Aspergillus fumigatus extract modulates human eosinophils via NOD2 and oxidative stress.

BACKGROUND: Aspergillus fumigatus is a pathogenic fungus known to be associated with severe asthma and allergic bronchopulmonary mycosis. However, the precise mechanisms underlying airway inflammation remain unclear. In this study, we investigated the direct modulation of human eosinophils by A. fumigatus and identified the specific mechanism of airway inflammation. METHODS: Eosinophils isolated from healthy subjects were stimulated with extracts of A. fumigatus. Multi-omics analysis, comprising transcriptomic and proteomic analyses, was performed. The expression of specific factors was evaluated using quantitative real-time polymerase chain reaction and flow cytometry. Mechanistic analyses were performed using NOD2 inhibitor and N-acetyl-l-cysteine (NAC). RESULTS: The A. fumigatus extract changed the expression of adhesion molecules (CD62L and CD11b) and CD69 on the surface of eosinophils, without affecting their viability, via nucleotide-binding oligomerization domain-containing protein 2 (NOD2) but not protease activity. Investigation using kinase inhibitors showed that A. fumigatus extract-induced modulation was partly mediated via p38 mitogen-activated protein kinases. Multi-omics analysis revealed that A. fumigatus-induced gene and protein expression profiles were characterized by the upregulation of oxidative stress-related molecules, including heat shock proteins (HSP90AA1, HSP90AB1, SRXN1, and HMOX1). NOD2 inhibitor and NAC differentially inhibited A. fumigatus-induced inflammatory changes. Additional multi-omics analysis identified that NOD2 signaling induced gene signatures different from those of interleukin (IL)-5 and elicited synergistic change with IL-5. CONCLUSIONS: A. fumigatus modulates human eosinophils via NOD2 and oxidative stress-mediated signaling. NOD2 signaling potentiated IL-5-induced activation, suggesting its pathogenic role in type 2 inflammation. NOD2 inhibitors and antioxidants can have therapeutic potential against A. fumigatus-related allergic disorders.

A case of eosinophilic granulomatosis with polyangiitis preceded by allergic bullous lesions.

A 62-year-old man with a history of diabetes mellitus was hospitalised with numbness of lower limbs, bullous lesions of the whole body, kidney dysfunction, presence of eosinophils, and elevated antineutrophil cytoplasmic antibodies to myeloperoxidase and anti-bullous pemphigoid 180 antibodies and was diagnosed with mononeuritis multiplex. Kidney and muscle biopsies showed vasculitis with fibrinoid necrosis, whereas skin biopsies showed only blister formation between the epidermis and dermis; a high eosinophilic infiltrate was present in all three tissues. These findings led to a diagnosis of eosinophilic granulomatosis with polyangiitis combined with allergic bullous lesions. Immunohistological examination indicated cytolytic eosinophils and extracellular traps, suggesting the presence of eosinophil extracellular trap cell death (eosinophil ETosis) in diseased tissue.

Characteristics and Regulation of Human Eosinophil ETosis In Vitro.

Cytolytic ETosis is a type of programmed cell death distinct from apoptosis and necrosis and plays a major role in the innate immune system and disease progression. Through the process of ETosis, cells release their chromatin with diverse antimicrobial proteins into the extracellular milieu, forming extracellular traps (ETs). Although ETosis has been reported in several leukocyte types, few studies have compared ETosis and the component proteins of ETs in leukocytes. The aim of this study was to better understand the characteristics of eosinophil ETosis (EETosis) compared with other leukocytes. We isolated human blood eosinophils, neutrophils, basophils, monocytes, and lymphocytes and stimulated them with known ETosis inducers, a protein kinase C activator PMA, or a calcium ionophore A23187. Both stimuli induced eosinophil cell death and ET release after 180 minutes of stimulation in a NADPH-oxidase-dependent manner. PMA also induced NADPH-oxidase-dependent ETosis in neutrophils, whereas little or no significant ETosis was observed in basophils, monocytes, or lymphocytes at 180 minutes. Mass spectrometry-based proteomic analysis of eosinophil- and neutrophil-derived ETs identified 997 and 1415 proteins, respectively. Among the physiological stimuli tested, immobilized IgA and IgG induced EETosis. C-C motif chemokine ligand 11 (CCL11) and interleukin 5 (IL-5) were weak inducers of EETosis, but co-stimulation significantly induced rapid EETosis. Under high serum or albumin conditions, co-stimulation with CCL11 and IL-5 paradoxically prolonged cell survival by preventing spontaneous apoptosis. This study provides an in-depth characterization of EETosis and highlights the precise regulation of eosinophil survival and cell death pathways.

Clinical Case Report: Neonatal Mesenteric Traction Syndrome During Surgery for Congenital Duodenal Stenosis.

Mesenteric traction syndrome (MTS) is a common complication of major abdominal surgery, characterized by flushing, hypotension, and tachycardia. However, its occurrence in neonates has not yet been documented. This report details a neonatal case of MTS that emerged during surgery for congenital duodenal stenosis. The patient was a two-day-old girl, born at 39 weeks and three days of gestation via vaginal delivery, weighing 2708 g. She underwent general anesthesia for the surgery, and continuous IV administration of remifentanil at 0.2 µg/kg/min was commenced minutes before the surgery began. Initially, her arterial pressure was 60-70/40-50 mmHg. However, shortly after bowel manipulation began, her blood pressure rapidly declined to 31/25 mmHg. Concurrently, her heart rate increased from 120 to 170 beats per minute, and she displayed facial and upper body flushing. Arterial blood gas analysis indicated a PaO2 drop from 124 to 61 mmHg at an FiO2 of 0.3. Treatment consisted of infusion loading and two bolus doses of 2.5 µg of phenylephrine (diluted to 2.5 µg/mL), which normalized her blood pressure within approximately 10 minutes. The facial flushing gradually subsided and disappeared after 40 minutes. Subsequent circulatory stability allowed for the successful completion of the surgery. There was no alteration in airway pressure, and hemodynamic stability was only compromised following the commencement of bowel manipulation. Given the serious risks associated with prolonged hemodynamic instability in neonates, the potential for MTS should be considered during anesthetic management in such cases.

Comparison of Transient and Persistent Adverse Events After COVID-19 Vaccination: A Retrospective Analysis.

OBJECTIVE: Most reported adverse events following COVID-19 vaccination have been transient. However, persistent adverse events may occur with some frequency. This study aimed to analyze patient background characteristics and trends, with a focus on whether adverse events following COVID-19 vaccination were transient or persistent. METHODS: A retrospective study was performed at a single institution in Japan. PATIENTS: The study cohort included 47 patients who presented with symptoms after COVID-19 vaccination between May 2021 and September 2023. The patients were classified into two groups based on the duration of symptoms: transient group, less than four weeks; persistent group, greater than or equal to four weeks. Data on age, sex, body mass index, smoking history, underlying conditions, type of COVID-19 vaccination, number of doses, onset, symptoms, and treatments were collected retrospectively. RESULTS: The median age was 51.0 years and 74.5% were females, with a particularly high proportion of women in their 40s. The use of the bivalent omicron-containing booster vaccine (BA.1) was significantly more common in the persistent group than in the transient group (p = 0.0267). Onset in the transient group was more common after the first vaccination, whereas onset in the persistent group was more common after the second and subsequent vaccinations (p = 0.003). Regarding symptoms, pain was more frequent in the persistent group than in the transient group (60% vs. 13.6%; p = 0.001). CONCLUSIONS: This study investigated the presence of persistent symptoms, especially pain, after COVID-19 vaccination. Persistent symptoms were frequently reported after the second vaccination. It should be noted that the study does not negate the usefulness of COVID-19 vaccines.

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.

Galectin-10 in serum extracellular vesicles reflects asthma pathophysiology.

BACKGROUND: Novel biomarkers (BMs) are urgently needed for bronchial asthma (BA) with various phenotypes and endotypes. OBJECTIVE: We sought to identify novel BMs reflecting tissue pathology from serum extracellular vesicles (EVs). METHODS: We performed data-independent acquisition of serum EVs from 4 healthy controls, 4 noneosinophilic asthma (NEA) patients, and 4 eosinophilic asthma (EA) patients to identify novel BMs for BA. We confirmed EA-specific BMs via data-independent acquisition validation in 61 BA patients and 23 controls. To further validate these findings, we performed data-independent acquisition for 6 patients with chronic rhinosinusitis without nasal polyps and 7 patients with chronic rhinosinusitis with nasal polyps. RESULTS: We identified 3032 proteins, 23 of which exhibited differential expression in EA. Ingenuity pathway analysis revealed that protein signatures from each phenotype reflected disease characteristics. Validation revealed 5 EA-specific BMs, including galectin-10 (Gal10), eosinophil peroxidase, major basic protein, eosinophil-derived neurotoxin, and arachidonate 15-lipoxygenase. The potential of Gal10 in EVs was superior to that of eosinophils in terms of diagnostic capability and detection of airway obstruction. In rhinosinusitis patients, 1752 and 8413 proteins were identified from EVs and tissues, respectively. Among 11 BMs identified in EVs and tissues from patients with chronic rhinosinusitis with nasal polyps, 5 (including Gal10 and eosinophil peroxidase) showed significant correlations between EVs and tissues. Gal10 release from EVs was implicated in eosinophil extracellular trapped cell death in vitro and in vivo. CONCLUSION: Novel BMs such as Gal10 from serum EVs reflect disease pathophysiology in BA and may represent a new target for liquid biopsy approaches.

Rapidly progressive mucus plugs in allergic bronchopulmonary mycosis.

INTRODUCTION: Allergic bronchopulmonary mycosis (ABPM) is a chronic airway disease characterized by the presence of fungi that trigger allergic reactions and airway obstruction. Here, we present a unique case of ABPM in which a patient experienced sudden respiratory failure due to mucus plug-induced airway obstruction. The patient's life was saved by venovenous extracorporeal membrane oxygenation (VV-ECMO) and bronchoscopic removal of the plug. This case emphasizes the clinical significance of mucus plug-induced airway obstruction in the differential diagnosis of respiratory failure in patients with ABPM. CASE STUDY: A 52-year-old female clerical worker with no smoking history, presented with dyspnea. CT scan revealed mucus plugs in both lungs. Despite treatment, the dyspnea progressed rapidly to respiratory failure, leading to VV-ECMO placement. RESULTS: CT revealed bronchial wall thickening, obstruction, and extensive atelectasis. Bronchoscopy revealed extensive mucus plugs that were successfully removed within two days. The patient's respiratory status significantly improved. Follow-up CT revealed no recurrence. Fungal cultures identified Schizophyllum commune, confirming ABPM. Histological examination of the mucus plugs revealed aggregated eosinophils, eosinophil granules, and Charcot-Leyden crystals. Galectin-10 and major basic protein (MBP) staining supported these findings. Eosinophil extracellular traps (EETs) and eosinophil cell death (ETosis), which contribute to mucus plug formation, were identified by citrullinated histone H3 staining. CONCLUSION: Differentiating between asthma exacerbation and mucus plug-induced airway obstruction in patients with ABPM and those with acute respiratory failure is challenging. Prompt evaluation of mucous plugs and atelectasis using CT and timely decision to introduce ECMO and bronchoscopic mucous plug removal are required.

Aggregated eosinophils and neutrophils characterize the properties of mucus in chronic rhinosinusitis.

BACKGROUND: Airway obstruction caused by viscous mucus is an important pathophysiologic characteristic of persistent inflammation, which can result in organ damage. OBJECTIVE: We investigated the hypothesis that the biophysical characteristics of accumulating granulocytes affect the clinical properties of mucus. METHODS: Surgically acquired nasal mucus samples from patients with eosinophilic chronic rhinosinusitis and neutrophil-dominant, noneosinophilic chronic rhinosinusitis were evaluated in terms of computed tomography density, viscosity, water content, wettability, and protein composition. Isolated human eosinophils and neutrophils were stimulated to induce the formation of extracellular traps, followed by the formation of aggregates. The biophysical properties of the aggregated cells were also examined. RESULTS: Mucus from patients with eosinophilic chronic rhinosinusitis had significantly higher computed tomography density, viscosity, dry weight, and hydrophobicity compared to mucus from patients with noneosinophilic chronic rhinosinusitis. The levels of eosinophil-specific proteins in mucus correlated with its physical properties. Eosinophil and neutrophil aggregates showed physical and pathologic characteristics resembling those of mucus. Cotreatment with deoxyribonuclease and heparin, which slenderizes the structure of eosinophil extracellular traps, efficiently induced reductions in the viscosity and hydrophobicity of both eosinophil aggregates and eosinophilic mucus. CONCLUSIONS: The present study elucidated the pathogenesis of mucus stasis in infiltrated granulocyte aggregates from a novel perspective. These findings may contribute to the development of treatment strategies for eosinophilic airway diseases.

Through the MIRRA and what we found there.

A series of post hoc MIRRA studies have illuminated eosinophilic granulomatosis with polyangiitis as an eosinophil-driven disease from various perspectives https://bit.ly/468pj86.

Eosinophil-derived galectin-10 upregulates matrix metalloproteinase expression in bullous pemphigoid blisters.

BACKGROUND: Bullous pemphigoid (BP) is an autoimmune bullous disease in which abundant eosinophils accumulate in the blisters. Galectin-10 abounds in the cytoplasm of eosinophils and is released as a result of eosinophil extracellular trap cell death (EETosis). OBJECTIVE: To identify EETosis and the pathological roles of galectin-10 in BP. METHODS: EETosis and galectin-10 in BP blisters were confirmed by immunofluorescence and transmission electron microscopy. The concentrations of galectin-10 in serum and blister fluid from BP patients were studied by ELISA. The matrix metalloproteinase (MMP) expression in BP blisters was immunohistochemically compared to that in healthy controls. As an in vitro assay, normal human epidermal keratinocytes (NHEKs) and normal human dermal fibroblasts (NHDFs) were stimulated with galectin-10, followed by MMP expression measurement by real-time PCR and ELISA. The signaling pathways activated by galectin-10 were studied using Western blotting and confirmed by inhibition assays. RESULTS: Galectin-10-containing eosinophil infiltration and the extracellular deposition of major basic protein were observed in BP blisters. The ultrastructural characteristics of tissue eosinophils indicated piecemeal degranulation and EETosis. In the BP patients, the concentration of galectin-10 was higher in the blister fluid than in the serum. Several types of MMPs were upregulated in BP blisters. Galectin-10 upregulated the production of MMPs through the pathways of p38 MAPK, ERK and JNK in NHEKs and NHDFs. CONCLUSION: In the BP blisters, the eosinophils underwent EETosis and released galectin-10. Galectin-10 might contribute to BP blister formation through the production of MMPs by keratinocytes and fibroblasts.

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

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

Endovascular Retrieval of a Fractured Tunneled Hemodialysis Central Venous Catheter Using the Loop Snare Technique.

The tunneled cuffed hemodialysis catheter is a valuable vascular access option for patients with end-stage renal disease (ESRD). Healthcare providers have become more familiar with the insertion of medical devices, including central venous catheters, in their daily practice. The occurrence of foreign body fragmentation is rare with these catheters. This article presents a case in which a fracture of the distal portion of the hemodialysis catheter was inadvertently identified during a coronary angiography. Percutaneous removal of the fractured venous catheter was performed successfully using a loop snare catheter, which prevented the patient from experiencing further complications.