Allergology International最新文献

Background: Although randomized controlled trials (RCT) have demonstrated the efficacy of mepolizumab for asthma, they have excluded certain patient subgroups. To bridge the gap between RCT and real-world practice, the effectiveness of mepolizumab in a diverse population, including those potentially excluded from RCT, was assessed. Its effects on imaging findings and symptoms of chronic rhinosinusitis (CRS) with asthma were also assessed.

Methods: This retrospective observational study of patients in Japan (J-Real-Mepo: UMIN000045021) evaluated multiple endpoints and analyzed the relationship between clinical background and treatment outcomes.

Results: Mepolizumab significantly reduced exacerbations, improved Asthma Control Test (ACT) scores, and forced expiratory volume in 1 s, and reduced oral corticosteroid (OCS) dose, regardless of patient characteristics, including age, body mass index, smoking history, and comorbidities. Regarding RCT exclusion criteria, 29.4 % of patients had no history of exacerbations. Although 25.4 % of these patients required continuous OCS, the OCS dose was reduced similar to those with a history of exacerbations. Disease control and mepolizumab effectiveness in patients with a smoking history ≥10 pack-years was similar to that of never-smokers. Patients with eosinophil counts <150/μL had lower ACT scores and higher OCS use compared with patients with eosinophilia and comparable effectiveness regarding exacerbation and OCS reduction. Significant improvements in Lund-Mackay scores and CRS symptoms were observed.

Conclusions: Mepolizumab effectiveness was demonstrated in a broad range of patients including those with RCT exclusion criteria, who had significant disease or OCS burden. These findings may explain the consistent results between RCT and real-world studies of mepolizumab.

Background: Chronic rhinosinusitis (CRS) is a persistent inflammatory disease of various endotypes, including eosinophilic CRS (eCRS), which is characterized by marked eosinophilic infiltration and high refractory rates despite treatment. Recent findings suggest the interaction between local IgE and mast cells in nasal polyps (NPs) is key to eCRS pathogenesis; however, the details remain unclear. This study investigated the involvement of MS4A2, a component of the IgE receptor, in the pathogenesis of refractory eCRS.

Methods: NP tissue samples were collected from 47 patients with eCRS who underwent sinus surgery and classified into refractory and nonrefractory groups based on postoperative outcomes. Quantitative PCR was used to analyze the mRNA expression of IgE receptor components (MS4A2, FCER1A, and FCER1G) and cell-specific markers (CLC, TPSAB1, and GPR56) in NP tissues. Immunofluorescence staining was used to confirm MS4A2 expression and colocalization with tryptase, ProMBP1, and IgE. ROC analysis was conducted to assess MS4A2 mRNA levels as a predictor of refractory eCRS.

Results: MS4A2 mRNA expression was significantly elevated in the refractory group, whereas FCER1A and FCER1G mRNA expression levels showed no significant differences. Immunofluorescence revealed an increased number of MS4A2-positive cells, particularly those colocalized with tryptase-positive mast cells, in the refractory group. Cells coexpressing MS4A2 and IgE were more prevalent in this group. ROC analysis indicated that MS4A2 mRNA expression can predict prognosis with high specificity.

Conclusions: Our findings suggest the significance of the interaction between MS4A2-expressing mast cells and local IgE in the pathogenesis of refractory eCRS, highlighting MS4A2 as a potential therapeutic target.

Background: The detection of drug-specific activation of T cells in the lymphocyte transformation test (LTT) is mainly based on cell proliferation or cytokine secretion. However, the LTT presents with a varying sensitivity and specificity. The aim of our study was to analyse the genome wide gene expression of PBMC to identify drug allergy-specific gene regulation patterns. Additionally, gene expression differences related to the allergy-inducing drug or the type of allergy (immediate/delayed) were investigated.

Methods: Blood samples from 40 patients with allergy to different drugs and from 40 non-drug-allergic controls were recruited. PBMC were isolated and stimulated with the culprit drug ("LTT-platform"). Transcriptome analyses of PBMC were conducted after 3.5 days. The concentration of IFN-γ and IL-5 in the culture supernatants was measured by ELISA after 6 days.

Results: The transcriptome analyses revealed an allergy type and drug-specific gene regulation in PBMC from patients. Importantly, in the corresponding control groups these genes were barely or even opposingly regulated. It was also shown that in particular cefuroxime exerted a strong effect on the gene regulation in PBMC. Quantitative RT-PCR of selected genes identified by the transcriptome analyses revealed that CCL17, CISH and CD25 were specifically upregulated in patients. Notably, a strong upregulation of CCL17, CISH or CD25 did not necessarily correlate with the ELISA outcome of the patients and controls.

Conclusions: Our results could be helpful for the identification of one or a panel of regulated genes considering patient specific parameters like the type of the allergy-inducing drug.

Background: Solubility is a common feature of allergens. However, the causative relationship between this protein-intrinsic feature and sensitization capacity of allergens is not fully understood. This study aimed to proof the concept of solubility as a protein intrinsic feature of allergens.

Methods: The soluble birch pollen allergen Bet v 1 was covalently coupled to 1 μm silica particles. IgE-binding and -cross-linking capacity was assessed by inhibition ELISA and mediator release assay, respectively. Alterations in adjuvanticity by particle-loading were investigated by activation of dendritic cells, mast cells and the Toll-like receptor 4 pathway as well as by Th2 polarization in an IL-4 reporter mouse model. In BALB/c mice, particle-loaded and soluble Bet v 1 were compared in a model of allergic sensitization. Antigen uptake and presentation was analysed by restimulating human Bet v 1-specific T cell lines.

Results: Covalent coupling of Bet v 1 to silica particles resulted in an insoluble antigen with retained IgE-binding and -cross-linking capacity and no increase in adjuvanticity. In vivo, particle-loaded Bet v 1 induced significantly lower Bet v 1-specific (s)IgE, whereas sIgG1 and sIgG2a levels remained unaffected. The ratio of Th2 to Th1 cells was significantly lower in mice sensitized with particle-loaded Bet v 1. Particle-loading of Bet v 1 resulted in a 24-fold higher T cell activation capacity in Bet v 1-specific T cell lines, indicating more efficient uptake and presentation than of soluble Bet v 1.

Conclusions: Our results show that solubility is a decisive factor contributing to the sensitization capacity of allergens. The reduction in sensitization capacity of insoluble, particle-loaded antigens results from enhanced antigen uptake and presentation compared to soluble allergens.

Background: Epidemiological studies have identified associations between gastroesophageal reflux (GER) and cow's milk allergy (CMA) in infants. However, the role of GER in the development of CMA remains poorly understood. Our primary objectives were to develop a mouse model that suggests GER as a potential pathogenic mechanism for CMA and to elucidate the immunological mechanisms that connect lung innate immunity with CMA.

Methods: Mice were exposed to cow's milk (CM) treated with hydrochloric acid through repeated aspiration into their airways. Subsequently, they were challenged by intraperitoneal injection of CM extract. The immunological mechanisms were investigated using comprehensive single-cell RNA sequencing (scRNA-seq) analysis of the lungs, combined with the use of genetically modified mice.

Results: Mice exposed to CM mixed with hydrochloric acid via airway sensitization developed CMA, as evidenced by the production of antigen-specific IgE and IgG antibodies, and the induction of anaphylaxis upon systemic antigen administration. In contrast, aspiration of CM alone did not induce CMA. scRNA-seq analysis revealed potential roles of alveolar macrophages in response to hydrochloric acid. Mice lacking the TLR4 pathway were protected from developing CMA.

Conclusions: We have developed a novel mouse model for CMA that utilizes the natural antigen and follows the physiological airway sensitization pathway, thus potentially resembling clinical scenarios. This model, named the acidified milk aspiration-induced allergy model, has the potential to shed light on the role of early innate immunity by analyzing a more physiological model.

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.