function and clinical outcomes in patients with cystic fibrosis (CF).

Methods

We performed a double-blind randomized placebo-controlled pilot clinical trial involving 35 patients with CF whose sputum cultures were chronically positive for A. fumigatus. Participants were centrally randomized to receive either oral itraconazole 5 mg/kg/d (N = 18) or placebo (N = 17) for 24 weeks. The primary outcome was the proportion of patients who experienced a respiratory exacerbation requiring intravenous antibiotics over the 24 week treatment period. Secondary outcomes included changes in FEV₁ and quality of life.

Results

Over the 24 week treatment period, 4 of 18 (22%) patients randomized to itraconazole experienced a respiratory exacerbation requiring intravenous antibiotics, compared to 5 of 16 (31%) placebo treated patients, P = 0.70. FEV₁ declined by 4.62% over 24 weeks in the patients randomized to itraconazole, compared to a 0.32% improvement in the placebo group (between group difference = −4.94%, 95% CI: −15.33 to 5.45, P = 0.34). Quality of life did not differ between the 2 treatment groups throughout the study. Therapeutic itraconazole blood levels were not achieved in 43% of patients randomized to itraconazole.

Conclusion

We did not identify clinical benefit from itraconazole treatment for CF patients whose sputum was chronically colonized with A. fumigatus. Limitations of this pilot study were its small sample size, and failure to achieve therapeutic levels of itraconazole in many patients.

Trial Registration

ClinicalTrials.govNCT00528190

Lack of cystic fibrosis transmembrane conductance regulator in CD3+ lymphocytes leads to aberrant cytokine secretion and hyperinflammatory adaptive immune responses

Cystic fibrosis (CF), the most common fatal monogenic disease in the United States, results from mutations in CF transmembrane conductance regulator (CFTR), a chloride channel. The mechanisms by which CFTR mutations cause lung disease in CF are not fully defined but may include altered ion and water transport across the airway epithelium and aberrant inflammatory and immune responses to pathogens within the airways. We have shown that Cftr(-/-) mice mount an exaggerated IgE response toward Aspergillus fumigatus, with higher levels of IL-13 and IL-4, mimicking both the T helper cell type 2-biased immune responses seen in patients with CF. Herein, we demonstrate that these aberrations are primarily due to Cftr deficiency in lymphocytes rather than in the epithelium. Adoptive transfer experiments with CF splenocytes confer a higher IgE response to Aspergillus fumigatus compared with hosts receiving wild-type splenocytes. The predilection of Cftr-deficient lymphocytes to mount T helper cell type 2 responses with high IL-13 and IL-4 was confirmed by in vitro antigen recall experiments. Conclusive data on this phenomenon were obtained with conditional Cftr knockout mice, where mice lacking Cftr in T cell lineages developed higher IgE than their wild-type control littermates. Further analysis of Cftr-deficient lymphocytes revealed an enhanced intracellular Ca(2+) flux in response to T cell receptor activation. This was accompanied by an increase in nuclear localization of the calcium-sensitive transcription factor, nuclear factor of activated T cell, which could drive the IL-13 response. In summary, our data identified that CFTR dysfunction in T cells can lead directly to aberrant immune responses. These findings implicate the lymphocyte population as a potentially important target for CF therapeutics.

Clinical significance of microbial infection and adaptation in cystic fibrosis

A select group of microorganisms inhabit the airways of individuals with cystic fibrosis. Once established within the pulmonary environment in these patients, many of these microbes adapt by altering aspects of their structure and physiology. Some of these microbes and adaptations are associated with more rapid deterioration in lung function and overall clinical status, whereas others appear to have little effect. Here we review current evidence supporting or refuting a role for the different microbes and their adaptations in contributing to poor clinical outcomes in cystic fibrosis.

Aspergillus fumigatus colonization in cystic fibrosis: implications for lung function?

Aspergillus fumigatus is commonly found in the respiratory secretions of patients with cystic fibrosis (CF). Although allergic bronchopulmonary aspergillosis (ABPA) is associated with deterioration of lung function, the effects of A. fumigatus colonization on lung function in the absence of ABPA are not clear. This study was performed in 259 adults and children with CF, without ABPA. A. fumigatus colonization was defined as positivity of >50% of respiratory cultures in a given year. A cross-sectional analysis was performed to study clinical characteristics associated with A. fumigatus colonization. A retrospective cohort analysis was performed to study the effect of A. fumigatus colonization on lung function observed between 2002 and 2007. Longitudinal data were analysed with a linear mixed model. Sixty-one of 259 patients were at least intermittently colonized with A. fumigatus. An association was found between A. fumigatus colonization and increased age and use of inhaled antibiotics. In the longitudinal analysis, 163 patients were grouped according to duration of colonization. After adjustment for confounders, there was no significant difference in lung function between patients colonized for 0 or 1 year and patients with 2-3 or more than 3 years of colonization (p 0.40 and p 0.64) throughout the study. There was no significant difference in lung function decline between groups. Although colonization with A. fumigatus is more commonly found in patients with more severe lung disease and increased treatment burden, it is not independently associated with lower lung function or more severe lung function decline over a 5-year period.

Risk factors for Aspergillus colonization and allergic bronchopulmonary aspergillosis in children with cystic fibrosis

BACKGROUND

The annual prevalence of Aspergillus colonization (AC) and allergic bronchopulmonary aspergillosis (ABPA) has recently increased in pediatric patients with cystic fibrosis (CF). The reasons remain unclear although a number of factors have been suggested to be involved. This study was set up to investigate the association between potential predisposing factors, including new therapies recommended in CF, and the occurrence of AC or ABPA in children with CF.

METHODS

The medical records of 85 children monitored regularly in the Pediatric Reference Centre for Cystic Fibrosis Care (RCCFC) of the University Hospital of Marseille (France) were analyzed from the first time they attended the RCCFC until either the occurrence of an end event, or their last visit to the RCCFC. Risk factors for AC or ABPA were analyzed by univariate and multivariate logistic regression.

RESULTS

Eight children developed ABPA and 18 had AC. In univariate analysis, ABPA was significantly associated with RhDNase therapy, sensitization to Alternaria and Candida, and a low body mass index (BMI). Multivariate analysis identified an independent association between low BMI and ABPA (OR = 10.6, 95% CI [2.2-51.8], P = 0.004), and for the first time, between long-term azithromycin therapy and AC (OR = 6.4, 95% CI [2.1-19.5], P = 0.001). This latter association might be explained by the inhibitory effect of azithromycin on both the recruitment and the activation of neutrophils, which represent the first-line defenses against Aspergillus.

CONCLUSIONS

The risk factors associated with AC and ABPA in children with CF identified in this comprehensive exploratory study now need to be confirmed in further prospective studies.

The changing microbial epidemiology in cystic fibrosis

Infection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an immunologic pulmonary disorder caused by hypersensitivity to Aspergillus fumigatus. Clinically, a patient presents with chronic asthma, recurrent pulmonary infiltrates, and bronchiectasis. The population prevalence of ABPA is not clearly known, but the prevalence in asthma clinics is reported to be around 13%. The disorder needs to be detected before bronchiectasis has developed because the occurrence of bronchiectasis is associated with poorer outcomes. Because many patients with ABPA may be minimally symptomatic or asymptomatic, a high index of suspicion for ABPA should be maintained while managing any patient with bronchial asthma whatever the severity or the level of control. This underscores the need for routine screening of all patients with asthma with an Aspergillus skin test. Finally, there is a need to update and revise the criteria for the diagnosis of ABPA. This review summarizes the advances in the diagnosis and management of ABPA using a systematic search methodology.

Occurrence and relevance of filamentous fungi in respiratory secretions of patients with cystic fibrosis--a review

The colonization of airways by filamentous fungi and the development of respiratory infections require some predisposing factors as encountered in patients with cystic fibrosis (CF). Indeed, the defective mucociliary clearance which characterizes the disease is associated with local immunological disorders. In addition, the prolonged therapy with antibiotics and the use of corticosteroid treatments also facilitate fungal growth. An important fungal biota has been described in respiratory secretions of patients suffering from CF. Aspergillus fumigatus, Scedosporium apiospermum and Aspergillus terreus for filamentous fungi and Candida albicans for yeasts are the main fungal species associated with CF. Although less common, several fungal species including Aspergillus flavus and Aspergillus nidulans may be isolated transiently from CF respiratory secretions, while others such as Exophiala dermatitidis and Scedosporium prolificans may chronically colonize the airways. Moreover, some of them like Penicillium emersonii and Acrophialophora fusispora are encountered in humans almost exclusively in the context of CF. As fungal complications in CF patients are essentially caused by filamentous fungi the present review will not include works related to yeasts. In CF patients, fungi may sometimes be responsible for deterioration of lung function, as occurs in allergic broncho-pulmonary aspergillosis (ABPA) which is the most common fungal disease in this context. Additionally, although the clinical relevance of the fungal airway colonization is still a matter of debate, filamentous fungi may contribute to the local inflammatory response, and therefore to the progressive deterioration of the lung function.

The pros and cons of immunomodulatory IL-10 gene therapy with recombinant AAV in a Cftr-/- -dependent allergy mouse model

Cystic fibrosis (CF) patients have decreased levels of lung epithelial interleukin (IL)-10 and increased levels of proinflammatory cytokines (tumor necrosis factor-alpha, IL-4, IL-8 and IL-6). This has also been documented in Cftr (cystic fibrosis transmembrane conductance regulator)-deficient mice (Cftr 489X(-/-), FABP-hCFTR(+/+)). Our laboratory has recently characterized a peculiar hyper-IgE phenotype in these mice, in response to Aspergillus fumigatus crude protein extract (Af-cpe). Thus, we hypothesized that sustained systemic circulating IL-10 levels achieved through skeletal muscle transduction with recombinant adeno-associated vectors expressing IL-10 (rAAV1-IL-10) would serve to downregulate Th1 and Th2 cytokine production. This in turn would dampen the allergic response in the Cftr(-/-)-dependent mouse model of allergic bronchopulmonary aspergillosis. After Af-cpe sensitization and airway challenge, mice treated with rAAV1-IL-10 had markedly lower IgE levels when compared to the control-treated rAAV1-GFP group. This was accompanied by a significant reduction in the levels of IL-5, IL-4 and IL-13 in the lung compartment. The lower lung cytokine profiles resulted in a near absence of eosinophil recruitment in the lung and a lower inflammatory response in the lung tissue of mice receiving rAAV1-IL-10. Unfortunately, sustained secretion of IL-10 from transduced muscle did lead to thrombocytopenia and splenomegaly in mice injected with rAAV1-IL-10. These results highlight that while IL-10 gene therapy is very effective for treating allergic responses caution must be taken with the prolonged secretion of IL-10.

Allergy vaccines: dreams and reality

Allergy, extrinsic asthma and atopic eczema derive from deregulated immune responses against innocuous antigens. The incidence of atopic diseases is actually affecting approximately 30% of the population in industrialized countries. Although much progress has been achieved in the development of efficient symptomatic treatments for allergic diseases, the only curative treatment remains allergen-specific immunotherapy. In contrast to classical vaccines, which elicit strong host immune responses after one or a few injections, allergen-specific immunotherapy might require a long treatment time of 3-5 years with up to 80 injections to confer some protection. The reality is that 'allergy vaccines' achieve beneficial effects through immunomodulation, which takes a long time to establish. The dream would be to develop highly efficient allergy vaccines able to cure the disease with a few injections.

Partial correction of the CFTR-dependent ABPA mouse model with recombinant adeno-associated virus gene transfer of truncated CFTR gene

Recently, we have developed a model of airway inflammation in a CFTR knockout mouse utilizing Aspergillus fumigatus crude protein extract (Af-cpe) to mimic allergic bronchopulmonary aspergillosis (ABPA) 1, an unusual IgE-mediated hypersensitivity syndrome seen in up to 15% of cystic fibrosis (CF) patients and rarely elsewhere. We hypothesized that replacement of CFTR via targeted gene delivery to airway epithelium would correct aberrant epithelial cytokine signaling and ameliorate the ABPA phenotype in CFTR-deficient (CFTR 489X - /-, FABP-hCFTR + / +) mice. CFTR knockout mice underwent intra-tracheal (IT) delivery of recombinant adeno-associated virus serotype 5 (rAAV5Delta-264CFTR) or rAAV5-GFP at 2.58 x 10(12) viral genomes/mouse. All mice were then sensitized with two serial injections (200 microg) of crude Af antigen via the intra-peritoneal (IP) route. Untreated mice were sensitized without virus exposure. Challenges were performed 2 weeks after final sensitization, using a 0.25% solution containing Aspergillus fumigatus crude protein extract delivered by inhalation on three consecutive days. The rAAV5Delta-264CFTR-treated mice had lower total serum IgE levels (172513 ng/ml +/- 1312) than rAAV5-GFP controls (26 892 ng/ml +/- 3715) (p = 0.037) and non-treated, sensitized controls (24 816 +/- 4219 ng/ml). Serum IgG1 levels also were lower in mice receiving the CFTR vector. Interestingly, splenocytes from rAAV5Delta-264CFTR-treated mice secreted less IL-13, INFg, TNFa, RANTES and GM-CSF after ConA stimulation. Gene therapy with rAAV5Delta-264CFTR attenuated the hyper-IgE response in this reproducible CF mouse model of ABPA, with systemic effects also evident in the cytokine response of stimulated splenocytes.

Aspergillus fumigatus generates an enhanced Th2-biased immune response in mice with defective cystic fibrosis transmembrane conductance regulator

Cystic fibrosis (CF) lung disease is characterized by persistent airway inflammation and airway infection that ultimately leads to respiratory failure. Aspergillus sp. are present in the airways of 20-40% of CF patients and are of unclear clinical significance. In this study, we demonstrate that CF transmembrane conductance regulator (CFTR)-deficient (CFTR knockout, Cftr(tm1Unc-)TgN(fatty acid-binding protein)CFTR) and mutant (DeltaF508) mice develop profound lung inflammation in response to Aspergillus fumigatus hyphal Ag exposure. CFTR-deficient mice also develop an enhanced Th2 inflammatory response to A. fumigatus, characterized by elevated IL-4 in the lung and IgE and IgG1 in serum. In contrast, CFTR deficiency does not promote a Th1 immune response. Furthermore, we demonstrate that CD4+ T cells from naive CFTR-deficient mice produce higher levels of IL-4 in response to TCR ligation than wild-type CD4+ T cells. The Th2 bias of CD4+ T cells in the absence of functional CFTR correlates with elevated nuclear levels of NFAT. Thus, CFTR is important to maintain the Th1/Th2 balance in CD4+ T cells.