Journal of Allergy and Clinical Immunology最新文献

Background: The bead-based epitope assay (BBEA) has been used to identify epitope-specific (es) antibodies and successfully utilized to diagnose clinical allergy to milk, egg and peanut.

Objective: This study aimed to identify es-IgE, es-IgG4 and es-IgG1 of wheat proteins and determine the optimal peptides to differentiate wheat-allergic from wheat-tolerant using the BBEA.

Methods: Children and adolescents who underwent an oral food challenge to confirm their wheat allergy status were enrolled. Seventy-nine peptides from alpha/beta-gliadin, gamma-gliadin (γ-gliadin), omega-5-gliadin (ω-5-gliadin), high and low molecular weight glutenin were commercially synthesized and coupled to LumAvidin beads. Machine learning (ML) methods were used to identify diagnostic epitopes and performance was evaluated using DeLong's test.

Results: The analysis includes 122 children (83 wheat-allergic and 39 wheat-tolerant, 57.4% male). ML coupled with simulations identified wheat es-IgE, but not es-IgG4 or es-IgG1 to be most informative for diagnosing wheat allergy. Higher es-IgE binding intensity correlated with the severity of allergy phenotypes, with wheat anaphylaxis exhibiting the highest es-IgE binding intensity. In contrast, wheat-dependent exercise-induced anaphylaxis (WDEIA) showed lower es-IgG1 binding than all other groups. A set of 4 informative epitopes from ω-5-gliadin, and γ-gliadin were the best predictors of wheat allergy with an AUC of 0.908 (sensitivity=83.4%, specificity=88.4%), higher than the performance exhibited by wheat-specific IgE (AUC=0.646, p < 0.001). The predictive ability of our model was confirmed in an external cohort of 71 patients (29 allergic, 42 non-allergic), with an AUC of 0.908 (sensitivity=75.9%, specificity=90.5%).

Conclusion: The wheat BBEA demonstrated greater diagnostic accuracy compared to existing specific IgE tests for wheat allergy.

Background: Bidirectional interactions between eosinophils and mast cells (MCs) have been reported in various allergic diseases. Bone marrow (BM) eosinophilia, and to a lesser extent blood eosinophilia, is common in systemic mastocytosis (SM), but its significance remains unknown.

Objective: To describe blood and BM eosinophil characteristics in SM.

Methods: A large collection of BM biopsies was analyzed using immunohistochemical staining and whole-slide imaging. Eosinophil and extracellular granules were detected by eosinophil peroxidase (EPX) staining, and MCs by KIT staining. Complementary analyses were conducted using flow cytometry and immunofluorescence.

Results: Eosinophil infiltrates and large areas of eosinophil degranulation were observed within or around BM MC infiltrates in SM. EPX staining surface, highlighting intact eosinophils and eosinophil degranulation, was higher in non-advanced-SM (n=37 BM biopsies) compared to both controls (n=8, p=0.0003) and to advanced SM (n=24, p=0.014). In non-advanced SM, positive correlations were observed between serum tryptase levels and percentages of eosinophil counts in BM aspirations (Spearman r coefficient r=0.38, p=0.038), eosinophils count in BM biopsies (r=0.45, p=0.007), EPX staining (r=0.37, p=0.035) and eosinophil degranulation (r=0.39, p=0.023). Eosinophil counts in BM biopsies also correlated with MC counts (r=0.47, p=0.006) and KIT staining surface (r=0.49, p=0.003). BM MCs expressed interleukin-5 receptor and other usual eosinophil cytokine/chemokine receptors, and blood eosinophils display several increased surface markers compared to controls, suggesting an activated state.

Conclusion: Our data suggest a possible crosstalk between MCs and eosinophils, supporting MC tryptase release and MC activation-related symptoms. This suggests a rationale for targeting eosinophils in non-advanced-SM not fully controlled by other therapies.

Atopic dermatitis (AD) is a complex disease characterized by dry, pruritic skin and significant atopic and psychological sequelae. Although AD has always been viewed as multifactorial, early research was dominated by overlapping genetic determinist views of either innate barrier defects leading to inflammation or innate inflammation eroding skin barrier function. Since 1970, however, the incidence of AD in the United States has increased at a pace that far exceeds genetic drift, thus suggesting a modern, environmental etiology. Another implicated factor is Staphylococcus aureus; however, a highly contagious microorganism is unlikely to be the primary etiology of a noncommunicable disease. Recently, the roles of the skin and gut microbiomes have received greater attention as potentially targetable drivers of AD. Here too, however, dysbiosis on a population scale would require induction by an environmental factor. In this review, we describe the evidence supporting the environmental hypothesis of AD etiology and detail the molecular mechanisms of each of the AD-relevant toxins. We also outline how a pollution-focused paradigm demands earnest engagement with environmental injustice if the field is to meaningfully address racial and geographic disparities. Identifying specific toxins and their mechanisms can also inform in-home and national mitigation strategies.

Background: Responder analyses of SINUS phase 3 study data have shown clinically meaningful improvements across multiple chronic rhinosinusitis with nasal polyps (CRSwNP) outcomes with dupilumab.

Objective: To gain a better understanding of dupilumab response dynamics over 52 weeks.

Methods: Post hoc analysis using data from the SINUS-52 (NCT02898454) intention-to-treat population, of patients with severe CRSwNP who received dupilumab 300 mg once every 2 weeks (q2w) or placebo. Response, defined as an improvement from baseline of ≥ 1 point for Nasal Polyp Score (NPS), nasal congestion (NC), and loss of smell (LoS), and ≥ 8.9 points for 22-item Sino-Nasal Outcome Test (SNOT-22), was assessed for rapidity, maintenance, and durability.

Results: 303 patients (dupilumab, n = 150; placebo, n = 153) were included. For each outcome measure, a greater proportion of patients achieved first response by Week 16 (rapidity) with dupilumab vs placebo: NPS, 75.3% vs 39.2%; NC, 60.0% vs 24.2%; LoS, 60.7% vs 15.7%; and SNOT-22, 83.3% vs 66.0%. Among dupilumab patients with a response by Week 16, more than 80% maintained response at Week 52 (maintenance). Over 52 weeks, greater proportions of dupilumab patients were responders at ≥ 80% of time points: NPS, 46.7% vs 2.6%; NC, 46.7% vs 9.2%; LoS, 47.3% vs 3.9%; and SNOT-22, 62.0% vs 21.6% (durability).

Conclusion: Most CRSwNP patients achieve clinically meaningful responses to dupilumab by Week 16, and most of these patients had maintenance and durability of response with continued treatment over time.

Background: Agammaglobulinemia due to variants in IGLL1 has traditionally been considered an exceedingly rare form of severe B-cell deficiency, with only eight documented cases in the literature. Surprisingly, the first agammaglobulinemic patient identified by newborn screening (NBS) through quantification of kappa-deleting recombination excision circles harbored variants in IGLL1.

Objective: To provide a comprehensive overview of the clinical and immunological findings of patients with B-cell deficiency attributed to variants in IGLL1.

Methods: NBS programs reporting using kappa-deleting recombination excision circle assays, the European Society for Immunodeficiencies Registry, and authors of published reports featuring patients with B-cell deficiency linked to IGLL1 variants were contacted. Only patients with (likely) pathogenic variants, reduced CD19+ counts and no alternative diagnosis were included.

Results: The study included 13 patients identified through NBS, two clinically diagnosed patients, and two asymptomatic siblings. All had severely reduced CD19+ B-cells (< 0.1×10⁹/L) on first evaluation, yet subsequent follow-ups indicated residual immunoglobulin production. Specific antibody responses to vaccine antigens varied, with a predominant reduction observed during infancy. Clinical outcomes were favorable with immunoglobulin G substitution. Two patients successfully discontinued substitution without developing susceptibility to infections and maintaining immunoglobulin levels. The pooled incidence of homozygous or compound heterozygous pathogenic IGLL1 variants identified by NBS in Austria, Czechia, and Switzerland was 1.3:100´000, almost double of X-linked agammaglobulinemia.

Conclusion: B-cell deficiency resulting from IGLL1 variants appears to be more prevalent than initially believed. Despite markedly low B-cell counts, the clinical course in some patients may be milder than reported in the literature so far.

Background: Asthma is often accompanied by type 2 immunity rich in IL-4, IL-5 and IL-13 cytokines produced by T_H2 lymphocytes or type 2 innate lymphoid cells (ILC2s). Interleukin-2 family cytokines play a key role in the differentiation, homeostasis and effector function of innate and adaptive lymphocytes.

Objective: IL-9 and IL-21 boost the activation and proliferation of T_H2 and ILC2s, but the relative importance and potential synergism between these γc cytokines is currently unknown.

Methods: Using newly generated antibodies, we inhibited IL-9 and IL-21 alone or in combination, in various murine models of asthma. In a translational approach using segmental allergen challenge, we recently described elevated IL-9 levels in human allergic asthmatics in comparison to non-asthmatic controls. Here, we also measured IL-21 in both groups.

Results: IL-9 played a central role in controlling innate IL-33 induced lung inflammation by promoting proliferation and activation of ILC2s, in an IL-21 independent manner. Conversely, chronic house dust mite induced airway inflammation, mainly driven by adaptive immunity, was solely dependent on IL-21, that controlled T_H2 activation, eosinophilia, total serum IgE and formation of tertiary lymphoid structures. In a model of innate on adaptive immunity driven by papain allergen, a clear synergy was found between both pathways, since combined anti-IL-9 or anti-IL-21 blockade was superior in reducing key asthma features. In human bronchoalveolar lavage (BAL) samples we measured elevated IL-21 protein within the allergic asthmatic group, compared with the allergic control group. We also found increased IL21R transcripts and predicted IL-21 ligand activity in various disease-associated cell subsets.

Conclusion: IL-9 and IL-21 play important and non-redundant roles in allergic asthma by boosting ILC2s and T_H2 cells, revealing a dual IL-9 and IL-21 targeting strategy as a new and testable approach.

Background: Insight into the pathophysiology of inflammatory skin diseases, especially at the proteomic level, is severely hampered by the lack of adequate in situ data.

Objective: We characterized lesional and nonlesional skin of inflammatory skin diseases using skin microdialysis.

Methods: Skin microdialysis samples from patients with atopic dermatitis (AD, n = 6), psoriasis vulgaris (PSO, n = 7), or prurigo nodularis (PN, n = 6), as well as healthy controls (n = 7), were subjected to proteomic and multiplex cytokine analysis. Single-cell RNA sequencing of skin biopsy specimens was used to identify the cellular origin of cytokines.

Results: Among the top 20 enriched Gene Ontology (GO; geneontology.org) annotations, nicotinamide adenine dinucleotide metabolic process, regulation of secretion by cell, and pyruvate metabolic process were elevated in microdialysates from lesional AD skin compared with both nonlesional skin and controls. The top 20 enriched Kyoto Encyclopedia of Genes and Genomes (KEGG; genome.jp/kegg) pathways in these 3 groups overlapped almost completely. In contrast, nonlesional skin from patients with PSO or PN and control skin showed no overlap with lesional skin in this KEGG pathway analysis. Lesional skin from patients with PSO, but not AD or PN, showed significantly elevated protein levels of MCP-1 compared with nonlesional skin. IL-8 was elevated in lesional versus nonlesional AD and PSO skin, whereas IL-12p40 and IL-22 were higher only in lesional PSO skin. Integrated single-cell RNA sequencing data revealed identical cellular sources of these cytokines in AD, PSO, and PN.

Conclusion: On the basis of microdialysates, the proteomic data of lesional PSO and PN skin, but not lesional AD skin, differed significantly from those of nonlesional skin. IL-8, IL-22, MCP-1, and IL-12p40 might be suitable markers for minimally invasive molecular profiling.

Background: The abundance and diversity of intestinal commensal bacteria influence systemic immunity with impact on disease susceptibility and severity. For example, loss of short chain fatty acid (SCFA)-fermenting bacteria in early life (humans and mice) is associated with enhanced type 2 immune responses in peripheral tissues including the lung.

Objective: Our goal was to reveal the microbiome-dependent cellular and molecular mechanisms driving enhanced susceptibility to type 2 allergic lung disease.

Methods: We used low-dose vancomycin to selectively deplete SCFA-fermenting bacteria in wild-type mice. We then examined the frequency and activation status of innate and adaptive immune cell lineages with and without SCFA supplementation. Finally, we used ILC2-deficient and signal transducer and activator of transcription 6 (STAT6)-deficient transgenic mouse strains to delineate the cellular and cytokine pathways leading to enhanced allergic disease susceptibility.

Results: Mice with vancomycin-induced dysbiosis exhibited a 2-fold increase in lung ILC2 primed to produce elevated levels of IL-2, -5, and -13. In addition, upon IL-33 inhalation, mouse lung ILC2 displayed a novel ability to produce high levels of IL-4. These expanded and primed ILC2s drove B1 cell expansion and IL-4-dependent production of IgE that in turn led to exacerbated allergic inflammation. Importantly, these enhanced lung inflammatory phenotypes in mice with vancomycin-induced dysbiosis were reversed by administration of dietary SCFA (specifically butyrate).

Conclusion: SCFAs regulate an ILC2-B1 cell-IgE axis. Early-life administration of vancomycin, an antibiotic known to deplete SCFA-fermenting gut bacteria, primes and amplifies this axis and leads to lifelong enhanced susceptibility to type 2 allergic lung disease.

Background: There are pre-existing inequities in asthma care.

Objectives: We sought to evaluate effect modification by race of the effect of insurance on biologic therapy use in patients with asthma and related diseases.

Methods: We conducted inverse probability weighted analyses using electronic health records data from 2011 to 2020 from a large health care system in Boston, Mass. We evaluated the odds of not initiating omalizumab or mepolizumab therapy within 1 year of prescription for an approved indication.

Results: We identified 1132 individuals who met study criteria. Twenty-seven percent of these patients had public insurance and 12% belonged to a historically marginalized group (HMG). One-quarter of patients did not initiate the prescribed biologic. Among patients with asthma, individuals belonging to HMG had higher exacerbation rates in the period before initiation compared to non-HMG individuals, regardless of insurance type. Among HMG patients with asthma, those with private insurance were less likely to not initiate therapy compared to those with public insurance (odds ratio [OR]: 0.67, and 95% CI: 0.56-0.79). Among non-HMG with asthma, privately insured and publicly insured individuals had similar rates of not initiating the prescribed biologic (OR: 1.02; 95% CI: 0.95-1.09). Among those publicly insured with asthma, HMGs had higher odds of not initiating therapy compared to non-HMGs (OR: 1.16; 95% CI: 1.03-1.31), but privately insured HMG and non-HMG did not differ significantly (OR: 0.99; 95% CI: 0.91-1.07).

Conclusions: Publicly insured individuals belonging to HMG are less likely to initiate biologics when prescribed despite having more severe asthma, while there are no inequities by insurance in individuals belonging to other groups.

The Consortium of Eosinophilic Gastrointestinal disease Researchers (CEGIR) and The International Gastrointestinal Eosinophil Researchers (TIGERs) organized a daylong symposium at the 2024 annual meeting of the American Academy of Allergy, Asthma & Immunology. The symposium featured new discoveries in basic and translational research as well as debates on the mechanisms and management of eosinophilic gastrointestinal diseases. Updates on recent clinical trials and consensus guidelines were also presented. We summarize the updates on eosinophilic gastrointestinal diseases presented at the symposium.