Measurement of Blood Eosinophils in Asthma and Chronic Obstructive Pulmonary Disease

Guidance for type 2 inflammatory biomarkers

Type 2 inflammation in the airways and lungs is inflammation induced by type 2 cytokines such as IL-4, IL-5, and IL-13, produced primarily by type 2 helper T cells and type 2 innate lymphoid cells, and causes changes in the physiology and structure of the airways. Type 2 inflammation is currently in the spotlight because of its direct link to the treatment of several airway and lung diseases. Abundant evidences have accumulated that inflammatory biomarkers such as blood eosinophils, fractional exhaled nitric oxide, and IgE are essential clinical tools in the diagnosis and management of asthma and COPD. It is well known that asthma and COPD have diverse inflammatory phenotypes even when clinical features are similar, and it has been demonstrated that assessment of airway inflammation with biomarkers can improve diagnostic accuracy, determine safer and more effective treatment strategies, and predict future risks such as exacerbations and lung function decline. The Japanese Respiratory Society has published clinical practice guidelines for the evaluation of type 2 inflammation in the airways and lungs. In addition to asthma and COPD, the guide covers a wide range of airway and lung diseases, including interstitial lung disease, allergic bronchopulmonary mycosis, allergic rhinitis, and eosinophilic chronic rhinosinusitis. It also provides comprehensive guidelines covering a variety of clinical biomarkers. The purpose of this guidance is to provide evidences for the interpretation of type 2 inflammation measurements and to promote the widespread use of inflammation assessment to further improve the efficiency of airway and respiratory disease management.

The Effect of Mepolizumab on Blood Eosinophil Subtype Distribution and Granule Protein Gene Expression in Severe Eosinophilic Asthma

Purpose

Mepolizumab, which causes a decrease in the number of blood eosinophils, is used to treat patients with severe eosinophilic asthma (SEA). However, there is a relative lack of data on dynamic changes in blood eosinophil subtype distribution and their granule protein expression following anti-interleukin (IL)-5 treatment. Our objective was to evaluate blood inflammatory-like (iEOS-like) and resident-like (rEOS-like) eosinophil subtype distribution and CLC, EDN, EPX, ECP, and MBP gene expression following up to 24 weeks of treatment with mepolizumab in SEA patients.

Patients and Methods

Ten free of oral steroids SEA patients and 9 healthy control subjects (HS) were included. Patients were treated with mepolizumab 100 mg subcutaneously/4 weeks, and investigation tests were performed at 0, 4, 12, and 24 weeks. Blood eosinophils were isolated by Ficoll centrifugation and magnetic separation, then subtyped using magnetic separation against CD62L. Gene expression investigation was done using quantitative real time-polymerase chain reaction analysis.

Results

Approximately three-quarters of isolated blood eosinophils were iEOS-like cells before mepolizumab treatment, p<0.01. Blood eosinophil granule protein gene expression was increased in SEA patients compared to the HS, p<0.05, and iEOS-like cells EPX, MBP, and CLC gene expressions were higher than rEOS-like cells, p<0.05. Following 4, 12, and 24 weeks of treatment with mepolizumab, residual blood eosinophils shifted towards rEOS-like cells, p<0.05, and CLC, EPX, ECP, and MBP gene expression of both eosinophil subtypes decreased to HS levels.

Conclusion

Treating SEA patients with mepolizumab shifts blood eosinophil subtype distribution towards rEOS-like cells and reduces granule protein gene expression levels to those of healthy individuals.

Real-World Effectiveness of Mepolizumab in Severe Asthma: Results from the Multi-country, Self-controlled Nucala Effectiveness Study (NEST)

INTRODUCTION

The Nucala Effectiveness Study (NEST) assessed the effectiveness of mepolizumab in patients with severe asthma (SA) in countries previously underrepresented in real-world studies.

METHODS

A multi-country, bi-directional, self-controlled, observational cohort study conducted in Colombia, Chile, India, Türkiye, Saudi Arabia, United Arab Emirates, Kuwait, Oman, and Qatar. Historical and/or prospective data from patients with SA were assessed 12 months pre- and post-mepolizumab initiation.

PRIMARY ENDPOINT

incident rate ratio (IRR) of clinically significant exacerbations (CSEs). Key secondary endpoints: healthcare resource utilisation (HCRU), oral corticosteroid (OCS) use, lung function and symptom control (Asthma Control Test [ACT] scores).

RESULTS

Overall, 525 patients with SA burden pre-initiation (geometric mean blood eosinophil count [BEC] 490.7 cells/µl; 31.4% prior biologic use; 37.3% obese) received at least one dose of mepolizumab 100 mg subcutaneously. Post-initiation, a significant reduction in CSEs was observed (76% [p < 0.001]; IRR [95% confidence interval] 0.24 [0.19-0.30]); 72.0% of patients had no CSEs. Mepolizumab treatment led to a reduction in OCS use (52.8% pre-initiation vs. 16.6% post-initiation) and a mean (standard deviation [SD]) change in OCS dose of - 18.1 (20.7) mg post-initiation; 36.1% of patients became OCS-free. Fewer patients were hospitalised post-initiation (22.5% pre-initiation vs. 6.9% post-initiation). Improvements in mean (SD) forced expiratory volume in 1 s (62.8 [20.2]% pre-initiation vs. 73.0 [22.7]% post-initiation) and ACT scores (15.0% pre-initiation vs. 64.5% of patients post-initiation with well-controlled asthma) were observed. Proportion of patients with BEC ≥ 500 cells/µl decreased from 84.4% pre-initiation to 18.1% post-initiation.

CONCLUSION

Mepolizumab was effective in reducing the burden of SA by significantly reducing CSEs, reducing OCS use and HCRU, and improving lung function and asthma control, which could translate to improvements in health-related quality of life in patients with SA and high OCS dependency in the countries studied. A graphical abstract is available with this article.

Challenges With the Intolerance of Biologics in Severe Eosinophilic Asthma: The Risk of Exacerbations Is Time-Dependent With the Rise of Eosinophils

Patients with severe eosinophilic asthma (SEA) can benefit from biologic therapy but some subjects may present an immune-mediated side effect. These patients will not meet the treatment goals and might have an increased risk of exacerbations. Monitoring these patients by determining blood eosinophil (BE) levels could be one of the tools that may allow a follow-up to prevent a worsening of asthma or exacerbations. The patient was a 50-year-old female with a diagnosis of SEA who had six asthma exacerbations in the last year. Baseline spirometry showed a forced expiratory volume in one second (FEV1) (L) of 0.80 with 34%p (z-score: -4.18) post bronchodilator (BD) and a BE count of 15% (1080 µL cells). After three doses of benralizumab, the spirometry showed an FEV1 (L) of 2.31 with 97%p (z-score: -0.21) post BD and a BE count of 0%. No exacerbations were reported while the patient received biologic medication, but it had to be stopped due to a dermatological allergic reaction. The patient was well-controlled for four months after stopping biologic medication and the BE count also increased, associated with two emergency visits due to exacerbations despite maintenance therapy. Although intolerance or hypersensitivity reactions to the treatment with biologics in asthmatic patients are rare, these patients must discontinue treatment, which increases their risk of exacerbations. In routine medical clinical practice, an easy approach can be made with the follow-up of an accessible and inexpensive test, i.e., the BE count. Its increments should trigger an alert for a closer follow-up and early therapy adjustments.

Moderate-High Blood Eosinophilia Is Associated with Increased Hospitalization and Other Asthma Comorbidities

(1) Background: Eosinophilia has traditionally been linked to eosinophilic asthma, for which it is the gold-standard prognostic biomarker. However, the association between eosinophilia and the presence of other diseases and comorbidities is yet unclear. (2) Methods: For this retrospective study, we reviewed the electronic medical records of 49,909 subjects with blood eosinophilia to gather data on the presence of asthma, COPD, sleep apnea, tuberculosis, dyslipidemia, hypertension, and other cardiovascular diseases and severe CRSwNP among these subjects. Demographic features including age, sex, and smoking habits were collected, as well as the number of hospitalizations and emergency department visits. T-tests, ANOVA, Fisher test, and logistic regression models were used. (3) Results: For all age groups studied, eosinophilia was significantly more prevalent among asthmatic subjects than nonasthmatics, especially in patients also presenting CRSwNP, hypertension, and dyslipidemia. The likelihood of developing asthma, COPD, and CRSwNP, and hospitalization, was increased when BEC was above 600 eosinophils/μL. The association between asthma, CRSwNP, and BEC was corroborated by multiple logistic regressions models. (4) Conclusions: We demonstrated the association of having over 600 blood eosinophils/μL with a higher number of hospitalizations and comorbidities (CRSwNP and COPD), which proves that BEC is a highly useful parameter to consider in subjects who present blood eosinophilia.

Serum YKL-40 Levels, Leukocyte Profiles, and Acute Exacerbations of Advanced COPD

Little information exists on YKL-40-a key protein in tissue remodeling-and complete blood count (CBC) parameters during acute exacerbations of advanced chronic obstructive pulmonary disease (COPD). This pilot exploratory study (August 2020-January 2021) investigated the connection between serum YKL-40 levels and CBC profile in sex- and age-matched individuals with severe COPD (GOLD stage III, n = 23, median age = 66 years, 65.21% males) and very severe COPD (GOLD stage IV, n = 24, median age = 66.5 years, 74.81% males). The measured parameters were serum YKL-40, absolute leukocyte count (ALLC), absolute neutrophil count (ANC), neutrophil percentage, absolute lymphocyte count (ALC), lymphocyte percentage, neutrophil-to-lymphocyte ratio (NLR), absolute eosinophil count (AEC), eosinophil percentage, absolute monocyte count (AMC), monocyte percentage, absolute basophil count (ABC), basophil percentage, hemoglobin levels, and hematocrit concentrations. No significant inter-group differences were observed. However, high YKL-40 subjects (n = 23)-as stratified via median YKL-40 (3934.5 pg/mL)-showed significantly increased neutrophil percentage and NLR but significantly lower lymphocyte-, eosinophil-, and basophil-related parameters compared to low YKL-40 patients (n = 24). These results reveal multidimensional, YKL-40-associated changes in leukocyte profile of patients with advanced COPD during acute exacerbations, with potential implications for personalized treatment.

Practical Recommendations for a Selection of Inhaled Corticosteroids in COPD: A Composite ICO Chart

The use of inhaled corticosteroids (ICS) for the maintenance of bronchodilator treatment in patients with chronic obstructive pulmonary disease (COPD) is controversial. While some patients achieve clinical benefits, such as fewer exacerbations and improved symptoms, others do not, and some experience undesired side effects, such as pneumonia. Thus, we reviewed the evidence related to predictors of ICS therapy treatment response in patients with COPD. The first priority clinical markers when considering the efficacy of ICS are type 2 inflammatory biomarkers, followed by a history of suspected asthma and recurrent exacerbations. It is also necessary to consider any potential infection risk associated with ICS, and several risk factors for pneumonia when using ICS have been clarified in recent years. In this article, based on the evidence supporting the selection of ICS for COPD, we propose an ICS composite that can be added to the COPD (ICO) chart for use in clinical practice. The chart divided the type 2 biomarkers into three ranges and provided recommendations (recommend, consider, and against) by combining the history of suspected asthma, history of exacerbations, and risk of infection.

Stepwise management of COPD: What is next after bronchodilation?

Inhaled bronchodilator therapy with long-acting muscarinic antagonists (LAMAs) and long-acting β2-agonists (LABAs) in combination is currently the mainstay of treatment for chronic obstructive pulmonary disease (COPD). Treatment guidelines recommend the addition of inhaled corticosteroids (ICS) to LABA/LAMA only in patients with a history of frequent/severe exacerbations and high blood eosinophil counts, or in those with concomitant asthma. Despite this, real-world data suggest that clinicians are not adhering to this guidance and that ICS are frequently overused. This is possibly due to the incorrect assumption that when LABA/LAMA therapy is not sufficient, adding an ICS to the treatment regimen is the logical next step. In this narrative review, we describe global and country-specific guideline recommendations from Germany, Spain, and Japan and compare these with real-world data on LABA/LAMA and ICS use in clinical practice. We also provide a clinical guide to the use of add-on therapies with LABA/LAMA for different patient phenotypes, including (1) patients still symptomatic (but not exacerbating) despite LABA/LAMA treatment; (2) patients still exacerbating despite LABA/LAMA treatment who have high blood eosinophil counts; and (3) patients still exacerbating despite LABA/LAMA treatment who do not have high blood eosinophils or concomitant asthma.