Efficacy and Safety of Systemic Corticosteroids for Urticaria: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

BACKGROUND: Short courses of adjunctive systemic corticosteroids are commonly used to treat acute urticaria and chronic urticaria flares (both with and without mast cell-mediated angioedema), but their benefits and harms are unclear. OBJECTIVE: To evaluate the efficacy and safety of treating acute urticaria or chronic urticaria flares with versus without systemic corticosteroids. METHODS: We searched the MEDLINE, EMBASE, CENTRAL, CNKI, VIP, Wanfang, and CBM databases from inception to July 8, 2023, for randomized controlled trials of treating urticaria with versus without systemic corticosteroids. Paired reviewers independently screened records, extracted data, and appraised risk of bias with the Cochrane 2.0 tool. We performed random-effects meta-analyses of urticaria activity, itch severity, and adverse events. We assessed certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) approach. RESULTS: We identified 12 randomized trials enrolling 944 patients. For patients with low or moderate probability (17.5%-64%) to improve with antihistamines alone, add-on systemic corticosteroids likely improve urticaria activity by a 14% to 15% absolute difference (odds ratio [OR], 2.17, 95% confidence interval [CI]: 1.43-3.31; number needed to treat [NNT], 7; moderate certainty). Among patients with a high chance (95.8%) for urticaria to improve with antihistamines alone, add-on systemic corticosteroids likely improved urticaria activity by a 2.2% absolute difference (NNT, 45; moderate certainty). Corticosteroids may improve itch severity (OR, 2.44; 95% CI: 0.87-6.83; risk difference, 9%; NNT, 11; low certainty). Systemic corticosteroids also likely increase adverse events (OR, 2.76; 95% CI: 1.00-7.62; risk difference, 15%; number needed to harm, 9; moderate certainty). CONCLUSIONS: Systemic corticosteroids for acute urticaria or chronic urticaria exacerbations likely improve urticaria, depending on antihistamine responsiveness, but also likely increase adverse effects in approximately 15% more.

Biologic Therapy in Rare Eosinophil-Associated Disorders: Remaining Questions and Translational Research Opportunities.

Rare eosinophil-associated disorders (EADs), including hypereosinophilic syndrome, eosinophilic granulomatosis with polyangiitis and eosinophilic gastrointestinal disorders, are a heterogeneous group of conditions characterized by blood and/or tissue hypereosinophilia and eosinophil-related clinical manifestations. Although the recent availability of biologic therapies that directly and indirectly target eosinophils has the potential to dramatically improve treatment options for all EADs, clinical trials addressing their safety and efficacy in rare EADs have been relatively few. Consequently, patient access to therapy is limited for many biologics, and the establishment of evidence-based treatment guidelines has been extremely difficult. In this regard, multicenter retrospective collaborative studies focusing on disease manifestations and treatment responses in rare EADs have provided invaluable data for physicians managing patients with these conditions and helped identify important questions for future translational research. During the Clinical Pre-Meeting Workshop held in association with the July 2023 biennial meeting of the International Eosinophil Society in Hamilton, Ontario, Canada, the successes and limitations of pivotal multicenter retrospective studies in EADs were summarized, and unmet needs regarding the establishment of guidelines for use of biologics in rare EADs were discussed. Key topics of interest included: 1) clinical outcome measures, 2) minimally invasive biomarkers of disease activity, 3) predictors of response to biologic agents, and 4) long-term safety of eosinophil depletion. Herein, we report a summary of these discussions, presenting a state-of-the-art overview of data currently available for each of these topics, the limitations of the data, and avenues for future data generation through implementation of multidisciplinary and multicenter studies.

Plain Language Summary of principles for improving the care of people with eosinophil-associated diseases.

WHAT IS THIS SUMMARY ABOUT?: Eosinophil-associated diseases (EADs) are a group of conditions in which eosinophils (a type of white blood cell) are thought to play a key role in the disease and how it develops. Some EADs are common, such as atopic dermatitis (also called eczema) and a subtype of asthma called eosinophilic asthma, while others are rare, such as hypereosinophilic syndrome (a condition in which a person has a very high number of eosinophils in both the blood and one or more organs). People with EADs face many problems related to their conditions. Symptoms such as severe abdominal pain, itch, or shortness of breath impact both the patient as well as their friends and family. Patients with EADs also experience delays to diagnosis and treatment as well as financial barriers. Healthcare professionals sometimes fail to recognize the complex set of symptoms that characterize an EAD, and this may cause delays in reaching a correct diagnosis. As a result, it may take longer for a patient to get the best care and the most effective treatments, which may contribute to poor health. The goal of this charter is to describe the key elements of good quality care, which all people with EADs deserve, as well as to present an action plan to improve health and overall well-being for people with EADs. Proposed use of this patient charter: The principles described in this charter (a written guide to achieve an outcome) show the core elements of quality care that people with EADs must receive. They also describe clear steps to reduce the burden on patients and their caregivers and to improve patient health outcomes. We urge healthcare professionals, hospitals, and policymakers around the world to adopt these principles quickly. By doing this, people with EADs will be more likely to receive an accurate and timely diagnosis and have access to quality care and treatment in the right setting.

An open microfluidic coculture model of fibroblasts and eosinophils to investigate mechanisms of airway inflammation.

Interactions between fibroblasts and immune cells play an important role in tissue inflammation. Previous studies have found that eosinophils activated with interleukin-3 (IL-3) degranulate on aggregated immunoglobulin G (IgG) and release mediators that activate fibroblasts in the lung. However, these studies were done with eosinophil-conditioned media that have the capacity to investigate only one-way signaling from eosinophils to fibroblasts. Here, we demonstrate a coculture model of primary normal human lung fibroblasts (HLFs) and human blood eosinophils from patients with allergy and asthma using an open microfluidic coculture device. In our device, the two types of cells can communicate via two-way soluble factor signaling in the shared media while being physically separated by a half wall. Initially, we assessed the level of eosinophil degranulation by their release of eosinophil-derived neurotoxin (EDN). Next, we analyzed the inflammation-associated genes and soluble factors using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and multiplex immunoassays, respectively. Our results suggest an induction of a proinflammatory fibroblast phenotype of HLFs following the coculture with degranulating eosinophils, validating our previous findings. Additionally, we present a new result that indicate potential impacts of activated HLFs back on eosinophils. This open microfluidic coculture platform provides unique opportunities to investigate the intercellular signaling between the two cell types and their roles in airway inflammation and remodeling.

Omalizumab for treatment of idiopathic angioedema.

BACKGROUND: Omalizumab has been found to improve outcomes in patients with chronic spontaneous urticaria (CSU). Idiopathic angioedema (IAE) is increasingly being recognized as a condition with similar underlying mechanisms as CSU and a form of CSU. We hypothesized that add-on therapy with omalizumab would benefit patients with uncontrolled IAE. OBJECTIVE: To study the safety and efficacy of omalizumab for the treatment of IAE in adults. METHODS: We conducted a randomized, placebo-controlled trial to study the efficacy of omalizumab in adults with 2 or more episodes of angioedema (AE) in the past 6 months for which no clinical or laboratory cause of AE could be found. A total of 10 patients were randomized on a 1:1 basis to receive omalizumab 300 mg subcutaneously or placebo every 4 weeks for 24 weeks with a 12-week follow-up period. The primary endpoint was the change in the Angioedema Activity Score. Secondary endpoints included the Angioedema Quality of Life Questionnaire, the Visual Analogue Scale, and the number of angioedema episodes per month. RESULTS: We observed improvement in the Angioedema Activity Score (-2.93 ln odds; 95% confidence interval [CI], -4.84 to -1.02; P = .003), Visual Analogue Scale (-3.49 ln odds; 95% CI, -6.58 to -0.40; P = .03), Angioedema Quality of Life Questionnaire (-9.43 score; 95% CI, -17.63 to -1.24; P = .03), and number of angioedema episodes per month (-1.93 ln count; 95% CI, -3.23 to -0.63; P = .005) in patients who received omalizumab vs placebo. CONCLUSION: This study provides preliminary prospective evidence that omalizumab improves outcomes in patients with IAE. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02966314. CLINICALTRIALS: gov URL:https://clinicaltrials.gov/ct2/show/NCT02966314?term=omalizumab&cond=Angioedema&draw=2&rank=1.

Autophagy Protects against Eosinophil Cytolysis and Release of DNA.

The presence of eosinophils in the airway is associated with asthma severity and risk of exacerbations. Eosinophils deposit their damaging products in airway tissue, likely by degranulation and cytolysis. We previously showed that priming blood eosinophils with IL3 strongly increased their cytolysis on aggregated IgG. Conversely, IL5 priming did not result in significant eosinophil cytolysis in the same condition. Therefore, to identify critical events protecting eosinophils from cell cytolysis, we examined the differential intracellular events between IL5- and IL3-primed eosinophils interacting with IgG. We showed that both IL3 and IL5 priming increased the eosinophil adhesion to IgG, phosphorylation of p38, and production of reactive oxygen species (ROS), and decreased the phosphorylation of cofilin. However, autophagic flux as measured by the quantification of SQSTM1-p62 and lipidated-MAP1L3CB over time on IgG, with or without bafilomycin-A1, was higher in IL5-primed compared to IL3-primed eosinophils. In addition, treatment with bafilomycin-A1, an inhibitor of granule acidification and autophagolysosome formation, enhanced eosinophil cytolysis and DNA trap formation in IL5-primed eosinophils. Therefore, this study suggests that increased autophagy in eosinophils protects from cytolysis and the release of DNA, and thus limits the discharge of damaging intracellular eosinophilic contents.

Improving Care in Eosinophil-Associated Diseases: A Charter.

Eosinophil-associated diseases (EADs) are a range of heterogeneous conditions in which eosinophils are believed to play a critical pathological role. EADs include common illnesses such as eosinophilic asthma and chronic rhinosinusitis and rare conditions such as hypereosinophilic syndromes (HES) and eosinophilic gastrointestinal disorders (EGIDs). EADs are associated with substantial burdens for the patient, including chronic, debilitating symptoms, increased financial burden, decreased health-related quality of life, and the need for repeated visits to multiple different healthcare professionals (HCPs), emergency departments, and/or hospitals. Poor EAD recognition by HCPs often contributes to delayed diagnoses, which further delays patient access to appropriate care and effective treatments, contributing to poor health outcomes. The objective of this charter is to outline key patient rights and expectations with respect to the management of their condition(s) and to set forth an ambitious action plan to improve health outcomes for patients with EADs: (1) people with EADs, their caretakers, HCPs, and the public must have greater awareness and education about EADs; (2) people with EADs must receive a timely, accurate diagnosis; (3) all people with EADs must have access to an appropriate multidisciplinary team, when necessary; and (4) people with EADs must have access to safe and effective treatment options without unnecessary regulatory delays. The principles described in this charter demonstrate the core elements of quality care that people with EADs must receive, and they represent clear steps by which to reduce patient and caregiver burden and improve patient outcomes. We urge HCPs, healthcare systems, and policymakers worldwide to swiftly adopt these principles to ensure patients with EADs have an accurate diagnosis in a timely manner and access to high-level care and treatment in an appropriate setting.

An International, Retrospective Study of Off-Label Biologic Use in the Treatment of Hypereosinophilic Syndromes.

BACKGROUND: Treatment of hypereosinophilic syndrome (HES) often requires the use of immunomodulators with substantial side effect profiles. The emergence of biologics offers an alternative treatment modality. OBJECTIVE: To examine real-world practice data to describe the safety and consequences of various biologics suspected to directly or indirectly affect eosinophilic inflammation for the treatment of HES. METHODS: Retrospective data from 13 centers were collected via an online Research Electronic Data Capture repository. Inclusion criteria included (1) peripheral eosinophil count of 1,500/mm3 or greater without a secondary cause; (2) clinical manifestations attributable to the eosinophilia; and (3) having received mepolizumab (anti-IL-5), benralizumab (afucosylated anti-IL-5 receptor α), omalizumab (anti-IgE), alemtuzumab (anti-CD52), dupilumab (anti-IL-4 receptor α), or reslizumab (anti-IL-5) outside a placebo-controlled clinical trial. RESULTS: Of the 151 courses of biologics prescribed for 121 patients with HES, 59% resulted in improved HES symptoms and 77% enabled tapering of other HES medications. Overall, 105 patients were receiving daily systemic glucocorticoids at the time of a biologic initiation and were able to reduce the glucocorticoid dose by a median reduction of 10 mg of daily prednisone equivalents. Biologics were generally safe and well-tolerated other than infusion reactions with alemtuzumab. Thirteen of 24 patients had clinical improvement after switching biologics and nine patients responded to increasing the dose of mepolizumab after a lack of response to a lower dose. CONCLUSIONS: Biologics may offer a safer treatment alternative to existing therapies for HES, although the optimal dosing and choice for each subtype of HES remain to be determined. Limitations of this study include its retrospective nature and intersite differences in data collection and availability of each biologic.

Eosinophils, beyond IL-5.

New therapeutic monoclonal antibodies targeting the IL-5/IL-5 receptor pathway are extremely efficient in depleting blood eosinophils from subjects with asthma [...].

Platelet association with leukocytes in active eosinophilic esophagitis.

We previously demonstrated that the percentage of blood eosinophils that are associated with platelets and thus positive for CD41 (integrin αIIb-subunit) correlates with and predicts peak eosinophil count (PEC) in biopsies of eosinophilic esophagitis (EoE) patients after treatment. Thus, flow cytometric determination of CD41+ eosinophils is a potential measure of EoE disease activity. Determinants of association of platelets with eosinophils and other leukocytes in EoE are largely unknown. The objectives of this study were to test the hypotheses that platelets associate with blood leukocytes other than eosinophils in EoE and that such associations also predict EoE activity. Whole blood flow cytometry was performed on samples from 25 subjects before and after two months of standard of care EoE treatment. CD41 positivity of cells within gates for eosinophils, neutrophils, monocytes, lymphocytes, and natural killer cells was compared. We found that percent CD41+ neutrophils, monocytes, and eosinophils correlated with one another such that principal component analysis of the five cell types identified "myeloid" and "lymphoid" factors. Percent CD41+ neutrophils or monocytes, or the myeloid factor, like CD41+ eosinophils, correlated with PEC after treatment, and CD41+ neutrophils or the myeloid factor predicted PEC < 6/high power field after treatment, albeit with lower area under the curve than for CD41+ eosinophils. We conclude that the processes driving platelets to associate with eosinophils in EoE also drive association of platelets with neutrophils and monocytes and that association of platelets with all three cell types is related to disease activity. Clinicaltrials.gov identifier: NCT02775045.

Eosinophil Knockout Humans: Uncovering the Role of Eosinophils Through Eosinophil-Directed Biological Therapies.

The enigmatic eosinophil has emerged as an exciting component of the immune system, involved in a plethora of homeostatic and inflammatory responses. Substantial progress has been achieved through experimental systems manipulating eosinophils in vivo, initially in mice and more recently in humans. Researchers using eosinophil knockout mice have identified a contributory role for eosinophils in basal and inflammatory processes and protective immunity. Primarily fueled by the purported proinflammatory role of eosinophils in eosinophil-associated diseases, a series of anti-eosinophil therapeutics have emerged as a new class of drugs. These agents, which dramatically deplete eosinophils, provide a valuable opportunity to characterize the consequences of eosinophil knockout humans. Herein, we comparatively describe mouse and human eosinophil knockouts. We put forth the view that human eosinophils negatively contribute to a variety of diseases and, unlike mouse eosinophils, do not yet have an identified role in physiological health; thus, clarifying all roles of eosinophils remains an ongoing pursuit.

Add-on tiotropium versus step-up inhaled corticosteroid plus long-acting beta-2-agonist in real-world patients with asthma.

Background: A step-up approach (increasing inhaled corticosteroid [ICS] dose and/or add-on treatment) is recommended for asthma that is uncontrolled despite ICS plus long-acting beta-2-agonist (LABA) combination treatment. Understanding the impact of different treatment options on health outcomes can help guide treatment decision-making. Objective: To compare the effectiveness of add-on tiotropium 1.25 µg (two puffs once daily) versus an increased ICS plus LABA dose in a real-world cohort of patients with asthma initiated on ICS plus LABA. Methods: De-identified data from patients ages ≥12 years and with asthma who were initiated on ICS plus LABA, and then had tiotropium added (Tio group; index date) or an ICS plus LABA dose increased (inc-ICS group; index date) were collected from two medical and pharmacy claims data bases (2014-2018). To account for population/group differences, propensity score matching was performed. The primary end point was the exacerbation risk after the index date. Secondary end points included exacerbation rates 6 and 12 months postindex, health-care resource utilization, costs, and short-acting beta-2-agonist (SABA) refills 12 months postindex. Results: Overall, 7857 patients (Tio group, 2619; inc-ICS group, 5238) were included. The exacerbation risk was 35% lower in the Tio group than in the inc-ICS group (hazard ratio 0.65 [95% confidence interval, 0.43-0.99]; p = 0.044). Exacerbation rates in the Tio group also were significantly lower within 6 and 12 months postindex (64% and 73%, respectively). All-cause and asthma-related emergency department (ED) visits were 47% and 74% lower, respectively (p < 0.0001 for both), and all-cause and asthma-related hospitalizations were 48% (p < 0.01) and 76% (p < 0.001) lower, respectively, in the Tio group. Also, significantly fewer patients in the Tio group versus the inc-ICS group required SABA refills (56% versus 67%, p < 0.0001). Conclusion: Add-on tiotropium significantly decreased the risk and rate of exacerbations, decreased all-cause and asthma-related ED visits and hospitalizations, and reduced SABA refills compared with increasing the ICS plus LABA dose. The findings supported the use of add-on tiotropium for patients with uncontrolled asthma taking ICS plus LABA.

Effect of clinically significant thresholds of eosinophil elevation on health care resource use in asthma.

BACKGROUND: Blood eosinophil counts correlate with exacerbations, but there is a lack of consensus on a clinically relevant definition of eosinophil count elevation. OBJECTIVE: To analyze health care resource use among patients with elevated blood eosinophil counts defined at 150 cells/µL or greater and 300 cells/µL or greater. METHODS: Data on patients who received a diagnosis of asthma between 2007 and 2016 were extracted from EMRClaims + database. Patients were defined as having elevated eosinophil counts if any test result during 3 months before follow-up found blood eosinophil count of 150 cells/µL or more or 300 cells/µL or more. Hospitalizations, emergency department visits, outpatient visits, and associated costs were compared. With logistic regression, likelihood of hospitalization was assessed in the presence of eosinophil elevation. RESULTS: Among 3687 patients who met the study criteria, 1152 received a test within 3 months before the follow-up period, of whom 644 (56%) had elevated eosinophil counts of 150 cells/µL or greater and 322 (29%) had eosinophil counts of 300 cells/µL or greater. Overall, the mean (SD) number of hospitalizations for patients with elevated eosinophil counts vs the comparator was significantly greater (0.29 [0.92] vs 0.17 [0.57], P < .001 at ≥150 cells/µL and 0.30 [0.95] vs 0.18 [0.61] at ≥300 cells/µL, P = .001). The total mean cost was significantly greater for patients with elevated eosinophil counts (at ≥150 cells/µL: $10,262 vs $7149, P < .001 and at ≥300 cells/µL: $9966 vs $7468, P = .003). CONCLUSION: Patients with asthma incurred greater health care resource use when their blood eosinophil counts were elevated at 150 cells/µL or greater and 300 cells/µL or greater as measured within 3 months of follow-up.

Safety of Eosinophil-Depleting Therapy for Severe, Eosinophilic Asthma: Focus on Benralizumab.

Eosinophils play a pivotal role in the inflammatory pathology of asthma and have been the target of new biologic treatments for patients with eosinophilic asthma. Given the central role of interleukin (IL)-5 in the eosinophil lifecycle, several therapies directed against the IL-5 pathway have been developed, including the anti-IL-5 antibodies mepolizumab and reslizumab and the IL-5 receptor α (IL-5Rα)-directed cytolytic antibody benralizumab. Eosinophil-depleting therapies represent a relatively new class of asthma treatment, and it is important to understand their long-term efficacy and safety. Eosinophils have been associated with host protection and tumor growth, raising potential concerns about the consequences of long-term therapies that deplete eosinophils. However, evidence for these associations in humans is conflicting and largely indirect or based on mouse models. Substantial prospective clinical trial and postmarketing data have accrued, providing insight into the potential risks associated with eosinophil depletion. In this review, we explore the current safety profile of eosinophil-reducing therapies, with particular attention to the potential risks of malignancies and severe infections and a focus on benralizumab. Benralizumab is an IL-5Rα-directed cytolytic monoclonal antibody that targets and efficiently depletes blood and tissue eosinophils through antibody-dependent cell-mediated cytotoxicity. Benralizumab is intended to treat patients with severe, uncontrolled asthma with eosinophilic inflammation. The integrated analyses of benralizumab safety data from the phase III SIROCCO and CALIMA trials and subsequent BORA extension trial for patients with asthma, and the phase III GALATHEA and TERRANOVA trials for patients with chronic obstructive pulmonary disease, form the principal basis for this review.

Orosomucoid-like 3 Supports Rhinovirus Replication in Human Epithelial Cells.

Polymorphism at the 17q21 gene locus and wheezing responses to rhinovirus (RV) early in childhood conspire to increase the risk of developing asthma. However, the mechanisms mediating this gene-environment interaction remain unclear. In this study, we investigated the impact of one of the 17q21-encoded genes, ORMDL3 (orosomucoid-like 3), on RV replication in human epithelial cells. ORMDL3 knockdown inhibited RV-A16 replication in HeLa, BEAS-2B, A549, and NCI-H358 epithelial cell lines and primary nasal and bronchial epithelial cells. Inhibition varied by RV species, as both minor and major group RV-A subtypes RV-B52 and RV-C2 were inhibited but not RV-C15 or RV-C41. ORMDL3 siRNA did not affect expression of the major group RV-A receptor ICAM-1 or initial internalization of RV-A16. The two major outcomes of ORMDL3 activity, SPT (serine palmitoyl-CoA transferase) inhibition and endoplasmic reticulum (ER) stress induction, were further examined: silencing ORMDL3 decreased RV-induced ER stress and IFN-ß mRNA expression. However, pharmacologic induction of ER stress and concomitant increased IFN-ß inhibited RV-A16 replication. Conversely, blockade of ER stress with tauroursodeoxycholic acid augmented replication, pointing to an alternative mechanism for the effect of ORMDL3 knockdown on RV replication. In comparison, the SPT inhibitor myriocin increased RV-A16 but not RV-C15 replication and negated the inhibitory effect of ORMDL3 knockdown. Furthermore, lipidomics analysis revealed opposing regulation of specific sphingolipid species (downstream of SPT) by myriocin and ORMDL3 siRNA, correlating with the effect of these treatments on RV replication. Together, these data revealed a requirement for ORMDL3 in supporting RV replication in epithelial cells via SPT inhibition.