Journal of Allergy and Clinical Immunology

Background: Asthma is a heterogeneous inflammatory airway disease traditionally classified into T2 high (eosinophilic) and T2 low inflammatory phenotypes. Fractional exhaled nitric oxide (FeNO) is commonly used as a biomarker of T2 inflammation, although nitric oxide also regulates monocyte maturation and T cell polarization. We hypothesized that FeNO identifies distinct systemic immune phenotypes in asthma. Methods: Peripheral immune cell subsets were characterized using OMIP - 69, a 40 - color high dimensional immunophenotyping panel encompassing innate and adaptive immune populations. Adults with asthma and healthy controls underwent peripheral blood immunophenotyping. FeNO was dichotomized at 25 ppb (FeNO - high [&ge;] 25 vs FeNO - low <25). Immune-cell subset proportions were summarized as medians (IQRs) and compared using the Wilcoxon rank-sum test. Logistic regression was used to evaluate associations between immune subsets and FeNO status. Results: Eighteen participants with asthma and seven healthy controls were enrolled. Asthmatic participants had higher BMI than healthy controls (median [IQR] asthma: 35.1 [28.9 - 37.7] vs healthy: 25.4 [22.6 - 26.7] kg/m2; p=0.003), although demographics were otherwise similar. Among asthmatics, 10 participants had FeNO - low asthma, and eight had FeNO - high asthma. FeNO - high asthma demonstrated increased classical monocytes (CD14++CD16 -) and compared with healthy controls (p=0.027), whereas FeNO - low asthma more closely resembled healthy controls. Intermediate monocytes (CD14++CD16+) were increased in FeNO - high versus FeNO - low (p= 0.08); a similar association was noted for classical monocytes (p = 0.13). In contrast, CCR7+ TCR; T - cells were significantly enriched in FeNO - low asthma (p=0.002). Logistic regression demonstrated positive associations between high - FeNO and classical monocytes (OR 16.06, 95% CI 1.56 - 1304.69; p=0.007) and intermediate monocytes (OR 4.19, 1.22 - 132.30; p=0.017), whereas CCR7+ {gamma} {delta} T - cells were negatively associated with high FeNO (OR 0.06, 0.00 - 0.47; p=0.001). Conclusions: Distinct systemic immune signatures identified by high-dimensional cytometry support the existence of biologically divergent FeNO - defined asthma endotypes and may inform future biomarker-driven approaches to patient stratification and precision therapy.

Background: Approximately 30% of the North American population are affected by seasonal or perennial rhinitis. Allergens from cats are common triggers of allergic rhinitis. Importantly, cat allergic rhinitis (cat-AR) is a major risk factor for more severe allergic diseases, including asthma. Current therapies rarely achieve full symptom control and development of novel therapeutics is constrained by the lack of physiologically relevant preclinical models. Objective: Establishment of a clinically-informed mouse model of cat allergen exposure in humans. Methods: Controlled human exposure was performed using airborne natural cat dander (CD) in a validated environmental exposure facility. Nasal immune cells and IgE concentrations in serum and nasal samples were assessed. In mice, we established a 14-day intermittent intranasal sensitization and challenge protocol using the same CD allergens. Clinical signs in mice were objectively quantified using AI-based video detection. Cellular changes in the nose were assessed with level-specific, spatial resolution. Lastly, systemic sensitization was confirmed through serum IgE and intradermal ear challenge. Measurements and Main Results: Following CD exposure, cat-allergic participants displayed increased nasal symptoms and eosinophil influx. CD-sensitized mice recapitulated key clinical features, including increased nasal rubbing, elevated nasal immune cell infiltration, and systemic sensitization. Importantly, spatial investigation of the cellular changes revealed major changes in the turbinate and olfactory regions of the nose. Conclusions: This novel mouse model provides a translationally valuable platform for investigating local and systemic mechanisms of cat-AR. It will serve for mechanistic and therapeutic evaluations with the goal of improving clinical translation and therapeutic precision.

Prediction models for asthma remission in school-age are lacking, limiting clinicians' ability to tailor follow-up. Most prediction tools focus on pre-school diagnosis or require lung function testing. We developed and validated a simple, history-based clinical prediction tool for asthma remission. We analyzed prospective data from the Swiss Paediatric Airway Cohort (SPAC), including 1860 children (aged 5-16 years) with physician-diagnosed asthma. We derived asthma remission predictors from parental questionnaires capturing demographics, symptoms, triggers, and family history. We defined clinical remission at 2-3 years following asthma diagnosis, as absence of wheeze and inhaler use during the past 12 months. We developed the model using LASSO regression with multiple imputations for missing data, and assessed its performance by area under the curve (AUC), Hosmer-Lemeshow (HL) test, and calibration plots. We then derived a simplified score and validated it in the German All-Age Asthma Cohort (ALLIANCE). From 12 candidate variables, the final score retained: sex, wheeze frequency, night-time awakening, exercise-induced wheeze, pollen-triggered wheeze, animal-triggered wheeze, maternal asthma, and paternal asthma. The score demonstrated moderate discrimination in the development cohort (AUC 0.71) and maintained discriminative ability in the external validation (AUC 0.71). This practical, prognostic tool for asthma remission based only on clinical history, allows clinicians to identify children who have lower chances for remission, enabling their closer monitoring.

Background: Moderate-to-severe asthma affects 15-30% of asthma patients, but accounts for over 50% of healthcare costs and disproportionate morbidity. However, the genetic mechanisms underlying moderate-to-severe versus mild asthma remain poorly understood. Methods: We performed separate pooled multi-ancestry GWAS of mild (N = 14,372) and moderate-to-severe asthma (N = 7,096) versus non-asthma controls (N = 28,816) among adult participants in the NIH All of Us Research Program (version 8). European, African, and Latino/admixed ancestry-specific GWAS were combined using fixed-effect meta-analysis. Lung expression quantitative trait loci (eQTL) and pathway analyses were performed to identify candidate genes and biological pathways across asthma phenotypes. Results: Mild and moderate-to-severe asthma shared susceptibility loci at IL1RL1, IKZF3, and the GTF3AP1-IL33, GTF3AP1-RANBP6, LINC02757-EMSY and HLA-DRB1-HLA-DQA1 regions. Shared lung eQTLs implicated IL18R1, IL18RAP, HLA genes, IL33, LRRC32, GRB7, MIEN1 and GSDMB. In contrast, the phenotypes exhibited distinct genetic architectures. Mild asthma was characterized by broader HLA class II signals and associations at SMAD3 and GSDMB, with enrichment of antigen presentation, T-helper cell differentiation, and TGF-{beta} regulation, consistent with adaptive immune mechanisms. Moderate-to-severe asthma was characterized by WDR36 and PTCH1, with lung eQTLs implicating TSLP, CAMK4, and FANCC. Pathway analysis identified enrichment of IL-13, IL-6, and IL-10 production, myeloid leukocyte differentiation, and oxidative stress responses, consistent with innate inflammation and pathways implicated in steroid resistance. The IL33 signals showed a severity-gradient effect, with stronger associations in moderate-to-severe asthma. Conclusion: Mild and moderate-to-severe asthma exhibit shared and distinct genetic architectures that support existing biologic targets and suggest novel therapeutic candidates.

Background. Polygenic risk scores (PRS) capture inherited susceptibility to asthma, whereas methylation risk scores (MRS) may reflect disease-associated epigenetic variation. We assessed whether these scores differ in patients requiring biologic therapy and whether MRS change after mepolizumab initiation. Methods. Cross-sectional analyses in the GEMAS study included 699 participants with genotype data (428 with asthma, 271 controls) and 668 with blood DNA methylation data (408 with asthma, 260 controls). We evaluated 35 existing asthma PRS and derived six MRS from published epigenomic asthma studies. Longitudinal MRS changes after mepolizumab initiation were assessed in 16 GEMAS patients and were replicated in 20 patients from the MEGA study. Results. Twenty-eight PRS differentiated biologic-treated patients from controls (areas under the curve [AUC], 0.68-0.75), but none distinguished biologic-treated and non-treated patients after multiple-testing correction. MRS was higher in asthma without biologic than in controls (odds ratio [OR], 1.64; 95% CI, 1.34-1.99) and lower in biologic-treated than in asthma without biologic patients (OR, 0.54; 95% CI, 0.35-0.81). MRS did not differ significantly between biologic-treated patients and controls. Following mepolizumab initiation, MRS decreased at 6 and 12 months in GEMAS (p=4.81x10-5 and p=2.40x10-5, respectively). The 6-month decrease was also observed in MEGA (p=3.25x10-9). MRS epigenetic markers were predominantly hypermethylated, opposite to their described pattern in asthma risk. Conclusions. Asthma PRS did not differ significantly between biologic-treated and non-biologic-treated patients, but asthma MRS were lower in biologic-treated patients. The MRS decreased after mepolizumab initiation in two independent cohorts, consistent with a reversal of asthma-associated epigenetic patterns.

Background: GINA-based clinical assessment of asthma control provides limited insight into the molecular mechanisms driving disease progression and treatment response. Circulating microRNAs (miRNAs) are implicated in immune regulation and airway remodeling, but their relationship to longitudinal, treatment-specific asthma control is not well characterized. We aimed to identify treatment-specific miRNAs associated with longitudinal asthma control and evaluate their ability to discriminate well-controlled from uncontrolled asthma. Methods: Baseline serum miRNA sequencing data from 491 children in the Childhood Asthma Management Program (CAMP), a randomized trial of budesonide versus placebo, were analyzed, with GINA-based composite symptom scores assessed at baseline and 2, 4, 8, and 12 months. Cumulative link mixed models were fitted across 266 miRNAs to identify associations with longitudinal ordinal asthma control, adjusting for time, baseline status, and treatment. Random Forest classifiers were trained within each treatment group using Group K-Fold cross-validation. Pathway enrichment of validated miRNA targets was performed with DAVID. Results: In the budesonide group, hsa-miR-1224-5p was associated with lower symptom severity and hsa-miR-199a-3p|hsa-miR-199b-3p with higher severity; both associations persisted at 12 months. The placebo group showed a broader pattern, with ten miRNAs associated with symptoms. Random Forest classifiers achieved mean AUC of 0.776 (budesonide) and 0.714 (placebo) for 12-month control status. Budesonide-associated targets were enriched for glucocorticoid-responsive and MAPK/Ras signaling, while placebo-associated targets showed broad enrichment for general regulatory processes. Conclusion: Treatment-specific circulating miRNAs distinguish asthma control over time and implicate distinct signaling pathways, supporting their potential as complementary molecular markers for asthma monitoring in children.

Rationale Airway remodelling (AR) contributes to airflow limitation and poor symptom control in severe asthma. While anti-IL-5 therapy improves clinical outcomes in severe asthma, the cellular and molecular mechanisms underlying its effects on AR remain incompletely understood. Objectives. To determine whether IL-5 blockade directly modulates airway epithelial biology and contributes to attenuation of AR in severe asthma with eosinophilia (SAE). Methods. Patients with SAE underwent bronchoscopy before and after 24 weeks of anti-IL-5 therapy. Paired bronchial brushings (n=12) were analysed using single-cell RNA-sequencing. Histological features of AR were assessed in paired bronchial biopsies (n=16). Functional effects of IL-5 were investigated using wound healing assays in differentiated air-liquid interface (ALI) cultures. Measurements and Main Results. Anti-IL-5 treatment improved clinical outcomes without altering airway epithelial cellular composition. Differential gene expression was predominantly restricted to bronchial ciliated epithelial cells, which expressed IL5RA. ALI cultures showed IL-5R protein. Anti-IL-5 therapy induced a transcriptional signature in ciliated cells that opposed IL-5-responsive genes. Pseudotime analyses demonstrated preserved epithelial differentiation trajectories but altered programmes related to mucus regulation and ion transport. Cell-cell communication analyses revealed decreased T2-inflammatory processes alongside enrichment of epithelial repair and barrier integrity processes after treatment. Functionally, IL-5 directly impaired epithelial wound repair in ALI cultures. Histological assessment demonstrated increased epithelial E-cadherin expression and reduced sub-basement membrane thickness, extracellular matrix deposition and goblet cell hyperplasia in bronchial biopsies. Conclusions. IL-5 blockade modulates epithelial biology at transcriptional, functional and structural levels in SAE and is associated with improved epithelial integrity and reduced features of AR.

Asthma severity and immune responses are regulated by circadian rhythms, yet the role of circadian timing in fungal allergen-induced airway inflammation remains poorly defined. Alternaria alternata, a clinically relevant fungal allergen, is strongly associated with severe asthma exacerbations and persistent airway dysfunction. Using a preclinical mouse model, we investigated whether pulmonary responses to Alternaria exposure are influenced by time of day and sex. We demonstrate that Alternaria induces allergic airway inflammation, airway hyperresponsiveness (AHR), and epithelial barrier disruption in a circadian- and sex-dependent manner. Female mice exhibited enhanced eosinophilic, neutrophilic, interstitial macrophage, and dendritic cell infiltration predominantly at Zeitgeber Time 0 (ZT0), whereas males showed stronger inflammatory responses at ZT12. Alternaria exposure increased IL-33 release and promoted ILC2 and Th2 cell accumulation, with distinct temporal patterns between sexes. Cytokine and chemokine profiling revealed robust Th2, proinflammatory, and Th17 responses that varied with exposure time, with higher responses at ZT12 in females and ZT0 in males. Markers of tissue injury, including lactate dehydrogenase and uric acid, followed similar circadian-dependent trends. Functionally, Alternaria-exposed mice displayed greater AHR during the resting phase, particularly in males. Additionally, Alternaria disrupted epithelial junctional proteins (E-cadherin and ZO-1) and altered expression of core circadian clock proteins CLOCK, BMAL1, and REV-ERB. Mechanistically, peak inflammation coincided with enhanced STAT1, STAT3, and STAT6 activation. Collectively, these findings identify circadian timing and sex as key determinants of fungal allergen-induced airway inflammation and suggest chronotherapeutic approaches may improve asthma outcomes.

Introduction: Mast cells are central effectors of IgE-mediated allergic responses and reside in barrier tissues, where they encounter diverse environmental compounds. How naturally occurring bioactive compounds influence mast cell function under resting versus allergic conditions remains poorly defined. Methods: We compared the effects of cholera toxin, aconitine, and sennoside A on viability, degranulation, and cytokine production in murine bone marrow-derived mast cells. We then examined the acute physiological effects of oral sennoside A in an ovalbumin-induced mouse model of food allergy. Results: None of the compounds reduced mast cell viability at the concentrations tested. Sennoside A, but not cholera toxin or aconitine, induced modest degranulation in resting mast cells without increasing TNF- or IL-6 secretion. In contrast, sennoside A markedly suppressed IgE-dependent antigen-induced degranulation, TNF- and IL-6 secretion, and Il1b expression. Acute oral sennoside A induced dose-dependent diarrhea and hypothermia and increased colonic Tnfa, Il1b, Il33, and Hdc expression. In allergic mice, sennoside A attenuated allergen-induced hypothermia, reduced duodenal Tpsab1 expression, and decreased circulating total IgE, OVA-specific IgE, and OVA-specific IgG1, while increasing Il5 expression. Conclusion: Sennoside A differentially regulates mast cell responses according to activation state and attenuates features of experimental food allergy. These findings identify a previously unrecognized immunomodulatory effect of sennoside A on IgE-driven mast cell activation. However, the mechanisms and the contribution of mast cells to the in vivo phenotype remain to be defined.

Rationale: The role of DNA methylation (DNAm) markers in the upper-airway microbiome related to asthma exacerbations despite inhaled corticosteroid (ICS) treatment is unexplored. Objectives: To identify whole-blood DNAm markers associated with the upper-airway microbiome related to asthma exacerbations despite ICS treatment. Methods: We analyzed salivary, nasal, and pharyngeal microbiome in 242 asthma patients (GEMAS) for discovery. We tested associations between whole-blood DNAm at 703,505 CpGs and 21 exacerbation-related microbiome traits. Replication for the nasal microbiome was evaluated in 272 (Project Viva) and 66 (SysPharmPediA) children with and without asthma. We analyzed differentially methylated regions (DMRs), gene enrichment, associations with blood gene expression (RNA-seq, n=119), and DNAm predictors of plasma proteins. Measurements and Main Results: Whole-blood DNAm at 73 CpGs and 550 DMRs was associated with 17 exacerbation-related microbiome traits (false discovery rate [FDR]<0.05), including genes implicated in immune and inflammatory responses and the 17q12-q21 asthma locus ORMDL3. Most CpGs were associated with Campylobacter (pharyngeal) and Leptotrichia (nasal) abundance. Ten DNAm markers were replicated (p<0.05), including the corticosteroid insensitivity-related gene PTPRR associated with nasal bacterial richness. Enrichment analyses identified genes related to diabetes, obesity, smoking, TGF-{beta}, and Wnt signaling and regulated by trichostatin A, NF-{kappa}B, and the glucocorticoid receptor (FDR<0.05). The CpG cg18994033, associated with pharyngeal Tannerella, was associated with ITM2C whole-blood expression. Nine DNAm-predicted plasma proteins involved in inflammation, tissue remodeling, and TGF-{beta} signaling were associated with seven exacerbation-related microbiome traits, including Streptococcus and Selenomonas. Conclusions: Whole-blood DNAm markers implicated in inflammation, immunity, and asthma comorbidities are associated with the upper-airway microbiome linked to asthma exacerbations.

IMPORTANCE: CD4+ T helper (T) 1, T2 and T17 cells have helped identify asthma endotypes in predominantly non-Hispanic White adults. Identifying asthma endotypes in diverse subgroups should help develop personalized medicine in asthma. OBJECTIVE: To characterize asthma endotypes and their association with selected variables and asthma severity/control in adults. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional and longitudinal analyses of nasal samples from the SOL-Asthma study of Puerto Rican and Dominican adults with (cases, n=313) and without (controls, n=371) asthma in the Bronx (NY) and Chicago (IL), with replication of selected findings in 376 adults of African ancestry in CAAPA. MAIN OUTCOMES AND MEASURES: Our primary outcome was asthma endotypes identified through nasal expression of "signature genes" for 3 T2, 5 T1, and 5 T17 pathways. Multinomial logistic regression was used for the analysis of asthma endotypes (with controls as the reference outcome category) at a baseline visit, as well as for the analysis of severe asthma exacerbations (SAEs) at baseline and during a 1-year follow-up. We attempted to replicate the identified profiles in CAAPA. RESULTS: In SOL-Asthma, cases were more likely to be female, Puerto Rican, and current/former smokers, and to have physician-diagnosed COPD than controls. Five transcriptomic profiles were identified in cases: T2HIGH (n=16 [5.1%]), T1HIGH (n=71 [22.7%]), T17HIGH (n=96 [30.7%]), T1HIGH/T17HIGH (n=53 [16.9%]), and T2LOW/T1LOW/T17LOW (n=77 [24.6%]). In a multivariable analysis, Puerto Ricans were more likely to have a T17HIGH profile than Dominicans (odds ratio [OR]=2.48, 95% confidence interval [CI]=1.08-5.74) and female sex was associated with T1HIGH (OR=3.44, 95% CI=1.33-8.88), T1HIGH/T17HIGH and T2LOW/T1LOW/T17LOW profiles, while COPD was associated with profiles other than T2HIGH or T1HIGH. The T1HIGH profile was associated with [&ge;]1 SAE in the year prior to baseline and during the one-year follow-up (OR=4.31, 95% CI=1.26-14.77). Each profile had unique differentially expressed genes (DEGs), with substantial replication of the profile distribution and DEGs in CAAPA. CONCLUSIONS AND RELEVANCE: Nasal transcriptomics identified profiles corresponding to five asthma endotypes in a cohort of Puerto Rican and Dominican adults. Puerto Rican background, female sex, and physician-diagnosed COPD were associated with non-T2HIGH (T2LOW) asthma endotypes, and T1HIGH asthma was strongly associated with SAEs.

Background: Primary immune regulatory disorders (PIRDs) represent a rapidly growing group of inborn errors of immunity (IEIs) characterized by infection susceptibility, autoimmunity, inflammation, and lymphoproliferation. However, the core features of the gene-disease relationships underlying these conditions are often obscured by limitations in available published data. The Clinical Genome Resource (ClinGen) is an international collaborative effort that seeks to address this challenge for PIRDs and other monogenic diseases through a standardized framework for classifying the strength of gene-disease relationships. Objective: We sought to systematically evaluate the evidence for proposed PIRD gene-disease relationships and identify conserved phenotypic features across this heterogeneous group of disorders. Methods: Using the standardized ClinGen framework, the ClinGen PIRD Gene Curation Expert Panel (GCEP) identified potential gene-disease relationships for monogenic conditions characterized predominantly by immune dysregulation. We subsequently curated evidence relevant to these relationships, classified the strength of evidence for these gene-disease relationships, and evaluated clinical patterns among these conditions through standardized phenotyping using the Human Phenotype Ontology (HPO). Results: As of April 2026, the PIRD-GCEP has curated a total of 46 genes corresponding to 49 gene-disease relationships characterized by immune dysregulation. Of these, 28 were categorized as definitive, 2 as strong, 9 as moderate, 7 as limited, and 3 as disputed. Analysis of HPO-based phenotyping revealed 3 major phenotypic clusters corresponding to lymphoproliferation and systemic inflammation, atopic and gastrointestinal inflammation, and combined immune deficiency with autoimmunity. Conclusion: The PIRD-GCEP framework provides validated gene-disease classifications and identifies three distinct phenotypic clusters, facilitating improved diagnosis while revealing genes requiring further investigation to confirm their role in immune regulatory disorders.

Asthma is a chronic inflammatory disease affecting over 300 million people worldwide. This disease has multiple underlying etiologies, and a major endotype of asthma is characterized by cellular and molecular signatures of type 2 (allergic) inflammation. In this study we conducted bronchoscopies with airway segmental allergen challenge in allergic asthmatics to dissect airway responses to allergen. Using mass cytometry and single-cell RNA sequencing, we characterized with high resolution the airway immune landscape before and after allergen challenge and the heterogeneity present between subjects. This heterogeneity generally falls along a type 1/ type 2 axis. In type 2 high individuals, we identified allergen-reactive Th2 cells by using TCR sequences to barcode clonal T cell populations in single-cell genomic and activation-induced marker expression assays. These potentially pathogenic Th2 cell clones were present systemically and expanded following allergen challenge, connecting local lung inflammation to systemic clonal Th2 cell dynamics. Th2 cell airway ingress was coordinated with myeloid cell expression of T cell chemoattractants including CCL17 and CCL22. This study provides insight into the molecular and cellular components of allergen-induced tissue inflammation in asthma. Deeper resolution of the T cell response to aeroallergens may inform novel diagnostic and therapeutic strategies for asthma and other allergic airway diseases.

Objectives: Patients with pediatric acute-onset neuropsychiatric syndrome (PANS) frequently report pain and fatigue. While some patients experience resolution of pain and fatigue following improvement in psychiatric symptoms, others develop persistent symptoms resembling fibromyalgia. Understanding these trajectories is critical for early identification and intervention in patients at risk for chronic pain or fatigue. In this study we characterize fibromyalgia symptoms in PANS and identify predictors of symptom progression following a PANS flare. Design: Prospective observational cohort study. Setting: Stanford University Immune Behavioral Health (IBH) Clinic in Menlo Park, California, USA. Participants: 204 consecutive patients with PANS evaluated by the IBH Clinic. The average (SD) age at first neuropsychiatric deterioration was 8.2 (3.3) years. Main outcome measures: We prospectively collected data on pain, fatigue, and other fibromyalgia symptoms using the 2016 American College of Rheumatology (ACR) Fibromyalgia Survey Questionnaire (FSQ), which includes the Widespread Pain Index (WPI) and Symptom Severity Scale (SSS). For the reference standard, clinician-documented diagnoses of pain syndromes were ascertained through a retrospective review of participants' electronic medical records. We report the prevalence of these symptoms in PANS patients and controls and evaluate factors associated with time to meeting ACR fibromyalgia criteria threshold scores following clinic presentation using a Cox proportional hazards model. Results: Among 204 patients with PANS (110 boys [54%]), eighty-five (42%) met ACR fibromyalgia criteria threshold scores at least once during follow-up (95% CI at 10 years follow-up time: 60.5 [46.7-74.5]). Twenty-eight of these 85 patients (13.7% of total cohort) progressed to meet full ACR fibromyalgia criteria (95% CI at 10 years follow-up time: 24.1 [15.6-36.2]). Compared with controls, patients with PANS reported substantially elevated rates of pain, daytime fatigue, waking unrefreshed, and cognitive symptoms (brain fog). Higher scores on the WPI and SSS at presentation were associated with a higher hazard of subsequently meeting ACR fibromyalgia criteria threshold scores. Conclusions: Fibromyalgia symptoms were common in this PANS cohort, with a notable subset developing symptoms meeting full ACR fibromyalgia criteria. These findings suggest that pain and fatigue may represent post-inflammatory sequelae of PANS and may overlap mechanistically with other post-infectious conditions. Recognizing these symptom patterns may inform clinical management, development of outcome measures, and future clinical trials in these patients, as well as support investigation into shared neuroimmune mechanisms underlying post-infectious pain and fatigue syndromes.

INTRODUCTION: Asthma has been associated with obesity in both adults and children. We investigated the association between longitudinal BMI trajectories and asthma at ages 8-9, 12-13, and 16-17 years in a UK cohort of White and South Asian children and adolescents. METHODS: We analysed data from the Leicester Respiratory Cohorts, population-based cohort studies that recruited 0-4-year-old children in 1990 (N = 1650) and 1998 (N = 8700) and followed them up until 2010. Outcome data on asthma came from postal questionnaires throughout infancy, childhood, and adolescence. BMI data came from birth records, well-child visits, questionnaires, and a clinical study visit. We used Group-based trajectory modelling to identify distinct BMI trajectories and used multivariable logistic regression to investigate the association with asthma. RESULTS: Out of 10,350 participants in the Leicester Respiratory Cohorts, we were able to model BMI trajectories for 5571 (54%); 1801 (17%) had information on asthma at 8-9 years of age, 1269 (12%) at 12-13 years, and 575 (6%) at 16-17 years. We identified five BMI trajectories: stable normal BMI (47%), persistent low BMI (30%), early overweight resolving (8%), childhood onset obesity (4%) adolescent onset overweight (11%). The persistent low BMI trajectory was associated with lower odds for asthma at age 8-9 years (0.56 [0.37-0.83]) and 12-13 years (0.38 [0.22-0.63]). Early overweight resolving was very similar to the reference stable normal BMI. The childhood onset obesity trajectory was associated with higher odds for asthma at 16-17 years (5.58 [1.35-24.40]). The adolescent onset overweight trajectory was not associated with asthma. When analysed separately, boys and girls and children of European and South Asian ancestry showed similar associations. CONCLUSION: This study strengthens the current understanding of obesity as a contributing factor in asthma development and highlights that early intervention and management of overweight and obesity in childhood, to achieve a normal BMI, may prevent secondary health impairments such as asthma.

Background: Five biologics target sequential nodes of the type 2 (T2) inflammatory axis in severe asthma and have each been anecdotally linked to eosinophilic or paradoxical inflammatory adverse events. Whether these reflect a class effect or drug-specific signatures is untested. Methods: We performed a case-noncase disproportionality analysis of FAERS, 2022-2024. Asthma-indication reports naming tezepelumab, dupilumab, mepolizumab, benralizumab, or omalizumab as primary suspect were compared against the pooled other four (active-comparator design) across 7 pre-specified eosinophilic, vasculitic (including EGPA), cutaneous, and ocular outcomes. A signal was robust if the reporting odds ratio (ROR) 95% CI lower bound exceeded 1 and a Bayesian criterion was also met. Results: Among 50,360 reports (dupilumab n=29,652; mepolizumab n=8,846; omalizumab n=5,484; benralizumab n=4,372; tezepelumab n=2,006), benralizumab showed robust signals for EGPA (ROR 5.06), vasculitis (ROR 4.60), and peripheral eosinophilia (ROR 1.80). Mepolizumab showed a robust vasculitis signal (ROR 1.85); its similarly sized EGPA association narrowly missed the robustness criterion despite significance after correction for multiple testing. Dupilumab showed no EGPA/vasculitis excess but a robust ocular-inflammation signal (ROR 7.81). Tezepelumab and omalizumab showed no robust signal in any domain. EGPA/vasculitis onset occurred earlier after dupilumab (median 20-44 days) than anti-IL-5-axis agents (median 195-550 days; p[&le;]0.012); mepolizumab's signal did not reproduce over the full 2015-2024 window (calendar-time confounding). Conclusion: FAERS active-comparator analysis reveals drug-specific, not class-uniform, adverse-event reporting patterns: anti-IL-5-axis agents disproportionately report EGPA/vasculitis, and dupilumab disproportionately reports ocular inflammation with markedly earlier onset. These hypothesis-generating signals cannot establish causality and require confirmation through case-level or comparative pharmacoepidemiological studies.

BackgroundAsthma exacerbations are caused by dysregulated cellular interactions between airway and immune cell populations. Circulating microRNAs (miRNAs) are potential biomarkers for asthma exacerbations; however, their target airway cells remain poorly defined. ObjectiveTo identify the cell types that are regulated by the circulating microRNAs linked to asthma exacerbations and the extent to which the cells are regulated by miRNAs. MethodsWe integrated a curated panel of exacerbation-associated circulating miRNAs with single-cell RNA sequencing (scRNA-seq) profiles from induced sputum of 16 asthma patients and 8 healthy controls. Experimentally validated miRNA-target interactions were combined with cell-type-specific differential expression. Elastic Net regression and SHAP analysis quantified gene-level regulatory contributions, yielding a composite Regulation Strength metric. Findings were validated against four independent GEO datasets. ResultsImmune cells, including monocytes, dendritic cells, and macrophages, demonstrated the strongest statistically significant miRNA regulatory signals, in contrast to airway epithelial cells.hsa-miR-222-3p showed opposing regulatory effects in mature versus alveolar macrophages, indicating differentiation-state-dependent activity, while B_Plasma cells showed no detectable regulatory effect from any miRNA tested. Independent GEO validation confirmed higher expression of protective miRNAs (hsa-miR-126-3p, hsa-miR-146b-5p) in healthy individuals, consistent with prior CAMP cohort associations. ConclusionCirculating miRNAs show cell-type-specific regulatory activity, strongest in monocytes, dendritic cells, and macrophages. hsa-miR-222-3p showed opposing regulatory directions between macrophage subtypes, while B_Plasma cells showed no effect, validated across independent GEO cohorts.

Background: Sex differences in asthma are well recognized, but sex-associated airway DNA methylation (DNAm) patterns and their relationships with gene expression remain incompletely characterized. We therefore conducted cis- and trans-expression quantitative trait methylation (eQTM) analyses using sex-stratified and CpG-by-sex interaction models. Methods: We analyzed nasal airway epithelial DNAm and transcriptomic data from 298 participants in the CAAPA discovery cohort. Asthma-associated differentially methylated CpGs (DMCs) were identified using sex-combined and sex-stratified models. Cis- and trans-eQTM analyses were then performed in participants with asthma using sex-combined, sex-stratified, and CpG-by-sex interaction models. To prioritize asthma-associated regulatory relationships, eQTMs that were also significant in non-asthmatic controls were excluded from downstream analyses. Replication in an independent bronchial epithelial cohort was defined by concordant effect direction and P < 0.05. Replicated targets underwent pathway and network analyses. Findings: Asthma-associated DMCs were predominantly hypomethylated in females and hypermethylated in males. Among trans-eQTMs, 379 associations were shared across all four models, whereas the majority were model-specific, indicating extensive sex-dependent regulatory architecture. We replicated 3, 1, 9, and 2 cis-eQTMs and 96, 84, 216, and 41 trans-eQTMs in the sex-combined, female-stratified, male-stratified, and interaction models, respectively. Sex-combined targets implicated innate immune and inflammatory signaling (TNF, IRF8); female-stratified targets implicated cytoskeletal remodeling, focal adhesion, and PI3K-Akt signaling (ITGA10); male-stratified targets implicated transcriptional regulation and post-translational modification (MOV10, HDAC7, CSF1, KAT2A); and interaction targets implicated lipid-mediator metabolism and inflammatory signaling and resolution (CYP2C9, LTB4R, CCL19). Our sex-dependent analyses showed that the majority of eQTMs resided within the trans-regulatory architecture, suggesting that sex-dependent gene expression differences are associated predominantly with trans rather than cis regulatory mechanisms. Pathway analyses revealed enrichment of innate immunity in the sex-combined model, structural remodeling in females, transcriptional control in males, and inflammatory resolution in the sex-interaction model. Interpretation: Sex-specific and sex-dependent airway methylation-expression associations were largely undetected by sex-combined analysis. Sex-aware analytical models may help resolve epigenetic mechanisms underlying sex differences in asthma biology.

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by skin barrier dysfunction and immune activation. Antioxidants such as sulforaphane (SFN) have shown benefit in mouse models of AD and are being explored as topical therapies. Objectives: We investigated the immune mechanisms through which topical SFN affects skin pathology in the MC903-induced AD-like dermatitis. Materials and Methods: We used flow cytometry to characterize skin immune cell infiltration, activation, and cytokine production. Genetic and pharmacological loss-of-function studies were used to determine the contribution of specific immune cell populations and signaling pathways. Results: Although topical application of SFN by itself caused no skin inflammation, it exacerbated MC903-induced dermatitis. Disease exacerbation was accompanied by robust T cell infiltration to skin, particularly by CD8 + T cells, and was significantly attenuated in TCR{beta}-deficient and {beta}2 m-deficient mice. In addition to a Type 2 inflammatory response, the skin CD8 + T cells exhibited a Type 1 inflammatory program characterized by IFN{gamma} production that was largely absent among CD4 + T cells. Loss of IFN{gamma} signaling attenuated SFN-mediated disease exacerbation. Blocking lymphocyte egress with FTY720 markedly reduced the SFN-induced increase in skin CD8 + T cells, suggesting that the increase was primarily dependent on recruitment from the periphery rather than local expansion. Conclusion: Topical SFN worsens MC903-induced dermatitis through a mechanism involving the peripheral accumulation of IFN{gamma}-producing CD8 + T cells in skin. These findings demonstrate that SFN can exert context-dependent pro-inflammatory effects and underscore the need to evaluate its effects carefully when considering topical medical or cosmetic applications.

De novo mutations underlying early-onset systemic autoinflammatory diseases have identified key regulators of innate immunity, including pathways that drive IL-1-mmediated inflammation. Here we describe two unrelated girls presenting in infancy with systemic inflammation and sterile lung abscesses, who harbor the same de novo gain-of-function mutation in dysferlin (DYSF; p.P1449L) Myeloid expression of DYSF P1449L enhances COP-I binding, promotes dysferlin retention in the ER-Golgi, and disrupts vesicle trafficking and membrane homeostasis. Dysferlin-mutant monocytes and M2-like macrophages exhibit ectopic perinuclear NLRP3 inflammasome activation, increased IL-1{beta} production, and inflammatory cell death. Mutant M2-like macrophages further display defects in membrane expansion, exocytosis, efferocytosis, and debris clearance, promoting neutrophil recruitment and DAMP-signal amplification that culminate in sterile abscess formation. These findings identify dysferlin as a regulator of membrane homeostasis in myeloid cells, establish defective membrane-stress adaptation as trigger of NLRP3 inflammasome activation, and define a novel IL-1 mediated autoinflammatory disease caused by gain-of-function DYSF mutations.