Aspergillus fumigatus antigen-reactive Th17 cells are enriched in bronchoalveolar lavage fluid in severe equine asthma.

Introduction: Equine asthma (EA) is a common disease of adult horses with chronic respiratory pathology and common neutrophilic airway inflammation. It presents with hyperreactivity to hay dust components such as molds, and underlying dysregulated T cell responses have been suggested. Thus far, T cells have been analysed in EA with conflicting results and the antigen reactivity of T cells has not been demonstrated. Serological and epidemiological data point to the relevance of Aspergillus fumigatus as an antigen source in EA. Here, we aimed to identify and characterise Aspergillus antigen-reactive T cells in EA. Methods: Cryopreserved bronchoalveolar lavage cells (BALC) and peripheral blood mononuclear cells (PBMC) from healthy horses (HE, n=9) and those with mild-moderate (MEA, n=3) or severe asthma (SEA, n=8) were stimulated in vitro with the recombinant A. fumigatus antigens Asp f 1, or Asp f 7 combined with Asp f 8, to assess antigen reactivity, and with phorbol-12-myristat-13-acetate and ionomycin (P/i) to assess overall T cell reactivity. Stimulated cells were analysed by flow cytometry for CD4, CD8, IL-17, IL-4, and IFN-γ. Cytokine expression in all lymphocytes, and in CD4+ or CD8+ T cells, was quantified and compared between the groups. In BAL fluid (BALF), soluble cytokines and chemokines were quantified by bead-based assays. Results: Antigen restimulation of BALC with Asp f 1 or Asp f 7/8 provoked higher frequencies of IL-17+ lymphocytes, CD4+IL-17+ Th17 cells, and CD4+IL-4+ Th2 cells in SEA than in HE, whereas MEA and HE were similar. Antigen stimulation of PBMC did not result in group differences. P/i stimulation of BALC resulted in increased IL-17+ lymphocyte and CD4+IL-17+ Th17 cell frequencies in MEA compared with HE but the limited number of horses with MEA must be considered. P/i-stimulated PBMC from MEA or SEA contained more IL-17+ lymphocytes compared with HE. Cytokines were hardly detected in BALF and similar between the groups but CCL2 and CCL5 concentrations were increased in BALF from SEA or MEA, respectively, compared with HE. Conclusion: Horses with SEA have increased Aspergillus antigen-reactive Th17 cells in their airways, emphasising local T cell responses to this mold, which were quantified in EA for the first time here.

Retrospective Comparison of Two Aspergillus IgG Enzyme Immunoassays for Diagnosing Pulmonary Aspergillosis.

Aspergillus-specific antibodies are diagnostic indicators of allergic bronchopulmonary aspergillosis (ABPA) and chronic pulmonary aspergillosis (CPA). Tests for detecting Aspergillus-specific antibodies were not used clinically in Japan, and the production of the Aspergillus precipitin test was discontinued. Thus, alternative tests for diagnosing aspergillosis are urgently needed. We retrospectively evaluated 64 patients with suspected ABPA and CPA who underwent precipitin antibody testing. Serum Aspergillus IgG levels were measured and compared using the Bordier Aspergillus fumigatus ELISA and the Platelia Aspergillus IgG (Bio-Rad) kits. Of the participants, 18 were diagnosed with CPA, and 8 were diagnosed with ABPA. Both the Bordier and Bio-Rad kits showed high sensitivity and specificity for CPA and ABPA. The area under the receiver operating characteristic curves for the Bordier and Bio-Rad kits were 0.97 and 0.95, respectively, for CPA, and 0.89 and 0.91, respectively, for ABPA. In contrast to the Bordier kit, the Bio-Rad kit showed relatively low anti-Aspergillus IgG levels and lower sensitivity to non-fumigatus Aspergillus infections. The Aspergillus-specific IgG ELISA tests showed sufficient diagnostic accuracy. Therefore, these assays are recommended as alternatives to the precipitin kit for diagnosing aspergillosis in clinical settings in Japan.

Population prevalence of aspergillus sensitization and allergic bronchopulmonary aspergillosis in COPD subjects in North India.

BACKGROUND: Sensitization to Aspergillus fumigatus (AS) has been recently described in chronic obstructive pulmonary disease (COPD) patients. However, there is no data on the community prevalence of AS in COPD. OBJECTIVES: To assess the prevalence of AS among COPD subjects. The secondary objectives were to (1) assess the prevalence of allergic bronchopulmonary aspergillosis (ABPA) in COPD and (2) compare the lung function in COPD subjects with and without AS. METHODS: We conducted a cross-sectional study in rural (29 villages) and urban (20 wards) communities in North India. We identified individuals with respiratory symptoms (IRS) through a house-to-house survey using a modified IUATLD questionnaire. We then diagnosed COPD through specialist assessment and spirometry using the GOLD criteria. We assayed A.fumigatus-specific IgE in COPD subjects. In those with A. fumigatus-specific IgE ≥0.35 kUA/L (AS), ABPA was diagnosed with raised serum total IgE and raised A.fumigatus-specific IgG or blood eosinophil count. RESULTS: We found 1315 (8.2%) IRS among 16,071 participants >40 years and diagnosed COPD in 355 (2.2%) subjects. 291 (82.0%) were men and 259 (73.0%) resided in rural areas. The prevalence of AS and ABPA was 17.7% (95% CI, 13.9-21.8) and 6.6% (95% CI, 4.4-8.8). We found a lower percentage predicted FEV1 in COPD subjects with AS than those without (p =.042). CONCLUSIONS: We found an 18% community prevalence of AS in COPD subjects in a specific area in North India. Studies from different geographical areas are required to confirm our findings. The impact of AS and ABPA on COPD requires further research.

Aspergillus-sensitized asthma in children.

BACKGROUND: Asthma is the most common chronic respiratory disease in childhood. Aspergillus fumigatus sensitivity may be involved in the pathogenesis of asthma by leading to different clinical presentations. OBJECTIVE: To investigate the demographic, clinical, laboratory, and radiological characteristics of A. fumigatus sensitivity in childhood asthma and identify associated risk factors and diagnostic parameters. METHODS: A total of 259 children with asthma were included in the study, 7 (2.7%) with allergic bronchopulmonary aspergillosis (ABPA), 84 (32.4%) with A. fumigatus-sensitized asthma (Af-SA), and 168 (64.9%) with A. fumigatus-unsensitized asthma (Af-UA). RESULTS: Aspergillus sensitivity was associated with early asthma onset and longer asthma duration. Total IgE level and asthma severity are highest in ABPA and higher in Af-SA. Absolute eosinophil count was higher, and FEV1 was lower in Af-SA and ABPA. Aspergillus fumigatus was associated with greater odds of being male (odds ratio [OR], 2.45), having atopic dermatitis (OR, 3.159), Alternaria sensitivity (OR, 10.37), and longer asthma duration (OR, 1.266). The best cut-off values for detecting A. fumigatus positivity were 363.5 IU/mL for total IgE and 455 cells/µL for absolute eosinophil count. In Af-SA compared to Af-UA, centrilobular nodules and peribronchial thickening were more common, and the bronchoarterial ratio was higher. CONCLUSIONS: Aspergillus sensitivity is a strong allergic stimulus in asthma, leading to laboratory, structural, clinical, and functional consequences. Af-SA is a distinct asthma endotype independent of ABPA that is characterized by increased risk of severe clinical presentations and impaired lung function.

Type 2 Innate Lymphoid Cells and Skin Fibrosis in a Murine Model of Atopic Dermatitis-Like Skin Inflammation.

BACKGROUND: Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. Although murine studies have demonstrated that type 2 innate lymphoid cells (ILCs) mediate type 2 skin inflammation, their role in skin fibrosis in AD remains unclear. This study investigated whether type 2 ILCs are involved in skin fibrosis using an AD-like murine model. METHODS: C57BL/6 mice were treated epicutaneously with Aspergillus fumigatus (Af) for 5 consecutive days per week for 5 weeks to induce skin fibrosis. Mature lymphocyte deficient Rag1-/- mice were also used to investigate the role of type 2 ILCs in skin fibrosis. RESULTS: The clinical score and transepidermal water loss (TEWL) were significantly higher in the AD group than in the control group. The AD group also showed significantly increased epidermal and dermal thicknesses and significantly higher numbers of eosinophils, neutrophils, mast cells, and lymphocytes in the lesional skin than the control group. The lesional skin of the AD group showed increased stain of collagen and significantly higher levels of collagen than the control group (10.4 ± 2.2 µg/mg vs. 1.6 ± 0.1 µg/mg, P < 0.05). The AD group showed significantly higher populations of type 2 ILCs in the lesional skin compared to the control group (0.08 ± 0.01% vs. 0.03 ± 0.01%, P < 0.05). These findings were also similar with the AD group of Rag1-/- mice compared to their control group. Depletion of type 2 ILCs with anti-CD90.2 monoclonal antibodies significantly improved clinical symptom score, TEWL, and infiltration of inflammatory cells, and significantly decreased levels of collagen were observed in the AD group of Rag1-/- mice (1.6 ± 0.0 µg/mg vs. 4.5 ± 0.3 µg/mg, P < 0.001). CONCLUSION: In the Af-induced AD-like murine model, type 2 ILCs were elevated, with increased levels of collagen. Additionally, removal of type 2 ILCs resulted in decreased collagen levels and improved AD-like pathological findings. These findings suggest that type 2 ILCs play a role in the mechanism of skin fibrosis in AD.

Manipulation of host phagocytosis by fungal pathogens and therapeutic opportunities.

An important host defence mechanism against pathogens is intracellular killing, which is achieved through phagocytosis, a cellular process for engulfing and neutralizing extracellular particles. Phagocytosis results in the formation of matured phagolysosomes, which are specialized compartments that provide a hostile environment and are considered the end point of the degradative pathway. However, all fungal pathogens studied to date have developed strategies to manipulate phagosomal function directly and also indirectly by redirecting phagosomes from the degradative pathway to a non-degradative pathway with the expulsion and even transfer of pathogens between cells. Here, using the major human fungal pathogens Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans and Histoplasma capsulatum as examples, we discuss the processes involved in host phagosome-fungal pathogen interactions, with a focus on fungal evasion strategies. We also discuss recent approaches to targeting intraphagosomal pathogens, including the redirection of phagosomes towards degradative pathways for fungal pathogen eradication.

Interplay between host humoral pattern recognition molecules controls undue immune responses against Aspergillus fumigatus.

Pentraxin 3 (PTX3), a long pentraxin and a humoral pattern recognition molecule (PRM), has been demonstrated to be protective against Aspergillus fumigatus, an airborne human fungal pathogen. We explored its mode of interaction with A. fumigatus, and the resulting implications in the host immune response. Here, we demonstrate that PTX3 interacts with A. fumigatus in a morphotype-dependent manner: (a) it recognizes germinating conidia through galactosaminogalactan, a surface exposed cell wall polysaccharide of A. fumigatus, (b) in dormant conidia, surface proteins serve as weak PTX3 ligands, and (c) surfactant protein D (SP-D) and the complement proteins C1q and C3b, the other humoral PRMs, enhance the interaction of PTX3 with dormant conidia. SP-D, C3b or C1q opsonized conidia stimulated human primary immune cells to release pro-inflammatory cytokines and chemokines. However, subsequent binding of PTX3 to SP-D, C1q or C3b opsonized conidia significantly decreased the production of pro-inflammatory cytokines/chemokines. PTX3 opsonized germinating conidia also significantly lowered the production of pro-inflammatory cytokines/chemokines while increasing IL-10 (an anti-inflammatory cytokine) released by immune cells when compared to the unopsonized counterpart. Overall, our study demonstrates that PTX3 recognizes A. fumigatus either directly or by interplaying with other humoral PRMs, thereby restraining detrimental inflammation. Moreover, PTX3 levels were significantly higher in the serum of patients with invasive pulmonary aspergillosis (IPA) and COVID-19-associated pulmonary aspergillosis (CAPA), supporting previous observations in IPA patients, and suggesting that it could be a potential panel-biomarker for these pathological conditions caused by A. fumigatus.

Aspergillus fumigatus binding IgA and IgG1 are increased in bronchoalveolar lavage fluid of horses with neutrophilic asthma.

Introduction: Equine asthma (EA) is a common lower airway disease in horses, but whether its pathogenesis is allergic is ambiguous. Extrinsic stimuli like hay dust induce acute exacerbation of clinical signs and sustained local neutrophilic inflammation in susceptible horses. Aspergillus fumigatus is an EA stimulus, but it is unclear if it merely acts as an IgE-provoking allergen. We aimed to comprehensively analyze immunoglobulin (Ig) isotypes in EA, elucidating their binding to different A. fumigatus antigens, and their quantities systemically in serum and locally in bronchoalveolar lavage fluid (BALF). Methods: Serum and BALF from healthy horses (HE, n = 18) and horses with mild-moderate asthma (MEA, n = 20) or severe asthma (SEA, n = 24) were compared. Ig isotype (IgG1, IgG3/5, IgG4/7, IgG6, IgA, and IgE) binding to nine antigens (A. fumigatus lysate, and recombinant Asp f 1, Asp f 7, Asp f 8, dipeptidyl-peptidase 5, class II aldolase/adducin domain protein, glucoamylase, beta-hexosaminidase, and peptide hydrolase) was compared by enzyme-linked immunosorbent assays. Total Ig isotype contents were determined by bead-based assays. Results: MEA and SEA differed from HE but hardly from each other. Compared to HE, asthmatic horses showed increased anti-A. fumigatus binding of IgG (BALF and serum) and IgA (BALF). Serum and BALF IgE binding and total IgE contents were similar between HE and EA. Single antigens, as well as A. fumigatus lysate, yielded similar Ig binding patterns. Serum and BALF IgG1 binding to all antigens was increased in SEA and to several antigens in MEA. Serum IgG4/7 binding to two antigens was increased in SEA. BALF IgA binding to all antigens was increased in SEA and MEA. Total BALF IgG1 and IgG4/7 contents were increased in SEA, and serum IgG4/7 content was increased in MEA compared to HE. Yet, total isotype contents differentiated EA and HE less clearly than antigen-binding Ig. Discussion: A. fumigatus immunogenicity was confirmed without identification of single dominant antigens here. A. fumigatus provoked elevated BALF IgG1 and IgA binding, and these isotypes appear relevant for neutrophilic EA, which does not support allergy. BALF Ig isotype differentiation beyond IgE is crucial for a comprehensive analysis of immune responses to fungi in EA pathogenesis.

[Allergic bronchopulmonary aspergillosis with low serum IgE: a case report].

Here, we reported a case of delayed diagnosis of allergic bronchopulmonary aspergillosis (ABPA) with low serum IgE and normal Aspergillus fumigatus-specific IgE levels. During the course of the disease, the patient (female, 55 years old) had imaging manifestation of mass shadow and significant elevation of carcinoembryonic antigen, leading to suspicion of a lung tumor. Later, transbronchial lung biopsy tissue culture showed Aspergillus fumigatus. Combined with the history, clinical characteristics and imaging, she was diagnosed with allergic bronchopulmonary aspergillosis combined with invasive pulmonary aspergillosis. As the diagnostic criteria for ABPA do not cover all patients with ABPA, in rare cases where immunological evidence is insufficient, a combination of clinical and imaging features is required for early diagnosis and treatment.

New developments in Aspergillus fumigatus and host reactive oxygen species responses.

Aspergillus fumigatus is a filamentous fungus abundant in the environment and the most common causative agent of a spectrum of human diseases collectively termed aspergillosis. Invasive pulmonary aspergillosis is caused by deficiencies in innate immune function that result in the inability of the host to clear inhaled Aspergillus conidia that then germinate and form invasive hyphae. Myeloid cells, and their ability to generate reactive oxygen species (ROS), are essential for conidia clearance from the host. To combat ROS, A. fumigatus employs an expansive antioxidant system, though how these canonical antioxidant mechanisms contribute to infection initiation and disease progression remain to be fully defined. Recent research has identified noncanonical pathways in the A. fumigatus ROS response and new host populations with ROS deficiencies that are at-risk for invasive aspergillosis. Here, we highlight recent developments in the understanding of ROS at the interface of the dynamic A. fumigatus-host interaction.

CD56-mediated activation of human natural killer cells is triggered by Aspergillus fumigatus galactosaminogalactan.

Invasive aspergillosis causes significant morbidity and mortality in immunocompromised patients. Natural killer (NK) cells are pivotal for antifungal defense. Thus far, CD56 is the only known pathogen recognition receptor on NK cells triggering potent antifungal activity against Aspergillus fumigatus. However, the underlying cellular mechanisms and the fungal ligand of CD56 have remained unknown. Using purified cell wall components, biochemical treatments, and ger mutants with altered cell wall composition, we herein found that CD56 interacts with the A. fumigatus cell wall carbohydrate galactosaminogalactan (GAG). This interaction induced NK-cell activation, degranulation, and secretion of immune-enhancing chemokines and cytotoxic effectors. Supernatants from GAG-stimulated NK cells elicited antifungal activity and enhanced antifungal effector responses of polymorphonuclear cells. In conclusion, we identified A. fumigatus GAG as a ligand of CD56 on human primary NK cells, stimulating potent antifungal effector responses and activating other immune cells.

Rethinking Aspergillosis in the Era of Microbiota and Mycobiota.

Aspergillosis encompasses a wide range of clinical conditions based on the interaction between Aspergillus and the host. It ranges from colonization to invasive aspergillosis. The human lung provides an entry door for Aspergillus. Aspergillus has virulence characteristics such as conidia, rapid growth at body temperature, and the production of specific proteins, carbohydrates, and secondary metabolites that allow A. fumigatus to infiltrate the lung's alveoli and cause invasive aspergillosis. Alveolar epithelial cells play an important role in both fungus clearance and immune cell recruitment via cytokine release. Although the innate immune system quickly clears conidia in immunocompetent hosts, A. fumigatus has evolved multiple virulence factors in order to escape immune response such as ROS detoxifying enzymes, the rodlet layer, DHN-melanin and toxins. Bacterial co-infections or interactions can alter the immune response, impact Aspergillus growth and virulence, enhance biofilm formation, confound diagnosis, and reduce treatment efficacy. The gut microbiome's makeup influences pulmonary immune responses generated by A. fumigatus infection and vice versa. The real-time PCR for Aspergillus DNA detection might be a particularly useful tool to diagnose pulmonary aspergillosis. Metagenomics analyses allow quick and easy detection and identification of a great variety of fungi in different clinical samples, although optimization is still required particularly for the use of NGS techniques. This review will analyze the current state of aspergillosis in light of recent discoveries in the microbiota and mycobiota.

Broad Protection against Invasive Fungal Disease from a Nanobody Targeting the Active Site of Fungal ß-1,3-Glucanosyltransferases.

Invasive fungal disease accounts for about 3.8 million deaths annually, an unacceptable rate that urgently prompts the discovery of new knowledge-driven treatments. We report the use of camelid single-domain nanobodies (Nbs) against fungal ß-1,3-glucanosyltransferases (Gel) involved in ß-1,3-glucan transglycosylation. Crystal structures of two Nbs with Gel4 from Aspergillus fumigatus revealed binding to a dissimilar CBM43 domain and a highly conserved catalytic domain across fungal species, respectively. Anti-Gel4 active site Nb3 showed significant antifungal efficacy in vitro and in vivo prophylactically and therapeutically against different A. fumigatus and Cryptococcus neoformans isolates, reducing the fungal burden and disease severity, thus significantly improving immunocompromised animal survival. Notably, C. deneoformans (serotype D) strains were more susceptible to Nb3 and genetic Gel deletion than C. neoformans (serotype A) strains, indicating a key role for ß-1,3-glucan remodelling in C. deneoformans survival. These findings add new insight about the role of ß-1,3-glucan in fungal biology and demonstrate the potential of nanobodies in targeting fungal enzymes to combat invasive fungal diseases.

Fungal chitin is not an independent mediator of allergic fungal asthma severity.

Chitin, a polysaccharide found in the fungal cell wall and the exoskeletons of house dust mites and cockroaches, has garnered attention as a potential immunoreactive allergen. Mammals have evolved to express chitin-degrading chitinases (acidic mammalian chitinase/AMCase and chitotriosidase) that may modulate immune responses to chitin. We have previously reported that mice deficient in AMCase (Chia-/-) demonstrated better lung function during allergic fungal asthma. As expected, we show that mice overexpressing AMCase (SPAM mice) had worse airway hyperreactivity (AHR) during allergic fungal asthma. We further demonstrate that chitin-positive Aspergillus fumigatus conidia are detectable in the allergic lung during chronic exposure. Lung function in Chia-/- and SPAM mice is directly correlated with the level of chitinase activity during chronic fungal exposure (Chia-/- mice, negligible chitinase activity, lower AHR; SPAM mice, heightened chitinase activity, higher AHR), suggesting that the breakdown of chitin promoted AHR. However, chronic exposure of normal mice to purified A. fumigatus chitin resulted in only moderate inflammatory changes in the lung that were not sufficient to induce AHR. Moreover, despite having dramatic differences in chitinase activity, chronic exposure of Chia-/- and SPAM mice to purified A. fumigatus chitin likewise did not modulate AHR. Collectively, these results indicate that chronic exposure to fungal chitin alone is incapable of driving AHR. Furthermore, our data suggest that the chitinase-mediated degradation of chitin associated with A. fumigatus conidia may facilitate unmasking and/or liberation of other fungal cell wall components that drive inflammatory responses that contribute to AHR.NEW & NOTEWORTHY Humans with asthma sensitized to fungi often have more severe asthma than those who are not fungal-sensitized. Chitin makes up a significant portion of the cell wall of fungi and has been implicated as a pathogenic factor in allergic asthma. Ellis et al. demonstrate that chronic exposure to fungal chitin alone is unable to modulate lung function, even in the presence of differential lung chitinase activity.

The Inflammatory Response Induced by Aspergillus fumigatus Conidia Is Dependent on Complement Activation: Insight from a Whole Blood Model.

INTRODUCTION: We aimed to elucidate the inflammatory response of Aspergillus fumigatus conidia in a whole-blood model of innate immune activation and to compare it with the well-characterized inflammatory reaction to Escherichia coli. METHODS: Employing a human lepirudin whole-blood model, we analyzed complement and leukocyte activation by measuring the sC5b-9 complex and assessing CD11b expression. A 27-multiplex system was used for quantification of cytokines. Selective cell removal from whole blood and inhibition of C3, C5, and CD14 were also applied. RESULTS: Our findings demonstrated a marked elevation in sC5b-9 and CD11b post-A. fumigatus incubation. Thirteen cytokines (TNF, IL-1ß, IL-1ra, IL-4, IL-6, IL-8, IL-17, IFNγ, MCP-1, MIP-1α, MIP-1ß, FGF-basic, and G-CSF) showed increased levels. A generally lower level of cytokine release and CD11b expression was observed with A. fumigatus conidia than with E. coli. Notably, monocytes were instrumental in releasing all cytokines except MCP-1. IL-1ra was found to be both monocyte and granulocyte-dependent. Pre-inhibiting with C3 and CD14 inhibitors resulted in decreased release patterns for six cytokines (TNF, IL-1ß, IL-6, IL-8, MIP-1α, and MIP-1ß), with minimal effects by C5-inhibition. CONCLUSION: A. fumigatus conidia induced complement activation comparable to E. coli, whereas CD11b expression and cytokine release were lower, underscoring distinct inflammatory responses between these pathogens. Complement C3 inhibition attenuated cytokine release indicating a C3-level role of complement in A. fumigatus immunity.

Fractional exhaled nitric oxide, a potential biomarker for evaluating glucocorticoids treatment and prognosis in allergic bronchopulmonary aspergillosis.

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is characterized by enhanced TH2 inflammatory response. Fractional exhaled nitric oxide (FeNO) measurement has been used as a valuable tool in predicting the development and management of asthma, another typical TH2 inflammation. However, the clinical significance of FeNO in ABPA remains unclear. OBJECTIVE: To investigate the association between FeNO and the prognosis of patients with ABPA to provide a basis for the use of FeNO in evaluating the efficacy of glucocorticoids in ABPA treatment. METHODS: This study comprised 2 parts; 58 patients were enrolled in the retrospective study. Clinical indexes in patients with different prognoses were compared, and receiver operating characteristic curve analysis was used to determine the threshold value. The prospective observational study involved 61 patients who were regularly followed up at 4 to 6 weeks and 6 months since the initial treatment. Patients were grouped on the basis of baseline FeNO values; correlation analysis was performed in the clinical data. RESULTS: Different prognoses were observed between patients with high and low baseline FeNO values, with a threshold value of 57 parts per billion. The percentage of Aspergillus fumigatus-specific IgE, percentage of positive A fumigatus-specific IgG, and relapse/exacerbation rate differed significantly between the high and low FeNO groups. Patients with higher FeNO needed longer treatment duration and showed shorter interval between glucocorticoid withdrawal and the next relapse/exacerbation. CONCLUSION: Our findings indicate that the level of FeNO is associated with the prognosis of ABPA. It can serve as an independent and valuable biomarker for evaluating the effectiveness of glucocorticoid treatment.

BTK inhibitor-induced defects in human neutrophil effector activity against Aspergillus fumigatus are restored by TNF-α.

Inhibition of Bruton's tyrosine kinase (BTK) through covalent modifications of its active site (e.g., ibrutinib [IBT]) is a preferred treatment for multiple B cell malignancies. However, IBT-treated patients are more susceptible to invasive fungal infections, although the mechanism is poorly understood. Neutrophils are the primary line of defense against these infections; therefore, we examined the effect of IBT on primary human neutrophil effector activity against Aspergillus fumigatus. IBT significantly impaired the ability of neutrophils to kill A. fumigatus and potently inhibited reactive oxygen species (ROS) production, chemotaxis, and phagocytosis. Importantly, exogenous TNF-α fully compensated for defects imposed by IBT and newer-generation BTK inhibitors and restored the ability of neutrophils to contain A. fumigatus hyphal growth. Blocking TNF-α did not affect ROS production in healthy neutrophils but prevented exogenous TNF-α from rescuing the phenotype of IBT-treated neutrophils. The restorative capacity of TNF-α was independent of transcription. Moreover, the addition of TNF-α immediately rescued ROS production in IBT-treated neutrophils, indicating that TNF-α worked through a BTK-independent signaling pathway. Finally, TNF-α restored effector activity of primary neutrophils from patients on IBT therapy. Altogether, our data indicate that TNF-α rescued the antifungal immunity block imposed by inhibition of BTK in primary human neutrophils.

Serum Aspergillus fumigatus-Specific IgG as a Complementary Biomarker in Differentiating Endotypes of Chronic Rhinosinusitis: A Study on Its Role and Diagnostic Efficacy in Type 2 Inflammation.

BACKGROUND: Aspergillus is one of the most common pathogens causing fungal allergy in the respiratory tract. Serum Aspergillus fumigatus-specific immunoglobulin G (Af-sIgG) levels have been used as a biomarker for the diagnosis and treatment response monitoring in airway allergic diseases such as allergic bronchopulmonary aspergillosis and allergic fungal rhinosinusitis. However, its role in common primary chronic rhinosinusitis (CRS) was unclear. OBJECTIVE: This study aims to evaluate whether serum Af-sIgG level could serve as a biomarker for the disease presentation of primary CRS. METHODS: We obtained serum Af-sIgG levels from patients diagnosed as bilateral primary CRS refractory to medical treatment and evaluated the correlations between serum Af-sIgG levels and disease severity in patients with type 2 (T2) and non-T2 CRS. RESULTS: Patients with T2 CRS exhibited significantly higher serum Af-sIgG levels than non-T2 CRS patients. The cut-off value of serum Af-sIgG in T2 CRS was 20.9 mg/L, with an odds ratio of 3.8 (95% CI 1.17-12.20, P = .026). Furthermore, serum Af-sIgG levels were positively correlated with symptom scores evaluated by the Sino-Nasal Outcome Test-22 (SNOT-22) scores in T2 patients (P = .009). While stratified by SNOT-22 total scores, patients with severe disease had higher serum Af-sIgG levels only in T2 CRS (P = .034). In individual domains of SNOT-22 analysis, serum Af-sIgG levels showed a significant correlation with "ear/facial" symptom scores in the T2 group (P < .001). CONCLUSIONS: Serum Af-sIgG levels may serve as a supplementary objective biomarker that correlates with identification and subjective measurements of T2 CRS, and may be associated with symptoms arising from Eustachian tube dysfunction.

[In silico analysis of molecular mimicry between human aquaporin 3, Aspergillus fumigatus aquaporin and aquaporins from allergic sources]. / Análisis en silico del mimetismo molecular entre acuaporina 3 humana y Aspergillus fumigatus: implicaciones para el potencial de reactividad cruzada.

OBJECTIVE: Conduct an in-silico assessment of potential molecular mimicry between human aquaporins, A. fumigatus, and diverse allergenic sources. METHODS: Amino acid sequences of human AQP3 and A. fumigatus aquaporin were compared through multiple alignments with 25 aquaporins from diverse allergenic sources. Phylogenetic analysis and homology-based modeling were executed, and the ElliPro server predicted conserved antigenic regions on 3D structures. RESULTS: Global identity among studied aquaporins was 32.6%, with a specific conserved local region at 71.4%. Five monophyletic clades (A-E) were formed, and Group B displayed the highest identity (95%), including 6 mammalian aquaporins, notably AQP3. A. fumigatus aquaporin exhibited the highest identity with Malassezia sympodialis (35%). Three linear and three discontinuous epitopes were identified in both human and A. fumigatus aquaporins. The Root Mean Square Deviation (RMSD) from overlapping aquaporin structures was 1.006. CONCLUSION: Identification of potential linear and conformational epitopes on human AQP3 suggests likely molecular mimicry with A. fumigatus aquaporins. High identity in a specific antigenic region indicates potential autoreactivity and a probable antigenic site involved in cross-reactivity. Validation through in vitro and in vivo studies is essential for further understanding and confirmation.

OBJETIVO: Realizar una evaluación in silico del posible mimetismo molecular entre las acuaporinas humanas, A. fumigatus y diversas fuentes alergénicas. MÉTODOS: Se compararon secuencias de aminoácidos de AQP3 humana y acuaporina de A. fumigatus mediante alineamientos múltiples con 25 acuaporinas de diversas fuentes alergénicas. Se ejecutaron análisis filogenéticos y modelos basados en homología, y el servidor ElliPro predijo regiones antigénicas preservadas en estructuras 3D. RESULTADOS: La identidad global entre las acuaporinas estudiadas fue del 32.6%, con una región local específica preservada en el 71.4%. Se formaron cinco clados monofiléticos (A-E), y el grupo B mostró la identidad más alta (95%), incluidas 6 acuaporinas de mamíferos, en particular AQP3. A. fumigatus aquaporin exhibió la mayor identidad con Malassezia sympodialis (35%). Se identificaron tres epítopos lineales y tres discontinuos en acuaporinas tanto humanas como de A. fumigatus. La desviación cuadrática media (RMSD) de las estructuras de acuaporinas superpuestas fue de 1,006. CONCLUSIÓN: La identificación de posibles epítopos lineales y conformacionales en AQP3 humano sugiere un probable mimetismo molecular con acuaporinas de A. fumigatus. La identidad alta en una región antigénica específica indica autorreactividad potencial y un sitio antigénico probable implicado en la reactividad cruzada. La validación mediante estudios in vitro e in vivo es desicivo para una mayor comprensión y confirmación.

Serological Cross-Reactivity of Various Aspergillus spp. with Aspergillus fumigatus: A Diagnostic Blind Spot.

INTRODUCTION: Aspergillus fumigatus is the most common airborne allergen of the Aspergillus family. However, allergies to Aspergillus spp. are increasing, and subsequently, allergies to Aspergillus species other than fumigatus are also on the rise. Commercial diagnostic tools are still limited to Aspergillus fumigatus. Hence, there is a need for improved tests. We decided to investigate the correlation between serological sensitization to A. fumigatus and other Aspergillus species. METHODS: Hundred and seven patients with positive skin prick tests to A. fumigatus were included in this study. Immunoglobulin E (IgE) concentrations against A. fumigatus, A. terreus, A. niger, A. flavus, and A. versicolor were measured from specimens by fluorescent enzyme-linked immunoassays. RESULTS: Patients showed considerably higher IgE concentrations against A. fumigatus (6.00 ± 15.05 kUA/L) than A. versicolor (0.30 ± 1.01 kUA/L), A. niger (0.62 ± 1.59 kUA/L), A. terreus (0.45 ± 1.12 kUA/L), or A. flavus (0.41 ± 0.97 kUA/L). Regression analysis yielded weak positive correlations for all Aspergillus spp., but low r2 values and heteroscedastic distribution indicate an overall poor fit of the calculated models. CONCLUSION: Serological sensitization against A. fumigatus does not correlate with sensitization against other Aspergillus spp. To detect sensitization against these, other diagnostic tools like a skin prick test solution of different Aspergillus spp. are needed.