Fungal allergy in asthma-state of the art and research needs

Impact of urban air pollution on the allergenicity of Aspergillus fumigatus conidia: Outdoor exposure study supported by laboratory experiments

Understanding the chemical interactions of common allergens in urban environments may help to decipher the general increase in susceptibility to allergies observed in recent decades. In this study, asexual conidia of the allergenic mold Aspergillus fumigatus were exposed to air pollution under natural (ambient) and controlled (laboratory) conditions. The allergenic activity was measured using two immunoassays and supported by a protein mass spectrometry analysis. The allergenicity of the conidia was found to increase by 2-5 fold compared to the control for short exposure times of up to 12h (accumulated exposure of about 50 ppb NO2 and 750 ppb O3), possibly due to nitration. At higher exposure times, the allergenicity increase lessened due to protein deamidation. These results indicate that during the first 12h of exposure, the allergenic potency of the fungal allergen A. fumigatus in polluted urban environments is expected to increase. Additional work is needed in order to determine if this behavior occurs for other allergens.

Identifying risk factors for exposure to culturable allergenic moulds in energy efficient homes by using highly specific monoclonal antibodies

The aim of this study was to determine the accuracy of monoclonal antibodies (mAbs) in identifying culturable allergenic fungi present in visible mould growth in energy efficient homes, and to identify risk factors for exposure to these known allergenic fungi. Swabs were taken from fungal contaminated surfaces and culturable yeasts and moulds isolated by using mycological culture. Soluble antigens from cultures were tested by ELISA using mAbs specific to the culturable allergenic fungi Aspergillus and Penicillium spp., Ulocladium, Alternaria, and Epicoccum spp., Cladosporium spp., Fusarium spp., and Trichoderma spp. Diagnostic accuracies of the ELISA tests were determined by sequencing of the internally transcribed spacer 1 (ITS1)-5.8S-ITS2-encoding regions of recovered fungi following ELISA. There was 100% concordance between the two methods, with ELISAs providing genus-level identity and ITS sequencing providing species-level identities (210 out of 210 tested). Species of Aspergillus/Penicillium, Cladosporium, Ulocladium/Alternaria/Epicoccum, Fusarium and Trichoderma were detected in 82% of the samples. The presence of condensation was associated with an increased risk of surfaces being contaminated by Aspergillus/Penicillium spp. and Cladosporium spp., whereas moisture within the building fabric (water ingress/rising damp) was only associated with increased risk of Aspergillus/Penicillium spp. Property type and energy efficiency levels were found to moderate the risk of indoor surfaces becoming contaminated with Aspergillus/Penicillium and Cladosporium which in turn was modified by the presence of condensation, water ingress and rising damp, consistent with previous literature.

Serological diagnosis of allergic bronchopulmonary mycosis: Progress and challenges

Prompt diagnosis of allergic bronchopulmonary mycosis (ABPM) is an important clinical issue in preventing irreversible lung damage. Therefore, a good serological marker for the diagnosis of ABPM is desired in clinical practice. The measurement of IgE antibody to crude Aspergillus fumigatus allergen is considered the first step in screening asthmatic patients for allergic bronchopulmonary aspergillosis (ABPA). However, presence of IgE to A. fumigatus does not always indicate genuine sensitization to A. fumigatus because of cross-reactivity between crude extracts from different fungal sources. The application of molecular-based allergy diagnosis can solve this problem. The specificity of testing can be greatly improved by measuring the IgE antibody to Asp f 1 and f 2, specific allergen components for genuine A. fumigatus allergy. The problem of cross-reactivity between crude fungal extracts is also true for the identification of genuine causal fungi in each ABPM patient. Some patients with ABPM induced by fungi other than Aspergillus may be consistent with ABPA diagnostic criteria because current criteria depend on IgE/IgG reactivity to crude extracts. Accurate identification of genuine causal fungi for ABPM is of clinical importance, considering that clinical presentation, anti-fungal treatment strategies and disease prognosis can be influenced by different causal fungi. The diagnosis of causal fungi can be robustly validated by the confirmation of genuine sensitization to fungi after measuring IgE to specific allergen components, as well as repeated microbiological isolation of the fungi from their airway.

Activation of Melanin Synthesis in Alternaria infectoria by Antifungal Drugs

The importance of Alternaria species fungi to human health ranges from their role as etiological agents of serious infections with poor prognoses in immunosuppressed individuals to their association with respiratory allergic diseases. The present work focuses on Alternaria infectoria, which was used as a model organism of the genus, and was designed to unravel melanin production in response to antifungals. After we characterized the pigment produced by A. infectoria, we studied the dynamics of 1,8-dihydroxynaphthalene (DHN)-melanin production during growth, the degree of melanization in response to antifungals, and how melanization affected susceptibility to several classes of therapeutic drugs. We demonstrate that A. infectoria increased melanin deposition in cell walls in response to nikkomycin Z, caspofungin, and itraconazole but not in response to fluconazole or amphotericin B. These results indicate that A. infectoria activates DHN-melanin synthesis in response to certain antifungal drugs, possibly as a protective mechanism against these drugs. Inhibition of DHN-melanin synthesis by pyroquilon resulted in a lower minimum effective concentration (MEC) of caspofungin and enhanced morphological changes (increased hyphal balloon size), characterized by thinner and less organized A. infectoria cell walls. In summary, A. infectoria synthesizes melanin in response to certain antifungal drugs, and its susceptibility is influenced by melanization, suggesting the therapeutic potential of drug combinations that affect melanin synthesis.

The burden of serious human fungal infections in Brazil

In Brazil, human fungal infections are prevalent, however, these conditions are not officially reportable diseases. To estimate the burden of serious fungal diseases in 1 year in Brazil, based on available data and published literature. Historical official data from fungal diseases were collected from Brazilian Unified Health System Informatics Department (DATASUS). For fungal diseases for which no official data were available, assumptions of frequencies were made by estimating based on published literature. The incidence (/1000) of hospital admissions for coccidioidomycosis was 7.12; for histoplasmosis, 2.19; and for paracoccidioidomycosis, 7.99. The estimated number of cryptococcal meningoencephalitis cases was 6832. Also, there were 4115 cases of Pneumocystis pneumonia in AIDS patients per year, 1 010 465 aspergillosis and 2 981 416 cases of serious Candida infections, including invasive and non-invasive diseases. In this study, we demonstrate that more than 3.8 million individuals in Brazil may be suffering from serious fungal infections, mostly patients with malignant cancers, transplant recipients, asthma, previous tuberculosis, HIV infection and those living in endemic areas for truly pathogenic fungi. The scientific community and the governmental agencies should work in close collaboration in order to reduce the burden of such complex, difficult-to-diagnose and hard to treat diseases.

Sensitization to fungal allergens: Resolved and unresolved issues

Exposure and sensitization to fungal allergens can promote the development and worsening of allergic diseases. Although numerous species of fungi have been associated with allergic diseases in the literature, the significance of fungi from the genera Alternaria, Cladosporium, Penicillium, Aspergillus, and Malassezia has been well documented. However, it should be emphasized that the contribution of different fungal allergens to allergic diseases is not identical, but species-specific. Alternaria and Cladosporium species are considered to be important outdoor allergens, and sensitization and exposure to species of these genera is related to the development of asthma and rhinitis, as well as epidemics of asthma exacerbation, including life-threatening asthma exacerbation. In contrast, xerophilic species of Penicillium and Aspergillus, excluding Aspergillus fumigatus, are implicated in allergic diseases as indoor allergens. A. fumigatus has a high capacity to colonize the bronchial tract of asthmatic patients, causing severe persistent asthma and low lung function, and sometimes leading to allergic bronchopulmonary aspergillosis. Malassezia are common commensals of healthy skin, although they are also associated with atopic dermatitis, especially on the head and neck, but not with respiratory allergies. Despite its importance in the management of allergic diseases, precise recognition of species-specific IgE sensitization to fungal allergens is often challenging because the majority of fungal extracts exhibit broad cross-reactivity with taxonomically unrelated fungi. Recent progress in gene technology has contributed to the identification of specific and cross-reactive allergen components from different fungal sources. However, data demonstrating the clinical relevance of IgE reactivity to these allergen components are still insufficient.

The basophil surface marker CD203c identifies Aspergillus species sensitization in patients with cystic fibrosis

BACKGROUND

Colonization by Aspergillus fumigatus in patients with cystic fibrosis (CF) can cause A fumigatus sensitization and/or allergic bronchopulmonary aspergillosis (ABPA), which affects pulmonary function and clinical outcomes. Recent studies show that specific allergens upregulate the surface-expressed basophil marker CD203c in sensitized subjects, a response that can be readily measured by using flow cytometry.

OBJECTIVE

We sought to identify A fumigatus sensitization in patients with CF by using the basophil activation test (BAT).

METHODS

Patients with CF attending Beaumont Hospital were screened for study inclusion. BAT was used to identify A fumigatus sensitization. Serologic (total and A fumigatus-specific IgE), pulmonary function, and body mass index measurements were performed.

RESULTS

The BAT discriminates A fumigatus-sensitized from nonsensitized patients with CF. Persistent isolation of A fumigatus in sputum is a significant risk factor for A fumigatus sensitization. Levels of the A fumigatus-stimulated basophil activation marker CD203c inversely correlated with pulmonary function and body mass index in A fumigatus-sensitized but not nonsensitized patients with CF. Total and A fumigatus-specific IgE, but not IgG, levels are increased in A fumigatus-sensitized patients with CF and ABPA when compared with those in A fumigatus-sensitized and nonsensitized patients with CF without ABPA. Itraconazole treatment did not affect A fumigatus sensitization.

CONCLUSION

Combining the BAT with routine serologic testing allows classification of patients with CF into 3 groups: nonsensitized, A fumigatus-sensitized, and ABPA. Accurate and prompt identification of A fumigatus-associated clinical status might allow early and targeted therapeutic intervention, potentially improving clinical outcomes.

Development of chronic pulmonary aspergillosis in adult asthmatics with ABPA

BACKGROUND

Chronic pulmonary aspergillosis (CPA) is an occasional complication of allergic bronchopulmonaryaspergillosis (ABPA) but the transition is poorly understood.

METHODS

All patients referred to the UK's National Aspergillosis Centre with CPA between May 2009 and June 2012 were screened with serum total IgE and anti-Aspergillus IgE for a dual diagnosis of ABPA and CPA. Those patients suspected of having both conditions were re-evaluated and their imaging reviewed.

RESULTS

Of 407 referred patients, 42 screened positive and 22 were confirmed as having both ABPA and CPA. Asthma was present from early childhood in 19 (86%), the median interval between ABPA and onset of CPA was 7.5 years; one patient developed ABPA and CPA simultaneously. Aspergillus IgG levels varied from 23 to 771 mg/L, median 82 mg/L. All 22 patients had bronchiectasis. In patients with ABPA, CT typically demonstrated varicose or cystic bronchiectasis primarily affecting segmental and proximal subsegmental upper lobe bronchi. Other findings included mucoid impaction and centrilobular nodules. Radiological changes associated with CPA included pleural thickening which was often bilateral and accentuated by adjacent hypertrophied extrapleural fat, upper lobe volume loss, thick walled apical cavities, some of which contained aspergillomas, and cavitating pulmonary nodules. CPA secondary to ABPA has more subtle radiological appearances than when due to other underlying diseases.

CONCLUSIONS

CPA may complicate ABPA and have distinct radiology features, in addition to bronchiectasis. A novel biomarker is required to anticipate this serious complication, as current serology is not specific enough.

Antifungals in severe asthma

PURPOSE OF REVIEW

Despite guideline-based treatment, many patients with severe asthma continue to have uncontrolled disease. Fungal allergy is being increasingly recognized in the pathogenesis of severe asthma. Limited data exist on the approach to treatment of fungal asthma. This review summarizes existing evidence on the use of antifungal agents in allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitization (SAFS), and highlights needed areas of future investigation.

RECENT FINDINGS

Recent studies evaluating oral triazole therapy in ABPA appear to support triazole use in a carefully considered clinical setting, whereas studies assessing triazole use in SAFS have yielded mixed results. Despite early encouraging findings that oral triazole use may improve asthma symptoms, stabilize lung function, decrease inhaled and systemic corticosteroid requirements, and alter serum biomarkers, overall data are limited. Appropriate patient selection, as well as choice of the optimal drug, dose, frequency, and duration of therapy, remains poorly defined.

SUMMARY

The role of antifungal therapy in severe asthma remains unclear. Early studies have suggested a possible benefit of some antifungal agents, such as oral triazoles in ABPA and SAFS; however, routine clinical use of these agents in severe asthma without ABPA is not currently recommended. Further research is needed to better delineate the potential utility of antifungal medications in severe asthma and identify the asthma populations who benefit from such treatment.

The need to differentiate between adults and children when treating severe asthma

Severe asthma at all ages is heterogeneous incorporating several phenotypes that are distinct in children and adults, however, there are also numerous similar features including the limitation that they may not remain stable longitudinally. Severe asthma in both children and adults is characterized by eosinophilic airway inflammation and evidence of airway remodeling. In adults, targeting eosinophilia with anti-IL-5 antibody therapy is very successful, resulting in the recommendation that sputum eosinophils should be used to guide treatment. In contrast, data for the efficacy of blocking IL-5 remain unavailable in children. However, its effectiveness is uncertain since many children with severe asthma have normal blood eosinophils and the dominance of Th2-mediated inflammation is controversial. Approaches that have revealed gene signatures and biomarkers such as periostin that are specific to adult disease now need to be adopted in children to identify effective pediatric specific therapeutics and minimize the extrapolation of adult therapeutics to children.

Diagnosis of allergic bronchopulmonary aspergillosis: a case-based approach

Allergic bronchopulmonary aspergillosis is a pulmonary disease occurring in patients with asthma or cystic fibrosis, consequent to a dysregulated immune response to inhaled Aspergillus conidia. The usual presentation is with poorly controlled asthma. Patients may also present with expectoration of mucus plugs, hemoptysis, constitutional symptoms and radiological opacities. Patients may experience smoldering lung destruction despite well-controlled asthma. With emerging data, the diagnostic criteria transcribed by an International Expert Committee in 2013 are the latest evidence-based guidelines. Herein, we utilize a case-based approach to elaborate on the diagnosis of this disease. The review intends to provide a lucid understanding of the diagnostic process for the expert as well as the primary physician, involved in management of this enigmatic disorder.

The diagnostic criteria for allergic bronchopulmonary aspergillosis in children with poorly controlled asthma need to be re-evaluated

AIM

The aim of this study was to examine the association between allergic bronchopulmonary aspergillosis (ABPA) and poorly controlled asthma in children and appraise the diagnostic criteria.

METHODS

The study included 100 children with poorly controlled asthma. We diagnosed ABPA using the Aspergillus skin test, pulmonary function test, total and specific immunoglobulin E (IgE) to Aspergillus fumigatus, chest radiograph and high-resolution computed tomography. Patients were diagnosed and classified according to the Rosenberg-Patterson criteria for ABPA. The cut-off value for total serum IgE was calculated by receiver operating characteristics curve analysis.

RESULTS

Of 100 children with poorly controlled asthma, 26 patients were ABPA positive. There was a significant difference in the forced expiratory volume in 1-sec/forced vital capacity ratio between ABPA positive (0.78 ± 0.14) and negative (0.87 ± 0.15) children (p = 0.008). ABPA positive children were categorised as seropositive, central bronchiectasis and other radiological findings. The receiver operating characteristics curve was constructed, and a value of 1200 IU/mL of total IgE was observed, with 88.5% sensitivity and 70.5% specificity.

CONCLUSION

This study showed an association between ABPA and poorly controlled asthma in children and suggests a higher cut-off value of total IgE for the diagnosis of ABPA.

Decreased FEV1 % in asthmatic adults in Scottish homes with high Environmental Relative Moldiness Index values

BACKGROUND

Exposures to indoor biological contaminants have been implicated in asthma's aetiology but their effect on lung function is not well quantified.

OBJECTIVE

The aim of this cross-sectional study of non-smoking, asthmatic adults in Scotland was to determine the correlation between the results from a standard spirometry test, forced expiratory volume in one-second percent (FEV1 %), and quantitative estimates of some biological exposures.

METHODS

A population (n = 55) of non-smoking, adult asthmatics in Scotland was included in this study and each completed a questionnaire that allowed the determination of the Asthma Control Questionnaire scores (ACQ) and St. George's Respiratory Questionnaire scores (SGRQ), as well as corticosteroid use. Spirometry testing was completed and the pre-bronchodilator FEV1 % value calculated. At about the same time, floor dust samples were collected in the living room and in the bedroom. These dust samples were analysed for mould contamination, as described by the Environmental Relative Moldiness Index (ERMI) values and by (1, 3)-β-D-glucan concentrations, for endotoxin, and for dust mite, cat, and dog allergen concentrations. The asthmatics' FEV1 % values were tested for correlation (Pearson) to questionnaire-based estimates of health. Also, each biological exposure was tested for correlation (Pearson) to the FEV1 % values.

RESULTS

FEV1 % results were correlated with ACQ scores (ρ -0.586, P < 0.001), SGRQ scores (ρ -0.313, P = 0.020), and weakly with corticosteroid use (ρ -0.221, P = 0.105). The ERMI values in the homes (average 5.3) were significantly correlated with FEV1 % values (ρ -0.378, P = 0.004). There was no correlation between FEV1 % and concentrations of endotoxin, (1, 3)-β-D-glucan, or any of the allergens.

CONCLUSION AND CLINICAL RELEVANCE

Although these results do not prove that mould exposures caused the deficit in lung function observed in this study, it might be advisable for asthmatics to avoid high ERMI environments.

Pediatric severe asthma with fungal sensitization is mediated by steroid-resistant IL-33

Background

The mechanism underlying severe asthma with fungal sensitization (SAFS) is unknown. IL-33 is important in fungus-induced asthma exacerbations, but its role in fungal sensitization is unexplored.

Objective

We sought to determine whether fungal sensitization in children with severe therapy-resistant asthma is mediated by IL-33.

Methods

Eighty-two children (median age, 11.7 years; 63% male) with severe therapy-resistant asthma were included. SAFS (n = 38) was defined as specific IgE or skin prick test response positivity to Aspergillus fumigatus, Alternaria alternata, or Cladosporium herbarum. Clinical features and airway immunopathology were assessed. Chronic exposure to house dust mite and A alternata were compared in a neonatal mouse model.

Results

Children with SAFS had earlier symptom onset (0.5 vs 1.5 years, P = .006), higher total IgE levels (637 vs 177 IU/mL, P = .002), and nonfungal inhalant allergen-specific IgE. Significantly more children with SAFS were prescribed maintenance oral steroids (42% vs 14%, P = .02). SAFS was associated with higher airway IL-33 levels. In neonatal mice A alternata exposure induced higher serum IgE levels, pulmonary IL-33 levels, and IL-13⁺ innate lymphoid cell (ILC) and T_H2 cell numbers but similar airway hyperresponsiveness (AHR) compared with those after house dust mite exposure. Lung IL-33 levels, IL-13⁺ ILC numbers, T_H2 cell numbers, IL-13 levels, and AHR remained increased with inhaled budesonide during A alternata exposure, but all features were significantly reduced in ST2^−/− mice lacking a functional receptor for IL-33.

Conclusion

Pediatric SAFS was associated with more oral steroid therapy and higher IL-33 levels. A alternata exposure resulted in increased IL-33–mediated ILC2 numbers, T_H2 cell numbers, and steroid-resistant AHR. IL-33 might be a novel therapeutic target for SAFS.

The role of chitin, chitinases, and chitinase-like proteins in pediatric lung diseases

Chitin, after cellulose, the second most abundant biopolymer on earth, is a key component of insects, fungi, and house-dust mites. Lower life forms are endowed with chitinases to defend themselves against chitin-bearing pathogens. Unexpectedly, humans were also found to express chitinases as well as chitinase-like proteins that modulate immune responses. Particularly, increased levels of the chitinase-like protein YKL-40 have been associated with severe asthma, cystic fibrosis, and other inflammatory disease conditions. Here, we summarize and discuss the potential role of chitin, chitinases, and chitinase-like proteins in pediatric lung diseases.

The lung mycobiome: an emerging field of the human respiratory microbiome

The lung microbiome, which is believed to be stable or at least transient in healthy people, is now considered as a poly-microorganism component contributing to disease pathogenesis. Most research studies on the respiratory microbiome have focused on bacteria and their impact on lung health, but there is evidence that other non-bacterial organisms, comprising the viruses (virome) and fungi (mycobiome), are also likely to play an important role in healthy people as well as in patients. In the last few years, the lung mycobiome (previously named the fungal microbiota or microbiome) has drawn closer attention. There is growing evidence that the lung mycobiome has a significant impact on clinical outcome of chronic respiratory diseases (CRD) such as asthma, chronic obstructive pulmonary disease, cystic fibrosis, and bronchiectasis. Thanks to advances in culture independent methods, especially next generation sequencing, a number of fungi not detected by culture methods have been molecularly identified in human lungs. It has been shown that the structure and diversity of the lung mycobiome vary in different populations (healthy and different diseased individuals) which could play a role in CRD. Moreover, the link between lung mycobiome and different biomes of other body sites, especially the gut, has also been unraveled. By interacting with the bacteriome and/or virome, the respiratory mycobiome appears to be a cofactor in inflammation and in the host immune response, and therefore may contribute to the decline of the lung function and the disease progression. In this review, we report the recent limited explorations of the human respiratory mycobiome, and discuss the mycobiome’s connections with other local microbial communities, as well as the relationships with the different biomes of other body sites. These studies suggest several outlooks for this understudied emerging field, which will certainly call for a renewal of our understanding of pulmonary diseases.

Higher energy efficient homes are associated with increased risk of doctor diagnosed asthma in a UK subpopulation

INTRODUCTION

The United Kingdom (UK) has one of the highest prevalence of asthma in the world, which represents a significant economic and societal burden. Reduced ventilation resulting from increased energy efficiency measures acts as a modifier for mould contamination and risk of allergic diseases. To our knowledge no previous study has combined detailed asset management property and health data together to assess the impact of household energy efficiency (using the UK Government's Standard Assessment Procedure) on asthma outcomes in an adult population residing in social housing.

METHODS

Postal questionnaires were sent to 3867 social housing properties to collect demographic, health and environmental information on all occupants. Detailed property data, residency periods, indices of multiple deprivation (IMD) and household energy efficiency ratings were also investigated. Logistic regression was used to calculate odds ratios and confidence intervals while allowing for clustering of individuals coming from the same location.

RESULTS

Eighteen percent of our target social housing population were recruited into our study. Adults had a mean age of 59 (SD±17.3) years and there was a higher percentage of female (59%) and single occupancy (58%) respondents. Housing demographic characteristics were representative of the target homes. A unit increase in household Standard Assessment Procedure (SAP) rating was associated with a 2% increased risk of current asthma, with the greatest risk in homes with SAP >71. We assessed exposure to mould and found that the presence of a mouldy/musty odour was associated with a two-fold increased risk of asthma (OR 2.2 95%; CI 1.3-3.8). A unit increase in SAP led to a 4-5% reduction in the risk of visible mould growth and a mouldy/musty odour.

DISCUSSION

In contrast to previous research, we report that residing in energy efficient homes may increase the risk of adult asthma. We report that mould contamination increased the risk of asthma, which is in agreement with existing knowledge. Exposure to mould contamination could not fully explain the association between increased energy efficiency and asthma. Our findings may be explained by increased energy efficiency combined with the provision of inadequate heating, ventilation, and increased concentrations of other biological, chemical and physical contaminants. This is likely to be modified by a complex interaction between occupant behaviours and changes to the built environment. Our findings may also be confounded by our response rate, demographic and behavioural differences between those residing in low versus high energy efficient homes, and use of self-reported exposures and outcomes.

CONCLUSION

Energy efficiency may increase the risk of current adult asthma in a population residing in social housing. This association was not significantly modified by the presence of visible mould growth, although further research is needed to investigate the interaction between other demographic and housing characteristic risk factors, especially the impact of fuel poverty on indoor exposures and health outcomes.

STUDY IMPLICATIONS

A multidisciplinary approach is required to assess the interaction between energy efficiency measures and fuel poverty behaviours on health outcomes prior to the delivery of physical interventions aimed at improving the built environment. Policy incentives are required to address fuel poverty issues alongside measures to achieve SAP ratings of 71 or greater, which must be delivered with the provision of adequate heating and ventilation strategies to minimise indoor dampness. Changes in the built environment without changes in behaviour of domicile residents may lead to negative health outcomes.

No direct association between asthma and the microbiome based on currently available techniques

Current uses of culture-independent tools in previous studies have shown a significant relationship between microbiota and asthma. Although these studies are relatively new, there is also evidence of the possibility of new therapeutic strategies for the treatment or prevention of asthma. This article retrospectively examines the possible association between microorganisms and asthma. Data on all patients with different types of asthma were collected from hospital charts from the Department of Internal Medicine, Saarland University Medical Center, Germany, within the study period of 2011 to 2012. The tracheal secretions of asthmatics obtained by bronchoalveolar lavage, bronchial aspirates through flexible bronchoscopy, and directly in sputum were examined microbiologically for microorganisms. Thirty-one (10.47%, 95% CI, 6.98-13.96) of a total of 296 patients were found to have asthma microorganisms in their airways. We could not establish a causal relationship between microorganisms and asthma based on the results of our study (P = 0.893). Additionally, acute respiratory infections did not affect the microbiological colonization in asthmatics' airways (P = 0.472). We were unable to find a direct association between asthma and the microbiome based on existing diagnostic techniques.

Longitudinal increase in total IgE levels in patients with adult asthma: an association with poor asthma control

Background

Immunoglobulin (Ig) E is well-known to play a critical role in allergic diseases. We investigated the association between longitudinal change in total IgE level and the asthma control in patients with adult asthma.

Methods

For this retrospective study, 154 patients with asthma aged 21–82 years were recruited from the allergy and pulmonary units of the Showa University Hospital. Data on longitudinal changes in IgE over the preceding 10 years were collected and logarithmically transformed. Associations between longitudinal change in IgE and clinical characteristics including asthma control test (ACT) score, asthma control, pulmonary function test, and antigen specific IgE, were assessed.

Results

Patients with increased IgE tended to have significantly higher mean age, more episodes of acute exacerbation within a year, lower ACT scores, and used oral corticosteroids more frequently than those with decreased or unchanged IgE. The prevalence of uncontrolled asthma was higher in patients with increased IgE than in those with decreased or unchanged IgE. Mean %FEV₁ and FEV_1% were lower in patients with increased IgE than in those with decreased or unchanged IgE. Moreover, the prevalence of Aspergillus-specific IgE was higher in patients with increased IgE than in those with decreased or unchanged IgE.

Conclusions

These data suggest that a longitudinal increase in total IgE is associated with both poor asthma control and Aspergillus-specific IgE in patients with adult asthma.

Fungal culture and sensitisation in asthma, cystic fibrosis and chronic obstructive pulmonary disorder: what does it tell us?

Collectively asthma, chronic obstructive pulmonary disorder (COPD) and cystic fibrosis (CF) are very common, important causes of disease and ill health. Filamentous fungal colonisation of the airways can occur in all three disease groups, although the clinical relevance is unclear. Allergic bronchopulmonary aspergillosis (ABPA) is a well-recognised severe complication of airway colonisation associated primarily with Aspergillus fumigatus. Fungal colonisation may have a deleterious effect without fulfilling all the diagnostic criteria of ABPA; however, a lack of standardisation in processing respiratory samples hampers comparisons. Whilst mycology laboratory accreditation programs are common, most countries have no national standard guidelines for processing respiratory samples. Fungal recovery from sputum in CF, asthma and COPD can be around 40, 54 and 49%, respectively. Isolation of fungi from sputum has been associated with reduced lung function in asthma and CF, although no such associations have been found in COPD. It is unclear whether fungal colonisation contributes to lower lung function or is a marker of more severe lung disease and aggressive therapy. Fungal sensitisation may contribute to the persistence of active respiratory symptoms; however, the exact prevalence is unclear. Sensitisation to A. fumigatus has been associated with reduced lung function in asthma, COPD and CF. It has suggested that both skin prick tests and specific IgE measurement by the ImmunoCAP system should be used in diagnoses of allergy, due to discordance in test results; however, there is currently no widely adopted consensus as to which fungi to test for.

Indoor fungal diversity and asthma: a meta-analysis and systematic review of risk factors

BACKGROUND

Indoor dampness increases the risk of indoor fungal growth. A complex interaction between occupant behaviors and the built environment are thought to affect indoor fungal concentrations and species diversity, which are believed to increase the risk of having asthma, exacerbation of asthma symptoms, or both. To date, no systematic review has investigated this relationship.

OBJECTIVE

This review aims to assess the relationship between exposure to indoor fungi identified to the genera or species level on asthma outcomes in children and adults.

METHODS

Ten databases were systematically searched on April 18, 2013, and limited to articles published since 1990. Reference lists were independently screened by 2 reviewers, and authors were contacted to identify relevant articles. Data were extracted from included studies meeting our eligibility criteria by 2 reviewers and quality assessed by using the Newcastle-Ottawa scale designed for assessment of case-control and cohort studies.

RESULTS

Cladosporium, Alternaria, Aspergillus, and Penicillium species were found to be present in higher concentrations in homes of asthmatic participants. Exposure to Penicillium, Aspergillus, and Cladosporium species were found to be associated with increased risk of reporting asthma symptoms by a limited number of studies. The presence of Cladosporium, Alternaria, Aspergillus, and Penicillium species increased the exacerbation of current asthma symptoms by 36% to 48% compared with those exposed to lower concentrations of these fungi, as shown by using random-effect estimates. Studies were of medium quality and showed medium-high heterogeneity, but evidence concerning the specific role of fungal species was limited.

CONCLUSION

Longitudinal studies assessing increased exposure to indoor fungi before the development of asthma symptoms suggests that Penicillium, Aspergillus, and Cladosporium species pose a respiratory health risk in susceptible populations. Increased exacerbation of current asthma symptoms in children and adults were associated with increased levels of Penicillium, Aspergillus, Cladosporium, and Alternaria species, although further work should consider the role of fungal diversity and increased exposure to other fungal species.