Successful prevention of recurrent anaphylactic events with anti-immunoglobulin E therapy

Use of omalizumab for management of idiopathic anaphylaxis: A systematic review and retrospective case series

BACKGROUND

Patients with idiopathic anaphylaxis (IA) may fail to respond to a combination of high-dose H₁ and H₂ antihistamines and mast cell stabilizers. Treatment options for these patients are currently limited.

OBJECTIVE

To describe the clinical experience of omalizumab use for the treatment of patients with IA with no evidence of underlying clonal mast cell disorders.

METHODS

We performed a retrospective review at 2 separate institutions of medical records of patients with a diagnosis of IA without evidence of mast cell clonality who had received treatment with omalizumab. We searched PubMed for studies describing omalizumab use in similar patients. Information on symptoms and omalizumab therapy was compiled, and response pattern of anaphylaxis was determined.

RESULTS

A total of 35 patients with IA and no evidence of mast cell clonality who received omalizumab were identified. The median age was 36 years at the start of omalizumab (range, 11-54 years; n = 29). The frequency of anaphylaxis episodes before omalizumab treatment varied from 2 total episodes to several episodes per month. The most often used initial omalizumab dose was 300 mg every 4 weeks (n = 16). Most patients ultimately achieved clinical response after starting omalizumab: complete response (63%, n = 22), partial response (28.5%, n = 10), with 3 nonresponders.

CONCLUSION

Omalizumab may be an effective treatment option for patients with IA who do not have evidence of mast cell clonality and fail to respond to antihistamines and mast cell stabilizers.

Successful prevention of severe allergic transfusion reactions with omalizumab

BACKGROUND

Allergic transfusion reactions (ATRs) are a common adverse reaction to transfusion therapy and can be potentially fatal. Washing blood products is the most effective strategy for preventing ATRs; however, washed products, especially platelets, are not available at many blood centers.

STUDY DESIGN AND METHODS

A 29-year-old female patient with an advanced myelodysplastic/myeloproliferative neoplasm, unclassifiable, developed severe ATRs after four platelet transfusions in a week. She showed no response to premedication with histamines and steroids and still had severe ATRs with the next three platelet transfusions. A laboratory workup revealed that her IgA level was slightly decreased, while her haptoglobin level was normal. Anti-IgA testing was not available. The patient decided to undergo allogeneic peripheral blood stem cell (PBSC) transplantation. As the onset of symptoms ATR, which were similar to Type 1 hypersensitivity reactions mediated by IgE antibodies, occurred immediately after transfusion and omalizumab is a humanized monoclonal anti-IgE, we elected to offer off-label use of omalizumab before administering the conditioning regimen.

RESULTS

Omalizumab was injected subcutaneously at a dose of 150 mg. Surprisingly, transfusion reactions fully resolved within 24 hours. No serious side effects were noticed. Another 150 mg of omalizumab was administered 1 day before PBSC infusion. The patient remained asymptomatic without any signs of ATRs throughout the whole period of transplantation. Seven months after transplantation, the patient was in complete remission without overt complications.

CONCLUSION

This case suggests that omalizumab is a promising new alternative treatment for the prevention of severe ATRs.

Human(ized) monoclonal antibodies in atopic patients - state of the art

Asthma is an important chronic disease affecting a lot of people worldwide. Treatment options for asthma like biological agents are being developed more frequently nowadays. Despite a lot of treatment options, some patients still remain symptomatic. As more and more practitioners choose treatment with biologic agents as a convenient way of therapy, biologic agents and other valuable methods must be discovered in order to cope with a growing number of treatment agents. This manuscript emphasizes on new generation monoclonal human(ized) antibodies in asthmatics and off-label use . The first developed biologic agent is the anti-immunoglobulin E monoclonal antibody called omalizumab. Currently it is an approved treatment option for asthma.

Management Strategies Of Idiopathic Anaphylaxis In The Emergency Room: Current Perspectives

Background

Idiopathic anaphylaxis (IA) is a diagnosis of exclusion and represents a major diagnostic and management challenge. There are no current guidelines for diagnosis and management of IA. We aim to present a systematic review of the literature on adult and pediatric IA.

Methods

We conducted a systematic review of original articles published in the past 22 years regarding diagnosis and management strategies of adult and pediatric IA.

Results

The current proposed diagnostic approach and treatment regimens are based on a few small studies. Future large-scale studies are required. IA is a diagnosis of exclusion and should be made only after extensive evaluation excludes potential anaphylaxis triggers as well as non-allergic conditions with a similar presentation. There is currently no diagnostic consensus for IA. Furthermore, the current proposed treatment regimens are limited and rely on prophylactic treatment with antihistamines and prednisone for patients with frequent episodes. However, daily treatment with systemic steroids has well-recognized serious adverse effects. More recently, the use of biologics was suggested to benefit patients with IA, although the optimal management protocol is not yet established.

Conclusion

Future studies are needed to optimize diagnosis and treatment strategies in adult and pediatric cases of IA. Omalizumab may be a promising novel therapeutic option for adult and pediatric IA.

Anti-IgE Treatment for Disorders Other Than Asthma

Immunoglobulin E (IgE) plays a key role in the pathogenesis of many allergic diseases. Thus, IgE-mediated immunologic pathways are an attractive target for intervention in allergic diseases. Omalizumab is a recombinant humanized monoclonal antibody that binds IgE and has been used treat allergic asthma for over a decade. Currently, omalizumab is approved for the treatment of both allergic asthma and chronic spontaneous urticaria. Since IgE plays a critical role in other allergic diseases, anti-IgE therapy has been evaluated in other allergic diseases in small clinical trials and case reports. Omalizumab has demonstrated efficacy in treating allergic rhinitis, atopic dermatitis, physical urticarias, mast cell disorders, food allergy, and other allergic diseases. In addition, the use of omalizumab with conventional allergen immunotherapy improves both safety and effectiveness.

Omalizumab's role in the treatment of steroid dependent malignant idiopathic anaphylaxis

If an anaphylaxis episode is not caused by an identifiable trigger, it is defined as idiopathic anaphylaxis. Although it is rarely observed, idiopathic anaphylaxis is clinically significant because of its morbidity and fatality risk. No effective treatment has been demonstrated to date. We report a girl aged 16 years who had had malignant idiopathic anaphylaxis since the age of 12 years who was treated successfully with omalizumab. Although she avoided allergic trigger foods such as tomato and seafood, she used to have these attacks twice a week. Attacks were averted by taking 60 mg prednisone. When prednisone was tapered down to 5 mg on every alternate day, the episodes recurred. Later, attacks could not be controlled on <30 mg of prednisone daily. After being steroid-dependent for 4 years, subcutaneous omalizumab 225 mg every two weeks was started. Under omalizumab therapy, the attacks disappeared and prednisone was discontinued.

Off-Label Uses of Omalizumab

The off-label use of medicines is a common and extensive clinical practice. Omalizumab has been licensed for use in severe allergic asthma and chronic urticaria. Omalizumab dosing was based on body weight and baseline serum IgE concentration. All patients are required to have a baseline IgE between 30 and 700 IU/ml and body weight not more than 150 kg. The use of off-label drugs may lead to several problems including adverse effects and an increased risk/benefit balance. In this article, there are summarized off-label uses of omalizumab in the last recent years in diseases in which IgE maybe or certainly has a corner role such as allergic rhinitis, allergic bronchopulmonary aspergillosis, anaphylaxis, keratoconjunctivitis, food allergy, drug allergy, urticaria, angioedema, non-atopic asthma, atopic dermatitis, nasal polyps, Churg-Strauss syndrome, eosinophilic otitis media, chronic rhinosinusitis, bullous pemphigoid, contact dermatitis, and others. Use in pregnancy asthmatic women and pre-co-administration with specific immunotherapy will also be revised.

SplitCore Technology Allows Efficient Production of Virus-Like Particles Presenting a Receptor-Contacting Epitope of Human IgE

Immunoglobulin E (IgE) plays a central role in type I hypersensitivity including allergy and asthma. Novel treatment strategy envisages development of a therapeutic vaccine designed to elicit autologous blocking antibodies against the IgE. We sought to develop an IgE-epitope antigen that induces antibodies against a receptor-contacting epitope on human IgE molecule. We designed the VLP immunogens which utilize hepatitis B virus core protein (HBcAg) as a carrier, and present arrays of the receptor-contacting epitopes of the human IgE on their surfaces. FG loop from the IgE domain Cε3 was engineered into the HBcAg. Two constructs explore a well-established approach of insertion into a main immunodominant region of the HBcAg. Third construct is different in that the carrier is produced in a form of an assembly of two polypeptide chains which upon expression remain associated in a stable VLP-forming subunit (SplitCore technology). No VLPs were isolated from E.coli expressing the IgE-epitope antigens with contiguous sequences. On the contrary, the SplitCore antigen carrying the FG loop efficiently formed the VLPs. Immunization of mice with the VLPs presenting receptor-contacting epitope of the IgE elicited antibodies recognizing the human IgE in ELISA.