Human Allergic Diseases Research Articles

Follicular Helper T Cells Mediate IgE Antibody Production and Allergic Immune Responses in Mice

Follicular helper T (Tfh) cells develop when animals are infected with helminths. However, little is known about the roles for Tfh cells in allergic airway diseases. Mice were exposed intranasally to endotoxin-free ovalbumin (OVA) with or without IL-33 or IL-1β. Adaptive immune responses to OVA were analyzed by using IL-4 reporter mice, gene-deficient animals, and adoptive transfer approaches. Airway exposure of naïve mice to OVA plus IL-33 induced OVA-specific IgE and IgG1; when challenged with OVA, these mice developed robust Th2 cytokine response and airway eosinophilia. Exposure of naïve mice to OVA plus IL-1β induced comparable levels of anti-OVA IgE/IgG1 and IL-4, but minimal IL-5, IL-13 and eosinophilia. Isolation of IL-4-positive CD4+ T cells and microarray analysis showed that IL-33 induces antigen-specific Th2 cells and Tfh cells and that IL-1β induces mainly Tfh cells. Mice deficient in ICOS (Icos-/-), which is critical for development of Tfh cells, developed Th2 cells and anti-IgE/IgG1 antibodies normally when exposed to OVA plus IL-33. In contrast, when exposed to OVA plus IL-1β, Icos-/-mice showed decreased numbers of Tfh cells and reduced levels of anti-OVA IgE/IgG1. Finally, CD4-deficient animals recovered production of anti-OVA IgE/IgG1 antibodies when they were reconstituted with Tfh cells. IL-1-family cytokines regulate development of antigen-specific Th2 cells and Tfh cells in the airway. Tfh cells mediate IgE antibody production and modest airway inflammation, while Th2 cells mediate both antibody production and inflammation. The roles for Tfh cells in human allergic diseases need to be investigated.

Ndfip1 mediates peripheral tolerance to self and exogenous antigen by inducing cell cycle exit in responding CD4+T cells

The NDFIP1 (neural precursor cell expressed, developmentally down-regulated protein 4 family-interacting protein 1) adapter for the ubiquitin ligase ITCH is genetically linked to human allergic and autoimmune disease, but the cellular mechanism by which these proteins enable foreign and self-antigens to be tolerated is unresolved. Here, we use two unique mouse strains--an Ndfip1-YFP reporter and an Ndfip1-deficient strain--to show that Ndfip1 is progressively induced during T-cell differentiation and activation in vivo and that its deficiency causes a cell-autonomous, Forkhead box P3-independent failure of peripheral CD4(+) T-cell tolerance to self and exogenous antigen. In small cohorts of antigen-specific CD4(+) cells responding in vivo, Ndfip1 was necessary for tolerogen-reactive T cells to exit cell cycle after one to five divisions and to abort Th2 effector differentiation, defining a step in peripheral tolerance that provides insights into the phenomenon of T-cell anergy in vivo and is distinct from the better understood process of Bcl2-interacting mediator of cell death-mediated apoptosis. Ndfip1 deficiency precipitated autoimmune pancreatic destruction and diabetes; however, this depended on a further accumulation of nontolerant anti-self T cells from strong stimulation by exogenous tolerogen. These findings illuminate a peripheral tolerance checkpoint that aborts T-cell clonal expansion against allergens and autoantigens and demonstrate how hypersensitive responses to environmental antigens may trigger autoimmunity.

Identification and immunophenotypic characterization of normal and pathological mast cells.

Mast cells (MCs) are secretory cells that are central players in human allergic disease and immune responses. With the exception of a few pathological situations, MCs are usually present at relatively low frequencies in most tissues. Since their first description, MCs in tissues were identified mostly using their morphological characteristics and their typical coloration when stained with aniline dyes. However, increasing availability of highly specific antibodies now permits the use of fluorescence-based flow cytometry as the method of choice for the quantification, characterization, and purification of cells in suspension. This technique allows for a rapid analysis of thousands of events and for the identification of cells present at frequencies as low as one event in 10(6) unwanted cells. This method also permits for simultaneous characterization of multiple antigens at a single-cell level, which is ideal in order to study rare populations of cells like MCs. Here we describe the basis of flow cytometry-based immunophenotyping applied to the study of MC. The protocol focuses on the study of human MCs present in body fluids (mainly bone marrow) but can easily be adapted to study MCs from other tissues and species.

Direct analysis of airborne mite allergen (Der f1) in the residential atmosphere by chemifluorescent immunoassay using bioaerosol sampler.

Dermatophagoides farinae allergen (Der f1) is one of the most important indoor allergens associated with allergic diseases in humans. Mite allergen Der f1 is usually associated with particles of high molecular weight; thus, Der f1 is generally present in settled dust. However, a small quantity of Der f1 can be aerosolized and become an airborne component. Until now, a reliable method of detecting airborne Der f1 has not been developed. The aim of this study was to develop a fiber-optic chemifluorescent immunoassay for the detection of airborne Der f1. In this method, the Der f1 concentration measured on the basis of the intensity of fluorescence amplified by an enzymatic reaction between the labeled enzyme by a detection antibody and a fluorescent substrate. The measured Der f1 concentration was in the range from 0.49 to 250 ng/ml and a similar range was found by enzyme-linked immunosorbent assay (ELISA). This method was proved to be highly sensitive to Der f1 compared with other airborne allergens. For the implementation of airborne allergen measurement in a residential environment, a bioaerosol sampler was constructed. The airborne allergen generated by a nebulizer was conveyed to a newly sampler we developed for collecting airborne Der f1. The sampler was composed of polymethyl methacrylate (PMMA) cells for gas/liquid phases and some porous membranes which were sandwiched in between the two phases. Der f1 in air was collected by the sampler and measured using the fiber-optic immunoassay system. The concentration of Der f1 in aerosolized standards was in the range from 0.125 to 2.0 mg/m(3) and the collection rate of the device was approximately 0.2%.

A Microplate Assay to Assess Chemical Effects on RBL-2H3 Mast Cell Degranulation: Effects of Triclosan without Use of an Organic Solvent

Mast cells play important roles in allergic disease and immune defense against parasites. Once activated (e.g.by an allergen), they degranulate, a process that results in the exocytosis of allergic mediators. Modulation of mast cell degranulation by drugs and toxicants may have positive or adverse effects on human health. Mast cell function has been dissected in detail with the use of rat basophilic leukemia mast cells (RBL-2H3), a widely accepted model of human mucosal mast cells(3-5). Mast cell granule component and the allergic mediator β-hexosaminidase, which is released linearly in tandem with histamine from mast cells(6), can easily and reliably be measured through reaction with a fluorogenic substrate, yielding measurable fluorescence intensity in a microplate assay that is amenable to high-throughput studies(1). Originally published by Naal et al.(1), we have adapted this degranulation assay for the screening of drugs and toxicants and demonstrate its use here. Triclosan is a broad-spectrum antibacterial agent that is present in many consumer products and has been found to be a therapeutic aid in human allergic skin disease(7-11), although the mechanism for this effect is unknown. Here we demonstrate an assay for the effect of triclosan on mast cell degranulation. We recently showed that triclosan strongly affects mast cell function(2). In an effort to avoid use of an organic solvent, triclosan is dissolved directly into aqueous buffer with heat and stirring, and resultant concentration is confirmed using UV-Vis spectrophotometry (using ε280 = 4,200 L/M/cm)(12). This protocol has the potential to be used with a variety of chemicals to determine their effects on mast cell degranulation, and more broadly, their allergic potential.

Th9 cell development requires a BATF-regulated transcriptional network

T helper 9 (Th9) cells are specialized for the production of IL-9, promote allergic inflammation in mice, and are associated with allergic disease in humans. It has not been determined whether Th9 cells express a characteristic transcriptional signature. In this study, we performed microarray analysis to identify genes enriched in Th9 cells compared with other Th subsets. This analysis defined a transcriptional regulatory network required for the expression of a subset of Th9-enriched genes. The activator protein 1 (AP1) family transcription factor BATF (B cell, activating transcription factor–like) was among the genes enriched in Th9 cells and was required for the expression of IL-9 and other Th9-associated genes in both human and mouse T cells. The expression of BATF was increased in Th9 cultures derived from atopic infants compared with Th9 cultures from control infants. T cells deficient in BATF expression had a diminished capacity to promote allergic inflammation compared with wild-type controls. Moreover, mouse Th9 cells ectopically expressing BATF were more efficient at promoting allergic inflammation than control transduced cells. These data indicate that BATF is a central regulator of the Th9 phenotype and contributes to the development of allergic inflammation.

Neonatal colonization of germ-free mice with Bifidobacterium longum prevents allergic sensitization to major birch pollen allergen Bet v 1

The main goal in reversing the allergy epidemic is the development of effective prophylactic strategies. We investigated the prophylactic effect of neonatal mother-to-offspring mono-colonization with Bifidobacterium longum ssp. longum CCM 7952 on subsequent allergic sensitization. Adult male and female germ-free (GF) mice were mono-colonized with B. longum, mated and their offspring, as well as age-matched GF controls, were sensitized with the major birch pollen allergen Bet v 1. Furthermore, signaling pathways involved in the recognition of B. longum were investigated in vitro. Neonatal mono-colonization of GF mice with B. longum suppressed Bet v 1-specific IgE-dependent β-hexosaminidase release as well as levels of total IgE and allergen-specific IgG2a in serum compared to sensitized GF controls. Accordingly, Bet v 1-induced production of both Th1- and Th2-associated cytokines in spleen cell cultures was significantly reduced in these mice. The general suppression of Bet v 1-specific immune responses in B. longum-colonized mice was associated with increased levels of regulatory cytokines IL-10 and TGF-β in serum. In vitro, B. longum induced low maturation status of bone marrow-derived dendritic cells and production of IL-10 in TLR2-, MyD88-, and MAPK-dependent manner. Our data demonstrate that neonatal mono-colonization with B. longum reduces allergic sensitization, likely by activation of regulatory responses via TLR2, MyD88, and MAPK signaling pathways. Thus, B. longum might be a promising candidate for perinatal intervention strategies against the onset of allergic diseases in humans.

CD11a polymorphisms regulate TH2 cell homing and TH2-related disease

TH2-dependent diseases vary in severity according to genotype, but relevant gene polymorphisms remain largely unknown. The integrin CD11a is a critical determinant of allergic responses, and allelic variants of this gene might influence allergic phenotypes. We sought to determine major CD11a allelic variants in mice and human subjects and their importance to allergic disease expression. We sequenced mouse CD11a alleles from C57BL/6 and BALB/c strains to identify major polymorphisms; human CD11a single nucleotide polymorphisms were compared with allergic disease phenotypes as part of the international HapMap project. Mice on a BALB/c or C57BL/6 background and congenic for the other strain's CD11a allele were created to determine the importance of mouse CD11a polymorphisms in vivo and in vitro. Compared with the C57BL/6 allele, the BALB/c CD11a allele contained a nonsynonymous change from asparagine to aspartic acid within the metal ion binding domain. In general, the BALB/c CD11a allele enhanced and the C57BL/6 CD11a allele suppressed TH2 cell-dependent disease caused by the parasite Leishmania major and allergic lung disease caused by the fungus Aspergillus niger. Relative to the C57BL/6 CD11a allele, the BALB/c CD11a allele conferred both greater T-cell adhesion to CD54 in vitro and enhanced TH2 cell homing to lungs in vivo. We further identified a human CD11a polymorphism that significantly associated with atopic disease and relevant allergic indices. Polymorphisms in CD11a critically influence TH2 cell homing and diverse TH2-dependent immunopathologic states in mice and potentially influence the expression of human allergic disease.

Increased Nerve Growth Factor Serum Levels in Top Athletes

The nerve growth factor (NGF) is the main neurotrophin, which, besides being an important growth factor for nerves, plays an important role as a mediator of inflammation. Nerve growth factor has been shown to increase in relation to stress stimuli and in allergic diseases in humans as well as after physical exercise in animal models. This study aims at evaluating NGF serum levels in top athletes, a population sample in which allergic and neuro-immune diseases are reported with a significantly increased prevalence. Observational, cross-sectional, multicenter study. Institutional, tertiary care. Ninety-six Italian pre-Olympic athletes (44 allergic and 52 nonallergic) and 49 matched controls selected within the Italian National Olympic delegation (n = 435). Nerve growth factor serum levels determined through an enzyme-linked immunosorbent assay. Parametric or nonparametric tests were used for comparing NGF serum levels among different study groups depending on value distributions. Nerve growth factor serum levels were significantly higher in athletes than in controls independently from the presence of allergy. Nerve growth factor mean values were 368.3 ± 776.3 pg/mL in the sample of athletes and 174.1 ± 483.7 pg/mL in the control group (P < 0.001). This is the first study showing that intense and prolonged physical exercise is associated with an increase of NGF serum levels in athletes. Whether the increased NGF production might be linked to the prevalent Th2 response observed in allergic diseases and after physical exercise and whether it might be related to the patophysiology of neuro-immune disorders as such amyotrophic lateral sclerosis, reported with a higher prevalence in athletes, should deserve further investigations.

Characterization of allergen-specific T-cell responses in a humanized mouse model relying on a human mugwort-specific T-cell receptor and HLA-DR1 (P6208)

Abstract While mice expressing an I-Ad restricted murine T-cell receptor (TCR) specific for chicken ovalbumin (Ova) are widely used to mimic allergic diseases induced by aeroallergens in vivo, implications for human allergic diseases remain questionable, since Ova is not a human-relevant aeroallergen. We here created double tg mice expressing a human TCR specific for the major mugwort (Artemisia vulgaris) pollen allergen Art v 1 and HLA-DR1. In tg mice ninety percent of peripheral blood CD4+ T lymphocytes expressed the Art v 1-specific TCR, while CD14+ monocytes and B220+ B lymphocytes revealed HLA-DR1 expression. Splenocytes of tg mice specifically proliferated upon incubation with the human-relevant immuno-dominant Art v 125-36 peptide or whole Art v 1 protein when compared to control mice. In vivo, after allergen-specific sensitization, only tg mice showed enhanced airway-hyperreactivity (AHR) as assessed by methacholine or allergen-specific challenge. Three consecutive exposures to nebulized allergen were found to be sufficient for induction of AHR. The effects on bronchoalveolar lavage fluids, lung histology and specific antibody titers will be described and discussed. Humanized allergy models are amenable to the evaluation of human-relevant allergen formulations or cellular intervention protocols and will thus contribute to the further understanding of allergic diseases and their cure.

Regulation of Th9-Type Pulmonary Immune Responses

Regulation of Th9-Type Pulmonary Immune Responses

Progress of the intestinal microflora in human immune and allergic diseases in children

Microorganisms can affect the development of body immune system.Intestinal flora regulate immune function by promoting the intestinal immune system development,inducing T cell differentiation to avoid or reduce the incidence of immune-related diseases.Allergic diseases are related with the body's immune system hypoplasia and imperfect immune regulation mechanism.The immune system can be affected by intestinal flora,and the distribution of flora in the body between children with allergies and healthy children are significantly different,indicating that the occurrence of allergic diseases are associated with intestinal microflora.Studies have reported probiotic are helpful to the prevention and treatment of allergic disease,providing a new way for the prevention and treatment of allergic diseases. Key words: Intestinal flora; Immunity; Probiotics ; Allergic disease

Allergic diseases and climate changes: our experience and an update.

Recent research has shown that there are many effects of climate change on aeroallergens and thus allergic diseases in humans. It is not easy to evaluate the impact of climate change and air pollution on the prevalence of allergic diseases. The present study is devoted to decipher the possible relationships between climatic changes and allergic diseases, and in particular with atopic dermatitis (AD). To evaluate the aeroallergens effects on AD, we submitted to an allergological study protocol 59 children patients with AD to study the interaction between aeroallergens-atopy patch test (APT) and skin prick test (SPT). The same tests were performed on to the same patients after 24 months to assess the time trend. We found a high prevalence of house dust mites and grasses pollen APT positivity in AD's and in respiratory patients and we also found an increase in positive results in the same patients after 24 months. However, we observed a variation in the control group, in which in earlier tests all patients had negative results but after 24 months we found some positivity. We found a correlation between APT and SPT in AD and we observed a concordance between APT results and the atopy score index, underlying the triggering role of these aereoallergens in the atopic patient's skin reactivity.

The interaction between Lyn and FcεRIβ is indispensable for FcεRI-mediated human mast cell activation.

FcεRIβ reportedly functions as an amplifier of the FcεRIγ-mediated activation signal using a reconstitution system. However, the amplification mechanisms in human mast cells (MCs) are poorly understood. We previously reported the hyperexpression of FcεRIβ of MCs in giant papillae from vernal keratoconjunctivitis patients, compared with that in conjunctivae from nonallergic conjunctivitis patients. Elucidation of the molecular mechanisms of the amplification induced by FcεRIβ should provide new targets for novel therapeutic interventions. The aim is to understand in greater details the function of FcεRIβ in human MC FcεRI expression and signaling.FcεRIβ and Lyn expression was reduced using a lentiviral shRNA silencing technique. Localization of Lyn and FcεRIβ in cultured MCs was examined by confocal microscopic analysis. Mediators were measured by ELISAs.The diminution of FcεRIβ significantly downregulated cell surface FcεRI expression and FcεRI-mediated mediator release/production. The downregulation of FcεRI-mediated degranulation was not only due to the decrease in FcεRI expression. The diminution of FcεRIβ inhibited the redistribution of Lyn within the cell membrane following IgE sensitization. The diminution of Lyn in MCs significantly downregulated FcεRI-mediated degranulation. The recombinant cell-penetrating forms of phosphorylated FcεRIβ immunoreceptor tyrosine-based activation motif (ITAM) for intracellular delivery disturbed the interaction between Lyn and phosphorylated endogenous FcεRIβ ITAM, resulted in inhibiting IgE-dependent histamine release from MCs in vitro and from giant papillae specimens ex vivo.The interaction between Lyn and FcεRIβ is indispensable for FcεRI-mediated human MC activation, and specific inhibition of the interaction may represent a new therapeutic strategy for the treatment of human allergic diseases.

Iron supplementation decreases severity of allergic inflammation in murine lung.

The incidence and severity of allergic asthma have increased over the last century, particularly in the United States and other developed countries. This time frame was characterized by marked environmental changes, including enhanced hygiene, decreased pathogen exposure, increased exposure to inhaled pollutants, and changes in diet. Although iron is well-known to participate in critical biologic processes such as oxygen transport, energy generation, and host defense, iron deficiency remains common in the United States and world-wide. The purpose of these studies was to determine how dietary iron supplementation affected the severity of allergic inflammation in the lungs, using a classic model of IgE-mediated allergy in mice. Results showed that mice fed an iron-supplemented diet had markedly decreased allergen-induced airway hyperreactivity, eosinophil infiltration, and production of pro-inflammatory cytokines, compared with control mice on an unsupplemented diet that generated mild iron deficiency but not anemia. In vitro, iron supplementation decreased mast cell granule content, IgE-triggered degranulation, and production of pro-inflammatory cytokines post-degranulation. Taken together, these studies show that iron supplementation can decrease the severity of allergic inflammation in the lung, potentially via multiple mechanisms that affect mast cell activity. Further studies are indicated to determine the potential of iron supplementation to modulate the clinical severity of allergic diseases in humans.

Serological identification of house dust mite allergens in dogs with atopic dermatitis

House dust mite antigens have been used for decades to diagnose allergic diseases in humans and animals. The objective of this study was to identify allergens in commercial Dermatophagoides farinae and Blomia tropicalis extracts by immunoblotting using sera from allergic dogs and anti-dog IgE conjugate. The analysis of antigens present in the D. farinae extract (FDA Allergenic) using sera from 10 dogs allergic to D. farinae showed that eight sera recognized a band of approximately 102 kDa, eight recognized two bands of 52 to 76 kDa, five recognized one band of approximately 76 kDa, four recognized one band of 31 to 38 kDa, and two recognized one band of 12 to 17 kDa. Immunoblot assays of the B. tropicalis extract (FDA Allergenic) using sera from 10 animals allergic to B. tropicalis showed that five sera recognized two bands of 52 to 76 kDa. These results demonstrate the importance of the two house dust mite species for the pathogenesis of canine atopic dermatitis in Brazil. In addition, the results indicate which allergens should be present in allergenic extracts used for diagnosis and allergen-specific immunotherapy.

The interaction between Lyn and FcεRIβ is indispensable for FcεRI‐mediated human mast cell activation

FcεRIβ reportedly functions as an amplifier of the FcεRIγ-mediated activation signal using a reconstitution system. However, the amplification mechanisms in human mast cells (MCs) are poorly understood. We previously reported the hyperexpression of FcεRIβ of MCs in giant papillae from vernal keratoconjunctivitis patients, compared with that in conjunctivae from nonallergic conjunctivitis patients. Elucidation of the molecular mechanisms of the amplification induced by FcεRIβ should provide new targets for novel therapeutic interventions. The aim is to understand in greater details the function of FcεRIβ in human MC FcεRI expression and signaling. FcεRIβ and Lyn expression was reduced using a lentiviral shRNA silencing technique. Localization of Lyn and FcεRIβ in cultured MCs was examined by confocal microscopic analysis. Mediators were measured by ELISAs. The diminution of FcεRIβ significantly downregulated cell surface FcεRI expression and FcεRI-mediated mediator release/production. The downregulation of FcεRI-mediated degranulation was not only due to the decrease in FcεRI expression. The diminution of FcεRIβ inhibited the redistribution of Lyn within the cell membrane following IgE sensitization. The diminution of Lyn in MCs significantly downregulated FcεRI-mediated degranulation. The recombinant cell-penetrating forms of phosphorylated FcεRIβ immunoreceptor tyrosine-based activation motif (ITAM) for intracellular delivery disturbed the interaction between Lyn and phosphorylated endogenous FcεRIβ ITAM, resulted in inhibiting IgE-dependent histamine release from MCs in vitro and from giant papillae specimens ex vivo. The interaction between Lyn and FcεRIβ is indispensable for FcεRI-mediated human MC activation, and specific inhibition of the interaction may represent a new therapeutic strategy for the treatment of human allergic diseases.

Gene transcription abnormalities in canine atopic dermatitis and related human eosinophilic allergic diseases

Canine atopic dermatitis (AD) is clinically similar to human AD, implicating it as a useful model of human eosinophilic allergic disease. To identify cutaneous gene transcription changes in relatively early inflammation of canine AD, microarrays were used to monitor transcription in normal skin (n=13) and in acute lesional AD (ALAD) and nearby visibly nonlesional AD (NLAD) skin (n=13) from dogs. Scanning the putative abnormally transcribed genes, several potentially relevant genes, some abnormally transcribed in both NLAD and ALAD (e.g. IL6, NFAM1, MSRA, and SYK), were observed. Comparison for abnormally transcribed genes common to two related human diseases, human AD and asthmatic chronic rhinosinusitis with nasal polyps (aCRSwNP), further identified genes or gene sets likely relevant to eosinophilic allergic inflammation. These included: (1) genes associated with alternatively activated monocyte-derived cells, including members of the monocyte chemotactic protein (MCP) gene cluster, (2) members of the IL1 family gene cluster, (3) eosinophil-associated seven transmembrane receptor EMR1 and EMR3 genes, (4) interferon-inducible genes, and (5) keratin genes associated with hair and nail formation. Overall, numerous abnormally transcribed genes were observed only in canine AD; however, many others are common to related human eosinophilic allergic diseases and represent therapeutic targets testable in dogs with AD.

Reduced T‐bet in addition to enhanced STAT6 and GATA3 expressing T cells contribute to human allergen‐induced late responses

T-bet and GATA-3 are transcriptional factors involved in Th1 and Th2 cell differentiation, although their concomitant roles at protein levels in target organs during human allergic disease have not been assessed. We investigated the expression of T-bet and GATA-3 in nasal and cutaneous models of Th2 (grass-pollen allergen) and a cutaneous model of Th1 (PPD) responses in man. Nasal biopsies were obtained at 8h and skin biopsies at 8 and 48h after allergen and PPD challenges, respectively, from 10 allergic rhinitics and 6 non-atopic controls. T cells were assessed using immunofluorescence microscopy. There were increases in CD3(+)STAT6(+)cells (P=0.01 for nose and skin) and CD3(+)GATA3(+)cells (P=0.03 for skin) in response to allergen compared with diluent in allergics. When compared with non-atopics after allergen challenge the difference between the two groups was also significant for CD3(+)STAT6(+) (P=0.001 and 0.03) and for CD3(+)GATA3(+)cells (P=0.04 and 0.001) for nose and skin respectively. Following PPD challenge CD3(+)STAT4(+)cells and CD3(+)T-bet(+)cells increased in both groups compared with diluent (P=0.02 and 0.03 for both TFs), whereas only CD3(+)T-bet(+) cells were significantly greater in non-atopics compared with allergics (P=0.04). The ratio of GATA3(+):T-bet(+) T cells in allergen-induced responses was significantly greater in the allergics (P=0.008 and 0.01 nose and skin respectively), whereas the ratio of T-bet:GATA3(+)T cells was significantly higher in the non-atopics during PPD-induced responses (P=0.003). Dysregulation of Th1 transcription may contribute to heightened expression of STAT6 and GATA3 leading to exaggerated Th2-driven manifestations of allergic disease.

Surface plasmon resonance analysis of free IgE in allergic patients receiving omalizumab (Xolair)

The diagnosis of human allergic disease involves an initial clinical history based association of allergic symptoms with an allergen exposure. This is followed by confirmation of sensitization (IgE antibody positivity) with skin test, serology or provocation testing. Once diagnosed, the allergic individual can be managed using one or several modalities that involve allergen avoidance, pharmacotherapy, allergen immunotherapy and anti-IgE therapy. This report examines Law of Mass Action considerations for the design of immunological methods which permit the quantification of free (non-Omalizumab bound) IgE in the serum of patients receiving anti-IgE therapy. The rationale for and design and performance of a surface plasmon resonance assay for the detection of “free” IgE (unbound with anti-IgE) is presented as an alternative to microtiter plate based ELISAs.