Peanut-specific IgG subclasses as biomarkers of peanut allergy in LEAP study participants.

Antigen-specific IgG2 and IgG3 are rarely measured in food allergy clinical trials despite known function in preventing mast cell and basophil activation. Our objective was to determine whether measuring peanut-specific IgG2 and IgG3 levels would correlate with peanut allergy status. Peanut-specific IgG subclasses were measured via ELISA assays in Learning Early About Peanut allergy (LEAP) trial participants at 5 years of age and were correlated with peanut allergy vs peanut sensitization vs non-peanut allergic and peanut consumption vs peanut avoidance. Peanut-specific IgG1, IgG2, IgG3, and IgG4 levels were significantly different between participants with peanut allergy vs peanut sensitization vs non-peanut allergic, and a multivariate logistic regression model and stepwise selection found that IgG1 most closely associated with peanut allergy status. Similarly, all subclasses differentiated those consuming vs those avoiding peanut, but subsequent modeling found that IgG4 most closely associated with consumption status. Amongst the peanut-specific IgG subclasses, IgG1 was the best biomarker for peanut allergy, while IgG4 was the best biomarker for peanut antigen exposure in this highly atopic cohort. Our study did not find added value from evaluating peanut-specific IgG 2 and 3 as biomarkers of peanut allergy, although they did correlate with peanut allergy. Subsequent studies should assess the value of adding IgG subclasses to multivariate models predicting peanut allergy status.

Determinants of Persistence and Recovery of Chronic COVID19 Chemosensory Dysfunction.

BACKGROUND: In 2-4% of patients, COVID19 chemosensory dysfunction (CSD) persists beyond six months, accounting for up to 4 million people in the US. The predictors of persistence and recovery require further exploration. OBJECTIVE: To define the predictors of recovery and assess the quality of CSD in registry subjects with self-reported persistent smell and taste dysfunction after COVID19. METHODS: COVID19 CSD participants (n=408) from the four major waves of the pandemic completed questionnaires at four time points between 2021 and 2023, assessing demographics, sinonasal symptoms and self-assessed recovery. Objective measurements of smell (UPSIT) and taste (BWETT) were performed on a sub-cohort (n=108). RESULTS: In this chronic CSD cohort, the average symptom duration was 24±5 months but 70% those who contracted COVID19 in 2020 have ongoing dysfunction. Phantosmia and dysgeusia were most prevalent in the early waves of COVID19, while most participants reported disrupted ability to distinguish scents and flavors and undulating chemosensory function. Subjects reported low incidence of subjective sinonasal symptoms but high prevalence of sleep and mood disturbance. Cigarette phantom smells were predictive of persistence of CSD. Conversely, self-reported environmental allergies were predictive of recovery and dust mite allergies, specifically, were negative predictors of cigarette phantom smells. Finally, no treatment resolved CSD, but nasal steroids were reported effective by recovered CSD subjects. Objective measures of both smell and taste were significantly reduced in chronic CSD compared to controls. CONCLUSIONS: Chronic COVID19 CSD is a syndrome resistant to standard anti-inflammatory therapy. Pre-existing environmental allergies and hypertension predict recovery, while cigarette smoke phantosmia predicts persistence.

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.

Mast cells control lung type 2 inflammation via prostaglandin E2-driven soluble ST2.

Severe asthma and sinus disease are consequences of type 2 inflammation (T2I), mediated by interleukin (IL)-33 signaling through its membrane-bound receptor, ST2. Soluble (s)ST2 reduces available IL-33 and limits T2I, but little is known about its regulation. We demonstrate that prostaglandin E2 (PGE2) drives production of sST2 to limit features of lung T2I. PGE2-deficient mice display diminished sST2. In humans with severe respiratory T2I, urinary PGE2 metabolites correlate with serum sST2. In mice, PGE2 enhanced sST2 secretion by mast cells (MCs). Mice lacking MCs, ST2 expression by MCs, or E prostanoid (EP)2 receptors by MCs showed reduced sST2 lung concentrations and strong T2I. Recombinant sST2 reduced T2I in mice lacking PGE2 or ST2 expression by MCs back to control levels. PGE2 deficiency also reversed the hyperinflammatory phenotype in mice lacking ST2 expression by MCs. PGE2 thus suppresses T2I through MC-derived sST2, explaining the severe T2I observed in low PGE2 states.

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.

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.).

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.

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.

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.

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.

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.

Should Biologics Be Used Before Aspirin Desensitization in Aspirin-Exacerbated Respiratory Disease?

There has been a paradigm shift in the management of aspirin-exacerbated respiratory disease (AERD). It started in 2015 when the first biologic was Food and Drug Administration (FDA) approved for severe eosinophilic asthma. Thus, there emerged a new era in the treatment of patients with type 2-mediated airway diseases. This has led to an increasing number of options for patients, undoubtably a great thing, but has left clinicians without a clear answer for how to balance the therapies that exist for AERD, what to recommend for treatment, and how to best assess the benefits and risks of each therapy. This paper aims to explore these benefits and risks, and to provide a roadmap for future studies.

Nasal polyp antibody-secreting cells display proliferation signature in aspirin-exacerbated respiratory disease.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) causes nasal obstruction and olfactory dysfunction. Aspirin-exacerbated respiratory disease (AERD) is the triad of CRSwNP, asthma, and respiratory reactions to COX-1 inhibitors. Patients with AERD have elevated nasal IL-5 levels and high numbers of antibody-secreting cells (ASCs), including plasma cells and plasmablasts, in their polyp tissue; in addition, their nasal polyp (NP) IgE levels are correlated with disease severity and recurrence of nasal polyposis. OBJECTIVE: We sought to explore differences in the transcriptomic profile, activation markers, and IL-5Rα expression and function of NP ASCs from patients with AERD and CRSwNP. METHODS: NP tissue was collected from patients with AERD and CRSwNP and digested into single-cell suspensions. NP cells were analyzed for protein expression by mass cytometry. For IL-5Rα functional studies, plasma cells were purified and cultured in vitro with or without IL-5 and analyzed by bulk RNA sequencing. RESULTS: Compared with polyp tissue from patients with CRSwNP, polyp tissue from patients with AERD contained significantly more ASCs and had increased ASC expression of IL-5Rα. ASCs from patients with AERD expressed higher protein levels of B-cell activation and regulatory markers (CD40, CD19, CD32, and CD38) and the proliferation marker Ki-67. ASCs from patients with AERD also expressed more IL5RA, IGHE, and cell cycle- and proliferation-related transcripts (CCND2, MKI67, CDC25A, and CDC25B) than did ASCs from patients with CRSwNP. Stimulation of plasma cells from patients with AERD with IL-5 induced key cell cycle genes (CCND2 and PTP4A3), whereas IL-5 stimulation of ASCs from patients with CRSwNP induced few transcriptomic changes. CONCLUSION: NP tissue ASCs from patients with AERD express higher levels of functional IL-5Rα and markers associated with cell cycling and proliferation than do ASCs from patients with aspirin-tolerant CRSwNP.

Nonsteroidal anti-inflammatory drug "allergy" labeling is associated with increased postpartum opioid utilization.

BACKGROUND: Current guidelines recommend a stepwise approach to postpartum pain management, beginning with acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), with opioids added only if needed. Report of a prior NSAID-induced adverse drug reaction (ADR) may preclude use of first-line analgesics, despite evidence that many patients with this allergy label may safely tolerate NSAIDs. OBJECTIVE: We assessed the association between reported NSAID ADRs and postpartum opioid utilization. METHODS: We performed a retrospective cohort study of birthing people who delivered within an integrated health system (January 1, 2017, to December 31, 2020). Study outcomes were postpartum inpatient opioid administrations and opioid prescriptions at discharge. Statistical analysis was performed on a propensity score-matched sample, which was generated with the goal of matching to the covariate distributions from individuals with NSAID ADRs. RESULTS: Of 38,927 eligible participants, there were 883 (2.3%) with an NSAID ADR. Among individuals with reported NSAID ADRs, 49.5% received inpatient opioids in the postpartum period, compared to 34.5% of those with no NSAID ADRs (difference = 15.0%, 95% confidence interval 11.4-18.6%). For patients who received postpartum inpatient opioids, those with NSAID ADRs received a higher total cumulative dose between delivery and hospital discharge (median 30.0 vs 22.5 morphine milligram equivalents [MME] for vaginal deliveries; median 104.4 vs 75.0 MME for cesarean deliveries). The overall proportion of patients receiving an opioid prescription at the time of hospital discharge was higher for patients with NSAID ADRs compared to patients with no NSAID ADRs (39.3% vs 27.2%; difference = 12.1%, 95% confidence interval 8.6-15.6%). CONCLUSION: Patients with reported NSAID ADRs had higher postpartum inpatient opioid utilization and more frequently received opioid prescriptions at hospital discharge compared to those without NSAID ADRs, regardless of mode of delivery.

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.