The use of biologics in patients suffering from chronic rhinosinusitis with nasal polyps - a 4-year real life observation.

PURPOSE: Antibody therapy for chronic rhinosinusitis with nasal polyps (CRSwNP) has been established in Germany since 2019. With limited long-term data on biologic treatment for CRSwNP, we conducted a comprehensive evaluation of our 4-year data. This monocentric study aims to assess the real-world effects of this treatment on clinical course, quality of life, treatment adherence, biologic switching, dual therapy, and comorbidities. METHODS: We retrospectively analysed biologic therapy data in patients with severe chronic rhinosinusitis with nasal polyps. 191 patients with CRSwNP treated with Dupilumab, Mepolizumab, or Omalizumab were observed for up to 4 years in a real-life setting. RESULTS: We observed clear symptom improvements with few side effects. No loss of efficacy or tolerability was noted during the 4-year period. Patients reported high satisfaction compared to previous therapies, with overall improved quality of life. Revision surgery or oral steroid use during biologic therapy was rare. Some patients prolonged injection intervals or discontinued steroid nasal spray. Biologic switching occurred infrequently due to side effects or inadequate response and was generally well tolerated. Many patients reported additional positive effects such as asthma or allergy symptom improvement and reduced medication intake. CONCLUSION: In summary, this study confirms the potency and tolerability of biologics for CRSwNP treatment, with sustained efficacy over 4 years. Biologic switching is a viable option for inadequate response or intolerable side effects. Therapy positively impacts Th2 comorbidities, corticosteroid requirements, surgery need, and overall compliance remains high. CLINICAL TRIAL REGISTRATION: Project No.: 22-0802. Registry name: Biologika bei Patient*innen mit chronischer Sinusitis mit Nasenpolypen.

Clinical Remission Criteria and Serum Levels of Type 2 Inflammation Mediators during 24 Weeks of Treatment with the Anti-IL-5 Drug Mepolizumab in Patients with T2-High Severe Asthma.

Anti-interleukin (IL) 5 is an effective treatment modality for inhibiting eosinophilic inflammation in patients with T2-high severe asthma. The aim of this study was to determine the clinical efficacy and serum levels of type 2 inflammatory mediators during 24 weeks of mepolizumab treatment in patients with T2-high severe asthma. Eighteen patients with T2-high severe asthma were enrolled in this study. All patients received 100 mg of mepolizumab subcutaneously every 4 weeks and were retested at 4, 12, and 24 weeks. A clinical examination, asthma control test (ACT), and spirometry were performed; fractional exhaled nitric oxide (FeNO) levels were evaluated; and blood samples were drawn at every visit. Type 2 inflammation mediator levels were measured using enzyme-linked immunosorbent assay (ELISA). The blood eosinophil level significantly decreased, the ACT score and FEV1 increased after 4 weeks of mepolizumab treatment with the same tendency after 12 and 24 weeks (p < 0.05), and the FeNO level did not change (p > 0.05). A total of 27.8% of patients reached clinical remission criteria after 24 weeks of mepolizumab treatment. IL-33 and eotaxin significantly increased (p < 0.05) while IL-5, IL-13, thymic stromal lymphopoietin (TSLP), soluble IL-5 receptor subunit alpha (sIL-5Rα), and soluble high-affinity immunoglobulin E receptor (sFcεRI) decreased, with the same tendency after 12 and 24 weeks (p < 0.05). The serum levels of immunoglobulin (Ig) E and IL-4 and IL-25 levels did not change during mepolizumab treatment compared to baseline (p > 0.05). In conclusion, treatment with mepolizumab over 24 weeks improved lung function and asthma control in T2-high severe asthma patients, with nearly one-third achieving clinical remission criteria, and affected the balance of type 2 inflammatory mediators.

Sustained clinical and histopathological remission in a patient with eosinophilic esophagitis and type-2 comorbidities at 18 months after discontinuation of dupilumab.

Eosinophilic esophagitis (EoE) is a chronic, allergen-mediated, type-2 inflammatory disease with the potential to significantly impact an individual's quality of life. Conventional treatments often result in varied responses, prompting the need for novel therapeutic approaches. We present the case of a 19-year-old male with a medical history marked by eosinophilic esophagitis, severe atopic dermatitis (AD), asthma, and allergic rhinitis. Despite undergoing diverse topical and systemic interventions to address his AD and EoE, the patient's symptoms persisted. However, following the initiation of dupilumab therapy-a dual IL-4 and IL-13 receptor antagonist-the patient experienced a substantial reduction in his Eczema Area and Severity Index score. Notably, a marked improvement was also seen regarding his symptoms of eosinophilic esophagitis. A subsequent esophageal biopsy revealed a significant decrease in eosinophilic inflammation, consistent with established clinical and histologic remission criteria. These findings corroborate the patient's reported relief from symptoms. This case underscores the potential efficacy of dupilumab as a promising therapeutic agent in managing eosinophilic esophagitis. Dupilumab offers a dual benefit of alleviating symptoms and achieving histologic and clinical remission. This novel approach presents a noteworthy advancement in the treatment of EoE.

Immune stimulus exposure as a trigger for the development of chronic pruritus and circulating blood type 2 inflammation.

Background: Chronic pruritus (CP) is a poorly characterized condition associated with intense pruritus without a primary skin eruption. This condition tends to emerge more commonly in older adults, and there is limited research on triggering factors. Objective: To explore the clinical characteristics and pathophysiology of CP following exposure to an immune stimulus. Methods: Clinical characteristics and plasma samples were collected from 15 patients who developed CP following an immune stimulus such as checkpoint inhibitors or vaccination. A multiplex panel was used to analyze plasma cytokine concentrations within these patients. Results: Most immunotherapy-treated patients experienced CP during treatment or after 21 to 60 days of receiving treatment, while vaccine-stimulated patients developed pruritus within a week of vaccination. Plasma cytokine analysis revealed elevated levels of 12 cytokines in patients with immune-stimulated CP compared to healthy controls. Notably, T helper 2 (Th2) related cytokines interleukin (IL)-5 (fold change 2.65; q < 0.25) and thymic stromal lymphopoietin (fold change 1.61 q < 0.25) were upregulated. Limitations: Limitations of this study include limited sample size, particularly in the plasma cytokine assay. Conclusions and Relevance: This study reveals triggers of CP development and describes alterations in blood Th2 markers in patients with CP, including IgE, increased blood eosinophils, and cytokines IL-5 and thymic stromal lymphopoietin.

The relevance of eosinophils in chronic obstructive pulmonary disease: inflammation, microbiome and clinical outcomes.

Chronic obstructive pulmonary disease (COPD) is caused by the inhalation of noxious particles such as cigarette smoke. The pathophysiological features include airway inflammation, alveolar destruction and poorly reversible airflow obstruction. A sub-group of COPD patients have higher blood eosinophil counts (BECs), associated with an increased response to inhaled corticosteroids and increased biomarkers of pulmonary type 2 (T2) inflammation. Emerging evidence shows that COPD patients with increased pulmonary eosinophil counts have an altered airway microbiome. Higher BECs are also associated with increased lung function decline, implicating T2 inflammation in progressive pathophysiology in COPD. We provide a narrative review of the role of eosinophils and T2 inflammation in the pathophysiology of COPD, encompassing the lung microbiome, pharmacological targeting of T2 pathways in COPD, and the clinical use of BEC as a COPD biomarker.

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

BACKGROUND: Eicosanoids are lipid mediators including thromboxanes (TXs), prostaglandins (PGs), and leukotrienes with a pathophysiological role in established atopic disease. However, their role in the inception of disease is unclear. This study aimed to investigate the association between urinary eicosanoids in early life and development of atopic disease. METHODS: This study quantified the levels of 21 eicosanoids in urine from children from the COPSAC2010 (Copenhagen Prospective Studies on Asthma in Childhood 2010) (age 1 year, n = 450) and VDAART (Vitamin D Antenatal Asthma Reduction Trial) (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 false discovery rate of 5% (FDR5%) multiple testing correction. RESULTS: In 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 < .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 < .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%). CONCLUSIONS: This 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.

Type 2 Inflammation and Asthma in Children: A Narrative Review.

Increased understanding of the underlying pathophysiology has highlighted the heterogeneity of asthma and identified that most children with asthma have type 2 inflammation with elevated biomarkers, such as blood eosinophils and/or fractional exhaled nitric oxide. Although in the past most of these children may have been categorized as having allergic asthma, identifying the type 2 inflammatory phenotype provides a mechanism to explain both allergic and non-allergic triggers in pediatric patients with asthma. Most children achieve control with low to medium doses of inhaled corticosteroids. However, in a small but significant proportion of children, asthma remains uncontrolled despite maximum conventional treatment, with an increased risk of severe exacerbations. In this review, we focus on the role of type 2 inflammation and allergic processes in children with asthma, together with evidence of the efficacy of available treatment options for those who experience severe symptoms.

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.

Effect of dupilumab on asthma and aeroallergen sensitization in pediatric atopic dermatitis patients: Results of the BioDay registry.

BACKGROUND: Atopic dermatitis (AD) is frequently associated with asthma and allergic rhinitis (AR). Dupilumab is an effective treatment for pediatric AD, although the effect on atopic comorbidities in pediatric AD patients is limited. OBJECTIVE: To investigate the prevalence of asthma and AR in pediatric AD patients starting dupilumab treatment and to evaluate the effect of dupilumab on these comorbidities. METHODS: This study included pediatric AD patients (aged 3-17 years) treated with dupilumab between 2019 and 2023. Patients were screened at baseline by a pulmonologist for the presence of asthma and AR. Screening included evaluation of medical history and current symptoms, spirometry (including Forced Expiratory Volume in 1 s (FEV1)), Fractional exhaled Nitric Oxide (FeNO), and measurement of aeroallergen-specific IgE levels. In patients diagnosed with comorbid asthma and/or AR, measurements were repeated at weeks 16 and 52. Spirometry measurements, FeNO, and aeroallergen-specific IgE levels during treatment were analyzed using a covariance pattern model. RESULTS: Eighty-four patients were included. Asthma was diagnosed in 50 patients (59.5%) and AR in 72 patients (85.7%). Baseline FeNO levels were elevated in both patients with (29.0 ppb (95% CI 22.0-54.0)) and without asthma (26.0 ppb (95% CI 22.0-30.0)). During treatment, FeNO levels decreased (p < .001) and FEV1 scores increased (p < .001) in patients with asthma. In patients with asthma and/or AR, all aeroallergen-specific IgE levels decreased between 61.3% and 89.1% at 52 weeks of treatment. CONCLUSION: One year of dupilumab treatment, primarily indicated for AD, resulted in a significant improvement in comorbid asthma and a profound decrease in aeroallergen-specific IgE levels in patients with asthma and/or AR.

Management of chronic rhinosinusitis with nasal polyps in the Asia-Pacific region and Russia: Recommendations from an expert working group.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a chronic inflammatory condition of the nasal and paranasal tissues, characterized by the presence of bilateral nasal polyps. An expert panel of specialists from the Asian-Pacific region and Russia was convened to develop regional guidance on the management of CRSwNP through a consensus approach. The present article presents the chief observations and recommendations from this panel to provide guidance for clinicians in these areas. Etiology and pathogenetic mechanisms in CRSwNP are heterogeneous and complex. In many patients, CRSwNP is primarily driven by type 2 inflammation, although this may be less important in Asian populations. Frequent comorbidities include asthma and other inflammatory diseases such as non-steroidal anti-inflammatory drug (NSAID)/aspirin-exacerbated respiratory disease or atopic dermatitis. Clinical management of CRSwNP is challenging, and a multidisciplinary approach to evaluation and treatment is recommended. While many patients respond to medical treatment (topical irrigation and intranasal corticosteroids, and adjunctive short-term use of systemic corticosteroids), those with more severe/uncontrolled disease usually require endoscopic sinus surgery (ESS), although outcomes can be unsatisfactory, requiring revision surgery. Biological therapies targeting underlying type 2 inflammation offer additional, effective treatment options in uncontrolled disease, either as an alternative to ESS or for those patients with persistent symptoms despite ESS.

The New Paradigm: The Role of Proteins and Triggers in the Evolution of Allergic Asthma.

Epithelial barrier damage plays a central role in the development and maintenance of allergic inflammation. Rises in the epithelial barrier permeability of airways alter tissue homeostasis and allow the penetration of allergens and other external agents. Different factors contribute to barrier impairment, such as eosinophilic infiltration and allergen protease action-eosinophilic cationic proteins' effects and allergens' proteolytic activity both contribute significantly to epithelial damage. In the airways, allergen proteases degrade the epithelial junctional proteins, allowing allergen penetration and its uptake by dendritic cells. This increase in allergen-immune system interaction induces the release of alarmins and the activation of type 2 inflammatory pathways, causing or worsening the main symptoms at the skin, bowel, and respiratory levels. We aim to highlight the molecular mechanisms underlying allergenic protease-induced epithelial barrier damage and the role of immune response in allergic asthma onset, maintenance, and progression. Moreover, we will explore potential clinical and radiological biomarkers of airway remodeling in allergic asthma patients.

An updated reappraisal of dupilumab in children and adolescents with moderate-severe atopic dermatitis.

Atopic dermatitis (AD) is still a demanding challenge in clinical practice. Type 2 inflammation is the most common inflammatory pathway in children and adolescents with AD. Anti-inflammatory drugs, mainly corticosteroids (CS) and immunomodulant agents are the primary therapeutic approach to dampening type 2 inflammation. However, AD patients may require long-term high CS doses or drug combinations with possibly significant adverse effects to achieve and maintain disease control. In this regard, the advent of biologics constituted a breakthrough in managing this condition. Dupilumab is a monoclonal antibody directed against the IL-4 receptor α-subunit (IL-4Rα), antagonizing both IL-4 and IL-13 and is approved for pediatric severe AD. This review presents and discusses the most recent published studies on dupilumab in children and adolescents with AD. There is convincing evidence that dupilumab is safe and effective in managing AD. It can reduce skin lesions and associated itching, reduce the need for additional medications, and improve disease control and quality of life. However, a thorough diagnostic pathway is mandatory, especially considering the different AD phenotypes. The ideal eligible candidate is a child or adolescent with AD requiring systemic treatment because of severe clinical manifestations and impaired quality of life.

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.

Interstitial macrophage phenotypes in Schistosoma-induced pulmonary hypertension.

Background: Schistosomiasis is a common cause of pulmonary hypertension (PH) worldwide. Type 2 inflammation contributes to the development of Schistosoma-induced PH. Specifically, interstitial macrophages (IMs) derived from monocytes play a pivotal role by producing thrombospondin-1 (TSP-1), which in turn activates TGF-ß, thereby driving the pathology of PH. Resident and recruited IM subpopulations have recently been identified. We hypothesized that in Schistosoma-PH, one IM subpopulation expresses monocyte recruitment factors, whereas recruited monocytes become a separate IM subpopulation that expresses TSP-1. Methods: Mice were intraperitoneally sensitized and then intravenously challenged with S. mansoni eggs. Flow cytometry on lungs and blood was performed on wildtype and reporter mice to identify IM subpopulations and protein expression. Single-cell RNA sequencing (scRNAseq) was performed on flow-sorted IMs from unexposed and at day 1, 3 and 7 following Schistosoma exposure to complement flow cytometry based IM characterization and identify gene expression. Results: Flow cytometry and scRNAseq both identified 3 IM subpopulations, characterized by CCR2, MHCII, and FOLR2 expression. Following Schistosoma exposure, the CCR2+ IM subpopulation expanded, suggestive of circulating monocyte recruitment. Schistosoma exposure caused increased monocyte-recruitment ligand CCL2 expression in the resident FOLR2+ IM subpopulation. In contrast, the vascular pathology-driving protein TSP-1 was greatest in the CCR2+ IM subpopulation. Conclusion: Schistosoma-induced PH involves crosstalk between IM subpopulations, with increased expression of monocyte recruitment ligands by resident FOLR2+ IMs, and the recruitment of CCR2+ IMs which express TSP-1 that activates TGF-ß and causes PH.

Effect of Chloroquine on Type 2 Inflammatory Response in MC903-Induced Atopic Dermatitis Mice.

Introduction: Atopic dermatitis (AD) is a chronic, non-infectious inflammatory dermatosis. Chloroquine (CQ) has long been proven to possess anti-inflammatory properties. Objective: This paper aims to investigate the impact of CQ on type 2 inflammatory response in MC903-induced AD mice. Methods: An AD mouse model was established via MC903 induction. After CQ treatment, AD mice were intraperitoneally injected with polyinosinic: polycyclic acid [poly (I:C)] or Nigericin. Dermatitis severity was scored, and the thickness of the left ear was measured. The pathological changes in mouse skin tissues were observed by H&E staining. The number of mast cells was counted via TB staining. The content of peripheral blood T-helper 2 (Th2) cells and levels of immunoglobulin E (IgE), thymic stromal-derived lymphopoietin (TSLP), interleukin (IL)-4, IL-13, interferon (IFN)-γ, IL-1ß, and IL-18 were assessed by flow cytometry and ELISA. The levels of toll-like receptor 3 (TLR3), NLRP3, ASC, and cleaved caspase-1 proteins in skin tissues were determined by Western blot. Results: CQ treatment abated dermatitis severity and left ear thickness in AD mice, alleviated skin damage, reduced mast cell number, diminished IgE, TSLP, IL-4, and IL-13 levels, and peripheral blood Th2 cell content, with no significant changes in IFN-γ level. CQ alleviated type 2 inflammatory response in AD mice by inhibiting the activation of TLR3. CQ suppressed NLRP3 inflammasome activation. Activating TLR3/NLRP3 annulled CQ-mediated alleviation on type 2 inflammatory response in AD mice. Conclusion: CQ alleviated type 2 inflammatory response in AD mice by inhibiting TLR3 activation and NLRP3 inflammasome activation.

Xiaoqinglong decoction mitigates nasal inflammation and modulates gut microbiota in allergic rhinitis mice.

Introduction: Allergic rhinitis (AR) is a respiratory immune system disorder characterized by dysregulation of immune responses. Within the context of AR, gut microbiota and its metabolites have been identified as contributors to immune modulation. These microorganisms intricately connect the respiratory and gut immune systems, forming what is commonly referred to as the gut-lung axis. Xiaoqinglong Decoction (XQLD), a traditional Chinese herbal remedy, is widely utilized in traditional Chinese medicine for the clinical treatment of AR. In this study, it is hypothesized that the restoration of symbiotic microbiota balance within the gut-lung axis plays a pivotal role in supporting the superior long-term efficacy of XQLD in AR therapy. Therefore, the primary objective of this research is to investigate the impact of XQLD on the composition and functionality of the gut microbiota in a murine model of AR. Methods: An ovalbumin-sensitized mouse model to simulate AR was utilized, the improvement of AR symptoms after medication was investigated, and high-throughput sequencing was employed to analyze the gut microbiota composition. Results: XQLD exhibited substantial therapeutic effects in AR mice, notably characterized by a significant reduction in allergic inflammatory responses, considerable alleviation of nasal symptoms, and the restoration of normal nasal function. Additionally, following XQLD treatment, the disrupted gut microbiota in AR mice displayed a tendency toward restoration, showing significant differences compared to the Western medicine (loratadine) group. Discussion: This results revealed that XQLD may enhance AR allergic inflammatory responses through the regulation of intestinal microbiota dysbiosis in mice, thus influencing the dynamics of the gut-lung axis. The proposal of this mechanism provides a foundation for future research in this area.

The value of biomarkers in the therapy of CRSwNP with biologicals-a long-term follow-up of dupilumab therapy.

PURPOSE: Since its release, Dupilumab has shown great results in treating severe uncontrolled CRSwNP. However, there is a lack of real-world data beyond 12 months of follow-up, and it is not clear to what extent biomarkers are appropriate for monitoring and predicting the Dupilumab therapy success. Hence, this study aims to analyze biomarkers for monitoring therapy, predicting therapy success and assess the effect of Dupilumab in real-world settings. METHODS: The follow-up was performed with 104 patients retrospectively up to 22 months, assessing SNOT-22, NPS, olfactometry, ACS, FEV-1, and blood biomarkers (total serum IgE, Eosinophils, ECP). Patients were divided into subgroups depending on their pretherapeutic biomarker levels and subsequent development was analyzed. RESULTS: There was substantially improvement in all clinical parameters up to 1 year and then continuously up to month 22. Patients with initially elevated baseline blood eosinophil counts (> 0.5 billion/L) had a trend of better SNOT-22 development after 1 year (- 12.19 points, p = 0.03). The course of total serum IgE showed moderate correlation with almost all clinical variables obtained. Therapy was well tolerated with only mild and transient adverse events. CONCLUSION: Dupilumab has considerably reduced symptoms and disease severity even beyond 1 year of treatment, supporting its role as targeted and effective treatment option for CRSwNP. Our data shows that total serum IgE is a promising biomarker for the monitoring during the treatment with Dupilumab. Elevated pre-therapeutic serum eosinophil counts may be a predictor of good subjective response to therapy. Larger cohorts and a long-term-follow-up over years are needed to further consolidate these findings.

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

BACKGROUND: Rhinovirus (RV) infections trigger wheeze episodes in children. Thus, understanding of the lung inflammatory response to RV in children with wheeze is important. OBJECTIVES: This study sought to examine the associations of RV on bronchoalveolar lavage (BAL) granulocyte patterns and biomarkers of inflammation with age in children with treatment-refractory, recurrent wheeze (n = 616). METHODS: Children underwent BAL to examine viral nucleic acid sequences, bacterial cultures, granulocyte counts, and phlebotomy for both general and type-2 inflammatory markers. RESULTS: Despite 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 < .05) isolated neutrophilia (43% vs 16%), mixed eosinophils and neutrophils (26% vs 11%), and less pauci-granulocytic (27% vs 61%) BAL. Children with RV alone furthermore had biomarkers of active infection with higher total blood neutrophils and serum C-reactive protein, but no differences in blood eosinophils or total IgE. With advancing age, the log odds of BAL RV alone were lower, 0.82 (5th-95th percentile CI: 0.76-0.88; P < .001), but higher, 1.58 (5th-95th percentile CI: 1.01-2.51; P = .04), with high-dose daily corticosteroid treatment. CONCLUSIONS: Children 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 is not informed by markers of type-2 inflammation. The investigators speculate that dysregulated mucosal innate antiviral immunity is a responsible mechanism.

Exacerbated lung inflammation in offspring with high maternal antibody levels following secondary RSV exposure.

Respiratory syncytial virus (RSV) is the primary cause of bronchiolitis-related hospitalizations among children under 5 years of age, with reinfection being common throughout life. Maternal vaccination has emerged as a promising strategy, delivering elevated antibody levels to newborns for immediate protection. However, limited research has explored the protective efficacy of maternal antibodies (matAbs) against secondary RSV infections in offspring. To address this gap, we employed a mouse model of maternal RSV vaccination and secondary infection of offspring to evaluate lung pathology following RSV reinfection in mice with varying levels of maternal antibody (matAb). Additionally, we aimed to investigate the potential causes of exacerbated lung inflammation in offspring with high matAb levels following secondary RSV exposure. Our findings revealed that offspring with elevated levels of maternal pre-F antibody demonstrated effective protection against lung pathology following the initial RSV infection. However, this protection was compromised upon reinfection, manifesting as heightened weight loss, exacerbated lung pathology, increased expression of RSV-A N genes, eosinophilia, enhanced IL-5, IL-13, MUC5AC, and eosinophils Major Basic Protein (MBP) production in lung tissue compared to offspring lacking matAbs. Importantly, these unexpected outcomes were not attributed to antibody-dependent enhancement (ADE) resulting from declining matAb levels over time. Notably, our findings showed a decline in secretory IgA (sIgA), mucosal IgA, and mucosal IgG levels in offspring with high matAb levels post-primary RSV challenge. We propose that this decline may be a critical factor contributing to the ineffective protection observed during secondary RSV exposure. Overall, these findings offer valuable insights into maternal vaccination against RSV, contributing to a comprehensive understanding and mitigation of potential risks associated with maternal RSV vaccination.

The interleukin-4/interleukin-13 pathway in type 2 inflammation in chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is predominantly a type 2 inflammatory disease associated with type 2 (T2) cell responses and epithelial barrier, mucociliary, and olfactory dysfunction. The inflammatory cytokines interleukin (IL)-4, IL-13, and IL-5 are key mediators driving and perpetuating type 2 inflammation. The inflammatory responses driven by these cytokines include the recruitment and activation of eosinophils, basophils, mast cells, goblet cells, M2 macrophages, and B cells. The activation of these immune cells results in a range of pathologic effects including immunoglobulin E production, an increase in the number of smooth muscle cells within the nasal mucosa and a reduction in their contractility, increased deposition of fibrinogen, mucus hyperproduction, and local edema. The cytokine-driven structural changes include nasal polyp formation and nasal epithelial tissue remodeling, which perpetuate barrier dysfunction. Type 2 inflammation may also alter the availability or function of olfactory sensory neurons contributing to loss of sense of smell. Targeting these key cytokine pathways has emerged as an effective approach for the treatment of type 2 inflammatory airway diseases, and a number of biologic agents are now available or in development for CRSwNP. In this review, we provide an overview of the inflammatory pathways involved in CRSwNP and describe how targeting key drivers of type 2 inflammation is an effective therapeutic option for patients.