Update on Omalizumab for Urticaria: What's New in the Literature from Mechanisms to Clinic

Burden of and Trends in Urticaria Globally, Regionally, and Nationally from 1990 to 2019: Systematic Analysis

BACKGROUND

Urticaria presents a significant global health challenge due to its sudden onset and potential for severe allergic reactions. Past data on worldwide prevalence and incidence is inconsistent due to differing study methodologies, regional differences, and evolving diagnostic criteria. Past studies have often provided broad ranges instead of specific figures, underscoring the necessity for a cohesive global perspective to inform public health strategies.

OBJECTIVE

We aimed to assess the global burden of urticaria using the 2019 Global Burden of Disease (GBD) study data and systematically analyze urticaria prevalence, incidence, and disability-adjusted life years (DALYs) at global, regional, and national levels, thereby informing more effective prevention and treatment strategies.

METHODS

We analyzed the global, regional, and national burden of urticaria from 1990 to 2019 using the 2019 GBD study coordinated by the Institute for Health Metrics and Evaluation. Estimations of urticaria prevalence, incidence, and DALYs were derived using DisMod-MR 2.1, a Bayesian meta-regression tool. The Socio-demographic Index (SDI) was used to correlate development status with health outcomes. The GBD's division of the world into 21 regions and 204 countries and territories facilitated a comprehensive assessment. Age-standardized estimated annual percentage changes were generated for urticaria metrics to quantify temporal trends, with age standardization adjusting for potential confounding from age structure.

RESULTS

From 1990 to 2019, the global age-standardized prevalence, incidence, and DALY rates of urticaria showed marginal changes. In 2019, 65.14 million individuals were affected, with a prevalence rate of 841.88 per 100,000 population. The DALY rate was 50.39 per 100,000 population. Compared to 1990, the global age-standardized prevalence, incidence, and DALY rates saw increases of 2.92, 4.84, and 0.31 per 100,000 population, respectively. Women persistently had higher rates than men. At a regional level in 2019, low-middle SDI regions exhibited the highest age-standardized metrics, whereas high SDI regions reported the lowest. Central Europe showed the highest rates, contrasting with Western Europe's lowest rates. Nationally, urticaria prevalence in 2019 varied dramatically, from a low of 27.1 per 100,000 population in Portugal to a high of 92.0 per 100,000 population in Nepal. India reported the most DALYs at 749,495.9, followed by China, Pakistan, and the United States. Agewise data showed higher rates in younger age groups, which diminished with age and then experienced a slight resurgence in the oldest populations. This pattern was pronounced in women and younger populations, with the largest rises seen in those aged less than 40 years and the smallest in those aged more than 70 years.

CONCLUSIONS

Urticaria remains a significant global health issue, with considerable variation across regions, countries, and territories. The increased burden among women, the rising burden in younger populations, and the regional differences in disease burden call for tailored interventions and policies to tackle this emerging public health issue.

Omalizumab for the treatment of severe allergic asthma in children: A tale of two

Omalizumab is a monoclonal antibody which targets immunoglobulin E. It is approved as an add-on therapy for children with severe allergic asthma. Assessment of endotype and phenotype is necessary in order to correctly identify those patients who are most likely to respond to omalizumab. Children with severe asthma represent a complex heterogeneous group. This report outlines the background, management, and outcomes for two children initiated on omalizumab for severe allergic asthma in Children's Health Ireland at Tallaght. It demonstrates the difficulties faced by this cohort and the positive impact targeted biological therapy can have. Given the substantial cohort of children with asthma attending our tertiary center, it also indicates that comprehensive stepwise care can achieve adequate control in the vast majority of cases without the requirement for additional therapies.

Multicentric and Observational Study of Omalizumab for Chronic Spontaneous Urticaria in Real-Life in Colombia

Background

Although chronic urticaria (CU) is a common, cause of medical consulting both in general practitioners and allergist specialists worldwide, there is little information about its behavior and management in Latin America. Currently, national and international guidelines recommend using Omalizumab for cases refractory to management with antihistamines. Despite advances in the knowledge of Omalizumab for the management of CU, although there are few studies in underdeveloped countries, there are many studies evaluating the impact of Omalizumab treatment. There is not clinical information related with CSU-Omalizumab in patient settled in the Caribbean area. This research aims to evaluate the management of CU with Omalizumab in a real-life scenario in Colombia.

Methodology

We conducted an observational, descriptive, and retrospective study with patient recruitment between 2014 and 2017 of individuals diagnosed with Chronic Urticaria (CU) treating allergology specialists in five Colombian cities. We included patients with CU who failed to achieve disease control after treatment for 4 weeks with fourfold doses of second-generation H1-antihistamines, as recommended by the EAACI/GA²LEN/EDF/WAO guidelines and who received treatment with Omalizumab.

Results

We included 123 patients, 73.1% (n = 90) were women. The mean age was 47.1 years (Standard Deviation, SD: 16.2). The median of the total months of disease evolution was 30 (IQR = 13–58). 81.3 % (n = 100) of patients were diagnosed with chronic spontaneous urticarial (CSU). 4.8% (n = 6) had inducible CU (CIndU), and 13.8% (n = 17) reported mixed urticaria (spontaneous CU with at least one inducible component). Regarding emotional factors, 34.9% (n = 43) of subjects indicated anxiety symptoms, 34.1% (n = 42) had exacerbations associated with stress, and 14.6% (n = 18) manifested episodes of sadness. The percentage of patients with CSU controlled according to medical criteria at 3 months with Omalizumab were 80% (n = 80/100) and at 6 months 87% (n = 87/100). The frequency of adverse events was 29.2% (n = 36), with headache being the most frequent adverse event.

Conclusions

This real-life study with Omalizumab at CU describes percentages of effectiveness and safety similar to those observed in pivotal and real-life studies conducted in other regions around the world.

Expert consensus on the use of omalizumab in chronic urticaria in China

Chronic urticaria (CU) is a debilitating skin disease that lasts for more than 6 weeks with wheals and/or angioedema, including chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU). In China, the prevalence of this disease is high, more than 1%, and on the rise. CU has a major impact on the quality of life (QoL) of patients who frequently experience sleep disturbance, depression, and anxiety. Nearly one-third of patients with CSU, in China, are resistant to second-generation H1-antihistamines (sgAHs), even at a fourfold dose (second line; off-label). Omalizumab is approved for the treatment of CSU treatment in Europe and shows remarkable efficacy and safety. In China, regulatory approval for the use of omalizumab is pending, and its use in clinical practice varies widely. Consensus on omalizumab CU treatment in China is urgently needed. The aim of this article is to propose a practical omalizumab treatment algorithm for the management of antihistamine-resistant CSU and CIndU in adults and special population including children and adolescents, and pregnant or breast feeding women, to guide daily clinical practice in China. In the development of this consensus, an expert group including mainly dermatologists, allergists, but also pulmonologists, ENTs, immunologists, and pediatricians in Allergic Disease Prevention and Control Committee, Chinese Preventive Medicine Association, reviewed the existing evidence and developed consensus on the use of omalizumab in CU patients from China. The goal of this consensus is to assist clinicians in making rational decisions in the management of refractory CU with omalizumab. The key clinical questions covered by the treatment algorithm are: 1) Omalizumab treatment routine strategy in both CSU and CIndU patients; 2) Recommended dose and treatment duration for different age stratification; 3) Treatment duration for CU patients with other allergic comorbidities; 4) Recommendation on omalizumab stopping strategy.

Chronic urticaria in children under 15 years of age: Clinical experience beyond the clinical trials

BACKGROUND/OBJECTIVES

The aim of the study was to describe the clinical characteristics, management, and outcome of a series of children with chronic urticaria (CU).

METHODS

We retrospectively studied children aged <15 years diagnosed with CU in a tertiary teaching hospital in Palma de Mallorca, Spain, between January 2014 and March 2019. CU was defined as persistence of symptoms of wheals, with or without angioedema, for >6 weeks.

RESULTS

Twenty-nine patients (17 girls, mean age 8 years) were included. Family history of atopy was found in 31% of the cases. In 41.3% of patients, episodes of CU were associated with angioedema. Physical triggers were found in 34.5% of the cases. Most episodes of CU were successfully managed with the recommended (60.7%) or double the recommended dose (17.2%) of H1-antihistamines. Quadruple the recommended dose of H1 antihistamines was used in six patients, five of whom were finally treated with off-label omalizumab. Treatment with anti-leukotrienes was needed in one patient. Associated thyroiditis was diagnosed in one patient, which was controlled with levothyroxine.

CONCLUSIONS

Pediatric CU showed features similar to CU in adulthood, including a greater predominance in females and frequent association with personal or family history of atopy. Adult guidelines for the treatment of CU are currently extrapolated to the pediatric population. Specific tools for the assessment of disease activity and impairment of quality of life in pediatric CU are needed for use in prospective studies aimed to define treatment strategies for children with CU.

Omalizumab Updosing in Chronic Spontaneous Urticaria: an Overview of Real-World Evidence

Chronic spontaneous urticaria (CSU) is defined as the spontaneous development of itchy hives and/or angioedema due to known or unknown causes that last for at least 6 weeks. At any given time, CSU is believed to affect 0.5–1% of the global population. Omalizumab (a recombinant, humanized anti-immunoglobulin-E antibody) is the only approved treatment for antihistamine refractory CSU. However, ~ 30% of patients remain symptomatic at licensed doses of omalizumab 150 mg and 300 mg, even after a treatment period of over 6 months. In the recent years, there have been several studies on updosing of the drug, suggesting that the individualized approach for urticaria treatment with omalizumab is useful. In this article, we provide an overview of these studies and the real-world data on omalizumab updosing as it became necessary to obtain complete CSU symptom control in a proportion of patients. Published observational studies (from June 2003 to October 2019) on the updosing of omalizumab in CSU were identified using PubMed and Ovid databases. Reports mainly show that updosing/dose adjustment evaluated with the assessment of disease activity (Urticaria Activity Score) and control (Urticaria Control Test) achieves better clinical response to omalizumab with a good safety profile in a pool of patients with CSU. These real-world data will provide an overview of updosing of omalizumab in CSU and aid in setting informed clinical practice treatment expectations.

Advances and novel developments in molecular allergology

The continuous search for new allergens and the design of allergen derivatives improves the understanding of their allergenicity and aids the design of novel diagnostic and immunotherapy approaches. This article discusses the recent developments in allergen and epitope discovery, allergy diagnostics and immunotherapy. Structural information is crucial for the elucidation of cross-reactivity of marker allergens such as the walnut Jug r 6 or that of nonhomologous allergens, as shown for the peanut allergens Ara h 1 and 2. High-throughput sequencing, liposomal nanoallergen display, bead-based assays, and protein chimeras have been used in epitope discovery. The binding of natural ligands by the birch pollen allergen Bet v 1 or the mold allergen Alt a 1 increased the stability of these allergens, which is directly linked to their allergenicity. We also report recent findings on the use of component-resolved approaches, basophil activation test, and novel technologies for improvement of diagnostics. New strategies in allergen-specific immunotherapy have also emerged, such as the use of virus-like particles, biologics or novel adjuvants. The identification of dectin-1 as a key player in allergy to tropomyosins and the formyl peptide receptor 3 in allergy to lipocalins are outstanding examples of research into the mechanism of allergic sensitization.

Efficacy of omalizumab treatment for pediatric chronic spontaneous urticaria: A multi-center retrospective case series

BACKGROUND

Chronic urticaria is defined by the presence of itchy wheals, sometimes accompanied by angioedema, lasting for at least 6 weeks. In children, most cases occur without an eliciting factor and are defined as chronic spontaneous urticaria (CSU). CSU affects up to 0.75% of children with a negative impact on quality of life and school performance. CSU is treated in adults with second-generation antihistamines, increased up to four times normal doses for second-line treatment. Omalizumab (a monoclonal antibody to IgE) may be recommended as third-line therapy. A similar protocol is used in children, yet little is known of its efficacy and safety.

OBJECTIVES

To summarize our multi-center experience in treating children with recalcitrant CSU with omalizumab.

METHODS

A retrospective multi-center case series conducted in 5 tertiary care centers in Israel. Patients included were children <18 years old diagnosed with recalcitrant CSU who were treated with omalizumab. Patients were followed up throughout the duration of omalizumab therapy/symptom remission. Patients' electronic medical records were used to gather data.

RESULTS

Nineteen participants (11 F; 8 M) presented with CSU between ages 6 and 16.9 years. Sixteen (84%) responded to omalizumab, including children <12 years old, although two became non-responsive after 6-12 months of therapy. Another three patients (16%) were resistant to treatment, achieving remission through fourth-line (Cyclosporine A) or other therapies.

CONCLUSION

Children with recalcitrant CSU, even those <12 years old, respond well to standard-dose, third-line omalizumab therapy at rates similar to adults. Yet, some cases may become non-responsive with ongoing treatment.

Omalizumab usage in chronic urticaria and atopic dermatitis: data from South-East province of Turkey

Introduction

Omalizumab is a current treatment option for IgE-associated dermatoses, such as urticaria and atopic dermatitis.

Aim

To evaluate the clinical and laboratory findings of patients with chronic urticaria and atopic dermatitis who received omalizumab.

Material and methods

This study was planned as a cross-sectional and retrospective one. One hundred forty-six cases were included in the study. Omalizumab at a dose of 300 mg for patients with chronic urticaria and 600 mg for patients with atopic dermatitis, was given every 4 weeks. The response to the given treatment and remission status of patients were investigated.

Results

Of 146 patients included in the study, 70.5% (n = 103) were female and their mean age was 42.3 ±13.8 (min.–max.: 14–85). Of the patients, 136 had chronic urticaria and 10 had atopic dermatitis. 29.9% (n = 26) of patients with chronic urticaria had a complete response to omalizumab treatment, whereas 40% (n = 4) of patients with atopic dermatitis had remission.

Conclusions

The decline of complaints with different treatment schemes in different patients suggests that treatment should be designed individually and that personal biomarkers playing a role in the effectiveness of the drug are important. Patients with the high IgE and eosinophil percentages and positive autologous serum test had a better treatment response to omalizumab treatment. Meanwhile, remission was found to be more frequent in atopic dermatitis patients with omalizumab treatment compared to the patients with urticaria. It may be more appropriate to choose patients based on certain criteria to ensure cost-effectiveness in omalizumab treatment.

Structural and clinical impact of anti-allergy agents: An overview

Allergic disorders are markedly rising in industrialized countries. The identification of compounds that trigger the immunoglobulin E (IgE)-dependent allergic reaction remain the means to improve the quality of life by limiting patient's exposure to critical allergens. Information concerning the treatment and onset of allergic disorders including atopic dermatitis, allergic rhinitis, and bronchial asthma has been provided by the research over the past decade. Recent studies also indicated that allergic inflammation is associated closely with their exacerbation and progression and indeed is the basic pathophysiology of allergic diseases. As a result of immunological and molecular biological studies our understanding of the mechanism of allergic inflammation with regard to therapeutic agents has improved. While much effort has been paid to developing a new anti-allergic agent, the allergic disease has yet to be completely conquered. The more extensive research will allow the development of new therapeutics to combat allergic diseases. Currently, with respect to mechanism of action anti-allergy drugs are classified into five types including histamine H₁ antagonists, leukotriene antagonists, Th₂ cytokine inhibitors, thromboxane A₂ inhibitors and mediator-release inhibitors. The use of two or more anti-allergy agents together is not acknowledged at present, but this will be the subject of research in the future because with different mechanisms of action anti-allergy agents used at the same time will theoretically increase their effects. This review article focuses on anti-allergy agents highlighting their applications, clinical trials and recent advancement on drugs.

Ligelizumab for Chronic Spontaneous Urticaria

BACKGROUND

In the majority of patients with chronic spontaneous urticaria, most currently available therapies do not result in complete symptom control. Ligelizumab is a next-generation high-affinity humanized monoclonal anti-IgE antibody. Data are limited regarding the dose-response relationship of ligelizumab and the efficacy and safety of ligelizumab as compared with omalizumab and placebo in patients who have moderate-to-severe chronic spontaneous urticaria that is inadequately controlled with H₁-antihistamines at approved or increased doses, alone or in combination with H₂-antihistamines or leukotriene-receptor antagonists.

METHODS

In a phase 2b dose-finding trial, we randomly assigned patients to receive ligelizumab at a dose of 24 mg, 72 mg, or 240 mg, omalizumab at a dose of 300 mg, or placebo, administered subcutaneously every 4 weeks for a period of 20 weeks, or a single 120-mg dose of ligelizumab. Disease symptoms of hives, itch, and angioedema were monitored by means of weekly activity scores. The main objective was to determine a dose-response relationship for the complete control of hives (indicated by a weekly hives-severity score of 0, on a scale from 0 to 21, with higher scores indicating greater severity); the primary end point of this response was assessed at week 12. Complete symptom control was indicated by a weekly urticaria activity score of 0 (on a scale from 0 to 42, with higher scores indicating greater severity). Safety was analyzed throughout the trial.

RESULTS

A total of 382 patients underwent randomization. At week 12, a total of 30%, 51%, and 42% of the patients treated with 24 mg, 72 mg, and 240 mg, respectively, of ligelizumab had complete control of hives, as compared with 26% of the patients in the omalizumab group and no patients in the placebo group. A dose-response relationship was established. At week 12, a total of 30%, 44%, and 40% of the patients treated with 24 mg, 72 mg, and 240 mg, respectively, of ligelizumab had complete control of symptoms, as compared with 26% of the patients in the omalizumab group and no patients in the placebo group. In this small and short trial, no safety concerns regarding ligelizumab or omalizumab emerged.

CONCLUSIONS

A higher percentage of patients had complete control of symptoms of chronic spontaneous urticaria with ligelizumab therapy of 72 mg or 240 mg than with omalizumab or placebo. (Funded by Novartis Pharma; ClinicalTrials.gov number, NCT02477332.).

Real-life approach and treatment of chronic urticaria in Argentina: A National Survey

The management of chronic urticaria (CU) has been controversial. Recently updated international guidelines propose evidence-based diagnosis and treatment. Nevertheless, dermatologists have heterogeneous approaches to managing CU. To estimate the percentage of dermatologists who have an optimal approach to CU according to the international guidelines, and to explore the variables associated with optimal management a cross-sectional study using a 17-question survey was delivered by email to dermatologists from Argentina. Optimal first, second, and third line treatment were considered when dermatologists chose a nonsedative antihistamine; increased the dosage of nonsedative antihistamines, and added omalizumab, respectively. Logistic regression was used to identify variables associated with optimal management. A total of 165 questionnaires were available for analysis. An optimal first, second, and third-line treatment approach was identified in 50%, 35%, and 15% of the dermatologists, respectively. The dermatologists' age being above 55 years old (OR: 0.12, 95% CI: 0.01-0.99, p .005) and having more than 5 years of expertise (OR: 0.4, 95% CI: 0.19-0.81, p .001) were significantly associated with a suboptimal approach in second-line treatment. We could not find variables associated with an optimal first or third-line treatment. The real-life management of CU in Argentina is partly suboptimal according to the international guidelines.

A retrospective analysis omalizumab treatment patterns in patients with chronic spontaneous urticaria: a real-world study in Belgium

Background

Chronic spontaneous urticaria (CSU) is characterized by the repeated occurrence of persistent hives and/or angioedema for ≥6 weeks, without specific external stimuli. H₁‐antihistamines have long been the standard of care of CSU, but many patients remain uncontrolled even at 4× the approved dose. Add‐on therapy with omalizumab has proven effective in clinical trials, but little is known about omalizumab treatment in Belgium.

Objective

To collect real‐world clinical data on omalizumab treatment in adults with CSU in Belgium.

Methods

This was an observational, retrospective chart review of adults with CSU, who initiated omalizumab treatment between August 2014 and December 2016 (maximum 28 months follow‐up).

Results

In total, 235 patients were included (median time from symptom onset to diagnosis, 5.4 months; median time from diagnosis to commencing omalizumab, 6.7 months). Treatments used before/after commencing omalizumab did not always adhere to guidelines; many patients (26.4%/11.1%) received first‐generation H₁‐antihistamines, while 20.4% used omalizumab monotherapy after initiating treatment. The mean interval between omalizumab administrations was 4.8 (SD 1.7) weeks; 67.8% of patients had ≥1 interval prolongation and/or shortening. Mean baseline 7‐day Urticaria Activity Score (UAS7) was 32.0 (SD 6.05); this improved to 12.6 (SD 11.2) after 1 month of omalizumab. About 67.2% of patients reached UAS7 ≤ 6 (well controlled) during the study. A total of 87 patients stopped omalizumab and never restarted before the end of the observation period; the most prevalent reason was remission of symptoms (49.4% of patients), followed by lack of effect (12.6%), lost to follow‐up (6.9%) and adverse events (3.4%). Headache was the most common adverse event (n = 8/82). No anaphylaxis was reported.

Conclusions

This study revealed that patients initiated on omalizumab in Belgium had severe CSU at baseline, and showed substantial improvements after 1 month of treatment. Greater adherence to the prescription of guideline‐recommended medications is needed for the treatment of CSU.

Learnings from real-life experience of using omalizumab for chronic urticaria in Latin America

Background

Updated urticaria guidelines recommend that patients should be assessed for disease activity, severity, control, and quality of life at baseline and follow up. Regarding treatment, guidelines consider second generation antihistamines as the cornerstone in therapy for chronic urticaria (CU), while other drugs, such as omalizumab, are conceived as second-line alternatives. In regards to omalizumab, despite advances in the management of CU, there are still open questions about timing, dosing, and objective measures for clinical response. This study was designed to portray the use of patient-reported outcomes (PROs) in chronic urticaria management, as well as the effectiveness and treatment patterns of omalizumab in CU, as seen in a real-life setting in Latin America.

Methods

This is a retrospective observational study, involving 72 Latin American patients with chronic urticaria treated with omalizumab. Patient reported outcomes and treatment patterns, response, quality of life improvement and discontinuation were analyzed.

Results

From the 72 patients, 91.7% (n = 66) were assessed through PROs, where urticaria control test (UCT) was the most used (79.2%; n = 57). Overall, 80.0% (n = 44) responded to omalizumab at some point of the treatment. Omalizumab 300 mg was associated with earlier response compared to lower doses. Regardless of dosage, most patients assessed with CU-Q2oL improved quality of life (80.8%; n = 21). With respect to omalizumab discontinuation, 20.8% (n = 15) patients interrupted omalizumab before the 3rd month of treatment (p = .000).

Conclusions

The present study highlights how the use of PROs and omalizumab in Latin America differ from guidelines' recommendations and clinical trials. Even though most patients were initiated under omalizumab 300 mg, most of them finished with lower doses. Regardless of dosage, most patients responded to omalizumab and improved quality of life at some point during treatment. However, such features were seen earlier with omalizumab 300 mg. Regarding treatment discontinuation, one-fifth of patients interrupted omalizumab before the third month.

Treatment of chronic spontaneous urticaria with an inadequate response to H1-antihistamine

The second-generation H1-antihistamines (sgAH) are the first-line symptomatic treatment of patients with chronic spontaneous urticaria (CSU). Up to 50% of the patients will not respond to licensed doses of sgAH. According to the guidelines, the dose of sgAH may be increased up to 4 times the conventional dose. However, even at higher doses, there is a subgroup of patients refractory to the antihistamine treatment. The purpose of this article was to review the different treatment options of antihistamine-refractory CSU patients. This revision examines the available literature for therapies used in chronic urticaria, including omalizumab, ciclosporin A, oral glucocorticoids, leukotriene receptor antagonists, H2 antihistamines, doxepin, dapsone, hydroxychloroquine, phototherapy, methotrexate, mycophenolate mofetil, azathioprine, autohemotherapy, intravenous immunoglobulins and rituximab, between others. After the exhaustive review of the medical literature only few high-quality studies have been identified, mostly for omalizumab. Omalizumab is an anti-immunoglobulin E monoclonal antibody, approved for the treatment of CSU, that has radically changed the management of the patients without good response to sgAH, allowing to reach complete responses in a high percentage of patients. Although actually the therapeutic management of CSU is more effective and safer than before 2014, there is place even for new and more effective treatments. A good number of partial responders and slow responders to omalizumab and a little percentage still of non-responders to available therapies stimulate the development of new drugs that will also be discussed.

Activation of Human Peripheral Basophils in Response to High IgE Antibody Concentrations without Antigens

Basophils and mast cells have high affinity IgE receptors (FcεRI) on their plasma membrane and play important roles in FcεRI-associated allergic diseases, such as pollen allergy, food allergy, chronic spontaneous urticarial (CSU), and atopic dermatitis (AD). To date, several reports have revealed that high IgE antibody concentrations activate mast cells—which reside in tissue—in the absence of any antigens (allergens). However, IgE antibody-induced activation of basophils—which circulate in blood—has not been reported. Here, we investigated whether IgE antibodies may regulate functions of human peripheral basophils without antigens in vitro. We successfully removed IgE antibodies bound to FcεRI on the surface of human peripheral basophils by treating with 0.1% lactic acid. We also demonstrated that high IgE antibody concentrations (>1 μM) induced histamine release, polarization, and CD203c upregulation of IgE antibody-stripped basophils. Thus, high IgE antibody concentrations directly activate basophils, which express IgE-free FcεRI on the cell surface. This mechanism may contribute to the pathogenesis of patients with AD and CSU who have higher serum IgE concentrations compared to healthy donors.

Chronic spontaneous urticaria treated with omalizumab: report of two cases

Background: Chronic spontaneous urticaria (CSU) is a relatively common skin disease whose etiopathogenesis, as well as other factors influencing disease manifestations, are not fully understood. Mast cell function is recognised as having a central role in CSU signs and symptoms. Therapeutic options are limited; a number of drugs, recommended by international guidelines for the management of urticaria, lack regulatory approval for CSU and are prescribed off label. Omalizumab, a recombinant humanized anti IgE antibody, has recently received the approval for CSU treatment in Europe after an appropriate clinical development. Patients and results: Two case reports, that describes our encouraging experience with this therapeutic option in a real-life setting are discussed and deeply investigate the different scenario for the omalizumab use. Conclusion: In both cases, a complete remission of CSU symptoms after omalizumab treatment are demonstrated. Moreover, 6 months therapy gave the better results, whit a relapse, in one subject, 1 month after discontinuing omalizumab. Accordingly, a better understanding of long-term safety and efficacy should be needed to allow long-term administration in responding patients through a changing in prescription rules.