Pathobiology of Type 2 Inflammation in Asthma and Nasal Polyposis

Clinical remission in severe asthma: lights and shadows on an ambitious goal

PURPOSE OF REVIEW

The aim of this study was Describe the latest evidence related to the concept of clinical remission in patients with severe asthma, focusing on the lights and shadows of this concept.

RECENT FINDINGS

The idea of clinical remission in severe asthma patients brings about a significant shift in the way asthma is treated and managed. Although there has yet to be unanimous agreement among various scientific societies on the precise definition, this concept can be extremely useful in advancing the treatment of the disease.

SUMMARY

Asthma is a common respiratory condition that affects more than 300 million people globally. It has variable symptoms and severity levels, with about 10% of patients experiencing severe asthma. While there have been advancements in treatment, severe asthma poses significant challenges. Recent approaches have focused on achieving clinical remission, which goes beyond symptom control to address underlying inflammation and biological processes. Clinical remission criteria include the absence of symptoms, reduced medication usage, and normalized inflammatory markers. Various biologic therapies show promise, with some patients achieving remission. However, remission's definition varies globally, hindering standardization and a valid comparison. Standardizing remission criteria and refining predictive factors are crucial for effective asthma management. Overall, achieving clinical remission offers hope for improved long-term outcomes in severe asthma patients.

Type 2 severe asthma: pathophysiology and treatment with biologics

INTRODUCTION

The hallmark of most patients with severe asthma is type 2 inflammation, driven by innate and adaptive immune responses leading to either allergic or non-allergic eosinophilic infiltration of airways. The cellular and molecular pathways underlying severe type 2 asthma can be successfully targeted by specific monoclonal antibodies.

AREAS COVERED

This review article provides a concise overview of the pathophysiology of type 2 asthma, followed by an updated appraisal of the mechanisms of action and therapeutic efficacy of currently available biologic treatments used for management of severe type 2 asthma. Therefore, all reported information arises from a wide literature search performed on PubMed.

EXPERT OPINION

The main result of the recent advances in the field of anti-asthma biologic therapies is the implementation of a personalized medicine approach, aimed to achieve clinical remission of severe asthma. Today this accomplishment is made possible by the right choice of the most beneficial biologic drug for the pathologic traits characterizing each patient, including type 2 severe asthma and its comorbidities.

The role of ACT score in mepolizumab discontinuation

BACKGROUND

Mepolizumab is a therapy for severe asthma. We have little knowledge of the characteristics of people in the US that discontinue mepolizumab in clinical care.

OBJECTIVE

To investigate the real-world efficacy and time to clinical discontinuation of mepolizumab, we evaluated individuals with asthma started on mepolizumab at the Cleveland Clinic. We hypothesized that individuals that discontinue mepolizumab have more severe and uncontrolled asthma at baseline.

METHODS

Between 2016 and 2022, patients who started on mepolizumab consented to be assessed over 18 months. At baseline, a questionnaire including demographic and medical history was collected. Laboratory findings such as ACT score, FENO (Fractional Excretion of Nitric Oxide), and spirometry were recorded. At the conclusion of the observation period, the participants were divided into two categories: Group A and Group B.

RESULTS

Group B [N = 28] discontinued mepolizumab (p < 0.05) at an average of 5.8 months (SD 4.2 months). Group A [N = 129] stayed on the therapy for at least 1 year. A participant with an ACT score less than 13 has an odds ratio of 6.64 (95% CI, 2.1 - 26.0) of discontinuing mepolizumab therapy. For a male, the odds of discontinuing mepolizumab therapy is 3.39 (95% CI, 1.1-11.2).

CONCLUSION

In this real-world study, we find that high eosinophil count may not be adequate in screening which individuals will benefit from mepolizumab. Up to 17% of patients fail therapy within 6 months, with male sex and low ACT score increasing risk of mepolizumab discontinuation at Cleveland Clinic.

Airways Type-2 Related Disorders: Multiorgan, Systemic or Syndemic Disease?

Chronic rhinosinusitis (CRS) has recently undergone a significant paradigm shift, moving from a phenotypical classification towards an "endotype-based" definition that places more emphasis on clinical and therapeutic aspects. Similar to other airway diseases, like asthma, most cases of CRS in developed countries exhibit a dysregulated type-2 immune response and related cytokines. Consequently, the traditional distinction between upper and lower airways has been replaced by a "united airway" perspective. Additionally, type-2 related disorders extend beyond respiratory boundaries, encompassing conditions beyond the airways, such as atopic dermatitis. This necessitates a multidisciplinary approach. Moreover, consideration of possible systemic implications is crucial, particularly in relation to sleep-related breathing diseases like Obstructive Sleep Apnoea Syndrome (OSAS) and the alteration of systemic inflammatory mediators such as nitric oxide. The trends in epidemiological, economic, and social burden are progressively increasing worldwide, indicating syndemic characteristics. In light of these insights, this narrative review aims to present the latest evidence on respiratory type-2 related disorders, with a specific focus on CRS while promoting a comprehensive perspective on the "united airways". It also introduces a novel concept: viewing these conditions as a multiorgan, systemic, and syndemic disease.

Remission in Type 2 Inflammatory Diseases: Current Evidence, Unmet Needs, and Suggestions for Defining Remission in Chronic Rhinosinusitis with Nasal Polyps

PURPOSE OF REVIEW

The development of biological therapies for type 2 inflammatory diseases raises the possibility of addressing remission in those dis-immune conditions. No consensus exists for a definition of remission in chronic rhinosinusitis with nasal polyps (CRSwNP). This review aims to critically evaluate the published data to provide the basis for defining remission in CRSwNP.

RECENT FINDINGS

The published evidence has yet to provide an unequivocal definition on remission in type 2 inflammatory diseases, in part reflecting differences in approaches to diagnosis and follow-up. A multidimensional evaluation is necessary when considering complete remission, including clinical, inflammatory, and histologic criteria, but how to combine or tailor the three perspectives according to disease severity at baseline or timing of assessment of treatment category is yet to reach consensus. We suggest defining remission starting from the approach taken in asthma and eosinophilic esophagitis, that is, including the resolution of symptoms and improvements in objective parameters of disease severity and/or inflammatory activity. Future studies and consensuses should provide validated criteria with cutoffs for the day-to-day definition of remission. The definition of remission in CRSwNP should include the following criteria, to be verified and maintained for a period of ≥ 12 months: absence of symptoms (nasal obstruction, loss of smell, rhinorrhea as the main ones); no impact of symptoms on quality of life; no need of surgery; no chronic or rescue medications (systemic corticosteroids or antibiotics); and recovery of smell function, possibly evaluated by objective test. Assessment of underlying inflammation should also be considered once accurate and feasible biomarkers are available in clinical practice.

Asthma Phenotypes in the Era of Personalized Medicine

Asthma is a widespread disease affecting approximately 300-million people globally. This condition leads to significant morbidity, mortality, and economic strain worldwide. Recent clinical and laboratory research advancements have illuminated the immunological factors contributing to asthma. As of now, asthma is understood to be a heterogeneous disease. Personalized medicine involves categorizing asthma by its endotypes, linking observable characteristics to specific immunological mechanisms. Identifying these endotypic mechanisms is paramount in accurately profiling patients and tailoring therapeutic approaches using innovative biological agents targeting distinct immune pathways. This article presents a synopsis of the key immunological mechanisms implicated in the pathogenesis and manifestation of the disease's phenotypic traits and individualized treatments for severe asthma subtypes.

Eosinophil Cationic Protein Variation in Patients with Asthma and CRSwNP Treated with Dupilumab

BACKGROUND

Asthma is a clinical syndrome characterized by recurrent episodes of airway obstruction, bronchial hyperresponsiveness and airway inflammation. Most patients with asthma present a "type 2" (TH2) inflammation. ILC2 and TH2 cells release cytokines IL4, IL-13 and IL-5. CRSwNP is a condition characterized by hyposmia or anosmia, nasal congestion, nasal discharge, and face pain or pressure that last for at least 12 weeks in a row without relief. Both asthma and CRSwNP are often characterized by a type 2 inflammation endotype and are often present in the same patient. Dupilumab is a fully human monoclonal antibody targeting the interleukin-4 receptor α (IL-4Rα) subunit, blocking IL4/IL-4Rα binding and IL13. It has been labelled for the treatment of moderate to severe asthma in patients from the age of 12 years with an eosinophilic phenotype, and it has demonstrated efficacy and acceptable safety. Our study aims to investigate the effects of dupilumab on type 2 inflammatory biomarkers, such as eosinophils and eosinophil cationic protein (ECP). ECP is an eosinophil-derived substance contained in granules that are released during inflammation and causes various biological effects, including tissue damage in asthmatic airways.

METHODS

ECP, Eosinophil counts (EOS), and total immunoglobulin E (IgE) levels were longitudinally measured using immunoassays in the serum of 21 patients affected by CRSwNP, of which 17 had asthma as a comorbidity, receiving 300 mg dupilumab every two weeks.

RESULTS

The EOS and ECP, after a first phase of significant increase due to the intrinsic characteristic of the block of IL-4 and IL-13, returned to the baseline 10 months after the initial administration of dupilumab. Fractional exhaled nitric oxide (FeNO) and serum total IgE decreased significantly after 9 months. Asthma Control Test (ACT) scores improved after dupilumab treatment. FEV1% and FEV1 absolute registered a significant improvement at 10 months.

CONCLUSIONS

Patients who received 300 milligrams of dupilumab every two weeks first experienced a temporary increase in eosinophils (EOS) and eosinophil cationic protein (ECP), then exhibited a gradual decline in these variables with a subsequent return to the initial baseline levels. When compared to the baseline, we observed that the levels of IgE and FeNO decreased over time, while there was an increase in both FEV1 and FEV1%.

Effect of Obesity on the Expression of Genes Associated with Severe Asthma-A Pilot Study

Asthma is a complex condition resulting from the interaction of genes and environment. Obesity is a risk factor to develop asthma and contributes to poor response to asthma therapy and severity. The aim of the study was to evaluate the effect of obesity on the expression levels of genes previously associated with severe asthma. Three groups of subjects were studied: non-obese asthmatics (NOA), obese asthma patients (OA), and non-asthmatic obese subjects (O). Previously reported overexpressed (IL-10, MSR1, PHLDA1, SERPINB2, and CD86) and underexpressed genes (CHI3L1, CPA3, IL-8, and PI3) in severe asthma were analyzed by RT-qPCR in peripheral blood mononuclear cells (PBMCs). In the overexpressed genes, obesity significantly decreased the expression of MSR1 and PHLDA1 and had no effects on CD86, IL-10, and SERPINB2. In underexpressed genes, obesity did not affect PI3, CHI3L1, and IL-8 and significantly reduced CPA3 expression. The results of this study show that obesity should be included among the known factors that can contribute toward modifying the expression of genes associated with asthma and, in particular, severe asthma.