The clinical characteristics and prognosis of ABPA are closely related to the mucus plugs in central bronchiectasis

Eosinophilic mucus diseases

Eosinophilic inflammation is primarily characterized by type 2 immune responses against parasitic organisms. In the contemporary human being especially in developed countries, eosinophilic inflammation is strongly associated with allergic/sterile inflammation, and constitutes an undesired immune reaction. This situation is in stark contrast to neutrophilic inflammation, which is indispensable for the host defense against bacterial infections. Among eosinophilic inflammatory disorders, massive accumulation of eosinophils within mucus is observed in certain cases, and is often linked to the distinctive clinical finding of mucus with high viscosity. Eosinophilic mucus is found in a variety of diseases, including chronic allergic keratoconjunctivitis, chronic rhinosinusitis encompassing allergic fungal sinusitis, eosinophilic otitis media, eosinophilic sialodochitis, allergic bronchopulmonary aspergillosis/mycosis, eosinophilic plastic bronchitis, and eosinophilic asthma. In these pathological conditions, chronic inflammation and tissue remodeling coupled with irreversible organ damage due to persistent adhesion of toxic substances and luminal obstruction may impose a significant burden on the body. Eosinophils aggregate in the hyperconcentrated mucus together with cell-derived crystals, macromolecules, and polymers, thereby affecting the biophysical properties of the mucus. This review focuses on the clinically significant challenges of mucus and discusses the consequences of activated eosinophils on the mucosal surface that impact mucus and persistent inflammation.

CT Imaging Assessment of Response to Treatment in Allergic Bronchopulmonary Aspergillosis in Adults With Bronchial Asthma

BACKGROUND

One of the major challenges in managing allergic bronchopulmonary aspergillosis remains consistent and reproducible assessment of response to treatment.

RESEARCH QUESTION

What are the most relevant changes in CT scan parameters over time for assessing response to treatment?

STUDY DESIGN AND METHODS

In this ancillary study of a randomized clinical trial (NebuLamB), patients with asthma with available CT scan and without exacerbation during a 4-month allergic bronchopulmonary aspergillosis exacerbation treatment period (corticosteroids and itraconazole) were included. Changed CT scan parameters were assessed by systematic analyses of CT scan findings at initiation and end of treatment. CT scans were assessed by two radiologists anonymized to the clinical data. Radiologic parameters were determined by selecting those showing significant changes over time. Improvement of at least one, without worsening of the others, defined the radiologic response. Agreement between radiologic changes and clinical and immunologic responses was likewise investigated.

RESULTS

Among the 139 originally randomized patients, 132 were included. We identified five CT scan parameters showing significant changes at end of treatment: mucoid impaction extent, mucoid impaction density, centrilobular micronodules, consolidation/ground-glass opacities, and bronchial wall thickening (P < .05). These changes were only weakly associated with one another, except for mucoid impaction extent and density. No agreement was observed between clinical, immunologic, and radiologic responses, assessed as an overall response, or considering each of the parameters (Cohen κ, -0.01 to 0.24).

INTERPRETATION

Changes in extent and density of mucoid impaction, centrilobular micronodules, consolidation/ground-glass opacities, and thickening of the bronchial walls were found to be the most relevant CT scan parameters to assess radiologic response to treatment. A clinical, immunologic, and radiologic multidimensional approach should be adopted to assess outcomes, probably with a composite definition of response to treatment.

TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT02273661; URL: www.

CLINICALTRIALS

gov).

Th2-skewed peripheral T-helper cells drive B-cells in allergic bronchopulmonary aspergillosis

INTRODUCTION

Patients with allergic bronchopulmonary aspergillosis (ABPA) suffer from repeated exacerbations. The involvement of T-cell subsets remains unclear.

METHODS

We enrolled ABPA patients, asthma patients and healthy controls. T-helper type 1 (Th1), 2 (Th2) and 17 (Th17) cells, regulatory T-cells (Treg) and interleukin (IL)-21+CD4+T-cells in total or sorted subsets of peripheral blood mononuclear cells and ABPA bronchoalveolar lavage fluid (BALF) were analysed using flow cytometry. RNA sequencing of subsets of CD4+T-cells was done in exacerbated ABPA patients and healthy controls. Antibodies of T-/B-cell co-cultures in vitro were measured.

RESULTS

ABPA patients had increased Th2 cells, similar numbers of Treg cells and decreased circulating Th1 and Th17 cells. IL-5+IL-13+IL-21+CD4+T-cells were rarely detected in healthy controls, but significantly elevated in the blood of ABPA patients, especially the exacerbated ones. We found that IL-5+IL-13+IL-21+CD4+T-cells were mainly peripheral T-helper (Tph) cells (PD-1+CXCR5-), which also presented in the BALF of ABPA patients. The proportions of circulating Tph cells were similar among ABPA patients, asthma patients and healthy controls, while IL-5+IL-13+IL-21+ Tph cells significantly increased in ABPA patients. Transcriptome data showed that Tph cells of ABPA patients were Th2-skewed and exhibited signatures of follicular T-helper cells. When co-cultured in vitro, Tph cells of ABPA patients induced the differentiation of autologous B-cells into plasmablasts and significantly enhanced the production of IgE.

CONCLUSION

We identified a distinctly elevated population of circulating Th2-skewed Tph cells that induced the production of IgE in ABPA patients. It may be a biomarker and therapeutic target for ABPA.

High attenuation mucus in bronchi with allergic bronchopulmonary mycosis

BACKGROUND

High-attenuation mucus (HAM) is a specific manifestation of allergic bronchopulmonary mycosis (ABPM) on chest computed tomography (CT).

OBJECTIVES

To compare the diagnostic accuracy of the two definitions of HAM and to clarify the clinical and radiographic characteristics of HAM-positive and HAM-negative ABPM.

METHODS

CT images at the diagnosis of ABPM using Asano's criteria were retrospectively analysed. In Study #1, radiographic data obtained using the same CT apparatus in a single institute were analysed to determine the agreement between the two definitions of HAM: a mucus plug that is visually denser than the paraspinal muscles or that with a radiodensity ≥70 Hounsfield units. In Study #2, HAM was diagnosed by comparison with the paraspinal muscles in patients with ABPM reporting to 14 medical institutes in Japan.

RESULTS

In Study #1, 93 mucus plugs from 26 patients were analysed. A substantial agreement for HAM diagnosis was observed between the two methods, with a κ coefficient of 0.72. In Study #2, 60 cases of ABPM were analysed; mucus plugs were present in all cases and HAM was diagnosed in 45 (75%) cases. The median A. fumigatus-specific IgE titre was significantly lower in HAM-positive patients than in HAM-negative patients (2.5 vs. 24.3 UA /mL, p = .004). Nodular shadows were observed more frequently in the airways distal to HAM than in those distal to non-HAM mucus plugs (59% vs. 32%, p < .001).

CONCLUSION

In conclusion, agreement between the two methods to diagnose HAM was substantial. HAM was associated with some immunological and radiographic characteristics, including lower levels of sensitization to A. fumigatus and the presence of distal airway lesions.

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.

The Difference in All-Cause Mortality Between Allergic Bronchopulmonary Aspergillosis with and without Chronic Obstructive Pulmonary Disease

Background

Allergic bronchopulmonary aspergillosis (ABPA) primarily complicates the course of asthma, cystic fibrosis, and chronic obstructive pulmonary disease (COPD). Mortality data of ABPA and the difference in all-cause mortality between ABPA with and without COPD are not available.

Objective

We investigated the difference in all-cause mortality between ABPA with and without COPD.

Methods

A retrospective review was performed among patients with the diagnosis of ABPA at Peking University People's Hospital between January 2010 and March 2022. Logrank test was performed to investigate the difference between all-cause mortality for ABPA with and without COPD and Cox regression analysis was performed to investigate the independent risk factors for all-cause mortality in patients with ABPA.

Results

Sixty-one patients with ABPA were enrolled in this study. The follow-up duration was 50.38 months (3-143 months). In the COPD group, 7 patients died (7/10), while in the non-COPD group, 4 patients died (4/51). The 1-year survival rates of ABPA with and without COPD were 60% and 97.8%, respectively. The 5-year survival rates of ABPA with and without COPD were 40% and 94%, respectively. The Cox regression analysis showed that higher C-reactive protein (CRP) (HR = 1.017, 95% CI 1.004-1.031, P = 0.013) and complicating COPD (HR = 8.525, 95% CI 1.827-39.773, P = 0.006) were independent risk factors associated with mortality in patients with ABPA.

Conclusion

The all-cause mortality for ABPA with COPD is higher than that for ABPA without COPD. Higher CRP and complicating COPD are independent risk factor for mortality in patients with ABPA.

Pathophysiology of Bronchiectasis

Bronchiectasis is a complex, heterogeneous disorder defined by both a radiological abnormality of permanent bronchial dilatation and a clinical syndrome. There are multiple underlying causes including severe infections, mycobacterial disease, autoimmune conditions, hypersensitivity disorders, and genetic conditions. The pathophysiology of disease is understood in terms of interdependent concepts of chronic infection, inflammation, impaired mucociliary clearance, and structural lung damage. Neutrophilic inflammation is characteristic of the disease, with elevated levels of harmful proteases such as neutrophil elastase associated with worse outcomes. Recent data show that neutrophil extracellular trap formation may be the key mechanism leading to protease release and severe bronchiectasis. Despite the dominant of neutrophilic disease, eosinophilic subtypes are recognized and may require specific treatments. Neutrophilic inflammation is associated with elevated bacterial loads and chronic infection with organisms such as Pseudomonas aeruginosa. Loss of diversity of the normal lung microbiota and dominance of proteobacteria such as Pseudomonas and Haemophilus are features of severe bronchiectasis and link to poor outcomes. Ciliary dysfunction is also a key feature, exemplified by the rare genetic syndrome of primary ciliary dyskinesia. Mucus symptoms arise through goblet cell hyperplasia and metaplasia and reduced ciliary function through dyskinesia and loss of ciliated cells. The contribution of chronic inflammation, infection, and mucus obstruction leads to progressive structural lung damage. The heterogeneity of the disease is the most challenging aspect of management. An understanding of the pathophysiology of disease and their biomarkers can help to guide personalized medicine approaches utilizing the concept of "treatable traits."

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.

A case of allergic bronchopulmonary aspergillosis with marked peripheral blood eosinophilia successfully treated with benralizumab

We herein report a case of allergic bronchopulmonary aspergillosis (ABPA) with marked eosinophilia and high attenuation mucus (HAM) on chest computed tomography (CT), which demonstrated a rapid and remarkable improvement with benralizumab treatment. A 67-year-old Japanese woman, who was diagnosed with asthma at the age of 64 years, was admitted with dyspnea. Her blood test results showed marked eosinophilia (peripheral blood eosinophil count 24403/μL) and elevated serum IgE levels. Chest CT also revealed ground-glass opacity. Sputum cytology detected filamentous fungi, suggesting an infection with Aspergillus spp. Based on these findings, ABPA was diagnosed. Following systemic corticosteroid treatment, her respiratory symptoms and chest radiography findings showed improvements. However, with the gradual tapering and eventual discontinuance of the corticosteroid therapy, a concomitant increase in the peripheral blood eosinophils and a recurrence of the clinical symptoms, was observed. In addition, her pulmonary function decreased and chest CT revealed worsened bronchial mucus plugs. To control the asthma with ABPA exacerbation, benralizumab was administered. Following treatment with benralizumab, the patient's asthmatic symptoms improved, together with a decrease in her peripheral eosinophil count. Mucus plugs were no longer visible on chest CT. Pulmonary function test result also showed a remarkable improvement. There was no relapse of dyspnea and no reappearance of the mucus plugs. This case suggests that benralizumab may be a suitable treatment option for patients with ABPA with marked eosinophilia and HAM on chest CT.

Ungewöhnliche Manifestationsform einer allergischen bronchopulmonalen Aspergillose während des COVID-19-Lockdowns. Ein Fallbericht

Hintergrund

Die Lockdown-Phasen während der anhaltenden Coronavirus-Pandemie mit der Erkrankung COVID-19 haben die Art und Weise verändert, wie Personen und Gemeinschaften leben, arbeiten und interagieren.

Fallvorstellung

Der vorliegende Fallbericht beschreibt eine ungewöhnliche, aber bedeutende Manifestationsform der allergischen bronchopulmonalen Aspergillose (ABPA) bei einem zuvor gesunden Mann, der zu Beginn des landesweiten Lockdowns in Italien während der COVID-19-Pandemie beschloss, in den Keller seines Hauses zu ziehen. Da eine hochauflösende Computertomographie (HRCT) des Thorax bei Aufnahme des Patienten diffuse miliäre Noduli zeigte, bestand initial der Verdacht auf eine Miliartuberkulose. Weitergehende Untersuchungen führten allerdings zur Diagnose einer ungewöhnlichen Manifestationsform der ABPA.

Schlussfolgerungen

Der vorliegende Fall unterstreicht die Bedeutung einer ungebrochenen Aufmerksamkeit in Bezug auf Aspergillus-assoziierte Erkrankungen des Respirationstrakts während der COVID-19-Pandemie, insbesondere aufgrund dessen, dass Änderungen der Lebensführung im Zusammenhang mit häuslicher Isolation mit dem erhöhten Risiko für eine Exposition gegenüber Schimmelpilzsporen in einigen Wohnräumen verbunden sind.

Uncommon presentation of allergic bronchopulmonary aspergillosis during the COVID-19 lockdown: a case report

BACKGROUND

During the ongoing pandemic of coronavirus disease 2019 (COVID-19), lockdown periods have changed the way that people and communities live, work and interact.

CASE PRESENTATION

This case report describes an uncommon but important presentation of allergic bronchopulmonary aspergillosis (ABPA) in a previously healthy male, who decided to live in the basement of his house when Italy entered a nationwide lockdown during the COVID-19 pandemic. As high resolution computed tomography (HRCT) of the chest on admission showed diffuse miliary nodules, a miliary tuberculosis was initially suspected. However, further investigations provided a diagnosis of unusual presentation of ABPA.

CONCLUSIONS

This case highlights the importance of maintaining awareness of Aspergillus-associated respiratory disorders during the COVID-19 pandemic, especially because lifestyle changes associated with home isolation carry an increased risk of exposure to mold spores present in some indoor environments.

Which Are the Optimal Criteria for the Diagnosis of Allergic Bronchopulmonary Aspergillosis? A Latent Class Analysis

BACKGROUND

The ideal criteria for diagnosing allergic bronchopulmonary aspergillosis (ABPA) remain unknown because of the lack of a criterion standard. Latent class analysis using a probabilistic modeling technique can circumvent the need for a reference standard.

OBJECTIVE

To compare the diagnostic performance of various criteria used for evaluating ABPA.

METHODS

We prospectively enrolled consecutive cases of bronchial asthma and performed a series of investigations used for the diagnosis of ABPA. We used latent class analysis to analyze the performance of various existing and novel diagnostic criteria.

RESULTS

Of the 543 subjects (mean age, 37 years; 319 women), 338 (62.2%) and 205 (37.8%) were labeled as "mild-to-moderate" and "severe" asthma cases, respectively. The subjects with severe asthma had a longer duration of asthma and a higher number of exacerbations in the previous year. The prevalence of Aspergillus fumigatus sensitization was 41% and 30%, using the A fumigatus-specific IgE and skin test, respectively. The prevalence of ABPA was 16%, using both the Rosenberg-Patterson and the International Society for Human and Animal Mycology (ISHAM)-ABPA Working Group criteria. The ISHAM criteria were slightly more sensitive (89% vs 81%) and specific (99% vs 98%) than the Patterson criteria. We obtained optimal diagnostic performance by altering the existing ISHAM criteria (serum total IgE >500 international units/mL, excluding the skin test, and using computed tomography of thorax instead of chest radiograph).

CONCLUSIONS

The ISHAM-ABPA Working Group criteria were only marginally better than the Patterson criteria in diagnosing ABPA among patients with asthma younger than 66 years. The diagnostic performance however improved by modifying the prevailing ISHAM criteria, but with increased cost.

Allergic Bronchopulmonary Aspergillosis in Children with Cystic Fibrosis: An Update on the Newest Diagnostic Tools and Therapeutic Approaches

Cystic fibrosis (CF), the most common autosomal-recessive genetic disease in the Caucasian population, is characterized by frequent respiratory infections and progressive lung disease. Fungal species are commonly found in patients with CF, and among them, Aspergillus fumigatus is the most frequently isolated. While bacteria, particularly Pseudomonas aeruginosa, have a well-established negative effect on CF lung disease, the impact of fungal infections remains unclear. In patients with CF, inhalation of Aspergillus conidia can cause allergic bronchopulmonary aspergillosis (ABPA), a Th2-mediated lung disease that can contribute to disease progression. Clinical features, diagnostic criteria and treatment of ABPA are still a matter of debate. Given the consequences of a late ABPA diagnosis or the risk of ABPA overdiagnosis, it is imperative that the diagnostic criteria guidelines are reviewed and standardized. Along with traditional criteria, radiological features are emerging as tools for further classification as well as novel immunological tests. Corticosteroids, itraconazole and voriconazole continue to be the bedrock of ABPA therapy, but other molecules, such as posaconazole, vitamin D, recombinant INF-γ and Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) modulators, have been showing positive results. However, few studies have been conducted recruiting CF patients, and more research is needed to improve the prevention and the classification of clinical manifestations as well as to personalize treatment. Early recognition and early treatment of fungal infections may be fundamental to prevent progression of CF disease. The aim of this narrative review is to give an update on ABPA in children with CF.

The clinical characteristics and prognosis of ABPA are closely related to the mucus plugs in central bronchiectasis

INTRODUCTION

The characteristics of Allergic Bronchopulmonary Aspergillosis (ABPA) based on its radiological classification is still unclear.

OBJECTIVES

To investigate the clinical significances of ABPA patients with central bronchiectasis (ABPA-CB) by different radiological classifications of mucus plugs.

METHODS

ABPA-CB patients from a pulmonary hospital between 2008 and 2015 were retrospectively included and analysed. According to the chest imaging in their first visit to physician, the ABPA-CB patients were divided into two groups based on the presence of high-attenuation mucus (HAM) or low-attenuation mucus (LAM). The primary endpoint was ABPA relapse within 1 year since the glucocorticoid withdrawal. The relationship between the imaging findings and the clinical prognosis was illuminated.

RESULTS

A total of 125 ABPA patients were analysed in this study. Compared to the LAM group, the HAM group presented higher blood eosinophil cells counts, higher rates of Aspergillus detection isolated in sputum and expectoration of brownish-black mucus plugs, more affected lobes and segments, poorer pulmonary function and higher rate of relapse.

CONCLUSIONS

The clinical characteristics and prognosis of ABPA-CB patients are closely related to its radiological phenotype of mucus plugs in the central bronchiectasis. Clinicians should promote a diversity of personalized treatments for different patients with different radiological characteristics.