The impact of fungal allergic sensitization on asthma

Bayesian analysis suggests independent development of sensitization to different fungal allergens

Background

Fungi are known for their ability to cause allergies, but data on individual sensitization to them are insufficient. The purpose of the study was to carry out a comprehensive analysis of the fungal allergens' sensitization profile in the Ukrainian population and to determine both population and individual sensitivity to these allergens.

Methods

We utilized a set of ALEX allergy test data from 20,033 inhabitants of 17 regions of Ukraine from 1 to 89 years conducted in 2020-2022. A complex of programs in the Python language was developed and Bayesian network analysis was applied to determine the sensitivity combinations in individual patients to various fungal components.

Results

Sensitivity to Alt a 1 dominated and was observed in 79.39% of patients, and 62.17% of them were sensitive solely to Alt a 1. Exclusive sensitivity to Mala s 6 was second in individual patient profiles with a frequency of 4.06%. Combined sensitivity to Alt a 1 - Asp f 3 was third with a share of 3.28%. Pen ch and Cla h extracts stimulated the production of the lowest median sIgE levels. The highest median sIgE levels were for Alt a 1, Mala s 11 and Asp f 6, respectively. Median sIgE levels increased in adults compared to children for all components of Aspergillus fumigatus, as well as for Mala s 5 and Mala s 11. In the rest of the cases, they decreased in adults compared to children. The sensitization rates to fungi in general and specifically to Alternaria were lower in the western parts of Ukraine, especially in the Carpathian region, situated within the Broad-leaved Forest zone. The results of Bayesian modeling revealed that in the case of Alt a 1, the simultaneous absence of sensitivity to Cla h 8, Mala s 11, Mala s 5 and Mala s 6 molecules could condition the presence of sensitization to the major Alternaria allergen with a probability of 92.42%. In all other cases, there was a high probability of absence of sensitivity to particular allergen against the background of absence of sensitivity to other ones, which may indicate the independent development of sensitization to different fungal allergens.

Conclusions

Sensitivity to Alt a 1 dominated in the studied population with a lower rate in the western regions. The highest median sIgE levels were induced by Alt a 1, Mala s 11 and Asp f 6. Bayesian Analysis suggest a high probability of the independent development of sensitization to different fungal allergens. The idea that sensitization to one allergen may be protective against sensitization to another one(s) requires further clinical study.

Sensitization with Fungal Protease Allergen Establishes Long-Lived, Allergenic Th Cell Memory in the Lung

Allergic asthma is a chronic inflammatory disease that affects millions of individuals worldwide. Exposure to allergens produced by a variety of otherwise harmless microbes, including fungi, predisposes individuals to immunopathologic disease upon subsequent encounters with allergen. We developed a mouse model that employs a purified protease produced by Aspergillus (Asp f 13) to investigate the contributions of CD4+ Th cells to recurrent lung inflammation. Notably, memory CD4+ T cells enhanced the eosinophil response of sensitized/rechallenged animals. In addition, memory CD4+ T cells maintained allergenic features, including expression of GATA-binding protein 3 and IL-5. Th2 memory T cells persisted in the peribronchiolar interstitium of the lung and expressed markers of tissue residence, such as CD69, CCR8, and IL-33R. Lastly, we identified a peptide epitope contained within Asp f 13 and generated a peptide-MHC class II tetramer. Using these tools, we further demonstrated the durability and exquisite sensitivity of memory T cells in promoting lung eosinophilia. Our data highlight important features of memory T cells that strengthen the notion that memory T cells are principal drivers of eosinophilic disease in murine models of allergic sensitization and episodic airway inflammation.

Outdoor Alternaria and Cladosporium spores and acute asthma

BACKGROUND

Outdoor Alternaria and Cladosporium spores are ubiquitous. Few studies have assessed their impact on asthma hospitalizations providing conflicting results, mainly focused on vulnerable paediatric populations. We aimed to study the impact of outdoor Alternaria and Cladosporium concentrations on acute hospitalizations in the Capital Region of Denmark.

METHODS

This is a bi-directional case-crossover study with 26 years of national registry data at individual level on acute asthma hospitalizations and daily average data on Alternaria and Cladosporium, pollen (Artemisia, Poaceae), maximal temperature, and air pollution. Conditional logistic regression models were applied to assess the associations. Concentration quartiles at lag 0 were used for categorizing the exposure.

RESULTS

For lags 0-2, the odds of hospitalization were significantly higher for both Alternaria and Cladosporium at concentration quartile 2-4 compared with quartile 1. When stratified for age and sex, odds of hospitalization at Alternaria quartiles 2-4 were significantly higher in males below 40 years at lag 0-2, and at lag 0 in females (18-30 years), while quartiles 2-4 of Cladosporium concentrations were associated with significantly higher odds in boys (0-17 years) at lag 1-3, males (18-39 years) at lag 0-1, females (18-39 years) at lag 1-2, males (40-64 years) at lag 0-2, females (40-64 years) at lag 0 and 2, in seniors (65+ years) male at lag 1-2 and female at lag 0-1. The effect of Alternaria varied significantly depending on the level of Cladosporium (p < .0001).

CONCLUSION

Ambient Alternaria and Cladosporium spores can induce asthma hospitalizations. Males are more susceptible to both genera. Males and females under age 40 years are more susceptible to Alternaria.

Investigations of a combination of atopic status and age of asthma onset identify asthma subphenotypes

OBJECTIVE

Subphenotypes of asthma may be determined by age onset and atopic status. We sought to characterize early or late onset atopic asthma with fungal or non-fungal sensitization (AAFS or AANFS) and non-atopic asthma (NAA) in children and adults in the Severe Asthma Research Program (SARP). SARP is an ongoing project involving well-phenotyped patients with mild to severe asthma.

METHODS

Phenotypic comparisons were performed using Kruskal-Wallis or chi-square test. Genetic association analyses were performed using logistic or linear regression.

RESULTS

Airway hyper-responsiveness, total serum IgE levels, and T2 biomarkers showed an increasing trend from NAA to AANFS and then to AAFS. Children and adults with early onset asthma had greater % of AAFS than adults with late onset asthma (46% and 40% vs. 32%; P < 0.00001). In children, AAFS and AANFS had lower % predicted FEV1 (86% and 91% vs. 97%) and greater % of patients with severe asthma than NAA (61% and 59% vs. 43%). In adults with early or late onset asthma, NAA had greater % of patients with severe asthma than AANFS and AAFS (61% vs. 40% and 37% or 56% vs. 44% and 49%). The G allele of rs2872507 in GSDMB had higher frequency in AAFS than AANFS and NAA (0.63 vs. 0.55 and 0.55), and associated with earlier age onset and asthma severity.

CONCLUSIONS

Early or late onset AAFS, AANFS, and NAA have shared and distinct phenotypic characteristics in children and adults. AAFS is a complex disorder involving genetic susceptibility and environmental factors.

[Unmet Needs in Severe Allergic Asthma]

Severe asthma affects 3%-10% of the world's population, according to estimates by the Global Initiative for ASTHMA (GINA). Allergic asthma is one of the most common phenotypes of severe asthma and it is characterized by allergen-induced type 2 inflammation in which immunoglobulin E (IgE) is a key mediator, making it an important therapeutic target. The introduction of targeted biological therapies or treatments has entered the management for severe asthma in the era of precision medicine, and the goal of treatment is clinical remission of the disease. There is a significant percentage of patients with severe allergic asthma who do not respond to treatments and whose symptoms are not controlled. In this paper, a group of experts in the management of severe allergic asthma reviewed and evaluated the most relevant evidence regarding the pathophysiology and phenotypes of severe allergic asthma, the role of IgE in allergic inflammation, allergen identification, techniques, biomarkers and diagnostic challenges, available treatments and strategies for disease management, with a special focus on biological treatments. From this review, recommendations were developed and validated through a Delphi consensus process with the aim of offering improvements in the management of severe allergic asthma to the professionals involved and identifying the unmet needs in the management of this pathology.

Allergic fungal rhinosinusitis: What we can learn from allergic bronchopulmonary mycosis

Allergic fungal rhinosinusitis (AFRS) and allergic bronchopulmonary mycosis (ABPM) are inflammatory disorders of the respiratory tract resulting from type 1 and 3 hypersensitivity reactions against fungi. The hallmark features of both diseases are eosinophil infiltration into the airway mucosa caused by localized type 2 inflammation and concomitant viscid secretions in the airways. Eosinophilic mucin-induced compression of adjacent anatomic structures leads to bone erosion and central bronchiectasis in the upper and lower respiratory tracts, respectively. Although these diseases share common features in their pathogenesis, they also exhibit notable differences. Epidemiologic findings are diverse, with AFRS typically presenting at a younger age, exhibiting less complicated bronchial asthma, and displaying lower total immunoglobulin E levels in laboratory findings compared with ABPM. Furthermore, despite their similar pathogenesis, the rarity of sinio-bronchial allergic mycosis in both AFRS and ABPM underscores the distinctions between these two diseases. This review aims to clarify the similarities and differences in the pathogenesis of AFRS and ABPM to determine what can be learned about AFRS from ABPM, where more is known.

Efficacy of dupilumab in patients with uncontrolled, moderate-to-severe asthma with fungal sensitization

BACKGROUND

Fungal sensitization (FS) exacerbates asthma in patients who have elevated type 2 inflammatory response. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin (IL)-4 and IL-13, key and central drivers of type 2 inflammation in multiple diseases.

OBJECTIVE

This post hoc analysis, funded by the manufacturers of dupilumab, was conducted to assess dupilumab efficacy in patients from the phase 3 LIBERTY ASTHMA QUEST trial (NCT02414854) and TRAVERSE open-label extension (NCT02134028) study who had uncontrolled, moderate-to-severe asthma with type 2 inflammatory phenotype (defined as blood eosinophil count ≥150 cells/μL or FeNO ≥25 ppb) and with FS (defined as IgE specific to Alternaria alternata, Aspergillus fumigatus or Cladosporium herbarum >0.35 IU/mL).

METHODS

We evaluated annualized rate of severe exacerbations (AER), change from baseline in pre-bronchodilator (BD) forced expiratory volume in 1 s (FEV1 ), asthma control (per 5-item Asthma Control Questionnaire [ACQ-5]) and biomarker levels (blood eosinophil count, fractional exhaled nitric oxide [FeNO], total IgE, fungal-specific IgEs, thymus and activation-regulated chemokine [TARC] and eotaxin-3).

RESULTS

Dupilumab vs. placebo reduced AER, improved pre-BD FEV1 and asthma control (ACQ-5), and reduced serum IgE levels, blood eosinophil count, TARC, eotaxin-3 and FeNO in patients both with and without FS after 52 weeks of treatment in QUEST. Reductions in asthma exacerbation rates and improvements in all other variables were sustained over the TRAVERSE open-label extension study.

CONCLUSION

Dupilumab demonstrated efficacy during prolonged treatment in patients with uncontrolled, moderate-to-severe asthma with FS.

Aspergillus-Specific IgG Antibodies are Associated With Fungal-Related Complications and Chronic Lung Allograft Dysfunction After Lung Transplantation

Fungal exposure and sensitization negatively affect outcomes in various respiratory diseases, however, the effect of fungal sensitization in lung transplant (LTx) recipients is still unknown. We performed a retrospective cohort study of prospectively collected data on circulating fungal specific IgG/IgE antibodies, and their correlation with fungal isolation, chronic lung allograft dysfunction (CLAD) and overall survival after LTx. 311 patients transplanted between 2014 and 2019 were included. Patients with elevated Aspergillus fumigatus or Aspergillus flavus IgG (10%) had more mold and Aspergillus species isolation (p = 0.0068 and p = 0.0047). Aspergillus fumigatus IgG was specifically associated with Aspergillus fumigatus isolation in the previous or consecutive year (AUC 0.60, p = 0.004 and AUC 0.63, p = 0.022, respectively). Elevated Aspergillus fumigatus or Aspergillus flavus IgG was associated with CLAD (p = 0.0355), but not with death. Aspergillus fumigatus, Aspergillus flavus or Aspergillus niger IgE was elevated in 19.3% of patients, but not associated with fungal isolation, CLAD or death. Mold isolation and Aspergillus species isolation from respiratory cultures were associated with CLAD occurrence (p = 0.0011 and p = 0.0005, respectively), and Aspergillus species isolation was also associated with impaired survival (p = 0.0424). Fungus-specific IgG could be useful in long-term follow-up post-LTx, as a non-invasive marker for fungal exposure, and thus a diagnostic tool for identifying patients at risk for fungal-related complications and CLAD.

Recent Advances in the Allergic Cross-Reactivity between Fungi and Foods

Airborne fungi are one of the most ubiquitous kinds of inhalant allergens which can result in allergic diseases. Fungi tend to grow in warm and humid environments with regional and seasonal variations. Their nomenclature and taxonomy are related to the sensitization of immunoglobulin E (IgE). Allergic cross-reactivity among different fungal species appears to be widely existing. Fungus-related foods, such as edible mushrooms, mycoprotein, and fermented foods by fungi, can often induce to fungus food allergy syndrome (FFAS) by allergic cross-reactivity with airborne fungi. FFAS may involve one or more target organs, including the oral mucosa, the skin, the gastrointestinal and respiratory tracts, and the cardiovascular system, with various allergic symptoms ranging from oral allergy syndrome (OAS) to severe anaphylaxis. This article reviews the current knowledge on the field of allergic cross-reactivity between fungal allergens and related foods, as well as the diagnosis and treatment on FFAS.

Asthma, bronchitis respiratory symptoms, allergies and home environment: how are they related?

Introduction

Home environmental conditions can affect the prevalence of childhood asthma and allergies.

Aim

To assess the relationship between the prevalence of childhood asthma, bronchitis, and allergies and the condition of the home environment.

Material and methods

In 2018 and 2019, a cross-sectional study on 2932 children from elementary schools in the Silesian Voivodship (Southern Poland) was conducted. The questionnaire was based on the International Study of Asthma and Allergies in Childhood (ISAAC). In order to determine the association between the home environment (presence of moulds, furry pets) and respiratory symptoms and diseases, a logistic regression analysis was performed by calculating the odds ratio (OR), determining p < 0.05 as the level of significance.

Results

Asthma risk factors were male sex, heating with solid fuel and presence of moulds. The prevalence of respiratory symptoms, bronchitis, and allergic diseases is statistically more common with the presence of moulds in dwellings. A protective effect of the presence of pets on the prevalence of asthma (OR = 0.77; 95% CI: 0.59–0.99), allergy to pet allergens (OR = 0.59; 95% CI: 0.45–0.76), allergy to house dust mite (OR = 0.70; 95% CI: 0.56–0.87) and wheeze in the last 12 months (OR = 0.70; 95% CI: 0.54–0.91) and ever (OR = 0.85; 95% CI: 0.70–1.02) was observed.

Conclusions

The study confirmed the known adverse influence of the presence of moulds and heating with solid fuel on the prevalence of asthma, bronchitis, respiratory symptoms and allergic diseases. The protective influence of pets on the occurrence of the health disorders under study was demonstrated.

Climate Change Related Catastrophic Rainfall Events and Non-Communicable Respiratory Disease: A Systematic Review of the Literature

Climate change is increasing the frequency and intensity of extreme precipitation events, the impacts of which disproportionately impact urban populations. Pluvial flooding and flooding related sewer backups are thought to result in an increase in potentially hazardous human-pathogen encounters. However, the extent and nature of associations between flooding events and non-communicable respiratory diseases such as chronic bronchitis, asthma, and chronic obstructive pulmonary disease (COPD) are not well understood. This research seeks to characterize the state of research on flooding and NCRDs through a systematic review of the scientific literature. We conducted a systematic search of PubMed, Web of Science, and Scopus for published scholarly research papers using the terms flooding, monsoon, and tropical storm with terms for common NCRDs such as asthma, COPD, and chronic bronchitis. Papers were included if they covered research studies on individuals with defined outcomes of flooding events. We excluded review papers, case studies, and opinion pieces. We retrieved 200 articles from PubMed, 268 from Web of Science and 203 from Scopus which comprised 345 unique papers. An initial review of abstracts yielded 38 candidate papers. A full text review of each left 16 papers which were included for the review. All papers except for one found a significant association between a severe weather event and increased risk for at least one of the NCRDs included in this research. Our findings further suggest that extreme weather events may worsen pre-existing respiratory conditions and increase the risk of development of asthma. Future work should focus on more precisely defining measure of health outcomes using validated tools to describe asthma and COPD exacerbations. Research efforts should also work to collect granular data on patients’ health status and family history and assess possible confounding and mediating factors such as neighborhood water mitigation infrastructure, housing conditions, pollen counts, and other environmental variables.

The Mediating Effect of Cytokines on the Association between Fungal Sensitization and Poor Clinical Outcome in Asthma

Sensitization to fungal allergens is one of the proposed phenotypes in asthma. An association between fungal sensitization and worse clinical outcomes is apparent. Moreover, fungal sensitization in asthma that is associated with different type of immunological mechanism has been reported. How the role of cytokines mediates the association between fungal sensitization and poorer asthmatic outcomes remains unclear. We aimed to determine role of cytokines in the relationship between fungal sensitization and worse clinical outcomes in asthma.

METHOD

We conducted a prospective study to recruit adult patients with asthma. Data including age, sex, height, weight, smoking history, medication, emergency visit and admission, pulmonary function testing result, and Asthma Control Test (ACT) scores were collected. We used the automated BioIC method to measure fungal allergen sIgE in sera. Serum levels of Interleukin (IL) -4, IL-13, IL-6, IL-9, IL-10, IL-17 A, IL-22, Interferon (IFN) -γ, Immunoglobulin E (IgE), Tumor necrosis factor-α (TNF-α), and Transforming growth factor-β (TGF-β) were measured using ELISA.

RESULT

IL-6 and IL-17A had a significant positive correlation between sensitization and most fungi species compared to IgE. Sensitization to Candida albicans had strongly positive association both with IL-6 and IL-17A. However, only IL-17A had significant relationship with ED visit times. The mediation analysis result indicates that IL-17A had a significant positively mediating effect (ME) on the association between Candida albicans and ED visit times.

CONCLUSION

IL-17A is a potential mediator to link Candida albicans sensitization and ED visits for asthma. We suggest that patients with fungal sensitization, such as Candida albicans, have poorer outcomes associated with Th17-mediated immune response rather than Th2.

Registry analysis of patients with severe allergic asthma and clinically relevant sensitization to fungal allergens treated with genetically engineered biologics

Background. Fungal sensitization (FS) often escapes the attention of clinicians when assessing the spectrum of sensitization in patients with atopic diseases. According to cohort studies is found in 310% of the general population and in 720% of asthmatics; the proportion of patients with severe bronchial asthma (SBA) with HS ranges from 35 to 75%. Fungal conidia have a 1000-fold higher exposure and are among the most important clinically relevant allergens in asthma. Exposure to fungal allergens is capable of generating a sustained T2 response with production of proinflammatory cytokines such as IL-5 and 13, which is indirectly related to the severity of airway eosinophilia. The identification of specific serum IgE is considered the benchmark diagnostic sign of FS, and the encapsulated hydrophobic carrier polymer system is considered preferable to skin prick tests. The process of reclassifying diseases with fungal lung lesions is confusing treatment strategies, leaving the FS problem underestimated. A series of publications have shown that omalizumab and other biologics targeting IL-5 or IL-5 receptor (IL5R) alpha are effective in treating SBA with FS. However, there remains an unmet need in real clinical practice for standardized approaches to genetically engineered biological therapies (BT) for different phenotypes of SBA, especially those associated with impaired microbiological homeostasis and this type of sensitization. Aim. Using retrospective analysis of clinical-dynamic observational data from patients on BT treatment in a real clinical setting to determine phenotypic features of severe allergic bronchial asthma with FS and to perform additional detailed analysis of a cohort of patients on anti-IgE therapy. Materials and methods. A retrospective observational single-center registry study was conducted between June 2017 and August 2021 at the City Reference Center for Allergology and Immunology. The baseline cohort consisted of 198 patients with severe allergic AD who were in the initial phase of BT. Inclusion criteria: age of patients over 18 years; presence of severe allergic bronchial asthma. Complex initial examination of patients included determination of FS by two methods: ImmunoCap ISAC to fungal allergic components alt a1, alt 6 (fungi of genus Alternaria) and asp f1, asp f3, asp f6 (fungi of genus Aspergillus). Specific IgE determinations on fungal panels. Sensitization to fungi was detected in 47 people during allergy examination. The following criteria were considered in evaluation of response to omalizumab: AST score less than 19 and/or difference between initial AST score and this score in dynamics less than 3 points; FEV 1 score less than 80; combination of 2 listed criteria. The minimum period of BT was 16 weeks. Nonparametric methods of descriptive statistics were used: median, interquartile range. Differences were considered significant at p0.05. Data were statistically processed using nonparametric methods in IBM SPSS Statistics V-22 program. MannWhitney U-test and KruskalWallis one-way analysis of variance were used to compare quantitative characteristics. Fisher's 2 test was used to compare qualitative characteristics. Results. Characteristics of the eosinophilic phenotype of SBA combined with FS: middle-aged patients, more often women, with relatively early onset of AD and high baseline eosinophil levels before prescription of biological drug therapy. Concomitant atopic dermatitis and food allergies are additional frequent features of this phenotype. Analysis of the effect of FS on achieving response to omalizumab and further consideration of switching to alternative therapy in SBA and FS patients showed the need to avoid premature revision and perform no earlier than the 10th month of therapy due to delayed response formation. Given the aggressive impact of FS on the barrier functions of the bronchial tree epithelium, it is advisable to test patients for FS at the initial diagnosis of AD. In the presence of atopic dermatitis and/or food allergy as T2 comorbidities in patients with SBA, early testing for FS and increased control of local and systemic inflammation are appropriate, which may improve long-term outcomes and reduce risks of further damage to natural barriers. Conclusion. Further research on various aspects of FS and its role in allergic diseases is extremely relevant in the current context.

Fungal Lung

Foot and nail care specialists spend a great portion of their day using nail drills to reduce nail thickness and smooth foot calluses. This process generates a large amount of dust, some of which is small enough to breathe in and deposit into the deepest regions of the respiratory tract, potentially causing health problems. Foot and nail dust often contains fungi, from both fungus-infected and healthy-appearing nails. Although the majority of healthy individuals can tolerate inhaled fungi, the immune systems of older, immunocompromised, and allergy-prone individuals often react using the inflammatory T helper cell type 2 pathway, leading to mucus overproduction, bronchoconstriction, and, in severe cases, lung tissue damage. To protect vulnerable podiatry professionals, wearing a surgical mask, using a water spray suppression system on nail drills, installing air filtration systems, and considering drilling technique can help reduce exposure to nail dust.

Real-World Effectiveness of Anti-IL-5/5R Therapy in Severe Atopic Eosinophilic Asthma with Fungal Sensitization

BACKGROUND

Severe asthma with fungal sensitization (SAFS) is a complex clinical phenotype associated with poorly controlled type 2 inflammation and significant morbidity from both the disease itself and a high steroid burden.

OBJECTIVE

To assess the effectiveness of biologic therapies targeting eosinophilic inflammation in SAFS.

METHODS

We assessed the effectiveness of treatment with mepolizumab or benralizumab in patients with SAFS, and compared outcomes with patients with severe atopic asthma without fungal sensitization and patients with severe nonatopic asthma. Baseline clinical characteristics and clinical outcomes at 48 weeks were evaluated. A subgroup analysis was performed of patients who met the criteria for allergic bronchopulmonary aspergillosis (ABPA) rather than SAFS.

RESULTS

A total of 193 patients treated with mepolizumab (n = 63) or benralizumab (n = 130) were included. Patients with SAFS had higher baseline IgE level compared with patients with severe atopic asthma without fungal sensitization and severe nonatopic asthma (733 ± 837 IU/mL vs 338 ± 494 and 142 ± 171, respectively; both P < .001). There were no other significant baseline differences in clinical characteristics between groups. At 48 weeks, there were significant improvements in 6-item asthma control questionnaire score and exacerbation frequency, and reduction in maintenance oral corticosteroid dose across all groups (all P < .05). No significant between-group differences in outcomes were observed at 48 weeks. Patients with ABPA (n = 9) had a significant reduction in exacerbation frequency (P = .013) with treatment.

CONCLUSIONS

Treatment with eosinophil-targeting biologics led to improvements in exacerbation frequency, oral corticosteroid requirements, and patient-reported outcomes in patients with SAFS, with a reduction in exacerbations in the subgroup of patients with ABPA. These data highlight the potential clinical utility of targeting eosinophilic inflammation in SAFS and ABPA.