The Role of Mast Cells in Aspirin-Exacerbated Respiratory Disease (AERD) Pathogenesis: Implications for Future Therapeutics

Biologics Reduce Symptoms of Alcohol Intolerance Better than Aspirin Desensitization in Patients with N-ERD and Nasal Polyps

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) exacerbated respiratory disease (N-ERD) is associated with chronic rhinosinusitis with nasal polyps (CRSwNP), asthma, and NSAID hypersensitivity. An overproduction of leukotrienes characterizes the pathomechanism of the disease. N-ERD patients often report breathing difficulties after consuming alcohol. These symptoms have been observed in patients receiving either aspirin therapy after desensitization (ATAD), therapy with the biologics dupilumab (anti-IL-4Ra antibody) and omalizumab (anti-IgE antibody), or intranasal corticosteroid treatment (INCS).

METHODS

This retrospective, real-world study assessed the severity of alcohol-related and non-alcohol-related respiratory symptoms in CRSwNP/N-ERD patients 3-6 months after ATAD, biologic (dupilumab or omalizumab), or INCS therapy. A total of 171 patients (98 women and 73 men) were enrolled in the study. All groups received standard INCS therapy. Sixty-three patients were treated with ATAD; 48 received biologics (dupilumab n = 31; omalizumab n = 17); and 60 received INCS only and served as a control group. Alcohol-dependent symptoms and typical CRS symptoms (alcohol-independent) were quantified using visual analog scales (VAS).

RESULTS

ATAD and biological therapy significantly reduced VAS scores for alcohol dependence and CRS symptoms. In the control group receiving INCS, only non-alcohol dependent CRS symptoms improved significantly (p < 0.05). The most significant differences in pre/post scores were observed in patients receiving dupilumab, with the most significant improvement in alcohol-dependent and CRS symptoms (dupilumab > omalizumab > ATAD).

CONCLUSIONS

This real-world study shows that alcohol-related respiratory symptoms are a relevant parameter in CRSwNP/N-ERD patients. Patients benefit more from biologic therapy than from ATAD in terms of their alcohol-related symptoms and other CRS symptoms. Future studies should include placebo-controlled oral alcohol challenge.

Immune endotyping and gene expression profile of patients with chronic rhinosinusitis with nasal polyps in the aspirin-exacerbated respiratory disease (AERD) and the non-AERD subgroups

BACKGROUND

Chronic Rhinosinusitis (CRS) is a paranasal sinus inflammatory disease and is divided into two subgroups defined as CRS with nasal polyps (CRSwNP) and CRS without nasal polyps (CRSsNP). CRSwNP displays a T helper (Th)2 biased phenotype, and based on sensitivity or tolerance to aspirin or non-steroidal anti-inflammatory drugs (NSAID), is further subdivided into Aspirin-exacerbated respiratory disease (AERD) and non-AERD groups. Considering the challenge of diagnosis and treatment in patients with CRSwNP, particularly the AERD subtype, and the significance of endotyping in these patients, we examined the immune profile and endotyping based on gene expression analysis in the AERD and the non-AERD groups of patients with CRSwNP.

MATERIAL AND METHOD

In this study, 21 patients were enrolled and were categorized into AERD (N = 10) and non-AERD (N = 11) groups based on their sensitivity to aspirin. After the special washing period, nasal polyps were biopsied in both groups, and the infiltration of eosinophils, neutrophils, plasma cells, and lymphocytes was compared between the AERD and the non-AERD groups. Also, gene expression levels of transcription factors including Tbet, GATA3, RoRγt, and FoxP3 and inflammatory cytokines including interleukin (IL)1β, IL1RAP (IL1 receptor accessory protein), IL2, IL4, IL5, IL10, IL13, IL17, TNFα, and IFNγ were investigated by quantitative Real-time PCR (qRT-PCR). Statistical analyses were performed using analytical tests including Kolmogorov-Smirnov, Mann-Whitney, and T-test. A P value less than 0.05 was considered statistically significant.

RESULTS

The mean ± SD age of the studied groups was 37 ± 8.7 years old (21-50) for the AERD, and 40.4 ± 7.7 years old (31-52) for the non-AERD. LMS/EPOS/SNOT scores and pulmonary function tests showed no difference between the two groups. Serum immunoglobulin E (IgE) levels were found to be higher in patients with AERD (p = 0.04), however, the peripheral blood counts of eosinophils were comparable in the two groups. In the histopathologic analysis, the AERD group showed higher percentages of eosinophils (p = 0.04), neutrophils (p = 0.04), and plasma cells (p = 0.04) than the non-AERD group. Additionally, the gene expression levels of GATA3 (p = 0.001), IL4 (p = 0.04), IL5 (p = 0.007), and IL17 (p = 0.03) were significantly higher in the AERD than the non-AERD groups.

CONCLUSION

Higher gene expression levels of GATA3, IL4, IL5, and IL17 were observed in the AERD group compared with the non-AERD group. These findings point to distinct patterns of inflammation in patients with AERD, with a predominance of Th2 inflammation.

Does NSAID exacerbated respiratory disease (N-ERD) accompanying severe asthma affect biological treatment response? Efficacy of omalizumab and mepolizumab in N-ERD

Introduction

Non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) accompanies severe asthma in about 15% of the patients and may adversely affect the prognosis. Omalizumab and mepolizumab are biologics used in patients with severe asthma. The objective of this study is to assess the respiratory improvements, after these biologics in severe asthmatic patients stratifed by the presence of concomitant Non-erosive reflux disease (N-ERD) and the effect of omalizumab and mepolizumab in severe asthmatics with N-ERD.

Material & method

The population of this three-center, retrospective, cross-sectional, observational study comprised patients using omalizumab or mepolizumab for severe asthma. Patients administered these biologics for severe asthma were comparatively analyzed for the presence of N-ERD; asthma control test (ACT) scores, number of attacks, and the changes in forced expiratory volume in 1 s (FEV1) were assessed. Subsequently, patients who were found to have N-ERD were analyzed using visual analog scale (VAS) in terms of the changes in their nasal parameters (ie, nasal obstruction, facial pain, anterior-posterior rhinitis, and hyposmia), according to whether they use omalizumab or mepolizumab.

Results

The use of biologics resulted in a significant improvement in ACT and FEV1 and reduction in attacks in 28 severe asthmatics with N-ERD and 125 without N-ERD. Although both biologics resulted in a significant improvement in the respiratory parameters, omalizumab treatment resulted in a significant improvement in nasal parameters except hyposmia, mepolizumab treatment resulted in a significant improvement only in posterior rhinitis, and nasal obstruction among the nasal parameters.

Conclusion

This study is the first to address both omalizumab and mepolizumab treatments in severe asthmatics with N-ERD. The improvement in nasal parameters was more pronounced in patients who were administered omalizumab. Large-scale randomized controlled studies are needed to corroborate the findings of this study.

Allergic Rhinitis: Pathophysiology and Treatment Focusing on Mast Cells

Allergic rhinitis (AR) is a common rhinopathy that affects up to 30% of the adult population. It is defined as an inflammation of the nasal mucosa, develops in allergic individuals, and is detected mostly by a positive skin-prick test. AR is characterized by a triad of nasal congestion, rhinorrhea, and sneezing. Mast cells (MCs) are innate immune system effector cells that play a pivotal role in innate immunity and modulating adaptive immunity, rendering them as key cells of allergic inflammation and thus of allergic diseases. MCs are typically located in body surfaces exposed to the external environment such as the nasal mucosa. Due to their location in the nasal mucosa, they are in the first line of defense against inhaled substances such as allergens. IgE-dependent activation of MCs in the nasal mucosa following exposure to allergens in a sensitized individual is a cardinal mechanism in the pathophysiology of AR. This review is a comprehensive summary of MCs' involvement in the development of AR symptoms and how classical AR medications, as well as emerging AR therapies, modulate MCs and MC-derived mediators involved in the development of AR.

The Role of Omalizumab in NSAID-Exacerbated Respiratory Disease: A Narrative Review

Nonsteroidal anti-inflammatory drug-exacerbated respiratory disease (N-ERD) is a condition characterized by the triad of chronic rhinosinusitis with nasal polyps, bronchial asthma, and hypersensitivity to nonsteroidal anti-inflammatory drugs. This article explores the current knowledge on the various pathological mechanism(s) of N-ERD-such as arachidonic acid metabolism, cysteinyl leukotrienes, prostaglandins, platelets, IgE, mast cells, eosinophils, basophils, and innate immune system-and the role of omalizumab in its management. The authors dive deep into the role of IgE in N-ERD and its potential as a therapeutic target. IgE plays a significant role in mediating allergic reactions, is intricately linked with mast cells, interacts with multiple immunopathological pathways involved in N-ERD, and tends to be elevated in patients with N-ERD. Multiple real-world studies, observational studies, and case series, as well as 2 phase III trials, have demonstrated the effectiveness of omalizumab in the management of N-ERD. For a disease with such a well-documented history, the pathophysiology of N-ERD and the most effective ways to manage it remain a mystery. With this background, the authors ask-is IgE a missing piece of the N-ERD puzzle, thus explaining the efficacy of omalizumab in the treatment of the disease?

Local and Systemic Production of Pro-Inflammatory Eicosanoids Is Inversely Related to Sensitization to Aeroallergens in Patients with Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is characterized by overproduction of the pro-inflammatory eicosanoids. Although immunoglobulin E-mediated sensitization to aeroallergens is common among AERD patients, it does not belong to the defining disease characteristics. In this study of 133 AERD patients, we sought to find a relationship between sensitization to aeroallergens and local (leukotriene E₄, prostaglandin E₂ and prostaglandin D₂) and/or systemic (leukotriene E₄) production of arachidonic acid metabolites. Interestingly, a negative association between pro-inflammatory eicosanoid levels in induced sputum supernatant or urine and sensitization to aeroallergens was observed. This inverse relationship might suggest the presence of a protective effect of atopic sensitization to aeroallergens against stronger local airway inflammation and higher systemic AERD-related inflammatory activity.

Emerging Biomarkers Beyond Leukotrienes for the Management of Nonsteroidal Anti-inflammatory Drug (NSAID)-Exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is a unique condition characterized by aspirin/NSAID hypersensitivity, adult-onset asthma, and/or chronic rhinosinusitis with nasal polyps. Arachidonic acid metabolism dysregulation and intense eosinophilic/type 2 inflammation are central mechanisms in NERD. Studies have been conducted on various biomarkers, and urinary leukotriene E4 is considered the most available biomarker of NERD. However, the pathophysiology of NERD is heterogeneous and complex. Epithelial cells and platelets can interact with immune cells in NERD, and novel biomarkers related to these interactions have recently been investigated. We summarize emerging novel biomarkers of NERD and discuss their roles in the management of NERD.

Urine Leukotriene E4: Implications as a Biomarker in Chronic Rhinosinusitis

OBJECTIVE

To provide a comprehensive state-of-the-art review of the emerging role of urine leukotriene E4 (uLTE4) as a biomarker in the diagnosis of chronic rhinosinusitis (CRS), aspirin-exacerbated respiratory disease (AERD), and asthma.

DATA SOURCES

Ovid MEDLINE(R), Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus.

REVIEW METHODS

A state-of-the-art review was performed investigating the role of uLTE4 as a diagnostic biomarker, predictor of disease severity, and potential marker of selected therapeutic efficacy.

CONCLUSIONS

uLTE4 has been shown to be a reliable and clinically relevant biomarker for CRS, AERD, and asthma. uLTE4 is helpful in ongoing efforts to better endotype patients with CRS and to predict disease severity.

IMPLICATIONS FOR PRACTICE

Aside from being a diagnostic biomarker, uLTE4 is also able to differentiate aspirin-tolerant patients from patients with AERD and has been associated with objective disease severity in patients with CRS with nasal polyposis. uLTE4 levels have also been shown to predict response to medical therapy, particularly leukotriene-modifying agents.