TCF1-LEF1 co-expression identifies a multipotent progenitor cell (TH2-MPP) across human allergic diseases.

Repetitive exposure to antigen in chronic infection and cancer drives T cell exhaustion, limiting adaptive immunity. In contrast, aberrant, sustained T cell responses can persist over decades in human allergic disease. To understand these divergent outcomes, we employed bioinformatic, immunophenotyping and functional approaches with human diseased tissues, identifying an abundant population of type 2 helper T (TH2) cells with co-expression of TCF7 and LEF1, and features of chronic activation. These cells, which we termed TH2-multipotent progenitors (TH2-MPP) could self-renew and differentiate into cytokine-producing effector cells, regulatory T (Treg) cells and follicular helper T (TFH) cells. Single-cell T-cell-receptor lineage tracing confirmed lineage relationships between TH2-MPP, TH2 effectors, Treg cells and TFH cells. TH2-MPP persisted despite in vivo IL-4 receptor blockade, while thymic stromal lymphopoietin (TSLP) drove selective expansion of progenitor cells and rendered them insensitive to glucocorticoid-induced apoptosis in vitro. Together, our data identify TH2-MPP as an aberrant T cell population with the potential to sustain type 2 inflammation and support the paradigm that chronic T cell responses can be coordinated over time by progenitor cells.

Nasal brushing molecular endotyping distinguishes patients with chronic rhinosinusitis with nasal polyps with better response to dupilumab.

BACKGROUND: There is evidence of pathophysiologic diversity in chronic rhinosinusitis with nasal polyps (CRSwNP), but data characterizing the molecular endotypes of CRSwNP and their association with treatment are lacking. OBJECTIVE: This study aimed to identify gene signatures associated with CRSwNP endotypes, clinical features, and dupilumab treatment response. METHODS: Nasal brushing samples were collected from 89 patients randomized to dupilumab 300 mg every 2 weeks or placebo in the SINUS-52 trial (NCT02898454). Microarrays were used to identify transcriptional clusters and assess the relationship between gene expression and baseline clinical features and clinical response to dupilumab. Endotype signatures were determined using differential expression analysis. RESULTS: Two distinct transcriptional clusters (C1 and C2) were identified, both with elevated type 2 biomarkers. At baseline, C2 patients had higher mean Nasal Polyp Score and higher type 2 biomarker levels than C1 patients. At week 24, significant improvements in clinical outcomes (dupilumab vs placebo) were observed in both clusters, although the magnitude of improvements was significantly greater in C2 than in C1, and more C2 patients demonstrated clinically meaningful responses. Gene set enrichment analysis supported the existence of 2 molecular endotypes: C2 was enriched in genes associated with type 2 inflammation (including periostin, cadherin-26, and type 2 cysteine protease inhibitors), while C1 was enriched in genes associated with T cell activation and IL-12 production. CONCLUSIONS: Two distinct gene signatures associated with CRSwNP clinical features were identified; the endotype signatures were associated with clinical outcome measures and magnitude of dupilumab response.

IL-4Rα signaling promotes barrier-altering oncostatin M and IL-6 production in aspirin-exacerbated respiratory disease.

BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) is a severe disease involving dysregulated type 2 inflammation. However, the role other inflammatory pathways play in AERD is poorly understood. OBJECTIVE: We sought to broadly define the inflammatory milieu of the upper respiratory tract in AERD and to determine the effects of IL-4Rα inhibition on mediators of nasal inflammation. METHODS: Twenty-two AERD patients treated with dupilumab for 3 months were followed over 3 visits and compared to 10 healthy controls. Nasal fluid was assessed for 45 cytokines and chemokines using Olink Target 48. Blood neutrophils and cultured human mast cells, monocytes/macrophages, and nasal fibroblasts were assessed for response to IL-4/13 stimulation in vitro. RESULTS: Of the nasal fluid cytokines measured, nearly one third were higher in AERD patients compared to healthy controls, including IL-6 and the IL-6 family-related cytokine oncostatin M (OSM), both of which correlated with nasal albumin levels, a marker of epithelial barrier dysregulation. Dupilumab significantly decreased many nasal mediators, including OSM and IL-6. IL-4 stimulation induced OSM production from mast cells and macrophages but not from neutrophils, and OSM and IL-13 stimulation induced IL-6 production from nasal fibroblasts. CONCLUSION: In addition to type 2 inflammation, innate and IL-6-related cytokines are also elevated in the respiratory tract in AERD. Both OSM and IL-6 are locally produced in nasal polyps and likely promote pathology by negatively affecting epithelial barrier function. IL-4Rα blockade, although seemingly directed at type 2 inflammation, also decreases mediators of innate inflammation and epithelial dysregulation, which may contribute to dupilumab's therapeutic efficacy in AERD.

Lung function trajectories in a cohort of patients with moderate-to-severe asthma on mepolizumab, omalizumab, or dupilumab.

BACKGROUND: Lung function is an independent predictor of mortality. We evaluated the lung function trajectories of a cohort of patients with asthma receiving biologic therapy. METHODS: We identified 229 monoclonal antibody-naïve adult patients with moderate-to-severe asthma who initiated omalizumab, mepolizumab, or dupilumab between 2010 and 2022 in a large healthcare system in Boston, MA. Generalized additive mixed models were used to estimate the lung function trajectories during the 156 weeks following biologic initiation. Response was defined as an improvement in FEV1 or a decrease of ≤0.5% per year. The Kaplan-Meier estimator was used to assess time to no additional improvement in FEV1 in responders. All models were adjusted for age, sex, body mass index, smoking status, baseline exacerbation rate, and baseline blood eosinophil count. RESULTS: Eighty-eight patients initiated mepolizumab, 76 omalizumab, and 65 dupilumab. Baseline eosinophil count was highest in the mepolizumab group (405 cells/mcL) and lowest for omalizumab (250 cells/mcL). Both FEV1 and FVC improved in the mepolizumab group (FEV1 + 20 mL/year; FVC +43 mL/year). For omalizumab, there was an initial improvement in the first year followed by decline with an overall FEV1 loss of -44 mL/year and FVC -32 mL/year. For dupilumab, both FEV1 (+61 mL/year) and FVC (+74 mL/year) improved over time. Fifty percent of the mepolizumab group, 58% omalizumab, and 72% of dupilumab were responders. The median time to no additional FEV1 improvement in responders was 24 weeks for omalizumab, 48 weeks for mepolizumab, and 57 weeks for dupilumab. CONCLUSION: In this clinical cohort, mepolizumab, omalizumab, and dupilumab had beneficial effects on FEV1 and FVC with distinct post-initiation trajectories.

Validation of a questionnaire assessing smell loss in an international aspirin-exacerbated respiratory disease population.

Background: Olfactory dysfunction (OD) and smell loss affects aspects of patients' everyday life and lowers their quality of life. OD questionnaires are considered one of the core-outcome measures in chronic rhinosinusitis, but many existing smell loss questionnaires contained pandemic-prohibitive questions on social gatherings or restaurant visits, were too culture specific or gender specific, or were overly long and cumbersome. Objective: We aimed to develop a new brief questionnaire to assess the impact and consequences of smell loss and its burden on daily life. This study validates this new, short, multicultural, dichotomized questionnaire in an international population that has aspirin-exacerbated disease (AERD). Methods: The Consequences of Smell Loss (COSL) questionnaire was developed and content validity was assessed by experts and patients at Brigham and Women's Hospital. The questionnaire, along with other validated quality-of-life surveys, was answered by 853 patients with AERD. We evaluated the factor structure, reliability, validity, and discriminative ability of the COSL questionnaire. Results: The final version of the COSL questionnaire consisted of 13 items divided into three subdomains (emotional distress, food and safety, and physical health) through factor analysis. The Cronbach α for internal consistency was 0.82. Convergent and discriminant validity with the 22-item Sinonasal Outcome Test (SNOT-22), Healthy Days Core Module-4, Patient Health Questionnaire-4, and a specific question on taste and smell were high (p < 0.0001 for all). The COSL questionnaire score was associated with SNOT-22 categories (p < 0.001) and was categorized as follows: normal, 0-1 points; very few consequences, 2-3 points; few, 4 points; moderate, 5-6 points; and severe, 7-13 points. Conclusion: The COSL questionnaire is a new, brief, valid, reliable tool that can effectively screen for a high burden of OD in patients with AERD and has the potential to be used in other patient populations with OD as well.

Ratio of plasma IL-13/TNF- ∝ and CXCL10/CCL17 predicts mepolizumab and omalizumab response in asthma better than eosinophil count or immunoglobulin E level.

To date, most studies to identify biomarkers associated with response to the anti-interleukin 5 agent, mepolizumab, and to the anti-immunoglobulin E agent, omalizumab have focused on clinically available biomarkers, such as the peripheral blood eosinophil counts (BEC) and total immunoglobulin E (IgE). However, these biomarkers often have low predictive accuracy, with many patients with eosinophilic or allergic asthma failing to demonstrate clinical response to mepolizumab or omalizumab respectively. In this study, we evaluated the association of baseline pre-biologic plasma levels of 26 cytokines and chemokines, including T-helper 1 (Th1)-, Th2-, Th17-related cytokines, and their ratios with subsequent clinical response to mepolizumab or omalizumab. We defined clinical response as a reduction in the baseline annual exacerbation rate by half or more over the one-year period following initiation of the biologic. Baseline levels of plasma IL-13 were differentially elevated in responders versus non-responders to mepolizumab and plasma CXCL10 levels were differentially elevated in responders to omalizumab. The ratio of IL-13/TNF-α had the best sensitivity and specificity in predicting response to mepolizumab and CXCL10/CCL17 to omalizumab, and these performed better as predictive biomarkers of response than BEC and IgE. Cytokines and chemokines associated with airway eosinophilia, allergic inflammation, or Th2 inflammation, such as IL-13 and CXCL10, may be better predictors of clinical response to mepolizumab and omalizumab, than IL-5 or IgE, the targets of mepolizumab and omalizumab.

Adult-onset asthma, allergy, and aspirin hypersensitivity associate with self-reported food avoidance.

Background: The adoption of avoidance diets by adult-onset asthmatics has not previously been studied. We hypothesized that avoidance diets would associate with adult-onset asthma, allergy, and aspirin-exacerbated respiratory disease (AERD). Methods: A total of 1247 subjects with adult-onset asthma (age range: 31-91) from the Finnish national registry, and age- and sex-matched controls (n = 1970) participated in a questionnaire study in 1997. We estimated the association between asthma/allergy/AERD and avoidance diets, adjusting for potential confounding factors and validated the results in two retrospective cohorts of 5080 rhinitis/rhinosinusitis patients and 167 AERD patients from 2019 to 2020. Results: The presence of asthma positively associated with adoption of any avoidance diet (adjusted OR [CI95%] 1.24 [1.02-1.51], p = 0.029) as did allergic disease and self-reported AERD within the asthmatic group (1.79 [1.29-2.48], p = 0.001 and 1.69 [1.15-2.49], p = 0.007, respectively). Asthmatics and allergic asthmatics were more likely to report avoidance of fish, fruits and vegetables, and spices (p ≤ 0.03) compared to controls and non-allergic asthmatics. The adjusted OR for multiple diets among AERD patients was 2.57 [1.34-4.95] p = 0.005. In the validation, 26.2% of the allergic asthmatics and 10.8% of AERD patients had documented avoidance diets. Conclusions: Our study shows a positive association between avoidance diets and adult-onset asthma, and with allergic disease or AERD within asthmatic patients. Although we lack information on the reason patients chose to observe a specific diet, our results reinforce the importance of asking patients about their diet and if needed, giving dietary advice for adult asthma patients to help them avoid the adoption of unnecessarily restrictive diets.

A nasal cell atlas reveals heterogeneity of tuft cells and their role in directing olfactory stem cell proliferation.

The olfactory neuroepithelium serves as a sensory organ for odors and forms part of the nasal mucosal barrier. Olfactory sensory neurons are surrounded and supported by epithelial cells. Among them, microvillous cells (MVCs) are strategically positioned at the apical surface, but their specific functions are enigmatic, and their relationship to the other specialized epithelial cells is unclear. Here, we establish that the family of MVCs comprises tuft cells and ionocytes in both mice and humans. Integrating analysis of the respiratory and olfactory epithelia, we define the distinct receptor expression of TRPM5+ tuft-MVCs compared with Gɑ-gustducinhigh respiratory tuft cells and characterize a previously undescribed population of glandular DCLK1+ tuft cells. To establish how allergen sensing by tuft-MVCs might direct olfactory mucosal responses, we used an integrated single-cell transcriptional and protein analysis. Inhalation of Alternaria induced mucosal epithelial effector molecules including Chil4 and a distinct pathway leading to proliferation of the quiescent olfactory horizontal basal stem cell (HBC) pool, both triggered in the absence of olfactory apoptosis. Alternaria- and ATP-elicited HBC proliferation was dependent on TRPM5+ tuft-MVCs, identifying these specialized epithelial cells as regulators of olfactory stem cell responses. Together, our data provide high-resolution characterization of nasal tuft cell heterogeneity and identify a function of TRPM5+ tuft-MVCs in directing the olfactory mucosal response to allergens.

Follow-up to Adolescence after Early Peanut Introduction for Allergy Prevention.

BACKGROUND: A randomized trial demonstrated consumption of peanut from infancy to age 5 years prevented the development of peanut allergy. An extension of that trial demonstrated the effect persisted after 1 year of peanut avoidance. This follow-up trial examined the durability of peanut tolerance at age 144 months after years of ad libitum peanut consumption. METHODS: Participants from a randomized peanut consumption trial were assessed for peanut allergy following an extended period of eating or avoiding peanuts as desired. The primary end point was the rate of peanut allergy at age 144 months. RESULTS: We enrolled 508 of the original 640 participants (79.4%); 497 had complete primary end point data. At age 144 months, peanut allergy remained significantly more prevalent in participants in the original peanut avoidance group than in the original peanut consumption group (15.4% [38 of 246 participants] vs. 4.4% [11 of 251 participants]; P<0.001). Participants in both groups reported avoiding peanuts for prolonged periods of time between 72 and 144 months. Participants at 144 months in the peanut consumption group had levels of Ara h2-specific immunoglobulin E (a peanut allergen associated with anaphylaxis) of 0.03 ± 3.42 kU/l and levels of peanut-specific immunoglobulin G4 of 535.5 ± 4.98 µg/l, whereas participants in the peanut avoidance group had levels of Ara h2-specific immunoglobulin E of 0.06 ± 11.21 kU/l and levels of peanut-specific immunoglobulin G4 of 209.3 ± 3.84 µg/l. Adverse events were uncommon, and the majority were related to the food challenge. CONCLUSIONS: Peanut consumption, starting in infancy and continuing to age 5 years, provided lasting tolerance to peanut into adolescence irrespective of subsequent peanut consumption, demonstrating that long-term prevention and tolerance can be achieved in food allergy. (Funded by the National Institute of Allergy and Infectious Diseases and others; ITN070AD, ClinicalTrials.gov number, NCT03546413.).