Serological diagnosis of allergic bronchopulmonary mycosis: Progress and challenges

ABPA and AFRS: addressing prevalence, early diagnosis, allergens, and occupational concerns

OBJECTIVE

This study aimed to comprehensively investigate the prevalence of ABPA and AFRS, scrutinize existing diagnostic criteria and immunoassays, pinpoint their limitations, highlight ABPA as an occupational health implication, and identify suggestive measures to improve ABPA diagnosis in the context of Occupational Health Nursing and primary healthcare.

DATA SOURCES

The data sources such as PubMed, Health and Safety Science Abstracts, OSH Update, Medline, and Google Scholar were searched.

STUDY SELECTIONS

All published studies in the English language from 1990 till Oct, 2023 using Mesh terms keywords "Allergic bronchopulmonary aspergillosis," "Allergic fungal rhinosinusitis," "Signs and Symptoms," "Rapid Diagnostic Tests," "Diagnosis," "Occupational Health," "Occupational Health Nursing," "Prevalence," "Allergens" following "Boolean operators" search strategy were selected.

RESULTS

This review succinctly covered signs, symptoms, and prevalence data concerning ABPA and AFRS. It briefly discussed existing diagnostic criteria and immunoassays, highlighted factors influencing the assay's variability, and underscored the role and scope of specific allergens toward improved, simple, and early ABPA diagnosis. ABPA as a neglected occupational health concern was emphasized, and the importance of RDTs in the context of healthcare professionals and OHNs was stated. Finally, this study suggested analyzing the impact of compromised post-pandemic immune status and the use of immunosuppressive drugs on ABPA prevalence among vulnerable communities and occupations.

CONCLUSION

To conclude, global and Indian ABPA and AFRS prevalence data, factors influencing existing assay variability, and the scope of improvement in RDTs for ABPA diagnosis in the background of primary healthcare professionals and OHNs were addressed.

Allergic bronchopulmonary mycosis in Schizophyllum commune with positive Aspergillus-specific IgE antibodies: A case report

Schizophyllum commune is the third most common causative fungus of allergic bronchopulmonary mycosis(ABPM). Two-thirds of ABPM caused by S. commune can be positive for Aspergillus fumigatus-specific IgE, which can be difficult to diagnose. Our patient presented to our hospital with wet cough for 3 months and chest pain for 3 days. Blood tests showed IgE 1522 IU/mL, eosinophils 688/mm3, A. fumigatus -specific IgE 2.24 UA/mL, and chest computed tomography showed high-attenuation mucus. Bronchoscopy showed mucus plugs and speculum examination showed filamentous fungi, but various culture tests did not detect A. fumigatus, Asp f 1-specific IgE was negative, and S. commune was detected in the culture of bronchial washing. Since he was positive for S. commune-specific IgE and IgG, he diagnosed ABPM caused by S. commune. These findings demonstrate the importance of identifying the causative fungus in ABPM by detailed examination.

Revised ISHAM-ABPA working group clinical practice guidelines for diagnosing, classifying and treating allergic bronchopulmonary aspergillosis/mycoses

BACKGROUND

The International Society for Human and Animal Mycology (ISHAM) working group proposed recommendations for managing allergic bronchopulmonary aspergillosis (ABPA) a decade ago. There is a need to update these recommendations due to advances in diagnostics and therapeutics.

METHODS

An international expert group was convened to develop guidelines for managing ABPA (caused by Aspergillus spp.) and allergic bronchopulmonary mycosis (ABPM; caused by fungi other than Aspergillus spp.) in adults and children using a modified Delphi method (two online rounds and one in-person meeting). We defined consensus as ≥70% agreement or disagreement. The terms "recommend" and "suggest" are used when the consensus was ≥70% and <70%, respectively.

RESULTS

We recommend screening for A. fumigatus sensitisation using fungus-specific IgE in all newly diagnosed asthmatic adults at tertiary care but only difficult-to-treat asthmatic children. We recommend diagnosing ABPA in those with predisposing conditions or compatible clinico-radiological presentation, with a mandatory demonstration of fungal sensitisation and serum total IgE ≥500 IU·mL-1 and two of the following: fungal-specific IgG, peripheral blood eosinophilia or suggestive imaging. ABPM is considered in those with an ABPA-like presentation but normal A. fumigatus-IgE. Additionally, diagnosing ABPM requires repeated growth of the causative fungus from sputum. We do not routinely recommend treating asymptomatic ABPA patients. We recommend oral prednisolone or itraconazole monotherapy for treating acute ABPA (newly diagnosed or exacerbation), with prednisolone and itraconazole combination only for treating recurrent ABPA exacerbations. We have devised an objective multidimensional criterion to assess treatment response.

CONCLUSION

We have framed consensus guidelines for diagnosing, classifying and treating ABPA/M for patient care and research.

Clinical Manifestation and Treatment of Allergic Bronchopulmonary Aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to airway colonization by Aspergillus fumigatus in patients with asthma and cystic fibrosis. The pathophysiology of ABPA involves a complex interplay between the fungus and the host immune response, which causes persistent inflammation and tissue damage. Patients present with chronic cough, wheezing, and dyspnea due to uncontrolled asthma. Characteristic symptoms include the expectoration of brownish mucus plugs. Radiographic findings often reveal fleeting pulmonary infiltrates, bronchiectasis, and mucus impaction. However, the definitive diagnosis of ABPA requires a combination of clinical, radiological, and immunological findings. The management of ABPA aims to reduce symptoms, prevent disease progression, and minimize the future risk of exacerbations. The treatment approach involves systemic glucocorticoids or antifungal agents to suppress the inflammatory response or fungal growth and prevent exacerbations. Biological agents may be used in patients with severe disease or glucocorticoid dependence. This review provides an overview of the clinical manifestations and current treatment options for ABPA.

Poorly controlled asthma - Easy wins and future prospects for addressing fungal allergy

Poorly controlled asthma is especially common in low resource countries. Aside from lack of access to, or poor technique with, inhaled beta-2 agonists and corticosteroids, the most problematic forms of asthma are frequently associated with both fungal allergy and exposure, especially in adults leading to more asthma exacerbations and worse asthma. The umbrella term 'fungal asthma' describes many disorders linked to fungal exposure and/or allergy to fungi. One fungal asthma endotype, ABPA, is usually marked by a very high IgE and its differential diagnosis is reviewed. Both ABPA and fungal bronchitis in bronchiectasis are marked by thick excess airway mucus production. Dermatophyte skin infection can worsen asthma and eradication of the skin infection improves asthma. Exposure to fungi in the workplace, home and schools, often in damp or water-damaged buildings worsens asthma, and remediation improves symptom control and reduces exacerbations. Antifungal therapy is beneficial for fungal asthma as demonstrated in nine of 13 randomised controlled studies, reducing symptoms, corticosteroid need and exacerbations while improving lung function. Other useful therapies include azithromycin and some biologics approved for the treatment of severe asthma. If all individuals with poorly controlled and severe asthma could be 'relieved' of their fungal allergy and infection through antifungal therapy without systemic corticosteroids, the health benefits would be enormous and relatively inexpensive, improving the long term health of over 20 million adults and many children. Antifungal therapy carries some toxicity, drug interactions and triazole resistance risks, and data are incomplete. Here we summarise what is known and what remains uncertain about this complex topic.

Relationship between Aspergillus and asthma

Fungal sensitization is highly prevalent in severe asthma. The relationship between fungus and asthma, especially Aspergillus fumigatus, has been the subject of extensive research. The ubiquitous presence of A. fumigatus, its thermotolerant nature, the respirable size of its conidia, and its ability to produce potent allergens are pivotal in worsening asthma control. Due to the diverse clinical manifestations of fungal asthma and the lack of specific biomarkers, its diagnosis remains intricate. Diagnosing fungal asthma requires carefully assessing the patient's clinical history, immunological tests, and imaging. Depending on the severity, patients with fungal asthma require personalized treatment plans, including inhaled corticosteroids and bronchodilators, and antifungal therapy. This review provides a comprehensive overview of the association between Aspergillus and asthma by reviewing the relevant literature and highlighting key findings. We discuss the diagnosis of various entities included in fungal asthma. We also debate whether newer definitions, including allergic fungal airway disease, offer any additional advantages over the existing ones. Finally, we provide the current treatment options for the individual entities, including A. fumigatus-associated asthma, severe asthma with fungal sensitization, and allergic bronchopulmonary mycoses.

Antigen specificity and cross-reactivity drive functionally diverse anti-Aspergillus fumigatus T cell responses in cystic fibrosis

BACKGROUNDThe fungus Aspergillus fumigatus causes a variety of clinical phenotypes in patients with cystic fibrosis (pwCF). Th cells orchestrate immune responses against fungi, but the types of A. fumigatus-specific Th cells in pwCF and their contribution to protective immunity or inflammation remain poorly characterized.METHODSWe used antigen-reactive T cell enrichment (ARTE) to investigate fungus-reactive Th cells in peripheral blood of pwCF and healthy controls.RESULTSWe show that clonally expanded, high-avidity A. fumigatus-specific effector Th cells, which were absent in healthy donors, developed in pwCF. Individual patients were characterized by distinct Th1-, Th2-, or Th17-dominated responses that remained stable over several years. These different Th subsets target different A. fumigatus proteins, indicating that differential antigen uptake and presentation directs Th cell subset development. Patients with allergic bronchopulmonary aspergillosis (ABPA) are characterized by high frequencies of Th2 cells that cross-recognize various filamentous fungi.CONCLUSIONOur data highlight the development of heterogenous Th responses targeting different protein fractions of a single fungal pathogen and identify the development of multispecies cross-reactive Th2 cells as a potential risk factor for ABPA.FUNDINGGerman Research Foundation (DFG), under Germany's Excellence Strategy (EXC 2167-390884018 "Precision Medicine in Chronic Inflammation" and EXC 2051-390713860 "Balance of the Microverse"); Oskar Helene Heim Stiftung; Christiane Herzog Stiftung; Mukoviszidose Institut gGmb; German Cystic Fibrosis Association Mukoviszidose e.V; German Federal Ministry of Education and Science (BMBF) InfectControl 2020 Projects AnDiPath (BMBF 03ZZ0838A+B).

Allergic bronchopulmonary aspergillosis (ABPA) in an atopic patient with difficult-to-expectorate airway secretions

In the workup of a 55-year-old atopic patient with cough and viscous secretions, we diagnosed an allergic bronchopulmonary aspergillosis (ABPA) on the basis of common diagnostic criteria for adult asthma patients (Rosenberg-Patterson and ISHAM), supported by the use of IgE antibodies against the Aspergillus components Asp f 2, f 4, and f 6. Initial treatment with prednisolone and itraconazole led to remission. In the long-term follow-up, there were few relapses until 2015, which responded well to standard treatment with oral steroids, and since 2016 the patient is in stable remission. The case highlights the valuable contribution of Aspergillus IgE measurements, including the specific IgEs against the components Asp f 1, f 2, f 4, and f 6 in the diagnosis of ABPA.

New Perspectives in the Diagnosis and Management of Allergic Fungal Airway Disease

Allergy to airway-colonising, thermotolerant, filamentous fungi represents a distinct eosinophilic endotype of often severe lung disease. This endotype, which particularly affects adult asthma, but also complicates other airway diseases and sometimes occurs de novo, has a heterogeneous presentation ranging from severe eosinophilic asthma to lobar collapse. Its hallmark is lung damage, characterised by fixed airflow obstruction (FAO), bronchiectasis and lung fibrosis. It has a number of monikers including severe asthma with fungal sensitisation (SAFS) and allergic bronchopulmonary aspergillosis/mycosis (ABPA/M), but these exclusive terms constitute only sub-sets of the condition. In order to capture the full extent of the syndrome we prefer the inclusive term allergic fungal airway disease (AFAD), the criteria for which are IgE sensitisation to relevant fungi in association with airway disease. The primary fungus involved is Aspergillus fumigatus, but a number of other thermotolerant species from several genera have been implicated. The unifying mechanism involves germination of inhaled fungal spores in the lung in the context of IgE sensitisation, leading to a persistent and vigorous eosinophilic inflammatory response in association with release of fungal proteases. Most allergenic fungi, including Alternaria and Cladosporium species, are not thermotolerant and cannot germinate in the airways so only act as aeroallergens and do not cause AFAD. Studies of the airway mycobiome have shown that A. fumigatus colonises the normal as much as the asthmatic airway, suggesting it is the tendency to become IgE-sensitised that is the critical triggering factor for AFAD rather than colonisation per se. Treatment is aimed at preventing exacerbations with glucocorticoids and increasingly by the use of anti-T2 biological therapies. Anti-fungal therapy has a limited place in management, but is an effective treatment for fungal bronchitis which complicates AFAD in about 10% of cases.

Allergic bronchopulmonary aspergillosis

Allergic bronchopulmonary aspergillosis (ABPA) is an inflammatory disease caused by immunologic reactions initiated against Aspergillus fumigatus colonizing the airways of patients with asthma and cystic fibrosis. The common manifestations include treatment-resistant asthma, transient and fleeting pulmonary opacities and bronchiectasis. It is believed that globally there are about five million cases of ABPA, with India alone accounting for about 1.4 million cases. The occurrence of ABPA among asthmatic patients in special clinics may be as high as 13 per cent. Thus, a high degree of suspicion for ABPA should be entertained while treating a patient with bronchial asthma, particularly in specialized clinics. Early diagnosis and appropriate treatment can delay (or even prevent) the onset of bronchiectasis, which suggests that all patients of bronchial asthma should be screened for ABPA, especially in chest clinics. The current review summarizes the recent advances in the pathogenesis, diagnosis and management of ABPA.

Prospective Evaluation of Aspergillus fumigatus-Specific IgG in Patients With Cystic Fibrosis

Background

In Cystic Fibrosis (CF), the airways are often colonized by opportunistic fungi. The most frequently detected mold is Aspergillus fumigatus (Af). Af diseases are associated with significant morbidity and mortality. The most common clinical picture caused by Af is allergic bronchopulmonary aspergillosis (ABPA), triggered by an immunological reaction against Af. Af bronchitis and invasive aspergillosis rarely occur in CF as a result of spore colonization and germination. Since pulmonary mycoses and exacerbations by other pathogens overlap in clinical, radiological, and immunological characteristics, diagnosis still remains a challenge. The search for reliable, widely available biomarkers for Af diseases is therefore still an important task today.

Objectives

Af-specific IgG m3 is broadly available. Sensitivity and specificity data are contradictory and differ depending on the study population. In our prospective study on pulmonary Af diseases in CF, we determined specific IgG m3 in order to test its suitability as a biomarker for acute Af diseases and as a follow-up parameter.

Methods

In this prospective single center study, 109 patients with CF were screened from 2016 to 2019 for Af-associated diseases. According to diagnostic criteria, they were divided into four groups (control, bronchitis, ABPA, pneumonia). The groups were compared with respect to the level of Af-specific IgG (ImmunoCAP Gm3). We performed a receiver operating characteristic (ROC) curve analysis to determine cut-off, sensitivity and specificity. Twenty-one patients could be enrolled for a follow-up examination.

Results

Of the 109 patients, 36 were classified as acute Af-disease (Af bronchitis, ABPA, Af pneumonia). Of these, 21 patients completed follow up-screening. The median Af-specific Gm3 was higher in the acute Af-disease groups. There was a significant difference in Af-specific IgG m3 compared to the control group without acute Af-disease. Overall, there was a large interindividual distribution of Gm3. A cut-off value of 78.05 mg/L for Gm3 was calculated to discriminate controls and patients with ABPA/pneumonia with a specificity of 75% and a sensitivity of 74.6%. The follow up examination of 21 patients showed a decrease of Gm3 in most patients without statistical significance due to the small number of follow up patients.

Conclusion

Af specific IgG may be a useful biomarker for acute ABPA and Af pneumonia, but not for Af bronchitis in CF. However, due to the large interindividual variability of Gm3, it should only be interpreted alongside other biomarkers. Therefore, due to its broad availability, it could be suitable as a biomarker for ABPA and Af pneumonia in CF, if the results can be supported by a larger multicenter cohort.

Optimal Aspergillus fumigatus and Asp f 1 serum IgG cut-offs for the diagnosis of allergic bronchopulmonary aspergillosis

BACKGROUND

The presence of IgG antibodies (Abs) to Aspergillus fumigatus (Af) is a crucial diagnostic criterion for allergic bronchopulmonary aspergillosis (ABPA). Although precipitation is traditionally used to document IgG Abs, anti-Af serum IgG levels can also be measured by enzyme immunoassay (EIA). However, there are insufficient data on the optimal cut-offs to assess diagnostic performance of the EIA method. This study aimed to determine cut-off levels of IgG binding crude Af extracts or recombinant Asp f 1 (by ImmunoCAP®) and to compare their efficacy for ABPA diagnosis with Af-precipitating Abs.

METHODS

The age distribution of levels of IgG to crude extracts of Af (Af-IgG) and recombinant Asp f 1 (Asp f 1-IgG) was established using sera from 694 healthy controls (HC). Receiver operating characteristic analysis for Af-IgG and Asp f 1-IgG levels for the purpose of ABPA diagnosis was performed in 306 Af-sensitized asthma patients (including 49 ABPA), and cut-offs were determined.

RESULTS

An age-dependent decline in the levels of Af-IgG was observed in HC. Thus, cut-offs for Af-IgG levels were determined separately by age as 60 mg/L for patients aged <55 years, and 45 mg/L for those aged ≥55 years. For Asp f 1-IgG, 6.6 mg/L was set as the cut-off regardless of age. Although such IgG testing by EIA allowed a sufficiently good diagnostic performance, Af-precipitating Abs had better diagnostic applicability for ABPA.

CONCLUSIONS

We determined cut-offs for Af-IgG and Asp f 1-IgG measured by EIA, which can be useful in clinical settings where precipitating Abs are unavailable.

Obstructive lung diseases and allergic bronchopulmonary aspergillosis

PURPOSE OF REVIEW

Allergic bronchopulmonary aspergillosis (ABPA) is a disease frequently complicating asthma and cystic fibrosis. ABPA is increasingly recognized in other obstructive lung diseases (OLDs), including chronic obstructive pulmonary disease (COPD) and noncystic fibrosis bronchiectasis. Herein, we summarize the recent developments in ABPA complicating OLDs.

RECENT FINDINGS

Recent research has described the clinical features and natural history of ABPA complicating asthma in children and the elderly. We have gained insights into the pathophysiology of ABPA, especially the role of eosinophil extracellular trap cell death and mucus plugs. The utility of recombinant fungal antigens in the diagnosis of ABPA has been established. Newer, more sensitive criteria for the diagnosis of ABPA have been proposed. Although ABPA is uncommon in COPD and noncystic fibrosis bronchiectasis, aspergillus sensitization is more common and is associated with a higher exacerbation rate.

SUMMARY

Several advances have occurred in the diagnosis and treatment of ABPA in recent years. However, there is an unmet need for research into the genetic predisposition, pathophysiology, and treatment of ABPA. Apart from asthma and cystic fibrosis, patients with other OLDs also require evaluation for Aspergillus sensitization and ABPA.

Johnson E, Littlechild J, Winlove CP, Vollmer F, Gow NAR. Biosensors and Diagnostics for Fungal Detection

Early detection is critical to the successful treatment of life-threatening infections caused by fungal pathogens, as late diagnosis of systemic infection almost always equates with a poor prognosis. The field of fungal diagnostics has some tests that are relatively simple, rapid to perform and are potentially suitable at the point of care. However, there are also more complex high-technology methodologies that offer new opportunities regarding the scale and precision of fungal diagnosis, but may be more limited in their portability and affordability. Future developments in this field are increasingly incorporating new technologies provided by the use of new format biosensors. This overview provides a critical review of current fungal diagnostics and the development of new biophysical technologies that are being applied for selective new sensitive fungal biosensors to augment traditional diagnostic methodologies.

Role of recombinant Aspergillus fumigatus antigens in diagnosing Aspergillus sensitisation among asthmatics

BACKGROUND

The diagnosis of Aspergillus-sensitised asthma (ASA) and allergic bronchopulmonary aspergillosis (ABPA) is made using IgE against crude antigens of A fumigatus (cAsp). However, the IgE against cAsp has limitations due to cross-reactivity with other fungi.

OBJECTIVE

To evaluate the utility of recombinant A fumigatus (rAsp) antigens in detecting ASA and their role in differentiating true from cross-sensitisation.

METHODS

We performed IgE against rAsp (f 1, f 2, f 3, f 4 and f 6), cAsp and other fungal (Alternaria, Candida, Cladosporium, Malassezia and Trichophyton) antigens in subjects with A fumigatus-unsensitised asthma (Af-UA [n = 51]), ASA (n = 71) and ABPA (n = 123). The diagnoses were made using cAsp-IgE and compared using rAsp-IgE. Subjects with elevated cAsp-IgE, but negative rAsp f 1 and f 2, were presumed to lack true A fumigatus sensitisation.

RESULTS

The prevalence of any rAsp antigen positivity (cut-off, 0.35 kUA/L) varied from 2%-22%, 32%-73% and 84%-98% for Af-UA, ASA and ABPA, respectively. The prevalence of sensitisation to other fungi ranged from 29%-65%, 59%-85% and 87%-95%, respectively, among subjects with Af-UA, ASA and ABPA. Nineteen subjects of ASA and one subject with ABPA were positive with cAsp-IgE but negative for rAsp f 1 and f 2 and were also cross-sensitised to at least one of the other fungi. Five subjects of Af-UA (cAsp-IgE negative) were rAsp f 1 or f 2 positive.

CONCLUSIONS

Crude Aspergillus antigens may misclassify Aspergillus sensitisation among asthmatics. IgE against rAsp antigens (f 1 and f 2) potentially detect true Aspergillus sensitisation and could be used for this purpose.

The allergenic activity and clinical impact of individual IgE-antibody binding molecules from indoor allergen sources

A large number of allergens have been discovered but we know little about their potential to induce inflammation (allergenic activity) and symptoms. Nowadays, the clinical importance of allergens is determined by the frequency and intensity of their IgE antibody binding (allergenicity). This is a rather limited parameter considering the development of experimental allergology in the last 20 years and the criteria that support personalized medicine. Now it is known that some allergens, in addition to their IgE antibody binding properties, can induce inflammation through non IgE mediated pathways, which can increase their allergenic activity. There are several ways to evaluate the allergenic activity, among them the provocation tests, the demonstration of non-IgE mediated pathways of inflammation, case control studies of IgE-binding frequencies, and animal models of respiratory allergy. In this review we have explored the current status of basic and clinical research on allergenic activity of indoor allergens and confirm that, for most of them, this important property has not been investigated. However, during recent years important advances have been made in the field, and we conclude that for at least the following, allergenic activity has been demonstrated: Der p 1, Der p 2, Der p 5 and Blo t 5 from HDMs; Per a 10 from P. americana; Asp f 1, Asp f 2, Asp f 3, Asp f 4 and Asp f 6 from A. fumigatus; Mala s 8 and Mala s 13 from M. sympodialis; Alt a 1 from A. alternata; Pen c 13 from P. chrysogenum; Fel d 1 from cats; Can f 1, Can f 2, Can f 3, Can f 4 and Can f 5 from dogs; Mus m 1 from mice and Bos d 2 from cows. Defining the allergenic activity of other indoor IgE antibody binding molecules is necessary for a precision-medicine-oriented management of allergic diseases.

The Pathogenesis of Fungal-Related Diseases and Allergies in the African Population: The State of the Evidence and Knowledge Gaps

The prevalence of allergic diseases in the African continent has received limited attention with the allergic diseases due to fungal allergens being among the least studied. This lead to the opinion being that the prevalence of allergic disease is low in Africa. Recent reports from different African countries indicate that this is not the case as allergic conditions are common and some; particularly those due to fungal allergens are increasing in prevalence. Thus, there is need to understand both the aetiology and pathogenies of these diseases, particularly the neglected fungal allergic diseases. This review addresses currently available knowledge of fungal-induced allergy, disease pathogenesis comparing findings from human versus experimental mouse studies of fungal allergy. The review discusses the potential role of the gut mycobiome and the extent to which this is relevant to fungal allergy, diagnosis and human health.

Current Approach in the Diagnosis and Management of Allergic Bronchopulmonary Aspergillosis in Children With Cystic Fibrosis

Allergic bronchopulmonary aspergillosis (ABPA) is a complex pulmonary disorder characterized by a hypersensitivity reaction to Aspergillus fumigatus, and almost always seen in patients with cystic fibrosis (CF) and asthma. Fungal hyphae leads to an ongoing inflammation in the airways that may result in bronchiectasis, fibrosis, and eventually loss of lung function. Despite the fact that ABPA is thought to be more prevalent in CF than in asthma, the literature on ABPA in CF is more limited. The diagnosis is challenging and may be delayed because it is made based on a combination of clinical features, and radiologic and immunologic findings. With clinical deterioration of a patient with CF, ABPA is important to be kept in mind because clinical manifestations mimic pulmonary exacerbations of CF. Early diagnosis and appropriate treatment are important in preventing complications related to ABPA. Treatment modalities involve the use of anti-inflammatory agents to suppress the immune hyperreactivity and the use of antifungal agents to reduce fungal burden. Recently, in an effort to treat refractory patients or to reduce adverse effects of steroids, other treatment options such as monoclonal antibodies have started to be used. Intensive research of these new agents in the treatment of children is being conducted to address insufficient data.

Allergic fungal rhinosinusitis accompanied by allergic bronchopulmonary aspergillosis: A case report and literature review

BACKGROUND

Concomitant allergic fungal rhinosinusitis (AFRS) and allergic bronchopulmonary aspergillosis (ABPA) are extremely rare, with no more than 20 cases reported in the English literature.

CASE SUMMARY

A 52-year-old female patient complained of right-sided nasal obstruction, rhinorrhea, sneezing, epistaxis, and hyposmia for a period of around 5 mo. Nasal examination detected paleness and edema of the nasal mucous membrane and a polyp in the right middle meatus. A computed tomography (CT) scan of the sinuses revealed a ground-glass opacity filling the right maxillary and ethmoid sinuses, along with bone absorption in the medial wall of the right maxillary sinus. Magnetic resonance images were obtained with T1-weighted, T2-weighted, and gadolinium-enhanced T1-weighted sequences. A well-defined mass, located in the right maxillary and ethmoid sinuses and displaying obvious hypointense features, was observed on both T1- and T2-weighted images, with peripheral enhancement on gadolinium-enhanced T1-weighted images. The patient also has a 20-year history of cough and dyspnea. Chest CT revealed columned and cystiform bronchiectasis in the bilateral bronchus, surrounded by a large number of spotted and funicular high-density lesions. The level of serum total IgE was > 5000 kU/L. Serum IgE levels related to house dust and aspergillus showed a positive result, with the values being 3.5 kU/L and 1.2 kU/L. We performed functional endoscopic sinus surgery under local anesthesia. After surgery, topical glucocorticoids and saline irrigation were applied in the nasal cavity until the present time. An oral glucocorticoid (methylprednisolone 16 mg/d) and antifungal agent (itraconazole 200 mg/d) were also used for a period of 4 wk. Montelukast was prescribed at 10 mg/d until the present time. An endoscopic examination showed that the patient was recovering well at 3 mo after surgery.

CONCLUSION

Since different specialists treat ABPA and AFRS, their coexistence may be overlooked. AFRS accompanied by ABPA requires surgical therapy combined with medical control to improve the symptoms.

Diagnostic Cutoffs and Clinical Utility of Recombinant Aspergillus fumigatus Antigens in the Diagnosis of Allergic Bronchopulmonary Aspergillosis

BACKGROUND

The clinical utility of IgE against recombinant Aspergillus fumigatus (rAsp)-specific antigens in allergic bronchopulmonary aspergillosis (ABPA) remains unclear.

OBJECTIVE

To identify the optimal diagnostic cutoffs of rAsp-specific IgE in differentiating ABPA from A fumigatus-sensitized asthma (ASA), and define their utility in the diagnosis of ABPA.

METHODS

We enrolled consecutive subjects with ASA and ABPA. IgE against rAsp f1, f2, f3, f4, and f6 was assayed in all the subjects. We evaluated 3 fixed cutoffs (0.35, 0.5, and 1.0 kU_A/L) for their diagnostic performance in the entire cohort. We also divided the study population into derivation and validation cohorts. Cutoffs for rAsp-specific IgE were obtained using the receiver-operating characteristic analysis in the derivation cohort. We then evaluated the diagnostic performance of these cutoffs in the validation cohort. We further correlated rAsp-specific IgE levels in ABPA with asthma control, spirometry, imaging, and immunologic markers.

RESULTS

We included 194 subjects (123 ABPA and 71 ASA). The statistically derived cutoffs proved superior to fixed cutoffs. IgE against rAsp f1 yielded the best combination of sensitivity (89%) and specificity (100%). The sensitivity and specificity of IgE against either rAsp f1 (cutoff, 4.465 kU_A/L) or f2 (cutoff, 1.300 kU_A/L) for diagnosing ABPA were 100% and 81%, respectively. The correlation between rAsp-specific IgE and most clinical parameters of ABPA was weak.

CONCLUSIONS

IgE against rAsp f1 and f2 (using receiver-operating characteristic-derived cutoffs) were found to be the most useful in differentiating ABPA from ASA. Because this study was conducted at a single center, our results require further validation.

Serum IgE and IgG reactivity to Aspergillus recombinant antigens in patients with cystic fibrosis

PURPOSE

The diagnosis of aspergillosis in cystic fibrosis (CF) patients remains a challenge due to overlapping features of both diseases. This is further complicated by inconsistent antibody reactivity to the currently used crude antigen, which has led a more focused evaluation of the efficacy of IgE response to a number of pure Aspergillus fumigatus recombinant proteins in patients with CF and asthma. In this study, we dissected the IgE and IgG responses to multiple A. fumigatus recombinant antigens in CF patients with different Aspergillus diseases.

METHODOLOGY

Serum IgE and IgG antibodies were measured in 12 CF patients with allergic bronchopulmonary aspergillosis (ABPA), 12 with Aspergillus sensitization (AS) and 12 with Aspergillus bronchitis (AB) against recombinant antigens Asp f1, f2, f3, f4 and f6.

RESULTS

The ABPA group showed significantly greater IgE reactivity to Asp f1, f2, f3 and f4 compared to patients with AS. Patients with AB expressed higher IgG positivity to Asp f1 and Asp f2 compared with those with ABPA. There were very low IgE antibody levels against all recombinant antigens in patients with AS. Aspf1 IgG reactivity in ABPA patients correlated with positive culture.

CONCLUSION

The use of multiple recombinant antigens may improve the diagnostic accuracy in CF complicated with ABPA or AB. Asp f1 reactivity may relate to the presence of actively growing Aspergillus spp., which might be a useful marker for guiding antifungal therapy in ABPA.

Prevalence of sensitization to Aspergillus flavus in patients with allergic bronchopulmonary aspergillosis

Aspergillus fumigatus is the most common Aspergillus species worldwide; however, A. flavus has also been shown to be prevalent in North India. Herein, we investigate the prevalence of sensitization to A. flavus in subjects with allergic bronchopulmonary aspergillosis (ABPA). We also evaluate the occurrence of allergic bronchopulmonary mycosis (ABPM) due to A. flavus. Treatment-naive subjects with ABPA underwent sputum culture; and, skin testing, fungal-specific immunoglobulin E (IgE) and serum precipitation tests for A. fumigatus and A. flavus. Sensitization to A. flavus was diagnosed if any immunological test for A. flavus was positive in subjects with ABPA. ABPM was labelled as probable if sputum cultures grew A. flavus and A. flavus-specific IgE was greater than A. fumigatus-specific IgE; and, possible if only A. flavus-specific IgE was greater than A. fumigatus-specific IgE. Fifty-three subjects with a mean (SD) age of 34.2 (12.8) years were included. Sensitization to A. flavus was seen in 51 (96.2%) subjects, with overlap occurring in 49 (92.5%), 21 (39.6%), and 12 (22.6%) instances on fungal-specific IgE, skin prick test and precipitins, respectively. Sputum culture was positive in 18 (33.9%; A. flavus [n = 12], A. fumigatus [n = 6]) subjects. ABPM due to A. flavus was diagnosed in 16 (30.2%) subjects (10 probable, 6 possible). They were more likely to have high-attenuation mucus and a trend towards higher occurrence of sinusitis, compared to ABPA. We found a high occurrence of sensitization to A. flavus in subjects with ABPA. Subjects with A. flavus-related ABPM had a higher likelihood of high-attenuation mucus and probability of sinusitis. More studies are required to confirm this observation.

Serological analysis of sensitization in allergic bronchopulmonary aspergillosis: a study on allergen components and interspecies relationships

Background: Serological testing for immunoglobulin (Ig) E or IgG is useful for diagnosing allergic bronchopulmonary aspergillosis (ABPA), as it detects type I and III allergic reactions to Aspergillus species. However, few reports have investigated the allergen component and cross-reactivity among Aspergillus species. We aimed to measure and analyze the levels of IgGs specific to each Aspergillus species and investigate the prevalence of IgEs specific to each allergen component of A. fumigatus (Af) in ABPA patients.Methods: Serum samples were collected from 12 ABPA patients who visited our hospital between February and December 2017, and 16 with Af-sensitized asthma and 41 with Af-unsensitized asthma were controls. Immuno-CAP was performed to analyze the IgEs and IgGs specific to Af, A. niger, A flavus and A. terreus, and IgEs specific to allergen components Asp f 1, 2, 3, 4 and 6.Results: The ABPA group was significantly more frequently sensitized to Asp f 1 and 2 than the control groups. Af-specific IgEs were significantly positively correlated to the IgEs specific to A. flavus, A. niger and A. terreus. Af-specific IgGs were positively correlated to the IgGs specific to all the other species.Conclusions: Tests using allergen components were useful for ABPA diagnosis. Both IgE and IgG were highly cross-reactive among the Aspergillus species. There were many patients apart from asthmatic patients with ABPA, who displayed high Aspergillus IgG values.

Allergic aspergillosis in asthmatic patients in a tertiary hospital in the Kingdom of Bahrain

BACKGROUND INFORMATION:

Aspergillosis is an alarming complication in asthma, leading to worsening symptoms and irreversible lung damage. It is underdiagnosed among asthmatics worldwide, especially in our geographical region.

AIM:

This research was aimed to shed some light on the prevalence of Aspergillus sensitization and allergic bronchopulmonary aspergillosis (ABPA) in asthmatic patients in the Kingdom of Bahrain.

IMPORTANCE:

This project has never been conducted in the region and hopefully will lead to a better care for asthmatics.

METHODOLOGY:

Our study population consisted of adult outpatients visiting the pulmonary and chest diseases clinic at Al-Salmaniya Medical Complex (SMC); the main inclusion condition was manifesting respiratory distress symptoms related to one or more respiratory tract diseases. 152 individuals were selected; the study group consisted of 119 asthmatic patients manifesting respiratory distress. The control group consisted of 33 nonasthmatic patients that manifested pulmonary distress symptoms due to respiratory tract diseases other than asthma like chronic obstructive pulmonary disease, bronchitis, among others. Sera samples were collected in SMC and analyzed via Phadia-250 fluoro-enzyme-immunoassay to determine the levels of Aspergillus fumigatus-specific IgE. The rAsp f1 antigen was used against IgE.

RESULTS:

Our results indicated a 16% prevalence of A. fumigatus sensitization in asthmatics; also, 75.6% of asthmatics were sensitized to pollen grains, and 22.3% reported one or many food allergies. Furthermore, details of patients with significant levels of A. fumigatus- specific IgE were analyzed, and ABPA prevalence was estimated to be 10.1% in asthmatics.

CONCLUSION:

Increasing awareness toward these indolent diseases is required, as well as, more efforts in determining the burden of aspergillosis in other parts of the region.

Precision medicine allergy immunoassay methods for assessing immunoglobulin E sensitization to aeroallergen molecules

Molecular-based allergy diagnosis for the in vitro assessment of a patient immunoglobulin E (IgE) sensitization profile at the molecular level uses allergen molecules (also referred to as allergen components), which may be well-defined, highly purified, natural allergen components or recombinant allergens. Modern immunoassay methods used for the detection of specific IgE against aeroallergen components are either singleplex (such as the fluorescence enzyme immunoassay with capsulated cellulose polymer solid-phase coupled allergens, the enzyme-enhanced chemiluminescence immunoassay and the reversed enzyme allergosorbent test, with liquid-phase allergens), multiparameter (such as the line blot immunoassay for defined partial allergen diagnostics with allergen components coating membrane strips) or multiplex (such as the microarray-based immunoassay on immuno solid-phase allergen chip, and the two new multiplex nanotechnology-based immunoassays: the patient-friendly allergen nano-bead array, and the macroarray nanotechnology-based immunoassay used as a molecular allergy explorer). The precision medicine diagnostic work-up may be organized as an integrated “U-shape” approach, with a “top-down” approach (from symptoms to molecules) and a “bottom-up” approach (from molecules to clinical implications), as needed in selected patients. The comprehensive and accurate IgE sensitization molecular profiling, with identification of the relevant allergens, is indicated within the framework of a detailed patient’s clinical history to distinguish genuine IgE sensitization from sensitization due to cross-reactivity (especially in polysensitized patients), to assess unclear symptoms and unsatisfactory response to treatment, to reveal unexpected sensitizations, and to improve assessment of severity and risk aspects in some patients. Practical approaches, such as anamnesis molecular thinking, laboratory molecular thinking and postmolecular anamnesis, are sometimes applied. The component-resolved diagnosis of the specific IgE repertoire has a key impact on optimal decisions making for prophylactic and specific immunotherapeutic strategies tailored for the individual patient.

Role of Serological Tests in the Diagnosis of Mold Infections

Purpose of Review

To understand the role of antibody detection in the diagnosis of infections caused by filamentous fungi (molds). Rapid and accurate profiling of infection-causing fungal pathogens remains a significant challenge in modern health care. Classical fungal culture and serology continue to be relevant even though over the past few decades, antigen (biomarker) assays such as ELISA and lateral flow devices have been developed and validated.

Recent Findings

This article reviews the current antibody detection systems (serological tests) for the diagnosis of mold infections associated with pulmonary disease and introduces new developments. Classic and more recently developed serological techniques and their performance characteristics, including immunodiffusion, complement fixation, and ELISA.

Summary

The diseases covered are allergic bronchopulmonary aspergillosis, chronic pulmonary aspergillosis, invasive aspergillosis, mucormycosis, diseases caused by filamentous basidiomycetes, infection caused by Talaromyces marneffei and pythiosis. Serology remains a cornerstone for fungal diagnostic testing.

Severe Allergic Bronchopulmonary Mycosis and Long-Term Follow-Up

Allergic bronchopulmonary aspergillosis (ABPA) is the most common immunologic reaction following fungal allergen exposure in asthmatic patients. A less frequent syndrome in response to other fungal species like candida is allergic bronchopulmonary mycosis (ABPM). This reaction is mostly associated with asthma exacerbation, changes in Immunoglobulin E levels, and nonspecific findings in high resolution computed tomography (HRCT). This study presents a 9-year-old girl, a known case of childhood asthma, resolved 4 years ago as a novel case of ABPM due to Candida albicans manifested by severe emphysema, bronchiectasis, and pneumothorax which consequently required long-term treatment to get relieved.

Utility of recombinant Aspergillus fumigatus antigens in the diagnosis of allergic bronchopulmonary aspergillosis: A systematic review and diagnostic test accuracy meta-analysis

BACKGROUND

The role of recombinant A. fumigatus (rAsp) antigens in the diagnosis of allergic bronchopulmonary aspergillosis (ABPA) has not been systematically evaluated. Herein, we evaluate the utility of recombinant A. fumigatus (rAsp) antigens in diagnosing ABPA.

METHODS

We systematically reviewed the PubMed, EmBase and Scopus databases for studies evaluating rAsp antigens in ABPA. The QUADAS-2 tool and the GRADE approach were used to assess the risk of bias and the quality of evidence, respectively. The diagnostic performance of IgE or skin test against rAsp f1, f2, f3, f4, f6 and their combination was evaluated separately for ABPA complicating asthma or cystic fibrosis (CF), using an HSROC model. The reference standard for diagnosing ABPA was the composite (clinical, radiological, immunological) criteria.

RESULTS

Our search yielded 26 studies (n = 1694) and 17 studies (n = 1131) for inclusion in the systematic review and meta-analysis, respectively. In asthmatics, the pooled sensitivity for diagnosing ABPA was best for IgE against a combination of rAsp f1 or f3 (96.7%; 95% confidence interval [CI], 87.6-99.2). The pooled specificity for diagnosing ABPA was highest (99.2%; 95% CI, 88.2-99.9) for IgE against a combination of f4 or f6. In CF patients, the pooled sensitivity of rAsp f1 or f3 was 93.3% (95% CI, 55.2-99.9) while the pooled specificity of rAsp f4 or f6 was 93.9% (95% CI, 68.8-99.9). The quality of evidence was low as per the GRADE approach.

CONCLUSIONS

A combination of IgE against rAsp antigens (f1, f2, f3, f4 and f6) is likely to be helpful in the diagnosis of ABPA.

Fungus-Specific CD4 T Cells as Specific Sensors for Identification of Pulmonary Fungal Infections

Patients with cystic fibrosis (CF) suffer from chronic lung infections, caused by bacterial, viral or fungal pathogens, which determine morbidity and mortality. The contribution of individual pathogens to chronic disease and acute lung exacerbations is often difficult to determine due to the complex composition of the lung microbiome in CF. In particular, the relevance of fungal pathogens in CF airways remains poorly understood due to limitations of current diagnostics to identify the presence of fungal pathogens and to resolve the individual host-pathogen interaction status. T-lymphocytes play an essential role in host defense against pathogens, but also in inappropriate immune reactions such as allergies. They have the capacity to specifically recognize and discriminate the different pathogens and orchestrate a diverse array of effector functions. Thus, the analysis of the fungus-specific T cell status of an individual can in principle provide detailed information about the identity of the fungal pathogen(s) encountered and the actual fungus-host interaction status. This may allow to classify patients, according to appropriate (protective) or inappropriate (pathology-associated) immune reactions against individual fungal pathogens. However, T cell-based diagnostics are currently not part of the clinical routine. The identification and characterization of fungus-specific T cells in health and disease for diagnostic purposes are associated with significant challenges. Recent technological developments in the field of fungus-specific T helper cell detection provide new insights in the host T cell-fungus interaction. In this review, we will discuss basic principles and the potential of T cell-based diagnostics, as well as the perspectives and further needs for use of T cells for improved clinical diagnostics of fungal diseases.

Clinical Diagnosis of the Dampness and Mold Hypersensitivity Syndrome: Review of the Literature and Suggested Diagnostic Criteria

A great variety of non-specific symptoms may occur in patients living or working in moisture-damaged buildings. In the beginning, these symptoms are usually reversible, mild, and present irritation of mucosa and increased morbidity due to respiratory tract infections and asthma-like symptoms. Later, the disease may become chronic and a patient is referred to a doctor where the assessment of dampness and mold hypersensitivity syndrome (DMHS) often presents diagnostic challenges. Currently, unanimously accepted laboratory tests are not yet available. Therefore, the diagnosis of DMHS is clinical and is based on the patient’s history and careful examination. In this publication, I reviewed contemporary knowledge on clinical presentations, laboratory methods, and clinical assessment of DMHS. From the literature, I have not found any proposed diagnostic clinical criteria. Therefore, I propose five clinical criteria to diagnose DMHS: (1) the history of mold exposure in water-damaged buildings, (2) increased morbidity to due infections, (3) sick building syndrome, (4) multiple chemical sensitivity, and (5) enhanced scent sensitivity. If all the five criteria are met, the patient has a very probable DMHS. To resolve the current problems in assigning correct DMHS diagnosis, we also need novel assays to estimate potential risks of developing DMHS.

Characteristics of severe asthma with fungal sensitization

BACKGROUND

Some patients with severe asthma also have fungal sensitization and are considered to have severe asthma with fungal sensitization. However, there is limited information on the clinical features of SAFS.

OBJECTIVE

To investigate the clinical characteristics of severe asthma with fungal sensitization.

METHODS

The present study enrolled 124 patients with severe asthma. We evaluated clinical aspects, such as various serum cytokines, fractional exhaled nitric oxide, pulmonary function, and serum immunoglobulin E (IgE). Fungal sensitization was assessed by determining serum levels of IgE specific to fungal allergens (Aspergillus, Alternaria, Candida, Cladosporium, Penicillium, and Trichophyton species and Schizophyllum commune). The protocol was registered at a clinical trial registry (www.umin.ac.jp/ctr/index-j.htm; UMIN 000002980).

RESULTS

Thirty-six patients (29%) showed sensitization to at least 1 fungal allergen. The most common species were Candida (16%), Aspergillus (11%), and Trichophyton (11%). The rate of early-onset asthma (<16 years of age) was higher in patients with fungal sensitization than in those without fungal sensitization (45% vs 25%; P = .02). Interleukin-33 levels were higher in patients with fungal sensitization than in those without fungal sensitization. Of patients with atopic asthma, Asthma Control Test scores were worse in patients with multiple fungal sensitizations than in patients with a single fungal sensitization or those without fungal sensitization.

CONCLUSION

Severe asthma with fungal sensitization is characterized by early onset of disease and high serum levels of interleukin-33. Multiple fungal sensitizations are associated with poor asthma control.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR; www.umin.ac.jp/ctr/index-j.htm): UMIN 000002980.

Developments in the diagnosis and treatment of allergic bronchopulmonary aspergillosis

INTRODUCTION

Allergic bronchopulmonary aspergillosis (ABPA) is a complex pulmonary disorder characterized by recurrent episodes of wheezing, fleeting pulmonary opacities and bronchiectasis. It is the most prevalent of the Aspergillus disorders with an estimated five million cases worldwide. Despite six decades of research, the pathogenesis, diagnosis and treatment of this condition remains controversial. The International Society for Human and Animal Mycology has formed a working group to resolve the controversies around this entity. In the year 2013, this group had proposed new criteria for diagnosis and staging, and suggested a treatment protocol for the management of this disorder. Since then, several pieces of new evidence have been published in the investigation and therapeutics of this condition. Areas covered: A non-systematic review of the available literature was performed. We summarize the current evidence in the evaluation and treatment of this enigmatic disorder. We suggest modifications to the existing criteria and propose a new scoring system for the diagnosis of ABPA. Expert commentary: All patients with asthma and cystic fibrosis should routinely be screened for ABPA using A. fumigatus-specific IgE levels. Glucocorticoids should be used as the first-line of therapy in ABPA, and itraconazole reserved in those with recurrent exacerbations and glucocorticoid-dependent disease.

Aspergillus serology: Have we arrived yet?

Aspergillosis presents in various clinical forms, among them chronic pulmonary aspergillosis, which is a spectrum of disease entities including aspergilloma, chronic cavitary pulmonary aspergillosis, and chronic fibrosing pulmonary aspergillosis. Aspergillus also contributes to fungal allergy and sensitization. Analysis of the immune response to Aspergillus and its antigens is an integral part of the diagnosis of these diseases. Over the past half century, the techniques used to determine antibody titers have evolved from testing for precipitating and agglutinating antibodies by agar gel double diffusion and immunolectrophoresis to enzyme-linked immunosorbent assays using recombinant proteins as capture antigens. A resurgence of interest in the detection of immunoglobulins, primarily Aspergillus-specific IgG, has hinted at the possibility of distinguishing between colonization and invasion in immunocompromised patients with invasive aspergillosis. Even though there appears to be a greater degree of discrimination between the clinical forms of aspergillosis there is still a long way to travel. This review presents illustrative examples of where new diagnostic platforms and technologies have been applied to this intriguing spectrum of diseases.

Immunoproteomics of Aspergillus for the development of biomarkers and immunotherapies

Filamentous fungi of the genus Aspergillus play significant roles as pathogens causing superficial and invasive infections as well as allergic reactions in humans. Particularly invasive mycoses caused by Aspergillus species are characterized by high mortality rates due to difficult diagnosis and insufficient antifungal therapy. The application of immunoproteomic approaches has a great potential to identify new targets for the diagnosis, therapy, and vaccine development of diseases caused by Aspergillus species. Serological proteome analyses (SERPA) that combine 2D electrophoresis with Western blotting are still one of the most popular techniques for the identification of antigenic proteins. However, recently a growing number of approaches have been developed to identify proteins, which either provoke an antibody response or which represent targets of T-cell immunity in patients with allergy or fungal infections. Here, we review advances in the studies of immune responses against pathogenic Aspergilli as well as the current status of diagnosis and immunotherapy of Aspergillus infections.