Dissociation between skin test reactivity and anti-aeroallergen IgE: Determinants among urban Brazilian children.

BACKGROUND: The dissociation between specific IgE and skin prick test reactivity to aeroallergens, a common finding in populations living in low and middle-income countries, has important implications for the diagnosis and treatment of allergic diseases. Few studies have investigated the determinants of this dissociation. In the present study, we explored potential factors explaining this dissociation in children living in an urban area of Northeast Brazil, focusing in particular on factors associated with poor hygiene. METHODS: Of 1445 children from low income communities, investigated for risk factors of allergies, we studied 481 with specific IgE antibodies to any of Blomia tropicalis, Dermatophagoides pteronyssinus, Periplaneta americana and Blatella germanica allergens. Data on demographic, environmental and social exposures were collected by questionnaire; serum IgG and stool examinations were done to detect current or past infections with viral, bacterial, protozoan and intestinal helminth pathogens. We measured atopy by skin prick testing (SPT) and specific IgE (sIgE) to aerollergens in serum (by ImmunoCAP). SIgE reactivity to B. tropicalis extract depleted of carbohydrates was measured by an in-house ELISA. Total IgE was measured by in house capture ELISA. SNPs were typed using Illumina Omni 2.5. RESULTS: Negative skin prick tests in the presence of specific IgE antibodies were frequent. Factors independently associated with a reduced frequency of positive skin prick tests were large number of siblings, the presence of IgG to herpes simplex virus, Ascaris lumbricoides and Trichuris trichiura infections, living in neighborhoods with infrequent garbage collection, presence of rodents and cats in the household and sIgE reactivity to glycosylated B. tropicalis allergens. Also, SNP on IGHE (rs61737468) was negatively associated with SPT reactivity. CONCLUSIONS: A variety of factors were found to be associated with decreased frequency of SPT such as unhygienic living conditions, infections, total IgE, IgE response to glycosylated allergens and genetic polymorphisms, indicating that multiple mechanisms may be involved. Our data, showing that exposures to an unhygienic environment and childhood infections modulate immediate allergen skin test reactivity, provide support for the "hygiene hypothesis".

Impaired CD23 and CD62L expression and tissue inhibitors of metalloproteinases secretion by eosinophils in adults with atopic dermatitis.

BACKGROUND: Eosinophils are multifunctional, polymorphonuclear leucocytes that secrete proteins within cytoplasmic granules, such as cytokines, chemokines, metalloproteinases (MMPs) and metalloproteinases tissue inhibitors (TIMPs). Although eosinophilia is a hallmark of atopic dermatitis (AD), several functional aspects of eosinophils remain unknown. OBJECTIVE: We aimed to evaluate the phenotype and functional response of eosinophils under staphylococcal enterotoxin B (SEB) and Toll-like receptor (TLR)-2/6 (FSL-1) stimulation in the secretion of CCL5, MMPs and TIMPs in adults with AD. METHODS: Forty-one adult patients with AD and 45 healthy controls enrolled for the study. Phenotype of eosinophils from granulocytes of peripheral blood was analysed by flow cytometry. We performed evaluation of CCL5 (cytometric bead array), MMP and TIMP (ELISA) secretion, in culture supernatants of purified eosinophils stimulated with SEB or TLR2/6 agonist (FSL-1). RESULTS: We found a higher frequency of LIN1- CCR3+ eosinophils, and decreased expression of CD23 and CD62L receptors in eosinophils of AD patients. There was no difference in MMP and TIMP serum levels between the evaluated groups. However, we detected decreased basal levels of TIMP-1, TIMP-2 and CCL5 in culture supernatants from purified, unstimulated eosinophils from AD patients. CONCLUSION: In adults with AD, phenotypical features of eosinophils reveal decreased expression of early activation and L-selectin receptors. Regarding the functional profile of purified eosinophils related to tissue remodelling in atopic dermatitis, innate immune stimulation (TLR2/6 agonist and SEB) did not affect the ratio of MMP/TIMPs secretion in AD. Our findings reinforce the potential breakdown in tissue remodelling process mediated by eosinophils in AD.

Protective Profile Involving CD23/IgE-mediated NO Release is a Hallmark of Cutaneous Leishmaniasis Patients from the Xakriabá Indigenous Community in Minas Gerais, Brazil.

In this study, we described, for the first time, specific aspects of an anti-Leishmania immune response in a Brazilian Xakriabá indigenous community. Induction of an intracellular NO pathway, triggered by the binding of IgE to CD23 receptor in IFN-γ/IL-4 cytokines environment, was evaluated in localized cutaneous leishmaniasis (LCL) carriers and positive Montenegro skin test (MST) individuals without skin lesion (MT(+) SL(-)). Our data demonstrated that the higher frequency of CD23(+) CD14(+) monocytes and the increased serum levels of IgE observed in the LCL group were even higher in LCL carriers with late lesions (LCL≥60). Furthermore, patients with LCL presented increased NO production after Leishmania (Viannia) braziliensis stimulation and this NO profile was independent of the time of the lesion (recent LCL<60 or late LCL≥60). We also showed that the increased frequency of IFN-γ(+) and IL-4(+) CD4(+) T cells is related to the MT(+) SL(-) group. The results of biomarker signature curves demonstrated that in the MT(+) SL(-) group, the index signature was characterized by DAF-2T(+) CD14(+)/IL-4(+) CD8(+)/IFN-γ(+) CD4(+)/IL-4(+) CD4(+). On the other hand, the LCL group presented a higher index of DAF-2T(+) CD14(+)/CD23(+) CD14(+)/IL-4(+) CD8(+), associated with a lower index of IFN-γ(+) CD8(+). Considering the time of lesion, data analysis demonstrated that the main differences observed were highlighted in LCL<60 patients, with a higher index of CD23(+) CD14(+), which was also present in LCL≥60 patients. In conclusion, our data suggest that the protective immune response involving CD23-IgE-mediated NO release is a hallmark of patients with LCL. However, in MT(+) SL(-) individuals, another different leishmanicidal mechanism seems to be involved.

IL-4 regulates Bim expression and promotes B cell maturation in synergy with BAFF conferring resistance to cell death at negative selection checkpoints.

IL-4 plays an essential role in the activation of mature B cells, but less is known about the role of IL-4 in B cell maturation and tolerance checkpoints. In this study, we analyzed the effect of IL-4 on in vitro B cell maturation, from immature to transitional stages, and its influence on BCR-mediated negative selection. Starting either from purified CD19(+)IgM(-) B cell precursors, or sorted bone marrow immature (B220(low)IgM(low)CD23(-)) and transitional (B220(int)IgM(high)CD23(-)) B cells from C57BL/6 mice, we compared the maturation effects of IL-4 and BAFF. We found that IL-4 stimulated the generation of CD23(+) transitional B cells from CD23(-) B cells, and this effect was comparable to BAFF. IL-4 showed a unique protective effect against anti-IgM apoptotic signals on transitional B cell checkpoint, not observed with BAFF. IL-4 and BAFF strongly synergized to promote B cell maturation, and IL-4 also rendered it refractory to BCR-mediated cell death. IL-4 blocked upregulation of proapoptotic Bim protein levels induced by BCR crosslinking, suggesting that diminished levels of intracellular Bim promote protection to BCR-induced cell death. Evidence was obtained indicating that downmodulation of Bim by IL-4 occurred in a posttranscriptional manner. Consistent with data obtained in vitro, IL-4 in vivo was able to inhibit Bim upregulation and prevent cell death. These results contribute to the understanding of the role of IL-4 in B lymphocyte physiology, unveiling a previously undescribed activity of this cytokine on the maturation of B cells, which could have important implications on the breaking of B cell central tolerance in autoimmunity.

Omalizumab beyond asthma.

INTRODUCTION: Omalizumab has been demonstrated to be a successful therapy in the management of asthma through reduction of patient's symptoms and use of inhaled corticosteroids. The effect of omalizumab is achieved by immunoglobulin E (IgE) blockage and other secondary mechanisms resulting from this blockage. Because other diseases have an important IgE mediation in their physiopathology, the question arises as to if omalizumab would be useful in the treatment of other IgE-mediated diseases. OBJECTIVE: We present an overview of the experimental studies and clinical reports evaluating the use of omalizumab in diseases different to asthma including atopic dermatitis, urticaria, eosinophilic gastrointestinal disorders, idiopathic anaphylaxis, latex allergy, hymenoptera venom allergy, and other IgE diseases. METHODS: We reviewed the literature using PUBMED, EMBASE, and LILACS for publications which used omalizumab in the treatment of patients with allergic diseases or any other diseases. Complete articles published in English, Spanish or Portuguese were included. CONCLUSION: There is not enough evidence to support the regular use of omalizumab in IgE diseases other than asthma. However, some experimental and clinical investigations indicate that omalizumab could be a therapeutic option in several allergic diseases like atopic dermatitis, urticaria, and eosinophilic gastrointestinal disorders. More control studies are needed in each IgE disease to evaluate the efficacy and safety of omalizumab in IgE mediated diseases.

The lectin ArtinM binds to mast cells inducing cell activation and mediator release.

Mast cells are inflammatory cells that respond to signals of innate and adaptive immunity with immediate and delayed release of mediators. ArtinM, a lectin from Artocarpus integrifolia with immunomodulatory activities, is able to induce mast cell activation, but the mechanisms remain unknown. This study sought to further investigate the effects of the lectin on mast cells. We showed that ArtinM binds to mast cells, possibly to the high affinity receptor for immunoglobulin E (IgE) - FcεRI - and/or to IgE bound to FcεRI. Binding of the lectin resulted in protein tyrosine phosphorylation and release of the pre- and newly-formed mediators, ß-hexosaminidase and LTB(4) by mast cells, activities that were potentiated in the presence of IgE. ArtinM also induced the activation of the transcription factors NFκB and NFAT, resulting in expression of some of their target genes such as IL-4 and TNF-α. In view of the established significance of mast cells in many immunological and inflammatory reactions, a better understanding of the mechanisms involved in mast cell activation by ArtinM is crucial to the pharmacological application of the lectin.

Endotoxin tolerance and cross-tolerance in mast cells involves TLR4, TLR2 and FcepsilonR1 interactions and SOCS expression: perspectives on immunomodulation in infectious and allergic diseases.

BACKGROUND: The study of the endotoxin tolerance phenomenon in light of the recently defined roles of mast cells and toll-like receptors as essential components of the innate immune response and as orchestrators of acquired immunity may reveal potentially useful mechanisms of immunomodulation of infectious and allergic inflammatory responses, such as sepsis or asthma. Here we evaluated the phenomenon of direct tolerance of endotoxins, as well as the induction of cross-tolerance and synergism by stimulation with toll-like receptor-2 (TLR2) and FcepsilonR1 agonists, in murine mast cells prestimulated with lipopolysaccharide (LPS). Additionally, we evaluated some stimulatory and inhibitory signaling molecules potentially involved in these phenomena. METHODS: MC/9 cells and primary bone marrow-derived mast cells obtained from C57BL/6 and TLR4-/- knock-out mice were sensitized to DNP-HSA (antigen) by incubation with DNP-IgE and were prestimulated with LPS for 18 hr prior to stimulation. Cultures were stimulated with LPS or Pam3Cys-Ser-(Lys)4 3HCl (P3C), a TLR2 agonist, individually or in combination with antigen. The production of IL-6 and TNFalpha, the phosphorylation of NFkappaB and p38 MAPK, and the expression of TLR4 and SOCS-1 and -3 were analyzed. RESULTS: We found that production of TNFalpha and IL-6 in murine mast cells that have been pretreated with LPS and challenged with TLR4 (LPS) or -2 (P3C) agonists was reduced, phenomena described as endotoxin tolerance (LPS) and cross-tolerance (P3C), respectively. The expression of TLR4 was not affected by LPS pretreatment. Our results show that the FcepsilonR1 agonist DNP-HSA (antigen) interacts synergistically with LPS or P3C to markedly enhance production of cytokines (TNFalpha and IL-6). This synergistic effect with LPS and P3C was also attenuated by LPS pretreatment and was mediated by TLR4. These results may be attributed to the reduction in phosphorylation of the mitogen-activated protein kinase (MAPK), p38, and the transcription factor NFkappaB, as well as to an increase in the expression of the suppressors of cytokine signaling (SOCS)-1 and -3 proteins in LPS-pretreated mast cells. CONCLUSIONS: These findings can be explored with respect to the modulation of inflammatory responses associated with infectious and allergic processes in future studies.

TGF-beta and CD23 are involved in nitric oxide production by pulmonary macrophages activated by beta-glucan from Paracoccidioides brasiliensis.

Pulmonary macrophages (PM), which are CD11b/CD18(+) and CD23(+), may be involved in the onset of inflammatory events caused by Paracoccidioides brasiliensis in the lungs. In the present study, we measured the nitric oxide (NO) and interleukin in PM production after intratracheal (i.t.) inoculation of an enriched beta-glucan cell wall fraction from P. brasiliensis (Fraction F1). BALB/c and C57/BL6 (B6) mice were i.t. treated with Fraction F1, and their PM were restimulated in vitro with LPS and interferon-gamma up to 14 days after treatment. Macrophages BALB/c mice produced less NO than PM from B6 mice. The lower NO production was caused by higher production of TGF-beta by pulmonary macrophages of BALB/c and was abrogated by anti-TGF-beta MoAb in vitro and in vivo. Other interleukins such as IL-10, IL-4 and a combination of IL-1, TNF-alpha and IL-6 were not involved in NO production induced by Fraction F1. Expression of CD11b increases and expression of CD23 decreases on PM of BALB/c mice after in vivo treatment whereas PM of B6 mice do not show a variation of their phenotype. Moreover, the ability of pulmonary macrophages to induce lymphocyte proliferation was reduced in mixed cultures of CD11b(+) or CD23(+) macrophages but was restored when lymphocytes were cultivated in the presence of NO inhibitor (L-NMMA). Thus, the results presented herein indicate that in BALB/c but not in B6 mice TGF-ss is strongly induced by Fraction 1 in PM in vivo and suppresses NO production. Low NO production by PM is associated with a change in CD11b/CD23 expression and with a high lymphocyte proliferative response. Thus, CD11b(+)/CD23(+) PM modulate NO and TGF-beta production in the pulmonary microenvironment.

[Urticaria and angioedema]. / Urticaria y angioedema.

Urticaria is considered a heterogeneous group of diseases that share different patterns of skin reactions. The wide diversity in urticaria subtypes have been identified and this reflects partial understanding of the causes or factors that trigger it, as well as the molecular and cellular mechanisms that are involved in their physiopathology. The objective of this article was to make an extensive review of the literature to be able to offer the readers a complete information and updating on the basic, ethiologic and physiophatologic mechanisms and mainly to make a special emphasis on diagnosis and treatment of urticaria, promoting the continuous medical education.

Anaphylaxis: an analysis of cases evaluated at the Puerto Rico Medical Center over a ten-year period

OBJECTIVE: To examine the clinical characteristics of patients with anaphylactic reactions evaluated at the Puerto Rico Medical Center over a ten year period. BACKGROUND: Anaphylaxis, an immunologic reaction classically initiated by the combination of an antigen and a mast cell fixed antibody (usually IgE), still carries a fatality rate of 500 to 1000 cases per year in the United States. It constitutes a medical emergency that needs to be identified promptly in order to install appropriate treatment. No studies of this condition have been conducted in Puerto Rico, specifically to assess the clinical presentation, main causes and outcome. METHODS: Eighty-three records of patients with a diagnosis of anaphylaxis were screened by retrospective and concurrent analysis. Of these, only 51 fulfilled the diagnostic criteria of anaphylaxis. Specific data gathered from those records assessed the clinical characteristics of each case, precipitating factors, severity of the reaction and outcome. A standard form was used for data gathering. A grading system was utilized to classify the severity of the clinical episodes. RESULTS: Cutaneous features were the most commonly found manifestations of anaphylactic reactions in the studied group. Only reactions graded 2 and 3 were identified. Reactions to medications were the most frequent identifiable causes of the entity. Multiple sensitivities to different allergens were not predictive of this clinical condition. CONCLUSIONS: The identification in this study that only cases with the more severe grades of anaphylaxis were evaluated and treated at our center, the inability to recognize an inciting cause in about one third of the patient sample and the fact that a minority of the treated patients received subsequent follow-up by an allergist, reflect the need to promote the training of physicians in the field of allergy in Puerto Rico and the continued education of all physicians in the Island regarding this clinical disorder.

Role of the low affinity IgE receptor (CD23) on the IgE response against Ascaris lumbricoides in Warao Amerindian children from Venezuela.

The objective of this study was to investigate the immune mechanisms against gastrointestinal helminths involved in the production of IgE, particularly the role of the low affinity IgE receptor (CD23) in Amerindian Warao children from the Orinoco Delta, Venezuela. We studied a group of unselected (n = 159) Warao school children with high prevalence and intensity of helminthic infection and a similar non- parasitized (n = 70) control group of a "creole" community also located at the Delta of the Orinoco. The levels of total and specific anti-Ascaris IgE, determined by ELISA, were extremely higher in the Warao children (p < 0.001) compared to the control group. However, only a reduced group of these children were able to develop a clinically significant (> 0.7 PRU/mL) IgE response against A lumbricoides antigens. Circulating T helper cells (CD3+CD4+), activated B (CD20+, CD20+CD21+) lymphocytes and the expression of the low affinity receptor for IgE (CD23), determined by flow cytometry, were significantly (p < 0.001) elevated in the Warao children, particularly in those with an enhanced capacity to mount efficient specific anti Ascaris IgE responses. Strong correlations (p < 0.001) were found between the number of circulating CD20+CD23+ cells and the level of total and anti-A lumbricoides IgE. Also, a significant (p < 0.005) correlation between CD20+CD23+ and CD4+ circulating cells was observed. We conclude that A lumbricoides antigens may stimulate the production of total and specific IgE through a CD23 dependent pathway. However the different environmental and genetics factors involved in the capacity to develop efficient specific responses among the Warao population still need to be elucidated.

Anaphylaxis: an analysis of cases evaluated at the Puerto Rico Medical Center over a ten-year period.

OBJECTIVE: To examine the clinical characteristics of patients with anaphylactic reactions evaluated at the Puerto Rico Medical Center over a ten year period. BACKGROUND: Anaphylaxis, an immunologic reaction classically initiated by the combination of an antigen and a mast cell fixed antibody (usually IgE), still carries a fatality rate of 500 to 1000 cases per year in the United States. It constitutes a medical emergency that needs to be identified promptly in order to install appropriate treatment. No studies of this condition have been conducted in Puerto Rico, specifically to assess the clinical presentation, main causes and outcome. METHODS: Eighty-three records of patients with a diagnosis of anaphylaxis were screened by retrospective and concurrent analysis. Of these, only 51 fulfilled the diagnostic criteria of anaphylaxis. Specific data gathered from those records assessed the clinical characteristics of each case, precipitating factors, severity of the reaction and outcome. A standard form was used for data gathering. A grading system was utilized to classify the severity of the clinical episodes. RESULTS: Cutaneous features were the most commonly found manifestations of anaphylactic reactions in the studied group. Only reactions graded 2 and 3 were identified. Reactions to medications were the most frequent identifiable causes of the entity. Multiple sensitivities to different allergens were not predictive of this clinical condition. CONCLUSIONS: The identification in this study that only cases with the more severe grades of anaphylaxis were evaluated and treated at our center, the inability to recognize an inciting cause in about one third of the patient sample and the fact that a minority of the treated patients received subsequent follow-up by an allergist, reflect the need to promote the training of physicians in the field of allergy in Puerto Rico and the continued education of all physicians in the Island regarding this clinical disorder.

[Autoimmune urticaria. Treatment with methotrexate]. / Urticaria autoinmunitaria. Tratamiento con metotrexato.

BACKGROUND: It has been established that 27-50% of patients with idiopathic chronic urticaria have antibodies directed against the alpha chain of the high-affinity IgE receptor, which are indirectly detected by cutaneous tests with autoserum. Thus, an autoimmune urticaria diagnosis can be settled. OBJECTIVE: To prove methotrexate's efficiency in patients with autoimmune urticaria. MATERIAL AND METHODS: Seven patients took part in the study. A series of tests was performed in order to rule out any possible infectious, metabolic, or physical etiology. Initial treatment with methotrexate with doses of 2.5 mg every 12 hours, two days a week was provided. In case there were no toxicity data, doses would increase to three days a week for a 6-week period. RESULTS: Statistically significant improvement was observed in the itching, as well as the presence of spots, repercussion on daily activities, sleep disorders. There was no statistical difference regarding the extension of the lesions and the presence of angioedema. Adverse effects were not significant. CONCLUSION: We conclude that methotrexate is effective in the treatment of autoimmune urticaria.

[Presence of anti-Helicobacter pylori, antithyroid, and high-affinity IgE receptor antibodies in patients with chronic urticaria]. / Presencia de anticuerpos anti-Helicobacter pylori, antitiroideos y antirreceptor de alta afinidad de la inmunoglobulina E en pacientes con urticaria crónica.

BACKGROUND: Chronic urticaria is characterized by erythematous wheals during more than 6 weeks. In 47% of the patients it is associated to Helicobacter pylori infection; in 50%, to antibodies (Abs) against the high affinity receptor of the IgE, and in 12 to 20% to antithyroid's antibodies (antithyroglobuline, mychrosomals) and, from these, 25% have alterations of the thyroid function. OBJECTIVE: To determine the presence of the anti-Helicobacter pylori and anttihyroids antibodies and the high affinity anti-receptor of the IgE in healthy subjects and patients with chronic urticaria. MATERIAL AND METHODS: Eighty subjects were included: 40 healthy subjects and 40 patients whit diagnosis of chronic urticaria. In all of them a blood sample was extracted to the determination of the antibodies and skin test applications with autologous serum to determine the antibody of the high affinity anti-receptor of IgE. For the analysis of the results descriptive statistics was used (central tendency measures, frequencies, means, averages and percentages), as well as multiple correlations and inferential analyses. RESULTS: Anti-Helicobacter pylori, antithyroid (antithyroglobulin, microsomal) antibodies and the skin test with autologous serum (antibody of the high affinity anti-receptor of IgE) were negative in the healthy group (mean age: 41 years, 36 women, 90%). Of the 40 patients with chronic urticaria (mean age: 42 years, 36 women, 90%), the frequency of the antibody of high affinity anti-receptor of the IgE was: 5 patients with negative skin test (12.5%), 1 (2.5%)+, 7 (17.5%)++, 9 (22.5%)+++, 18 (45%)++++. The anti-Helicobacter pylori antibodies were positive in 30 (75%) patients and negative in 10 (25%). The antithyroid's antibodies were as follows: antithyroglobulin: 4 (10%) positive, microsomal: 4 (10%) positive. The concomitant diseases found were: hypothyroidism (3, 7.5%) mixed rhinitis (2.5%) and autoimmunity 2 (5%). CONCLUSION: The test skin with autologous serum to determine the IgG antibody against the high affinity receptor of IgE is a simple and low-cost procedure leading to determine the cause of the idiopathic chronic urticaria in a high percentage of patients. As reported in literature, the Helicobacter pylori infection documented by the detection of the IgM antibodies against Helicobacter pylori is frequent in patients with chronic urticaria, which is important due to it could be implied in the diagnosis and treatment.

Role of immunoglobulin E and mast cells in murine models of asthma.

Immunoglobulin E (IgE) and mast cells are believed to play important roles in allergic inflammation. However, their contributions to the pathogenesis of human asthma have not been clearly established. Significant progress has been made recently in our understanding of airway inflammation and airway hyperresponsiveness through studies of murine models of asthma and genetically engineered mice. Some of the studies have provided significant insights into the role of IgE and mast cells in the allergic airway response. In these models mice are immunized systemically with soluble protein antigens and then receive an antigen challenge through the airways. Bronchoalveolar lavage fluid from mice with allergic airway inflammation contains significant amounts of IgE. The IgE can capture the antigen presented to the airways and the immune complexes so formed can augment allergic airway response in a high-affinity IgE receptor (FcepsilonRI)-dependent manner. Previously, there were conflicting reports regarding the role of mast cells in murine models of asthma, based on studies of mast cell-deficient mice. More recent studies have suggested that the extent to which mast cells contribute to murine models of asthma depends on the experimental conditions employed to generate the airway response. This conclusion was further supported by studies using FcepsilonRI-deficient mice. Therefore, IgE-dependent activation of mast cells plays an important role in the development of allergic airway inflammation and airway hyperresponsiveness in mice under specific conditions. The murine models used should be of value for testing inhibitors of IgE or mast cells for the development of therapeutic agents for human asthma.

[Chronic urticaria. Clinical evolution, autologous serum test, count and activation of basophils]. / Urticaria crónica. Evolución clínica, prueba del suero autólogo, recuento y activación de basófilos.

Recent advances on the pathogenesis of chronic urticaria have defined a group of patients with autoantibodies directed to the IgE or to the alpha chain of the Fc high affinity receptor of IgE, Fc epsilon RI alpha. These antibodies are detected in vivo through the autologous serum test (AST) and in vitro with a variety of techniques. We here describe 37 patients with chronic urticaria, 28 female and 9 male, with a f/m ratio of 3.1. Mean age at onset was 36.5 years (range 16-78). AST was positive in 25 (68%) of 37 patients. Serum induced a wheal significantly larger than plasma (122 +/- 78 mm2 vs 57 +/- 66 mm2, p < 0.05). Median persistence of the chronic urticaria, estimated by Kaplan-Meyer analysis, was 437 days, with no difference between AST(+) and AST(-) patients (437 vs. 369, p = 0.18). Mean IgE concentration was 157 +/- 173 IU/mL, as expected in an unselected population. Basophil count was lower in patients compared with controls (17 +/- 12 cel/microL vs. 43 +/- 27 cel/microL, p < 0.008). Only sera from 2/7 (28.6%) patients AST (+) and very low basophil count consistently induced expression of CD63. This effect was abrogated in non-releasing basophils, confirming the presence of antibodies directed to the Fc epsilon RI alpha-IgE. We conclude that functional antibodies are present in only a minority of patients and that their identification does not predict the outcome.

Urticaria cronica. Evolucion clinica, prueba del suero autologo, recuento y activacion de basofilos / Chronic urticaria. Clinical evolution, autologous serum test, count and activation of basophils

Recent advances on the pathogenesis of chronic urticaria have defined a group of patients with autoantibodies directed to the IgE or to the alpha chain of the Fc high affinity receptor of IgE, Fc epsilon RI alpha. These antibodies are detected in vivo through the autologous serum test (AST) and in vitro with a variety of techniques. We here describe 37 patients with chronic urticaria, 28 female and 9 male, with a f/m ratio of 3.1. Mean age at onset was 36.5 years (range 16-78). AST was positive in 25 (68%) of 37 patients. Serum induced a wheal significantly larger than plasma (122 +/- 78 mm2 vs 57 +/- 66 mm2, p < 0.05). Median persistence of the chronic urticaria, estimated by Kaplan-Meyer analysis, was 437 days, with no difference between AST(+) and AST(-) patients (437 vs. 369, p = 0.18). Mean IgE concentration was 157 +/- 173 IU/mL, as expected in an unselected population. Basophil count was lower in patients compared with controls (17 +/- 12 cel/microL vs. 43 +/- 27 cel/microL, p < 0.008). Only sera from 2/7 (28.6%) patients AST (+) and very low basophil count consistently induced expression of CD63. This effect was abrogated in non-releasing basophils, confirming the presence of antibodies directed to the Fc epsilon RI alpha-IgE. We conclude that functional antibodies are present in only a minority of patients and that their identification does not predict the outcome (AU)

From allergy to schistosomes: role of Fc receptors and adhesion molecules in eosinophil effector function.

The dual function of eosinophils has been evidenced in protective immunity against parasites as well as in pathological manifestations during allergic disorders. We have demonstrated that a new class of IgE receptors, Fc epsilon RII/CD23, was involved in the functional duality of eosinophils and other proinflammatory cells. More recently, we have shown that Fc epsilon RI, the high affinity IgE receptor thought to be only expressed by basophils and most cells, was involved in eosinophil-mediated cytotoxicity against schistosomes as well as in mediator release. These results favour the view that both IgE and its receptors have been primarily associated to a protective immune response, rather than to pathology. Not only IgE receptors but also members belonging to the family of adhesion molecules can participate as co-receptors in eosinophil effector function. The inhibitory role of monoclonal antibodies to Lewis(X) (Le(X) CD15) or to selectins in eosinophil-mediated cytotoxicity towards schistosomes and the detection of Le(X) and selectin-like molecules on schistosomula surface indicate a double interaction mediated by selectins and their carbohydrate ligands between eosinophils and schistosomula. These results suggest new functions for these adhesion molecules, previously known to be involved mainly in cell infiltration.