anti-IgE Receptor Research Articles

Human Neutrophils Couple Nitric Oxide Production and Extracellular Trap Formation in Allergic Asthma.

Rationale: Nitric oxide (NO) is increased in the airways and serum of patients with allergic asthma, suggesting an important role in asthma. NO production has been widely attributed to the canonical inducible NO synthase. Much effort has been made to inhibit this enzyme, with two outcomes: no asthma improvement and partial NO reduction, suggesting the involvement of an inducible NO synthase-independent source. Objectives: Neutrophils produce NO under inflammatory conditions, and their role in asthma has been overlooked. The present study analyzes their possible role as sources of NO. Methods: Our hypothesis was tested in 99 allergic patients with intermittent bronchial asthma and 26 healthy donors. NO production by blood and sputum neutrophils in response to allergens, anti-IgE, and anti-IgE receptor antibodies was assessed by Griess reagent, flow cytometry, and confocal microscopy. The formation of extracellular traps (ETs) as a possible consequence of NO production was quantified by Western blot and confocal microscopy, and reactive oxygen species were assessed with luminol-enhanced chemiluminescence. Measurements and Main Results: Among blood and sputum granulocytes from patients with allergic asthma, only neutrophils produce NO by an IgE-dependent mechanism. This production is independent of NO synthase, but dependent on a reaction between L-arginine and reactive oxygen species from NOX2 (NADPH oxidase). NO and ETosis are induced in parallel, and NO amplifies ET formation, which is a key mediator in asthma. Conclusions: Our findings reveal a novel role of neutrophils as the unique allergen/IgE-dependent NO source in allergic asthma, enhancing ET formation. These results suggest that NO produced by neutrophils needs further consideration in the treatment of allergic asthma.

Rituximab as Treatment of Chronic Idiopathic Urticaria

Conventional treatment of chronic idiopathic urticaria involves high doses of antihistamines followed by omalizumab in refractory cases, however, there are patients who do not achieve resolution of symptoms despite both of these therapies. The following case series describes two cases of chronic idiopathic urticaria successfully treated with rituximab. The first patient is a 43 year-old woman with psoriatic arthritis and autoimmune thyroiditis who presented to us with chronic idiopathic urticaria. She was found to have elevated levels of anti-IgE receptor antibodies with levels greater than maximum level of detection. She was unresponsive to high doses of antihistamines, cyclosporine, prednisone, dapsone, mycophenolate mofetil, hydroxychloroquine, and omalizumab and ultimately trialed on rituximab with complete resolution of urticaria. Our second patient is a 49 year-old woman with multiple sclerosis, allergic rhinitis, and atopic dermatitis who was referred with humoral immunodeficiency. She was diagnosed with common variable immune deficiency and started on SQ immune globulin therapy. She also had long-standing generalized urticaria refractory to antihistamines which responded to rituximab started by her neurologist for a flare of her multiple sclerosis. Use of rituximab in treatment of chronic idiopathic urticaria is not well documented in literature today and should be entertained as possible therapy for cases of treatment-resistant chronic urticaria, especially in the setting of other autoimmune conditions.

Polish Society of Allergology statement on the diagnosis and treatment of severe, difficult-to-control bronchial asthma.

Severe asthma requires at least high doses of inhaled corticosteroids (ICS) in combination with a long-acting β-agonist (LABA) or systemic corticosteroids (SCS) for more than 50% of days/year to avoid loss of control, or remains uncontrolled despite the treatment described above. The diagnosis of severe asthma should be confirmed in a reference centre as it requires careful differential diagnosis and the exclusion of factors hindering the achievement of optimal control. Severe asthma represents a significant burden for the patient, their family and the healthcare system. This is due to the severity of the symptoms, drug costs, significant impairment of everyday functioning and life quality, and limitation in the professional work. In the case of ineffectiveness of the step 4 GINA treatment, the patient should be referred to a specialist centre to consider additional treatment, including anti-IgE receptor (omalizumab), anti-IL-5 receptor (mepolizumab), or an antibody directed against the α-subunit of receptor for IL-5 (benralizumab). In the case of severe asthma, intensification of therapy should first of all include biological therapy and not the use of SCS. Biological drugs are available in Poland as a part of the therapeutic programme for the treatment of severe asthma. In practice, the therapeutic programme may change with subsequent notices of the Ministry of Health and does not have to be consistent with the Summary of Product Characteristics for individual preparations. The current review presents the basic principles of differential diagnosis of severe asthma and the selection of the optimal biological therapy in Polish conditions.

In vitro detection of allergen sensitized basophils by HSA-DNP antigen-anchored liquid crystal microdroplets

A simple and easy to handle biosensing technique for in vitro detection of HSA-DNP antigen induced allergen reactions in patients has been developed through the detection of sensitized basophils expressed with anti-IgE receptor (FcεRI) by using human serum albumin-dinitrophenol (HSA-DNP) antigen-anchored liquid crystal (LC) microdroplets emulsion. The radial to bipolar transition in nematic 4-cyano-4′-pentyl biphenyl liquid crystal molecules (5CB) confined in HSA-DNP antigen anchored LC microdroplets (8.5 pg HSA-DNP/LC microdroplet) is found to be sensitive in PBS solution in detection of allergen sensitized basophils expressed with a minimum amount of anti HSA-DNP (anti-IgE) receptor (≥4.5 pg/basophil). The detection of allergen sensitized basophils was possible within a contact time of 30 min in presence of control cells and with 10% solution of human blood plasma. The HSA-DNP antigen anchored LC microdroplets in presence of macrophages or non-sensitized basophils did not show radial to bipolar transition in 5CB molecules in PBS or solution with 10 wt% human blood plasma. Thus HSA-DNP antigen anchored LC microdroplets biosensor may be used for in vivo detection of stage I allergen reaction basophils in blood samples.

Charge-conversional polyprodrug amphiphiles for intracellular dual-responsive drug delivery

A simple and easy to handle biosensing technique for in vitro detection of HSA-DNP antigen induced allergen reactions in patients has been developed through the detection of sensitized basophils expressed with anti-IgE receptor (FcεRI) by using human serum albumin-dinitrophenol (HSA-DNP) antigen-anchored liquid crystal (LC) microdroplets emulsion. The radial to bipolar transition in nematic 4-cyano-4′-pentyl biphenyl liquid crystal molecules (5CB) confined in HSA-DNP antigen anchored LC microdroplets (8.5 pg HSA-DNP/LC microdroplet) is found to be sensitive in PBS solution in detection of allergen sensitized basophils expressed with a minimum amount of anti HSA-DNP (anti-IgE) receptor (≥4.5 pg/basophil). The detection of allergen sensitized basophils was possible within a contact time of 30 min in presence of control cells and with 10% solution of human blood plasma. The HSA-DNP antigen anchored LC microdroplets in presence of macrophages or non-sensitized basophils did not show radial to bipolar transition in 5CB molecules in PBS or solution with 10 wt% human blood plasma. Thus HSA-DNP antigen anchored LC microdroplets biosensor may be used for in vivo detection of stage I allergen reaction basophils in blood samples.

Autologous serum skin test for evaluation of chronic idiopathic urticaria patients: a tertiary hospital study from central India

Background: Majority of patients with chronic urticaria, having no definite etiology are considered chronic idiopathic urticaria (CIU). In recent years, relatively significant number of chronic idiopathic urticaria patients has been classified as having autoimmunity on the basis of presence of auto antibodies (IgG anti IgE receptor alpha subunit or less frequently IgG anti IgE itself) which are responsible for mast cell and basophil activation. Material and Methods: A hospital based crosssectional study was carried out in the Department of Skin, Chirayu Medical College and Hospital, Bhopal located in central India, during the period from August 2012 to February 2014 after institutional ethics committee approval. Total 53 Patients in the age range of 16 to 65 years of CIU were enrolled for study after detailed clinical history and physical examination. Results: Out of total 53 patients, 23(43.39%) showed wheal/ swelling of 1.5 mm or larger at test site as compared to that of control site, thus considered as ASST positive. Duration of CIU ranged from 4 months to 11 years with mean duration of 6.13±2.25 years. 19(82%) of the patients had lesions over whole body whereas only 4(17%) had lesions over face and limbs. 10(43%) patients had angioedema and 14(60%) had dermographism. Conclusion: ASST is simple, cheap and effective diagnostic method to detect presence of autoimmunity in CIU patients thus helps in identifying severity of disease and to choose appropriate therapeutic options accordingly. Our study did not elicit distinct clinical parameters of CIU (except number of wheals/ swelling and frequency of lesions, though statistically not significant) in ASST positive patients from those patients who didn’t show ASST positivity.

Clinicopathologic findings in (anti-FcepsilonR1alpha) autoimmune-related chronic urticaria.

One cause of chronic urticaria is autoreactivity which is diagnosed by detecting autoantibodies against the IgE receptor alpha subunit (anti-Fc R1alpha). To compare the histopathologic features of chronic urticaria patients testing positive for anti-IgE receptor antibody (Ab) to those testing negative. Totally, 438 patients with a clinical presentation of chronic urticaria (2011-2013) had anti-IgE receptor Ab tested and 37 of those patients had skin biopsy. We evaluated microscopic features including: spongiosis, dermal edema, presence of mast cells, density of lymphocytic infiltration, predomination of eosinophils/neutrophils; intravascular neutrophils and presence of vasculitis. The aforementioned features were compared between negative and positive anti-IgE receptor Ab groups. Of 37 patients , 69% were women and 31% were men. 49% had positive anti-IgE receptor Ab and 51% had negative anti-IgE receptor Ab. In the positive anti-IgE receptor Ab group, 83% showed intravascular neutrophils. Eosinophil predominance was identified in 72% and neutrophil predominance was identified in 28%. In the negative anti-IgE receptor Ab group, 89% showed intravascular neutrophils. Eosinophil predominance was identified in 53% and neutrophil predominance was identified in 47%. There was no evidence of vasculitis in either group. There were no significant histopathologic differences between the anti-IgE receptor Ab positive and negative cases. Therefore, serum testing for anti-IgE receptor Ab is required to identify this subgroup of chronic urticaria patients.

Links between autism and allergy

Methods 251 individuals participated in this study: 1. 42 with autism without allergies 2. 42 women (mothers of the autistic patients) without autism 3. 104 allergic patients without autism 4. 63 normal health controls The ASST was performed injecting intradermically 0,05 ml of the each own serum in the volar surface of the forearm. Saline was used as a negative control. After 15 minutes the weals were measured. A result was considered positive when the weal diameter with the serum (this weal was a result of the presence of anti-IgE and/ or anti-IgE receptor antibodies) was at least 3 mms greater than that one measured with the saline. Statistical analysis: chi-squared and Fisher’s methods were used to evaluate the results.

A Long Term Case Series Study of the Effect of Omalizumab on Chronic Spontaneous Urticaria

.2 . According to the classification guideline spontaneous urticaria can be divided into chronic and acute urticaria depending on whether the symptoms have lasted for more or less than 6 weeks. The chronic types of urticaria are divided into physical urticaria (cold, delayed pressure, vibratory urticaria, and urticaria factitia), other urticaria types (aquagenic, cholinergic, contact urticaria and exercise induced urticaria/anaphylaxis), and finally, spontaneous urticaria. Chronic spontaneous urticarias may be idiopathic (55%) or autoimmune (45%) as defined by the presence of the immunoglobulin (Ig)G anti-IgE receptor, α subunit antibodies, or IgG anti IgE antibodies. The EAACI/GA2LEN/WAO treatment guideline recommends the use of non-sedating antihistamines up to a fourfold dosage as the first line of treatment, followed by leukotriene antagonist, and lastly systemic immunosuppressants or Omalizumab 3

Pathogenesis of chronic urticaria

Chronic urticaria is defined as the presence of urticaria (hives) for at least 6 weeks with the assumption that it occurs daily or close to it. If we eliminate physical urticarias and urticarial vasculitis from consideration, the remainder can be divided into autoimmune chronic urticaria (45%) and idiopathic chronic urticaria (55%). The autoimmune subgroup is associated with the IgG anti-IgE receptor alpha subunit in 35-40% of patients and IgG anti-IgE in an additional 5-10%. These autoantibodies have been shown to activate blood basophils and cutaneous mast cells in vitro with augmentation of basophil activation by complement and release of C5a, in particular. Binding methods (immunoblot and ELISA) yield positives in many autoimmune diseases as well as occasional normal subjects or patients with other forms of urticaria but most such sera are non-functional. Activation of basophils or mast cells causing histamine release is quite specific for chronic urticaria and defines the autoimmune subgroup. Although pathogenicity is not formally proven, the antibodies cause wealing upon intradermal injection, and removal of the autoantibody leads to remission. A cellular infiltrate is seen to be characterized by mast cell degranulation and infiltration of CD4+ T lymphocytes, monocytes, neutrophils, eosinophils, and basophils. The intensity of the infiltrate and clinical severity of the disease (including accompanying angio-oedema) is more severe in the autoimmune subpopulation. This latter group also has a higher evidence of human leucocyte antigen DR alleles associated with autoimmunity and a 25% incidence of antithyroid antibodies with diagnosed hypothyroidism in some. Hypo-responsiveness of patients' basophils to anti-IgE and hyperresponsiveness to serum defines another subpopulation (at least 50%) that overlaps the idiopathic and autoimmune subgroups. Hypo-responsiveness to anti-IgE has been shown to be associated with elevated levels of cytoplasmic phosphatases that inhibit degranulation. Reversal of the abnormality is seen with disease remission. Further work will be needed to distinguish whether this is a cause or a consequence of persistent urticaria and to further assess the relationship (or lack thereof) of altered responsiveness (decreased or increased) with the presence or absence of activating autoantibodies.

Effect of omalizumab on patients with chronic urticaria

Chronic urticaria (CU) is often difficult to treat. Approximately 40% to 50% of patients with no apparent cause are believed to have an associated autoimmune profile that may play a pathogenetic role. To describe 3 patients with CU refractory to conventional treatment who responded to omalizumab therapy. Treatment was maximized with antihistamines, antileukotrienes, and histamine2 blockers with no improvement. Systemic steroids provided only temporary relief. Laboratory workup revealed 1 patient with a low IgE level and elevated anti-IgE receptor antibody level, 1 patient with an elevated IgE level but a normal anti-IgE receptor antibody level, and 1 patient with a very elevated IgE level and an elevated anti-IgE receptor antibody level. All 3 patients were prescribed omalizumab therapy every 2 weeks. Two patients had total clearing of urticaria within 1 week and 1 patient within 6 weeks of starting omalizumab therapy. The patient with the elevated anti-IgE receptor antibody level had normalization of the level after starting treatment. Omalizumab may have a beneficial effect in the treatment of CU. Further studies are needed to confirm this effect and better elucidate the mechanism for the observed improvement.

IL3 effect on basophils histamine release upon stimulation with chronic urticaria sera.

Chronic urticaria is thought to be an autoimmune disorder in 35-40% of patients because of the presence of an immunoglobulin G (IgG) antibody reactive with the IgE receptor. Patients possessing this antibody are identified by the ability of serum to degranulate donor basophils to release histamine. We questioned whether priming of basophils with interleukin 3 (IL3) would facilitate identification of patients and/or alter the percentage of patients who have a positive assay. We incubated 37 chronic urticaria sera with basophils from donors with no urticaria with and without priming with IL3 and compared histamine release in each instance. We also preincubated basophils from a 'non-releaser' with IL3, used these cells to assay chronic urticaria sera, and assessed the contribution of complement. Interleukin 3 increases the amount of histamine release by the sera which is able to activate basophils, but it does not convert negative sera into positive releasers. Interleukin 3 is able to partially reverse 'non-releaser' basophils into cells that respond to chronic urticaria sera, and complement cannot account for the augmentation seen. Preincubating basophils with IL3 facilitates the identification of sera with anti-IgE receptor antibody but does not affect the percentage of sera designated as positive.

Allergic Manifestations as the Results of a Conditional Autoimmune Response

By means of repertoire cloning we have isolated human anti-IgE antibodies as well as human anti-FcΕRI antibodies. Whether the naturally occurring anti-IgE autoantibodies play a pathophysiological role may be disputed, but the beneficial role of recombinant anti-IgE antibodies as a therapeutic agent has been shown. On the other hand, the natural antibodies isolated from an antibody library of a nonallergic individual against the FcΕRI α-chain are anaphylactogenic, if FcΕRI was not occupied. Thus, anti-FcΕRI autoantibodies may be part of a conditional autoimmune reaction, leading to urticaria if local IgE is consumed, e.g. after an immediate reaction. Thus, anti-FcΕRI antibodies may represent an amplification arm of the late reaction. The normal occurrence of anti-IgE and anti-IgE receptor autoantibodies may suggest that it might also be feasible to induce such autoantibodies by vaccination. In a monkey model using a mimotope of human IgE it was possible to induce a beneficial anti- IgE autoimmune response. The actual epitope of the IgE molecule was then also molecularly reconstructed by generating recombinant anti-idiotypic antibodies. These antibodies also induced effectively an anti-IgE response in monkeys, suggesting that not only mimotopes but also anti-idiotypic antibodies may be used to generate an autoimmune response. Both of our projects suggest that active immunization may be a new form of immunomodulation for the treatment of allergic disease.

Thyroid Autoimmunity in Chronic Urticaria

A subset of patients with idiopathic chronic urticaria (CU) has been recently classified as autoimmune on the basis of two main findings: association with thyroid autoimmunity and with anti-IgE and/or anti-IgE receptor antibodies. The association of CU with thyroid autoimmunity has been known since 1983, but its frequency varies in different reports. The objective of the present study was to verify the prevalence of thyroid antibodies (anti-thyroid peroxidase, TPO; thyroglobulin, TG; TSH-receptor, TSH-R) in two distinct series of CU: of known cause (70 cases, group A) and idiopathic (52 cases, group B). Twenty-three patients (M/F:7/16) of group A (33%) and 12 (M/F:4/8) of group B (23%) tested positive for at least one type of thyroid antibody. The difference was not statistically significant. Thyroid disease or altered serum TSH levels (requiring treatment) were present in 39% of group A and 42% of group B seropositive patients. In conclusion, the present study shows that CU, either of known cause or idiopathic, is more common in females than in males and is significantly associated with thyroid autoimmunity. These results were not expected on the assumption that autoimmune phenomena are a specific pattern of idiopathic CU. Thus, screening for thyroid autoimmunity and function is advisable in all patients with CU for the early identification of patients requiring either treatment of underlying thyroid dysfunction or follow-up.

Bi-directional relationship of in vitro mast cell-nerve communication observed by confocal laser scanning microscopy.

Communication between nerves and mast cells is a prototypic demonstration of neuro-immune interaction. Recently, we used an in vitro co-culture approach comprising cultured murine superior cervical ganglia (SCG) and rat basophilic leukemia (RBL) cells to study this interaction. Previously, we concentrated mainly on the activation signal from neurites to mast cells (RBL). However, it is proposed that mast cell-nerve communication is not a one-sided relationship but a bi-directional one. In the present work, we studied the communication from mast cells to neurites. We observed that binding of anti-IgE receptor antibodies to mast cells increases calcium ion concentration [Ca2+]i in SCG neurites. This indicates that mast cell-nerve communication is bi-directional. Confocal fluorescence microscopic images indicated that [Ca2+]i in neurites increased after an increase of [Ca2+]i in mast cells. The lag-time of neurite activation was several times longer than that of mast cell activation. The correlation coefficient between the lag-times for mast cell and nerve activation was calculated to be 0.81. In addition, the fluorescence images showed that calcium signals in SCG neurites were able to extend to a long distance (100-200 microm) from the site where mast cells (RBL) attached to neurites.

C-kit ligand: a unique potentiator of mediator release by human lung mast cells.

Mast cells (MC) play a central role in extrinsic allergic reactions such as asthma and may participate in other inflammatory and fibrotic processes. However, with the exception of immunoglobulin E (IgE) receptor-dependent stimulation, no secretagogues of human lung MC have yet been described. It is also unclear whether mediator release can be regulated by certain cytokines as demonstrated previously in basophils and other human inflammatory effector cells. Here, we show that the c-kit ligand (KL), a recently identified stem cell growth factor, at concentrations 10-100 times lower than that required to promote cell proliferation, enhances the release of histamine and leukotriene C4 in response to IgE receptor crosslinking of human lung MC. KL does not induce mediator release per se, but increases the sensitivity of MC to anti-IgE receptor stimulation and also enhances mediator release to maximally effective concentrations of anti-IgE receptor antibody. By contrast, a large number of cytokines examined, including the mast cell growth factors/agonists in rodents, interleukin 3 (IL-3), IL-4, IL-9, and nerve growth factor, were ineffective in this respect. These findings suggest a unique role of KL in regulating effector functions of human mucosal MC.

Natural cytotoxic (NC) cell activity in basophilic cells: release of NC-specific cytotoxic factor by IgE receptor triggering.

A murine interleukin 3 (IL 3)-dependent basophilic mast cell line, PT-18 (A17), and a rat basophilic leukemic cell line, RBL-2H3, were shown to be capable of selective natural cytotoxic (NC) but not natural killer (NK) cell activity. The basophilic cell types could also be augmented in their NC activity by bridging of their surface IgE receptors. IgE-mediated triggering of the basophilic cells was accomplished by coating the cells with IgE and exposing the IgE-bound cells to specific antigen or to anti-IgE monoclonal antibody. Another method of triggering was by direct binding of basophilic cells to anti-IgE receptor monoclonal antibody. Basophilic cells, triggered by these methods, not only displayed increased NC activity but also released a soluble factor capable of selectively lysing NC tumor targets, WEHI-164, but not three of the NK-sensitive targets, YAC-1, RLM1, and RBL-5. Normal C3H/HeJ mouse embryonic fibroblasts were also not lysed. Dose response and time course of the cytotoxic factor release from triggered RBL-2H3 cells were similar to those of tritiated serotonin release. As with serotonin or histamine release, the NC-specific cytotoxic factor (NCCF) was not released in the absence of extracellular calcium. Therefore, NCCF appears to be released along with other mediators during the triggering of basophilic cells by bridging of IgE receptors. The m.w. of the native form of this factor, determined by a gel filtration method, was about 43,000.

Structure and Function of Fc Receptors for IgE on Lymphocytes, Monocytes, and Macrophages

This chapter establishes that the Fc fragment of immunoglobulins E (IgE) binds with high affinity to specific cell surface receptors (FcɛR) on basophils and mast cells and that cross-linking of FcɛR by antigen–IgE antibody complexes, aggregated IgE or anti-IgE receptor antibodies induces histamine release from these cells. Immunologists were somewhat surprised when it was found that radiolabeled aggregated IgE binds to human lymphocytes and an IgE-dependent killing of schistosomules by rat macrophages (MФ) was described, two observations that suggested the presence of FcɛR on lymphocytes and MФ. Several other researches on the interaction of IgE with lymphocytes and MФ established that these cells carry specific IgE Fc receptors, albeit of a different nature than those on basophils and mast cells. By employing methods involving multiple IgE–FcɛR interactions, such as rosette formation with IgE-coated erythrocytes, cells expressing low-affinity FcɛR can be detected relatively easily. The binding properties of radiolabeled IgE to FcɛR+ human cultured lymphoblastoid cells mouse lymphocytes, cultured human U937 MФ and The binding properties of radiolabeled IgE to FcɛR+ human cultured lymphoblastoid cells, mouse lymphocytes , cultured human U937 MФ have been reported.