Type-2 Inflammation Research Articles

Prevalence of asthma in Catalonia (Spain): a retrospective, large-scale population-based study.

Asthma epidemiology reports an estimated global prevalence of about 4.3-8.6% in adults, with last differences among geographical regions. This study analyses a more significant population of asthma patients (473,737 individuals).To study the prevalence of medical diagnosis of asthma, overall and by age, gender, and disease severity, as well as comorbidities and type 2 biomarkers, and undergo medical treatments of a retrospective population-based asthma cohort from Catalonia (Spain). Individuals with a diagnosis of asthma established by medical records at different healthcare levels (primary, hospital, and emergency) from the Catalan Health System (CHS) were included. Socio-demographic characteristics, prevalence, overall and by age and gender, disease severity, comorbidities, and biomarkers of type-2 inflammation were evaluated, together with appropriate medical treatment. The overall diagnosed asthma prevalence in the population of Catalonia was 6.3%, where patients mainly had mild asthma (5.3%) and were significantly higher in females (6.8%) than males (5.7%). By age groups, asthma was more prevalent in boys and young men adults; however, being more prevalent in females above the age of 30y. The prevalence of severe asthma was 0.4%, 42.6% had uncontrolled asthma, and a high proportion (84.2%) were under systemic corticosteroid prescription. As expected, SABAs were the most prescribed drug (62.6%), followed by systemic corticosteroids (43.3%). More than half (53.8%) of patients showed type 2 inflammation. Asthma prevalence in Catalonia is similar to other areas studied in Spain, with a high prevalence in women and of T2 asthma.

Pathophysiology of Bullous Pemphigoid: Role of Type2 Inflammation and Emerging Treatment Strategies (Narrative Review).

Bullous pemphigoid (BP) is an autoimmune blistering disease that most often affects elderly individuals and has a significant negative impact on quality of life. The disease is characterized primarily by autoantibodies to hemidesmosomal proteins BP180 and/or BP230, and an inflammatory reaction with notable features of type2 inflammation, including elevated serum IgE, increased numbers of eosinophils in lesions and peripheral blood, and elevated expression of type2 cytokines and chemokines in skin lesions. In this review, we present what is known about BP pathophysiology, including the role of type2 inflammation, and discuss how findings from studies of biologics targeting type2 immune mediators have helped to clarify the biological mechanisms driving BP pathophysiology. Future studies of these targeted therapies and others in development will help to further elucidate the mechanisms underlying BP pathophysiology and potentially provide better treatment options for patients.

Role of specific immunoglobulin-E in chronic rhinosinusitis: Its clinical relevance according to nasal challenge test

BackgroundGuidelines for chronic rhinosinusitis (CRS) propose total IgE and eosinophils as important biomarkers to identify type-2 inflammation. Despite the fact that specific IgE (sIgE) have been identified as a clinical predictor in some type-2 diseases for different clinical outcomes, its role in CRS has yet to be explored in detail. ObjetiveTo describe systemic and local sIgE in CRS and explore its possible association with clinical outcomes using nasal challenge tests (NCT). MethodsIn CRS patients, we measure total IgE, serum sIgE (SsIgE) and nasosinusal sIgE (NsIgE) against 9 allergenic sources; Der p, Der f, Blo t, Can f, Fel d, Per a, grasses, Staphylococcus enterotoxin A, and B. NCT was done using the allergen with the higher sIgE prevalence (Der p). ResultsA total of 174 patients were included. Prevalence of SsIgE was 52.8% and NsIgE 46.5%; Der p was the principal allergen for SsIgE and NsIgE. The presence of nasal polyps, asthma comorbidity, NSAID hypersensitivity, and hyposmia, were significantly associated with the presence of SsIgE and NsIgE but not with total IgE. NCT-Der p was performed in 73 CRS patients, being positive in 33 (45.2%). SsIgE have the best diagnostic accuracy (79.4%) to predict NCT results (NsIgE 67.5% total IgE 52%). ConclusionSpecific IgE is a better biomarker in CRS than total IgE. Patients with clinically relevant SsIgE have a pheno-endotype associated with different clinical outcomes. Considering the clinical relevance of SsIgE demonstrated by NCT, interventions like allergen immunotherapy in CRS must be study.

From Pathogenesis to Treatment: Targeting Type-2 Inflammation in Eosinophilic Esophagitis.

Eosinophilic esophagitis (EoE) is a chronic inflammatory disorder of the esophagus. EoE shares a common pathogenetic mechanism with other chronic disorders pertaining to the type 2 inflammatory spectrum, such as atopic dermatitis (AD), allergic rhinitis (AR), asthma, and chronic rhinosinusitis with nasal polyps (CRSwNP). The recent advancements in EoE pathogenesis understanding have unveiled new molecular targets implied within the "atopic march" picture as well as specific to EoE. These discoveries have led to the clinical evaluation of several novel drugs (monoclonal antibodies and immune modulators), specifically aimed at the modulation of Th2 inflammation. In this comprehensive review, we have focused on the subtle mechanisms of type 2 inflammatory disorders, highlighting the similarities and differences with EoE, taking a deeper look into the evolving field of biologic therapies, already approved or under current investigation.

Proton pump inhibitors modulate esophageal epithelial barrier function and crosstalk with eosinophils.

Eosinophilic esophagitis (EoE) is a chronic allergic disease characterized by esophageal dysfunction, type-2 inflammation, and esophageal eosinophilic infiltrate. While proton pump inhibitor (PPI) therapy is commonly used for EoE management, the underlying mechanism of action remains unclear. Air-liquid interface culture of esophageal epithelial cells was employed to investigate the impact of the PPI omeprazole on barrier integrity in IL-13-treated cultures. Epithelial chemokine secretion was assessed following stimulation with IL-13 and omeprazole, and the migration of eosinophils from healthy human donors was evaluated using 3 μm pore-sized transwells. A co-culture system of epithelial cells and eosinophils was employed to study chemokine secretion and eosinophil adhesion and activation markers. Omeprazole treatment in the IL-13-treated air-liquid interface (ALI) model resulted in 186 differentially expressed genes and restored barrier integrity compared to ALI treated with IL-13 alone. Omeprazole treatment reduced STAT6 phosphorylation, downregulated calpain 14, and upregulated desmoglein-1 in the IL-13-treated air-liquid interface samples. IL-13-induced upregulation of Eotaxin-3, CXCL10, and periostin, but this was downregulated by omeprazole. Further, the expression of CD11b, CD18, and CD69 was lower on eosinophils from omeprazole-treated epithelial-eosinophil co-cultures, which also had lower levels of eotaxin-3, CXCL10, CCL2, and CCL4. Omeprazole reduced the effects of IL-13 in both the epithelial air-liquid interface model and eosinophil-epithelial co-cultures, reducing barrier dysfunction, chemokine expression, and upregulation of eosinophil adhesion markers.

Impaired Coordination of the Ciliary Movement in Patients with Chronic Rhinosinusitis with Nasal Polyps: The Role of Decreased Planar Cell Polarity Protein Expression

The planar cell polarity (PCP) of epithelial ciliated cells is essential for effective mucociliary clearance (MCC) in the sinonasal mucosa. We hypothesize that MCC coordination is impaired in nasal polyp (NP) mucosae due to the suppressed expression of a series of CPLANE (ciliogenesis and planar cell polarity effector) complex proteins in chronic rhinosinusitis (CRS) patients. To investigate this hypothesis, we subjected sinonasal mucosal samples to live video recording to measure mucociliary transport velocity (MCTV) and scanning electron microscopy to evaluate surface morphology. The expression and distribution of a panel of PCP proteins, e.g., WDPCP and FUZ, were investigated in relation to inflammatory cytokine levels and clinical features. The mean MCTV of NP mucosae was significantly lower than that of the inferior turbinate mucosae. The CRS group with NPs (CRSwNP group) (n = 28) showed increased expression of IL-13 and CCL26 mRNA compared to CRS patients without NPs (n = 25) and controls (n = 30). WDPCP and FUZ mRNA levels were significantly decreased in NP mucosae compared to ethmoid sinus mucosae in CRSwNP patients. WDPCP protein distribution was reduced in the cytoplasmic region of ciliated cells in CRSwNP patients. We conclude that suppression of WDPCP in ciliated cells is responsible for the impaired MCC of nasal polyps with type-2 inflammation. This mechanism might explain the decreased clearance and the potential for worsening symptoms of CRSwNP.

Airway proteomics reveals broad residual anti-inflammatory effects of prednisolone in mepolizumab-treated asthma

BackgroundMepolizumab is an anti-interleukin-5 monoclonal antibody treatment for severe eosinophilic asthma (SEA) that reduces asthma exacerbations. Residual airway inflammation on mepolizumab may lead to persistent exacerbations. Oral corticosteroids remain the main treatment for these residual exacerbations. ObjectiveOur study aimed to explore the corticosteroid-responsiveness of airway inflammation after mepolizumab treatment to find potentially treatable inflammatory mechanisms beyond the IL-5 pathway. MethodThe MAPLE trial was a multi-centre, randomized, double-blind, placebo-controlled, crossover study of 2 weeks of high-dose oral prednisolone treatment at stable state in 27 patients treated with mepolizumab for SEA. We analysed paired sputum (n=16) and plasma (n=25) samples from the MAPLE trial using high-throughput Olink® proteomics. We also analysed additional sputum proteins using ELISA. ResultsIn patients receiving mepolizumab, prednisolone significantly downregulated sputum proteins related to type-2 inflammation and chemotaxis including IL-4, IL-5, IL-13, CCL24, CCL26, EDN, CCL17, CCL22, OX40 receptor, FCER2, and the ST2 receptor. Prednisolone also downregulated cell adhesion molecules, prostaglandin synthases, mast cell tryptases, MMP1, MMP12, and neuroimmune mediators. Neutrophilic pathways were upregulated.Type-2 proteins were also downregulated in plasma, combined with IL-12, IFN-γ, and IP-10. IL-10 and amphiregulin were upregulated. ConclusionAt stable state, prednisolone has broad anti-inflammatory effects on top of mepolizumab. These effects are heterogeneous and may be clinically relevant in residual exacerbations.

Endotyping Chronic Respiratory Diseases: T2 Inflammation in the United Airways Model.

Over the past 15 years, the paradigm of viewing the upper and lower airways as a unified system has progressively shifted the approach to chronic respiratory diseases (CRDs). As the global prevalence of CRDs continues to increase, it becomes evident that acknowledging the presence of airway pathology as an integrated entity could profoundly impact healthcare resource allocation and guide the implementation of pharmacological and rehabilitation strategies. In the era of precision medicine, endotyping has emerged as another novel approach to CRDs, whereby pathologies are categorized into distinct subtypes based on specific molecular mechanisms. This has contributed to the growing acknowledgment of a group of conditions that, in both the upper and lower airways, share a common type 2 (T2) inflammatory signature. These diverse pathologies, ranging from allergic rhinitis to severe asthma, frequently coexist and share diagnostic and prognostic biomarkers, as well as therapeutic strategies targeting common molecular pathways. Thus, T2 inflammation may serve as a unifying endotypic trait for the upper and lower airways, reinforcing the practical significance of the united airways model. This review aims to summarize the literature on the role of T2 inflammation in major CRDs, emphasizing the value of common biomarkers and integrated treatment strategies targeting shared molecular mechanisms.

Patterns of recurrence in patients with CRSwNP who underwent complete FESS.

To analyze recurrence patterns of chronic sinusitis with nasal polyposis (CRSwNP) in patients who underwent complete FESS and identify predisposing factors for different patterns of recurrence. Retrospective analysis of patients with CRSwNP who underwent complete FESS at our tertiary medical center. Recurrence patterns were classified into edema, polyp and normal endoscopy, as well as into early (within 6 months) and late recurrence. Statistical analysis to identify risk factors for recurrence included univariate, multivariate logistic regression and cox regression models. 114 patients were included with an average follow-up of 27 months. 91% were categorized as type-2 inflammation. Recurrence was observed in 65.8% of patients within a mean of 12.9 months. 46.7% had polyp recurrence while 53.3% had edema recurrence. Early recurrence was observed in 41%. Serum eosinophilia > 500 cells/uL was found to be significantly associated with recurrence (RR = 1.62, p-value = 0.046), and particularly with polyp recurrence (RR = 3.9, p-value = 0.001). No predictive factors for early recurrence were identified. Edema recurrence was managed with intranasal corticosteroids while polyp recurrence required systemic therapy including biologic therapy. In this study, two thirds of patients experienced post operative recurrence, either mucosal edema or nasal polyps, with similar frequency during an average follow up of over 2 years. Early recurrence was noted in 41% of recurrent cases. Serum eosinophils > 500 cells/uL was the only risk factor for recurrence on multivariate analysis, more accurate markers are needed for improved treatment allocation to CRSwNP patients.

Mef2d potentiates type-2 immune responses and allergic lung inflammation.

Innate lymphoid cells (ILCs) and adaptive T lymphocytes promote tissue homeostasis and protective immune responses. Their production depends on the transcription factor GATA3, which is further elevated specifically in ILC2s and T helper 2 cells to drive type-2 immunity during tissue repair, allergic disorders, and anti-helminth immunity. The control of this crucial up-regulation is poorly understood. Using CRISPR screens in ILCs we identified previously unappreciated myocyte-specific enhancer factor 2d (Mef2d)-mediated regulation of GATA3-dependent type-2 lymphocyte differentiation. Mef2d-deletion from ILC2s and/or T cells specifically protected against an allergen lung challenge. Mef2d repressed Regnase-1 endonuclease expression to enhance IL-33 receptor production and IL-33 signaling and acted downstream of calcium-mediated signaling to translocate NFAT1 to the nucleus to promote type-2 cytokine-mediated immunity.

Understanding Breathlessness Burden and Psychophysiological Correlates in Asthma

BackgroundBreathlessness is a disabling symptom, with complexity that is often under recognised and under treated in asthma. ObjectiveTo highlight the burden of breathlessness in people with severe compared with mild-to-moderate asthma and identify psychophysiological correlates of breathlessness. MethodsThis was a cross-sectional study of people with mild-to-severe asthma, who attended two in-person visits to complete a multidimensional assessment. The proportion of people with mild-to-moderate versus severe asthma who reported physically limiting breathlessness (modified Medical Research Council [mMRC] dyspnoea score ≥2) was compared. Psychophysiological factors associated with breathlessness in people with asthma were identified via a directed acyclic graph and explored with multivariate logistic regression to predict breathlessness. Results144 participants were included, of which, 74 (51%) had mild-to-moderate asthma and 70 (49%) severe asthma. Participants were predominantly female (n=103, 72%) with a median (quartile 1, quartile 3) age of 63.4 (50.5,69.5) years and body mass index (BMI) of 31.3 (26.2, 36.0) kg/m2. The proportion of people reporting mMRC ≥2 was significantly higher in those with severe- (n=37, 53%) compared with mild-to-moderate (n=21, 31%) asthma (p=0.013). Dyspnoea-12 Total (8.00 [4.75, 17.00] versus 5.00 [2.00, 11.00], p=0.037) score was also significantly higher in the severe asthma group. Significant predictors of physically limiting breathlessness were: BMI, asthma control, exercise capacity, and hyperventilation symptoms. Airflow limitation and type-2 inflammation were poor breathlessness predictors. ConclusionOver half of people with severe asthma experience physically limiting breathlessness despite treatment. Targeting psychophysiological factors, or traits, associated with breathlessness may help relieve this distressing symptom, which is of high priority to people with asthma.

Inflammatory and Autoimmune Aspects of Multisystem Inflammatory Syndrome in Children (MIS-C): A Prospective Cohort Study.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a potentially life-threatening complication of COVID-19. The pathophysiological mechanisms leading to severe disease are poorly understood. This study leveraged clinical samples from a well-characterized cohort of children hospitalized with COVID-19 or MIS-C to compare immune-mediated biomarkers. Our objective was to identify selected immune molecules that could explain, in part, why certain SARS-CoV-2-infected children developed MIS-C. We hypothesized that type-2 helper T cell-mediated inflammation can elicit autoantibodies, which may account for some of the differences observed between the moderate-severe COVID-19 (COVID+) and MIS-C cohort. We enumerated blood leukocytes and measured levels of selected serum cytokines, chemokines, antibodies to COVID-19 antigens, and autoantibodies in children presenting to an academic medical center in Connecticut, United States. The neutrophil/lymphocyte and eosinophil/lymphocyte ratios were significantly higher in those in the MIS-C versus COVID+ cohort. IgM and IgA, but not IgG antibodies to SARS-CoV-2 receptor binding domain were significantly higher in the MIS-C cohort than the COVID+ cohort. The serum levels of certain type-2 cytokines (interleukin (IL)-4, IL-5, IL-6, IL-8, IL-10, IL-13, and IL-33) were significantly higher in children with MIS-C compared to the COVID+ and SARS-CoV-2-negative cohorts. IgG autoantibodies to brain antigens and pentraxin were higher in children with MIS-C compared to SARS-CoV-19-negative controls, and children with MIS-C had higher levels of IgG anti-contactin-associated protein-like 2 (caspr2) compared to the COVID+ and SARS-CoV-19-negative controls. We speculate that autoimmune responses in certain COVID-19 patients may induce pathophysiological changes that lead to MIS-C. The triggers of autoimmunity and factors accounting for type-2 inflammation require further investigation.

Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability of Stapokibart in Healthy Volunteers and Adult Subjects with Atopic Dermatitis.

Stapokibart, a novel humanized anti-interleukin (IL)-4 receptor alpha monoclonal antibody, inhibits the signaling of IL-4 and IL-13, which are key drivers of type2 inflammation in atopic dermatitis (AD). This study aimedto assess the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of stapokibart in a randomized, double-blind, placebo-controlled single ascending dose (SAD) study and a multiple ascending dose (MAD) study. The SAD study enrolled 33healthy male adults aged 18-65years at a single center. The MAD study enrolled 39 patients with moderate-to-severe AD aged 18-70years at seven centers. Enrolled subjects were randomized to subcutaneous (SC) doses of stapokibart (75-600mg) or placebo. Serum thymus and activation-regulated chemokine (TARC) and total immunoglobulinE (IgE) were measured as PD biomarkers for stapokibart. Similar PK characteristics were observed in healthy volunteers and subjects with AD after the initial administration. Stapokibart exhibited non-linear pharmacokinetics in both types of subjects. Following single doses, the mean maximum serum concentration (Cmax) ranged from 5.3 to 63.0μg/mL, median Tmax ranged from 3.0 to 7.0days, mean terminal half-life (t1/2z) ranged from 2.39 to 7.43days, and mean apparent volume (Vz/F) ranged from 3.64 to 6.73L in healthy subjects. The mean AUC accumulation ratio was 2.29 in subjects with AD after three doses of stapokibart 300mg administered every 2weeks. The median serum total IgE and TARC levels on day43 decreased from baseline by 14.9-25.2% and 48.6-77.0%, respectively, among subjects with AD receiving three doses of stapokibart. No subjects developed grade ≥ 3 adverse events (AEs) or serious AEs or discontinued the study because of AEs. The incidence of AEs was similar between stapokibart and placebo groups. Stapokibart showed favorable pharmacokinetics, pharmacodynamics, safety, and tolerability in the SAD and MAD studies. Based on these results, phaseII and phaseIII trials of stapokibart have been performed in subjects with moderate-to-severe AD. ClinicalTrials.gov Identifier NCT06161090 (29 November, 2023), NCT04893941 (15 May, 2021).

Urinary eicosanoid levels in early life and risk of atopic disease in childhood

IntroductionEicosanoids are lipid mediators including thromboxanes (TXs), prostaglandins (PGs) and leukotrienes (LTs) with a pathophysiological role in established atopic disease. However, their role in the inception of disease is unclear. We aimed to investigate the association between urinary eicosanoids in early life and development of atopic disease. MethodsWe quantified the levels of 21 eicosanoids in urine from children from the COPSAC2010 (age 1 year, n=450) and VDAART (age 3 years, n=575) mother-child cohorts and analyzed the associations with development of wheeze/asthma, atopic dermatitis, and biomarkers of Type-2 inflammation, applying FDR5% multiple testing correction. ResultsIn both cohorts, analyses adjusted for environmental determinants showed that higher TXA2 eicosanoids in early life were associated with increased risk of developing atopic dermatitis (P<FDR5%) and Type-2 inflammation (p<0.05). In VDAART, lower PGE2 and PGI2 eicosanoids and higher isoprostanes were also associated with increased risk of atopic dermatitis (P<FDR5%). For wheeze/asthma, analyses in COPSAC2010 showed that lower isoprostanes and PGF2 eicosanoids and higher PGD2 eicosanoids at age 1 year associated with an increased risk at age 1-10 years (p<0.05), whereas analyses in VDAART showed that lower PGE2 and higher TXA2 eicosanoids at age 3 years associated with an increased risk at 6 years (P<FDR5%). ConclusionsThis study suggests that early life perturbations in the eicosanoid metabolism are present before the onset of atopic disease in childhood, which provides pathophysiological insight in the inception of atopic diseases.

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.

Enhanced quality of documentation for biologic therapy of chronic rhinosinusitis through structured digital reporting and indication?

With targeted inhibition of type2 inflammation, biologics represent the standard add-on therapy for inadequately controlled severe forms of chronic rhinosinusitis with nasal polyps (CRSwNP). Despite standardization with paper-based checklists, the documentation of medical history and current findings pertinent to indication criteria are asignificant challenge for physicians. Through development of an application based on structured reporting, the current study aimed to improve documentation quality and simplify the decision-making process. Previously available paper checklists served as a comparison. For this study, adigital incremental tool was programmed to record current findings and check for fulfilment of indication criteria. The tool was compared with other checklists in terms of completeness, time required, and readability. Atotal of 20findings were collected for each of the three documentation options and included in the analysis. Documentation with the two paper-based checklists had comparable information content: 17.5 ± 5.1/21.7 ± 7.6points out of amaximum of 43points; p > 0.05. Documentation using the digital application led to asignificant increase in information content compared to all paper-based documentation. The average score was 38.25 ± 3.7 (88.9% of maximum; p < 0.001). On average, user satisfaction was high (9.6/10). Use of the digital application was initially more time consuming, but as more cases were documented, the time taken improved significantly. In the future, structured reporting using apps could replace paper-based reporting for the indication of biologic therapy in CRSwNP patients and offer additional benefits in terms of data quality and traceability of results. The increasing volume of documentation in the future, the progress of digitalization, and the possibility of networking between individual centers make introduction of the app in the near future both likely and economical.

Type-2 immunity associated with type-1 related skin inflammatory diseases: friend or foe?

Chronic inflammatory skin diseases are multifactorial diseases that combine genetic predisposition, environmental triggers, and metabolic disturbances associated with abnormal immune responses. From an immunological perspective, the better understanding of their physiopathology has demonstrated a large complex network of immune cell subsets and related cytokines that interact with both epidermal and dermal cells. For example, in type-1-associated diseases such as alopecia areata, vitiligo, and localized scleroderma, recent evidence suggests the presence of a type-2 inflammation that is well known in atopic dermatitis. Whether this type-2 immune response has a protective or detrimental impact on the development and chronicity of these diseases remains to be fully elucidated, highlighting the need to better understand its involvement for the management of patients. This mini-review explores recent insights regarding the potential role of type-2-related immunity in alopecia areata, vitiligo, and localized scleroderma.

Towards precision medicine in COPD: Targeting type 2 cytokines and alarmins

Chronic obstructive pulmonary disease (COPD) is a main global epidemic increasing as population age and affecting approximately 10% of subjects over 45 years. COPD is a heterogeneous inflammatory disease with several endo-phenotypes and clinical presentations. Although neutrophilic inflammation is canonically considered a hallmark of COPD, eosinophilic inflammation can also be present in a subgroup of patients. Several other immune cells and cytokines play a key role in orchestrating and perpetuating the inflammatory pathways in COPD, making them attractive targets for treating this disorder. Recent studies have started to evaluate the possible role of type 2 (T2) inflammation and epithelial-derived alarmins (TSLP and IL-33) in COPD. Two phase III randomized clinical trials (RCTs) showed a modest reduction in exacerbations in COPD patients with eosinophilic phenotype treated with mepolizumab (anti-IL-5) or benralizumab (anti-IL-5Rα). A phase III RCT showed a 30% reduction in exacerbations in COPD patients with ≥ 300 eosinophils/μL treated with dupilumab (anti-IL-4Rα). These results suggest that blocking a single cytokine (e.g., IL-5) or its main target (i.e., IL-5Rα) is less promising than blocking a wider spectrum of cytokines (i.e., IL-4 and IL-13) in COPD. TSLP and IL-33 are upstream regulators of T2-high and T2-low immune responses in airway inflammation. Several ongoing RCTs are evaluating the efficacy and safety of anti-TSLP (tezepelumab), anti-IL-33 (itepekimab, tozorakimab), and anti-ST2 (astegolimab) in patients with COPD, who experience exacerbations. In conclusion, targeting T2 inflammation or epithelial-derived alarmins might represent a step forward in precision medicine for the treatment of a subset of COPD.

A novel syndrome of silent rhinovirus-associated bronchoalveolitis in children with recurrent wheeze

BackgroundRhinovirus (RV) infections trigger wheeze episodes in children. Thus, understanding of the lung inflammatory response to RV in children with wheeze is important. ObjectiveTo examine the associations of RV on lung lavage (BAL) granulocyte patterns and biomarkers of inflammation with age in children with treatment-refractory, recurrent wheeze (n=616). MethodsChildren underwent BAL to examine viral nucleic acid sequences, bacterial cultures, granulocyte counts, and phlebotomy for both general and type-2 inflammatory markers. ResultsDespite the absence of cold symptoms, RV was the most common pathogen detected (30%), and when present, was accompanied by BAL granulocytosis in 75% of children. Compared to children with no BAL pathogens (n=341), those with RV alone (n=127) had greater (p < 0.05) isolated neutrophilia (43% versus 16%), mixed eosinophils and neutrophils (26% versus 11%), and less pauci-granulocytic (27% versus 61%) BAL. Children with RV alone furthermore had biomarkers of active infection with higher total blood neutrophils and serum c-reactive protein (CRP), but no differences in blood eosinophils or total IgE. With advancing age, the log odds of BAL RV alone were lower, 0.82 [0.76-0.88, p < 0.001], but higher, 1.58 [1.01-2.51, p = 0.04], with high-dose daily corticosteroid treatment. ConclusionsChildren with severe recurrent wheeze often (22%) have a silent syndrome of lung RV infection with granulocytic bronchoalveolitis and elevated systemic markers of inflammation. The syndrome is less prevalent by school age, and not informed by markers of type-2 inflammation. We speculate that dysregulated mucosal innate antiviral immunity is a responsible mechanism.

Angiogenin-mediated tsRNAs control inflammation and metabolic disorder by regulating NLRP3 inflammasome.

The cellular stress response system in immune cells plays a crucial role in regulating the development of inflammatory diseases. In response to cellular damage or microbial infection, the assembly of the NLRP3 inflammasome induces pyroptosis and the release of inflammatory cytokines. Meanwhile, Angiogenin (Ang)-mediated transfer RNA-derived small RNAs (tsRNAs) promote cell survival under stressful conditions. While both tsRNAs and inflammasomes are induced under stress conditions, the interplay between these two systems and their implications in regulating inflammatory diseases remains poorly understood. In this study, it was demonstrated that Ang deficiency exacerbated sodium arsenite-induced activation of NLRP3 inflammasome and pyroptosis. Moreover, Ang-induced 5'-tsRNAs inhibited NLRP3 inflammasome activation and pyroptosis. Mechanistically, 5'-tsRNAs recruit DDX3X protein into stress granules (SGs), consequently inhibiting the interaction between DDX3X and NLRP3, thus leading to the suppression of NLRP3 inflammasome activation. Furthermore, in vivo results showed that Ang deficiency led to the downregulation of tsRNAs, ultimately leading to an exacerbation of NLRP3 inflammasome-dependent inflammation, including lipopolysaccharide-induced systemic inflammation and type-2 diabetes-related inflammation. Altogether, our study sheds a new light on the role of Ang-induced 5'-tsRNAs in regulating NLRP3 inflammasome activation via SGs, and highlights tsRNAs as a promising target for the treatment of NLRP3 inflammasome-related diseases.