Management of severe asthma: summary of the European Respiratory Society/American Thoracic Society task force report

A real-world study on tezepelumab effectiveness in severe asthma focusing on small airway dysfunction

BACKGROUND

Severe asthma (SA) is a complex condition often involving small airway dysfunction (SAD). Tezepelumab has demonstrated efficacy in clinical trials, but real-world evidence is scarce, and its impact on SAD remains unexplored.

OBJECTIVE

This prospective study evaluated the effectiveness of tezepelumab in patients with SA, stratified by the SAD presence and asthma phenotype (type 2-high vs type 2-low).

METHODS

Seventeen SA patients received tezepelumab. A range of clinical and laboratory outcomes were assessed, including annualized asthma exacerbation rate (AAER), lung function, and oral corticosteroids (OCS) use. Respiratory parameters were assessed using spirometry, body plethysmography, and forced oscillation technique (FOT).

RESULTS

After 6 months of treatment, tezepelumab significantly reduced median AAER (from 5.0 to 0.0, p = 0.001) and OCS dose (from 14.6 mg/day to 0.0 mg/day, p < 0.001), alongside a marked reduction in median blood eosinophil count (from 130 to 60 cells/mm3, p = 0.032). Among respiratory parameters, total resistance, measured by body plethysmography, improved significantly in the overall population (median values from 0.49 to 0.37 KPa L s-1, p = 0.005). Spirometry and FOT measures, including total reactance (p = 0.018) and tidal expiratory flow limitation (p = 0.043), improved only in patients with SAD.

CONCLUSION

Tezepelumab significantly reduced exacerbations and improved asthma control, positively impacting respiratory parameters and small airway function in patients with SAD. These findings support SAD as a treatable trait, highlighting the importance of integrating advanced diagnostic tools, such as body plethysmography and FOT, into routine clinical practice.

Eosinophil-Driven vs. Eosinophil-Associated Severe Asthma: Practical Implications for Target Treatment

Severe asthma (SA) is a chronic inflammatory condition affecting approximately 10% of asthmatic patients, and eosinophils are considered key pathogenetic actors in a significant number of patients. Biological therapies have been demonstrated to improve asthma control by decreasing exacerbation rates and reducing the use of oral corticosteroids. In this context, phenotyping and endotyping patients with SA is essential for selecting the most effective therapeutic approach. For this purpose, biomarkers such as IgE, absolute blood eosinophil count, and fractional exhaled nitric oxide (FeNO) are crucial in defining a patient's inflammatory profile. Their integration provides a framework for classifying asthma into T2-high, T2-mild, or T2-low categories, guiding personalized treatment strategies. By incorporating multiple biomarkers into a unified model, it is possible to better stratify patients and optimize biologic therapy selection, paving the way for improved outcomes in SA management. This review aims to evaluate the role of phenotyping and endotyping SA patients, with particular attention to the impact of eosinophilic inflammation and combinatory biomarkers on decision-making processes for the selection of biological therapies.

Rhinovirus as a Driver of Airway T-Cell Dynamics in Children with Severe Asthma

Severe asthma in children is notoriously difficult to treat, and its immunopathogenesis is complex. In particular, the contribution of T cells and relationships to anti-viral immunity, remain enigmatic. Here, we coupled deep phenotyping with machine learning methods to resolve the dynamics of T cells in the diseased lower airways, and examined rhinovirus (RV) as a driver. Our strategy revealed a T-cell landscape dominated by type 1 and type 17 CD8+ signatures. Interrogation of phenotypic relationships coupled with trajectory mapping identified T-cell migratory and differentiation pathways spanning the blood and airways that culminated in tissue residency, and included transitions between type 1 and type 17 tissue-resident types. These T-cell dynamics were reflected in cytokine polyfunctionality in situ . Use of machine learning to cross-compare T-cell populations that were enriched in the airways of RV-positive children with those induced in the blood after RV challenge in an experimental infection model, precisely pinpointed RV-responsive signatures that mapped to T-cell differentiation pathways. Despite their rarity, these signatures were detected in the airways of uninfected children. Together, our results underscore the aberrant nature of type 1 immunity in the airways of children with severe asthma, and implicate an important viral trigger as a driver.

Altered control of breathing in a rat model of allergic lower airway inflammation

Obstructive sleep apnea (OSA) is highly prevalent in patients with asthma. Asthma, dose-dependently to its duration, promotes incident OSA, suggesting that asthma plays a role in OSA pathogenesis. We hypothesized that asthma-related inflammation alters breathing control mechanisms, specifically the carotid chemoreflex. Accordingly, we measured hypoxic ventilatory responses (HVR) in awake, unrestrained, ovalbumin (OVA)-sensitized Brown Norway rats and compared them with responses in sham-sensitized (SALINE) controls. To differentiate the role of allergic inflammation from bronchoconstriction, we repeated hypoxic ventilatory response (HVR) after administration of formoterol, a long-acting bronchodilator. Blood and bronchoalveolar lavage (BAL) fluid were collected for quantification of inflammatory cytokines. The rise in ventilatory equivalent for O2 evoked by acute exposure to hypoxia was augmented following sensitization by OVA, whereas it remained stable after SALINE. This augmentation was driven by increased breathing frequency with no change in tidal volume. Tachypneic hyperventilation in normoxia was also observed with OVA. Neither the increased HVR nor excessive normoxic ventilation was affected by formoterol, suggesting that they were not secondary to lung mechanical constraints. Higher levels of inflammatory cytokines were observed in BAL fluid and serum of OVA versus SALINE. In OVA, serum interleukin-5 levels significantly correlated with change from baseline in ventilatory responses to severe hypoxia ([Formula: see text], 0.09). These observations are consistent with inflammation-induced enhancement of carotid chemoreflex function, i.e., increased controller gain, and they suggest a possible role for asthma-related allergic inflammation in the ventilatory instability known to promote upper airway collapse and sleep apnea in humans.NEW & NOTEWORTHY Asthma is a risk factor for obstructive sleep apnea (OSA); however, the mechanisms are incompletely understood. In a rat model of allergic inflammation associated with asthma, we found that ventilation in normoxia and ventilatory responses to hypoxia were markedly enhanced and related with systemic inflammation. These alterations indicating carotid chemoreflex sensitization, known to promote ventilatory instability during sleep in humans, may contribute to the increased OSA risk in asthma.

Impact of biological therapies on laboratory outcomes and FEV1 in patients with severe eosinophilic asthma with chronic rhinosinusitis: a real-life study from Saudi Arabia

                                                                 Abstract Background: Few studies have addressed the effects of biological therapies on laboratory outcomes and changes in FEV1 in patients with severe asthma (SA) and chronic rhinosinusitis (CRS). We aimed to study the effect of three biological therapies on laboratory outcomes and FEV1 in Saudi Arabian patients with SA and CRS.

METHODS

From March to September 2022, a retrospective observational cohort study was undertaken at the severe asthma clinics of the Armed Forces Hospital-Southern Region (AFHSR) and King Khalid University Hospital, Abha, Saudi Arabia, to delineate the effects of 3 biological therapies (benralizumab, dupilumab, and omalizumab) in adults with SA and concomitant CRS in terms of FEV1 and laboratory parameters (serum IgE and eosinophilic counts).

RESULTS

Eighty patients were enrolled, with a mean age of 46.68. There were 45 (56%) females and 35 (44%) males. There were significant improvements in FEV1 and laboratory parameters (serum IgE and eosinophilic counts) after 6 &12 months of biological therapies compared to pre-biological therapies (p<0.001, each). The response was different among different biological therapies. The improvements in FEV1, serum IgE, and eosinophilic counts were manifest with benralizumab and dupilumab but not with omalizumab.

CONCLUSIONS

Results from the first study from two large Saudi Arabian tertiary centers for patients with severe asthma and chronic rhinosinusitis agree with and support those of worldwide real-life ones. One-year follow-up of patients with SA and CRS showed the effectiveness of benralizumab and dupilumab, but not omalizumab, regarding FEV1, serum IgE, and eosinophilic counts. Further prospective multicenter studies are warranted.

Update on Inflammatory Biomarkers for Defining Asthma Phenotype

Asthma is a chronic heterogeneous disease characterized by various symptoms and persistent airway inflammation, resulting in progressive lung function decline. Classifying asthma phenotypes/endotypes is crucial because the underlying mechanisms and long-term outcomes vary from patient to patient. Recent trials have identified several biomarkers for classifying asthma phenotypes/endotypes, and current treatments have been developed on the basis of these biomarkers. Conventional biomarkers, including immunoglobulin E, blood/sputum eosinophil counts, airway obstruction or reversibility, and fractional exhaled nitric oxide, are widely used to diagnose asthma. However, these markers have some limitations, necessitating the discovery of additional biomarkers. Therefore, this review summarizes recently suggested biomarkers for representing type 2-high (eosinophilic) vs. type 2-low (neutrophilic) asthma, non-steroidal anti-inflammatory drug-exacerbated respiratory disease, and severe asthma. Additionally, we discuss the potential benefits of these biomarkers in classifying specific phenotypes/endotypes and managing asthmatic patients.

Outcomes of biological therapy in patients with severe asthma with chronic rhinosinusitis in Saudi Arabia: patients with nasal polyps versus those without nasal polyps

BACKGROUND

This study's purposes were to evaluate the impact of biological therapies on outcomes in patients with severe asthma (SA) and chronic rhinosinusitis (CRS) and to compare these effects among those with NP (CRSwNP) versus those without NP (CRSsNP) in the "real-world" setting in Saudi Arabian patients.

METHODS

From March to September 2022, a retrospective observational cohort study was undertaken at the severe asthma clinics of the Armed Forces Hospital-Southern Region (AFHSR) and King Khalid University Hospital, Abha, Saudi Arabia, to delineate the effects of dupilumab therapy. Outcomes were assessed, including clinical outcomes, FEV1, and laboratory findings before and one year after dupilumab. Post-therapy effects were compared between CRSwNP and CRSsNP.

RESULTS

Fifty subjects were enrolled, with a mean age of 46.56. There were 27 (54%) females and 23(46%) males. Significant improvements in clinical parameters (frequency of asthma exacerbations and hospitalizations, the use of OCs, anosmia, SNOTT-22, and the ACT), FEV1, and laboratory ones (serum IgE and eosinophilic count) were observed 6 and 12 months after using dupilumab (p < 0.001), respectively. However, after 12 months of dupilumab therapy, there were no significant differences between those with and without NP with regards to clinical (anosmia, ACT, and OCs use), laboratory (eosinophilic count, serum IgE level) parameters, and FEV1%.

CONCLUSIONS

Patients with CRS experienced significant improvements in clinical, FEV1, and laboratory outcomes after dupilumab therapy. However, these improvements were not maintained when comparing CRSwNP with CRSsNP. There were no significant differences between those with and without NP regarding ACT and OCs use or laboratory (eosinophilic count, serum IgE level) parameters. Further prospective multicenter studies are warranted.

Peripheral blood eosinophilia in adult asthmatic patients and its association with the severity of asthma

BACKGROUND

Asthma is a diverse disease with various etiologic bases. Severe asthma can be associated with increased mortality, hospitalization, and decreased quality of life for asthma patients. High blood eosinophil counts were associated with severe asthma, but recent studies have failed to confirm this as a marker of severe asthma among adult asthma patients. As a result, the purpose of this study was to determine the association between the severity of asthma and high blood eosinophil count.

METHODOLOGY

A simple random sampling technique was used to select 291 asthmatic patients for an institution-based cross-sectional study. Socio-demographic, behavioral, and clinical characteristics were collected by using a pre-tested structured questionnaire. Four milliliters of venous blood were collected from asthmatic patients for complete blood count and peripheral morphology assessment. The eosinophil count was analyzed by the Unicel DxH 800 (Beckman Coulter, Ireland) analyzer. A statistical package for social science version 20 (SPSS) software was used to analyze the data. The non-parametric (Mann-Whitney U) test was used to compare the eosinophil count with different background variables. A binary logistic regression analysis was used to assess the factors associated with eosinophilia. A p-value less than 0.05 in multivariable logistic regression analysis was considered statistically significant.

RESULT

In this study, the overall magnitude of eosinophilia was 19.6% (95% CI = 14.8-24.1). Being admitted to the emergency department (AOR = 0.25; 95% CI: 0.09-0.69, p = 0.007) and being female (AOR = 0.49; 95% CI: 0.26-0.9, p = 0.025) were shown to have a statistically significant association with eosinophilia. Moreover, the absolute eosinophil count was significantly higher among asthmatic patients infected with intestinal parasitic infection (p < 0.045).

CONCLUSION

Being female and admission to the emergency department were negatively associated with eosinophilia. Lack of eosinophilia can be related to the low-T2 asthma phenotype. The absolute eosinophil counts were higher among intestinal parasite-infected patients. Therefore, different biomarkers will be considered for the proper diagnosis and management of adult asthma patients.

Heterogeneity of Treatment Response to Asthma

The definition of asthma has evolved over the years with significant heterogeneity of the disease increasingly recognized. Complex gene and environment interactions result in different pheno-endotypes of asthma that respond differently to the same treatment. Multiple studies have revealed pharmacogenomic and endophenotypic factors that predict treatment response to standard therapies for asthma. Recent advances in biologic medications have enabled a more tailored approach to the care of patients with moderate to severe asthma, taking into consideration clinical traits and measurable biomarkers. This chapter will review heterogeneity in treatment response to different medication classes for asthma: inhaled and systemic corticosteroids, beta-2 agonists, leukotriene modifiers, muscarinic antagonists, macrolides, and biologics.

Mesenchymal Stem Cells Suppress Severe Asthma by Directly Regulating Th2 Cells and Type 2 Innate Lymphoid Cells

Patients with severe asthma have unmet clinical needs for effective and safe therapies. One possibility may be mesenchymal stem cell (MSC) therapy, which can improve asthma in murine models. However, it remains unclear how MSCs exert their beneficial effects in asthma. Here, we examined the effect of human umbilical cord blood-derived MSCs (hUC-MSC) on two mouse models of severe asthma, namely, Alternaria alternata-induced and house dust mite (HDM)/diesel exhaust particle (DEP)-induced asthma. hUC-MSC treatment attenuated lung type 2 (Th2 and type 2 innate lymphoid cell) inflammation in both models. However, these effects were only observed with particular treatment routes and timings. In vitro co-culture showed that hUC-MSC directly downregulated the interleukin (IL)-5 and IL-13 production of differentiated mouse Th2 cells and peripheral blood mononuclear cells from asthma patients. Thus, these results showed that hUC-MSC treatment can ameliorate asthma by suppressing the asthmogenic cytokine production of effector cells. However, the successful clinical application of MSCs in the future is likely to require careful optimization of the route, dosage, and timing.