Clinical and immunological characteristics of Aspergillus fumigatus-sensitized asthma and allergic bronchopulmonary aspergillosis.

Background: Aspergillus fumigatus (A.f) is a common airborne allergen that contributes to allergic asthma. In some patients, A.f can colonize in the airway and lead to allergic bronchopulmonary aspergillosis (ABPA). However, our understanding of the pathogenesis of A.f-sensitized asthma and ABPA remains inadequate. Objective: We aimed to investigate the clinical and immunological characteristics of A.f-sensitized asthma and ABPA. Methods: A total of 64 ABPA and 57 A.f-sensitized asthma patients were enrolled in the study, and 33 non-A.f-sensitized asthma patients served as the control group. The clinical and immunological parameters included lung function, fractional exhaled nitric oxide (FeNO), induced sputum and blood cell analysis, specific IgE/IgG/IgA of A.f and its components, cytokines (IL-33, IL-25, and TSLP) and CD4+T cell subsets. Results: The eosinophils in blood, induced sputum, and FeNO were significantly higher in ABPA patients compared to that in A.f-sensitized patients. The combination of FeNO and eosinophils (EO) parameters presented good diagnostic efficiency in differentiating A.f (+) asthma from ABPA, with a sensitivity of 80% and a specificity of 100%. Specific IgE, IgG, and IgA against A.f also increased in ABPA patients. However, serum IL-25, IL-33, and TSLP showed no significant differences between the two groups. Cell analysis showed an increase in IFN-γ+Th1 cells in the ABPA patients. FlowSOM analysis further confirmed that the frequency of CD3+CD4+PD-1+CD127+IFN-γ+T cells was higher in ABPA patients. Conclusion: Our findings suggest the distinct humoral and cell immunological responses in A.f-sensitized asthma and ABPA patients. ABPA patients have more severe eosinophilic inflammation and enhanced Th1 responses compared with A.f-sensitized asthma patients.

Role of circulating microRNA-132 in allergic bronchopulmonary aspergillosis: A case-control study.

Allergic bronchopulmonary aspergillosis (ABPA) is an allergic respiratory disease. In the current study, we aimed to evaluate the roles of miRNA-21 and miRNA132 as biomarkers in the diagnosis of ABPA. A total of 30 controls, 30 allergic asthmatic patients, 30 severe asthma with fungal sensitization (SAFS) patients, and 30 ABPA patients were included. Real-time polymerase chain reaction was used to quantify the level of miRNAs expression. The expression level of miRNA-21 was significantly higher in allergic asthmatic, SAFS, and ABPA patients in comparison with controls (p < 0.001). However, no significant difference was detected in the expression level of miRNA-21 among the different patient groups (p > 0.05). The ABPA patients had significantly higher levels of miRNA-132 expression compared to controls, allergic asthmatic patients, and SAFS patients (p < 0.001), but there was a non-significant difference between controls and allergic asthmatic patients (p = 0.09). At a cut-off of 1.52, the sensitivity of miRNA-132 expression was 93.3% and the specificity was 100% different ABPA from healthy controls. At a cut-off of 6.5, miRNA-132 expression was found to reliably differentiate between ABPA and SAFS, with a sensitivity of 86.7% and a specificity of 80%. In ABPA patients, miRNA-132 expression positively correlation with the levels of serum IL-5 (r = 0.91, p < 0.001). miRNA-132 has a role in ABPA detection and distinguishing ABPA from allergic asthma and SAFS. These preliminary data from case-control study need further studies to confirm its finding.

A case report of aspergillosis accompanied by saccular bronchodilation after bronchial thermoplasty in a 19-year-old woman.

BACKGROUND: Fungal infections are rarely reported as a complication of bronchial thermoplasty (BT) in patients without immunosuppressive comorbidity. CASE PRESENTATION: A 19-year-old woman college student was admitted to our hospital owing to uncontrolled severe asthma despite using the maximum dose of steroid inhalation. She experienced asthmatic attacks more frequently while cheerleading, which is an extracurricular activity. She received BT because she wanted to continue cheerleading. After the second BT session, she developed more sputum and cough. During the third session, white secretion and saccular bronchodilation appeared in the left lower bronchus. Aspergillus fumigatus was detected in the culture of the bronchial lavage sample, and saccular bronchodilation in the affected bronchus was observed on computed tomography (CT). Five months after the start of oral itraconazole, her subjective symptoms as well as her CT findings improved. Her asthma condition improved enough for the patient to continue cheerleading without exacerbation. CONCLUSIONS: It is necessary to consider the possibility of respiratory tract infections including fungal infections after BT. Detailed observations of the entire bronchus and sample collection for microbial culture are highly recommended.

Allergic bronchopulmonary aspergillosis (ABPA) sans asthma: A distinct subset of ABPA with a lesser risk of exacerbation.

Allergic bronchopulmonary aspergillosis (ABPA) is a complex immunological disorder complicating asthma. Uncommonly, ABPA presents without underlying asthma. Herein, we describe the outcomes of ABPA with and without asthma. Of the 530 subjects (median follow-up, 39 months), 37 (7%) were ABPA sans asthma. Bronchiectasis was more frequent (97.3% vs. 83.2%, P = .02), and the lung function was significantly better in ABPA sans asthma. The incidence-rate of ABPA exacerbation was higher in those with asthma than without (112 vs. 242 per 1000 person-years, P = .0001). ABPA sans asthma appears to be a distinct subset of ABPA, with a better lung function and fewer exacerbations.

Allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) occurs in patients with asthma or cystic fibrosis, and results in pulmonary infiltrates, tenacious mucus plugs that harbor hyphae of Aspergillus fumigatus, elevations of total serum immunoglobulin E concentration and peripheral blood and sputum eosinophilia. Bronchiectasis is an irreversible complication of ABPA. The key to early diagnosis is to consider ABPA in anyone with asthma or cystic fibrosis and with a positive skin test result for Aspergillus, and/or recurrent infiltrates on radiographs. The differential diagnosis for ABPA in patients with asthma includes diseases in which there is an overlap of asthma, peripheral blood eosinophilia, and radiographic infiltrates. Examples include chronic eosinophilic pneumonia, Churg-Strauss syndrome, drug-induced pulmonary infiltrates, infection with a parasite, asthma with atelectasis, and lymphoma. Mucus plugging that causes a "tree in bud" pattern on computerized tomography examination of the lungs may be from ABPA or other conditions, such as nontuberculous (atypical) mycobacteria (Mycobacteria avium-Mycobacteria intracellulare complex). Prednisone is indicated to clear pulmonary infiltrates, and a usual course is for 3 months. Itraconazole and voriconazole are adjunctive, and drug-drug interactions must be considered because azoles decrease elimination of various medications. Although not familial in most patients, presentation of Aspergillus fumigatus f1 (Asp f1) antigen is restricted to specific major histocompatibility complex (MHC) class II molecules, Human Leukocyte Antigen-DR2 (HLA-DR2), and HLA-DR5. There is an increased number of CD4+ T-helper type 2 lymphocytes in bronchoalveolar lavage, and A. fumigatus can serve as a growth factor of eosinophils potentiating the effects of interleukin (IL) 3, IL-5, and Granulocyte-colony stimulating factor (G-CSF). Eosinophils interact directly with A. fumigatus spores and generate extracellular traps, which can injure the bronchial epithelium.

Development of Allergic Bronchopulmonary Aspergillosis in a Patient with Crohn's Disease.

Allergic bronchopulmonary aspergillosis (ABPA) is an eosinophilic inflammatory condition characterized by exaggerated immune responses to the fungal genus Aspergillus. Pulmonary manifestations in patients with Crohn's disease (CD) are frequent comorbidities. A 66-year-old man with CD treated with an anti-tumor necrosis factor-α antibody presented with dyspnea. Laboratory findings of elevated blood eosinophils and total serum IgE and positive aspergillus-specific antibodies as well as imaging findings of central bronchiectasis and mucoid impaction indicated a diagnosis of ABPA. To our knowledge, this is the first report of ABPA arising in a patient with CD. We discuss the pathophysiological mechanism of this rare complication.

CT evaluation of hyperattenuating mucus to diagnose allergic bronchopulmonary aspergillosis in the special condition of cystic fibrosis.

BACKGROUND: Mucus plugging (MP), central bronchiectasis (CB), and consolidation/atelectasia (CA) are conventional CT signs to diagnose allergic bronchopulmonary aspergillosis (ABPA) in cystic fibrosis (CF). Hyperattenuating mucus (HAM) has recently been described and may improve diagnostic accuracy. The goal of our study was to compare HAM versus conventional CT signs to diagnose ABPA in CF. Secondary objectives were to determine the optimal threshold of HAM quantitatively and to assess the diagnostic value of HAM using chest radiograph (CXR). METHODS: The study was retrospective and included 137 patients with CF, aged >6-year-old. The presence of HAM, CB, MP and CA were determined by two radiologists in consensus. HAM was quantified using an absolute mean density value (AMD) and a ratio between mucus and paraspinal muscle (DRM). Sensitivity (Se), Specificity (Sp) and Youden's J-index were calculated. The Cystic Fibrosis Conference Consensus criteria were chosen as Gold Standard. RESULTS: 23 out of 137 CF patients had ABPA. Using CT, the most sensitive structural alteration was MP (Se = 91%), followed by CB (Se = 87%) and CA (Se = 70%) whereas specificities were 28%, 19% and 58%, respectively. Conversely, HAM had the highest specificity (Sp = 100%) whereas Se was 69%. HAM had the highest Youden's J-index (p < 0.001) Quantitative optimal thresholds were AMD > 78 HU (Se/Sp = 71%/98%) and DRM > 1.3 (Se/Sp = 82%/97%). HAM was unseen using CXR (Se = 0%). CONCLUSION: HAM is the most specific CT biomarker of ABPA in CF, with good sensitivity. Our study suggests that characterization of mucus density may improve the accuracy of imaging criteria to diagnose ABPA early.

Posaconazole for the treatment of allergic bronchopulmonary aspergillosis in patients with cystic fibrosis.

OBJECTIVES: Allergic bronchopulmonary aspergillosis (ABPA) can accelerate lung function decline in patients with cystic fibrosis (CF). Antifungal medication can be used in addition to systemic corticosteroid treatment. PATIENTS AND METHODS: We evaluated Aspergillus-specific IgE and the use of therapeutic drug monitoring of triazoles in a retrospective analysis of 32 patients. RESULTS: There was a significant reduction in Aspergillus IgE with posaconazole but not with other triazoles (P = 0.026). Aspergillus IgE levels were inversely correlated with the therapeutic drug level of posaconazole. CONCLUSIONS: These data suggest that posaconazole is better than comparator azoles at decreasing serological response to Aspergillus and that this response was better with therapeutic levels of posaconazole.

High airborne level of Aspergillus fumigatus and presence of azole-resistant TR34/L98H isolates in the home of a cystic fibrosis patient harbouring chronic colonisation with azole-resistant H285Y A. fumigatus.

Azole-resistant Aspergillus fumigatus (ARAF) has been reported in the domestic environment of patients at risk for aspergillosis. Here, we assessed the mother's and father's homes of an 18-year-old cystic fibrosis patient harbouring chronic colonisation with H285Y CYP51A azole-resistant isolate, in order to explore the link between environmental exposure and ARAF infection. In one dwelling, a very high overall contamination level was found (710-7.240 CFU/m3), with a predominance of A. fumigatus (640-6.490 CFU/m3), and ARAF showing the TR34/L98H mutation was isolated. Mycological follow-up of the patient showed the persistence of H285Y isolates, but no acquisition of TR34/L98H isolates was observed. This could be due to the low proportion of TR34/L98H isolates (<3%), or the establishment of preventative measures and dwelling remediation taken after the environmental investigation. Our data underlines the value of an environmental assessment to establish preventative measures and limit the risk of A. fumigatus exposure and ARAF acquisition.

A Case of Allergic Broncopulmonary Aspergillosis Associated With Hematopoietic Stem Cell Transplantation Due to Chronic Granulomatous Disease.

Allergic bronchopulmonary aspergillosis is an immunologic pulmonary disorder caused by hypersensitivity to Aspergillus fumigatus. This disorder is most commonly seen in patients with poorly controlled asthma and cystic fibrosis. It is rarely reported in chronic granulomatous disease patients; however, there are no cases reported with hematopoietic stem cell transplantation in the English literature. Herein, we report a patient with chronic granulomatous disease who had hematopoietic stem cell transplantation and subsequently developed allergic bronchopulmonary aspergillosis.

Recurrence of allergic bronchopulmonary aspergillosis after adjunctive surgery for aspergilloma: a case report with long-term follow-up.

BACKGROUND: Coexistence of aspergilloma and allergic bronchopulmonary aspergillosis (ABPA) has rarely been reported. Although the treatment for ABPA includes administration of corticosteroids and antifungal agents, little is known about the treatment for coexisting aspergilloma and ABPA. Furthermore, the impact of surgical resection for aspergilloma on ABPA is not fully understood. Here, we present an interesting case of recurrent ABPA with long-term follow-up after surgical resection of aspergilloma. CASE PRESENTATION: A 53-year-old man with a medical history of tuberculosis was referred to our hospital with cough and dyspnea. Imaging revealed multiple cavitary lesions in the right upper lobe of the lung, with a fungus ball and mucoid impaction. The eosinophil count, total serum immunoglobulin E (IgE), and Aspergillus-specific IgE levels were elevated. Specimens collected on bronchoscopy revealed fungal filaments compatible with Aspergillus species. Based on these findings, a diagnosis of ABPA with concomitant aspergilloma was made. Although treatment with corticosteroids and antifungal agents was administered, the patient's respiratory symptoms persisted. Therefore, he underwent lobectomy of the right upper lobe, which resulted in a stable condition without the need for medication. Twenty-three months after discontinuation of medical treatment, his respiratory symptoms gradually worsened with a recurrence of elevated eosinophil count and total serum IgE. Imaging revealed recurrent bronchiectasis and cavities with mucoid impaction in the right lower lobe, suggesting relapse of aspergilloma and ABPA. Corticosteroids and antifungal agents were re-administered; aspergilloma improved slightly over a 5-year period, and ABPA remained well controlled with low-dose prednisolone (5 mg/day). CONCLUSIONS: We describe the long-term follow-up outcomes of a patient with concomitant ABPA and aspergilloma, who underwent surgical resection for aspergilloma. Physicians should carefully monitor patients with coexisting ABPA and aspergilloma, as the condition may relapse after remission, even despite surgical resection for aspergilloma. Additionally, surgical resection for aspergilloma could result in resolution of ABPA.

Allergic Bronchopulmonary Aspergillosis-A Luminal Hypereosinophilic Disease With Extracellular Trap Cell Death.

Allergic bronchopulmonary aspergillosis (ABPA) is characterized by an early allergic response and late-phase lung injury in response to repeated exposure to Aspergillus antigens, as a consequence of persistent fungal colonization of the airways. Here, we summarize the clinical and pathological features of ABPA, focusing on thick mucus plugging, a key observation in ABPA. Recent findings have indicated that luminal eosinophils undergo cytolytic extracellular trap cell death (ETosis) and release filamentous chromatin fibers (extracellular traps, ETs) by direct interaction with Aspergillus fumigatus. Production of ETs is considered to be an innate immune response against non-phagocytable pathogens using a "trap and kill" mechanism, although eosinophil ETs do not promote A. fumigatus damage or killing. Compared with neutrophils, eosinophil ETs are composed of stable and condensed chromatin fibers and thus might contribute to the higher viscosity of eosinophilic mucus. The major fate of massively accumulated eosinophils in the airways is ETosis, which potentially induces the release of toxic granule proteins and damage-associated molecular patterns, epithelial damage, and further decreases mucus clearance. This new perspective on ABPA as a luminal hypereosinophilic disease with ETosis/ETs could provide a better understanding of airway mucus plugging and contribute to future therapeutic strategies for this challenging disease.

Risk factors and impact of allergic bronchopulmonary aspergillosis in Pseudomonas aeruginosa-negative CF patients.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a major complication in cystic fibrosis (CF) patients. Risk factors for ABPA and clinical deterioration in CF patients, negative for Pseudomonas aeruginosa (Pa), were explored. METHODS: We performed a retrospective case-control study in 73 Pa-negative patients. Each patient was matched with 2 controls for age, gender, pancreas sufficiency, DeltaF508 mutation (homozygous or heterozygous), and Pa colonization. RESULTS: Median FEV1 at the year of diagnosis (index year) was significantly lower in patients with ABPA. The median of cumulative values of FEV1 and FVC before the index year was not significantly different. After the index year, the median of cumulative data for FEV1 and FVC was significantly lower; there were significantly more hospitalization days and more IV antibiotic days compared to controls. Comparing pre- and post-index year data in patients with ABPA, significantly more hospitalization days and more IV antibiotic days were observed after the index year. During the period preceding the index year, significantly more ABPA patients were treated with rhDNase and inhaled corticosteroids. CONCLUSIONS: Bronchial damage cannot be considered as a facilitating factor for ABPA. ABPA causes a significant increase in bronchial damage. In patients with ABPA, further bronchial damage can be controlled by an increase in hospitalization days and use of IV antibiotics. rhDNase and inhaled corticosteroids were associated with the development of ABPA.

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

BACKGROUND: Cystic fibrosis is an autosomal recessive multisystem disorder with an approximate prevalence of 1 in 3500 live births. Allergic bronchopulmonary aspergillosis is a lung disease caused by aspergillus-induced hypersensitivity with a prevalence of 2% to 15% in people with cystic fibrosis. The mainstay of treatment includes corticosteroids and itraconazole. The treatment with corticosteroids for prolonged periods of time, or repeatedly for exacerbations of allergic bronchopulmonary aspergillosis, may lead to many adverse effects. The monoclonal anti-IgE antibody, omalizumab, has improved asthma control in severely allergic asthmatics. The drug is given as a subcutaneous injection every two to four weeks. Since allergic bronchopulmonary aspergillosis is also a condition resulting from hypersensitivity to specific allergens, as in asthma, it may be a candidate for therapy using anti-IgE antibodies. Therefore, anti-IgE therapy, using agents like omalizumab, may be a potential therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. This is an updated version of the review. OBJECTIVES: To evaluate the efficacy and adverse effects of anti-IgE therapy for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. SEARCH METHODS: We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews. Last search: 29 September 2017.We searched two ongoing trial registries (Clinicaltrials.gov and the WHO trials platform). Date of latest search: 24 January 2018. SELECTION CRITERIA: Randomized and quasi-randomized controlled trials comparing anti-IgE therapy to placebo or other therapies for allergic bronchopulmonary aspergillosis in people with cystic fibrosis. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed the risk of bias in the included study. They planned to perform data analysis using Review Manager. MAIN RESULTS: Only one study enrolling 14 participants was eligible for inclusion in the review. The double-blind study compared a daily dose of 600 mg omalizumab or placebo along with twice daily itraconazole and oral corticosteroids, with a maximum daily dose of 400 mg. Treatment lasted six months but the study was terminated prematurely and complete data were not available. We contacted the study investigator and were told that the study was terminated due to the inability to recruit participants into the study despite all reasonable attempts. One or more serious side effects were encountered in six out of nine (66.67%) and one out of five (20%) participants in omalizumab group and placebo group respectively. AUTHORS' CONCLUSIONS: There is lack of evidence for the efficacy and safety of anti-IgE (omalizumab) therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis. There is a need for large prospective randomized controlled studies of anti-IgE therapy in people with cystic fibrosis and allergic bronchopulmonary aspergillosis with both clinical and laboratory outcome measures such as steroid requirement, allergic bronchopulmonary aspergillosis exacerbations and lung function.

[Allergic bronchopulmonary aspergillosis in patients with asthma: Results of a prospective study]. / Allergicheskii bronkholegochnyi aspergillez u bol'nykh bronkhial'noi astmoi: rezul'taty prospektivnogo issledovaniia.

AIM: To estimate the frequency of fungal sensitization and the incidence of allergic bronchopulmonary aspergillosis (ABPA) in asthmatic patients. SUBJECTS AND METHODS: A total of 140 asthmatic patients were examined. They underwent allergologic (skin tests for fungal allergens, estimation of total and fungal allergen-specific IgE levels) and mycological (microscopy and inoculation of respiratory biosubstrates) examinations. Chest computed tomography, when indicated, was done. A group of patients with ABPA and that of patients with severe asthma and fungal sensitization were identified. RESULTS: The frequency of fungal sensitization in asthmatic patients was 36%; the main allergenic fungi were Aspergillus and Alternaria. The incidence of ABPA was as high as 4% in the patients with asthma and 11% in those with severe asthma and fungal sensitization. CONCLUSION: The given current diagnostic criteria will assist practitioners to identify ABPA, to prevent its progression, and to initiate specific anti-inflammatory and antifungal therapy in due time.

Allergic bronchopulmonary aspergillosis in a patient with rheumatoid arthritis under adalimumab therapy: a case report.

A 77-year-old woman with a 15-year history of rheumatoid arthritis (RA) was admitted to our hospital because of a wet cough that persisted for 1 month. The patient had been taking methotrexate (MTX) and adalimumab (ADA) for the past 3 years, and disease activity of RA was low. Discontinuation of ADA and MTX and treatment with oral levofloxacin were not effective. On admission, laboratory examinations showed eosinophilia (2539/µL), elevated serum total immunoglobulin E (538.0 IU/ml) and Aspergillus-specific immunoglobulin E levels, and Aspergillus fumigatus serum precipitins. A chest radiograph revealed multiple bilateral pulmonary shadows, and computed tomography revealed multiple consolidations. Bronchoscopic examination showed mucous plugs. Pathological examination revealed diffuse infiltration of eosinophils and fungus in the plugs. These findings led to the diagnosis of allergic bronchopulmonary aspergillosis (ABPA). A combination of prednisolone (0.5 mg/kg/day) and itraconazole (200 mg/day) was administered. After 3 months, the pulmonary consolidations resolved. To our knowledge, this is the first report of ABPA in a patient with RA treated with ADA. If patients treated with biologic disease-modifying antirheumatic drugs present with eosinophilia and pulmonary consolidations, clinicians should consider ABPA in the differential diagnosis.

Aspergillus infections in cystic fibrosis.

Patients with cystic fibrosis (CF) suffer from chronic lung infection and airway inflammation. Respiratory failure secondary to chronic or recurrent infection remains the commonest cause of death and accounts for over 90% of mortality. Bacteria as Staphylococcus aureus, Pseudomonas aeruginosa and Burkholderia cepacia complex have been regarded the main CF pathogens and their role in progressive lung decline has been studied extensively. Little attention has been paid to the role of Aspergillus spp. and other filamentous fungi in the pathogenesis of non-ABPA (allergic bronchopulmonary aspergillosis) respiratory disease in CF, despite their frequent recovery in respiratory samples. It has become more apparent however, that Aspergillus spp. may play an important role in chronic lung disease in CF. Research delineating the underlying mechanisms of Aspergillus persistence and infection in the CF lung and its link to lung deterioration is lacking. This review summarizes the Aspergillus disease phenotypes observed in CF, discusses the role of CFTR (cystic fibrosis transmembrane conductance regulator)-protein in innate immune responses and new treatment modalities.

Serological diagnosis of allergic bronchopulmonary mycosis: Progress and challenges.

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

Phosphoinositide 3-kinase-δ regulates fungus-induced allergic lung inflammation through endoplasmic reticulum stress.

BACKGROUND: Sensitisation with Aspergillus fumigatus (Af) is known to be associated with severe allergic lung inflammation, but the mechanism remains to be clarified. Phosphoinositide 3-kinase (PI3K)-δ and endoplasmic reticulum (ER) stress are suggested to be involved in steroid-resistant lung inflammation. We aimed to elucidate the role of PI3K-δ and its relationship with ER stress in fungus-induced allergic lung inflammation. METHODS: Using Af-exposed in vivo and in vitro experimental systems, we examined whether PI3K-δ regulates ER stress, thereby contributing to steroid resistance in fungus-induced allergic lung inflammation. Moreover, we checked expression of an ER stress marker in lung tissues isolated from patients with allergic bronchopulmonary aspergillosis. RESULTS: Af-exposed mice showed that ER stress markers, unfolded protein response (UPR)-related proteins, phosphorylated Akt, generation of mitochondrial reactive oxygen species (mtROS), eosinophilic allergic inflammation, and airway hyperresponsiveness (AHR) were increased in the lung. Similarly, glucose-regulated protein 78 was increased in lung tissues of patients with ABPA. A PI3K-δ inhibitor reduced Af-induced increases in ER stress markers, UPR-related proteins, allergic inflammation and AHR in mice. However, dexamethasone failed to reduce Af-induced allergic inflammation, AHR and elevation of ER stress. Administration of an ER stress inhibitor or a mtROS scavenger improved Af-induced allergic inflammation. The PI3K-δ inhibitor reduced Af-induced mtROS generation and the mtROS scavenger ameliorated ER stress. In primary cultured tracheal epithelial cells, Af-induced ER stress was inhibited by blockade of PI3K-δ. CONCLUSIONS: These findings suggest that PI3K-δ regulates Af-induced steroid-resistant eosinophilic allergic lung inflammation through ER stress.