Allergen-specific IgE Levels Research Articles

Prevalence of and risk factors for increased serum levels of allergen-specific IgE in a population of Norwegian dogs.

BackgroundThe importance of different allergens in association with IgE production and canine atopic dermatitis (CAD) has been poorly studied and few studies exist on factors influencing allergen-specific IgE antibodies in serum. The aim of this cross-sectional study was to investigate the prevalence of elevated IgE levels to different environmental allergens in Norwegian dogs with a suspicion of CAD. The secondary aim was to identify risk factors associated with elevated serum levels of allergen-specific IgE.ResultsThe study sample consisted of serum from 1313 dogs of 161 different breeds. All samples were submitted for serologic IgE-testing (Fc epsilon R1 alpha-based ELISA) based on suspicion of CAD. Overall, 84.3% of the dogs had elevated IgE levels to one or more of the allergen(s). The predominant allergens amongst the positive results were the indoor allergens (Acarus siro 84.0%, Dermatophagoides farinae 80.2%, Tyrophagus putrescentiae 79.9%). Sheep sorrel was the most commonly encountered outdoor allergen (40.0%). Only 2.6% of the dogs with elevated IgE levels were positive to flea saliva.The test results varied significantly depending on when the serum samples were taken. Samples taken during summer and autumn more often came out positive than samples taken during winter and spring. Geographical variations were also demonstrated. A greater proportion of females than males had positive test results, and more females than males tested positive to outdoor allergens. The mean age was significantly higher in the dogs testing positive than amongst the dogs testing negative. The allergen-specific IgE levels varied with breed. The boxer was the only breed with a significantly higher proportion of positive test results compared to the other breeds. Boxers also had a higher prevalence of elevated IgE levels to outdoor allergens, whereas the Rottweiler had a higher prevalence of elevated IgE levels to indoor allergens compared to the other breeds.ConclusionsIgE hypersensitivity was most often associated with indoor allergens. Outdoor allergens were of minor importance and IgE reactivity to flea saliva was rare. Breed differences in allergen-specific IgE levels were identified. Season of sampling, and the dogs’ geographical localisation, sex and age also affected the results of the IgE analysis.

Transmission of allergen-specific IgG and IgE from maternal blood into breast milk visualized with microarray technology

Transmission of allergen-specific IgG and IgE from maternal blood into breast milk visualized with microarray technology

Genetic determinants in the development of sensitization to environmental allergens in early childhood.

Sensitization to environmental allergens remains one of the strongest risk factors for asthma, and there is likely a genetic basis. We sought to identify genetic determinants for the development of allergic sensitization to environmental allergens, particularly cockroach allergen, in early childhood. A total of 631 children with the information about genotypic data on 895 single nucleotide polymorphisms (SNPs) in 179 candidate genes were selected from an existing dataset (Boston Birth Cohort). Genetic analysis was performed for allergic sensitizations among all subjects and sub-population, Black/African, respectively. Eight SNPs in seven genes showed significant association with allergic sensitization with P < 0.05, including two top SNPs, rs7851969 in JAK2 (P = 0.003) and rs11739089 in CNOT6 (P = 0.008). When analyses were specifically performed for cockroach sensitization, 16 SNPs in 13 genes showed P < 0.05, including five genes with SNPs at P < 0.01 (JAK1, JAK3, IL5RA, FCER1A, and ADAM33). Particularly, haplotype analyses demonstrated that multiple-haplotypes in FCER1A were significantly associated with cockroach sensitization with the strongest association for a 2-marker haplotype (rs6665683T-rs12136904T, P = 0.001). Furthermore, SNP rs6665683 was marginally associated with the levels of cockroach allergen specific IgE. When a similar analysis was performed for house dust mite, four SNPs in three genes (JAK2, MAML1, and NOD1) had P < 0.01. Of these, JAK2 appeared to be an only gene showing association across the sensitizations we analyzed. Some of findings were further validated when analysis was limited to black population. Our study identified several loci that may confer the susceptibility to allergic sensitization, and suggested that sensitization to allergens may depend on their unique loci.

Genetically engineered Lactococcus lactis protect against house dust mite allergy in a BALB/c mouse model.

BackgroundMucosal vaccine based on lactic acid bacteria is an attractive concept for the prevention and treatment of allergic diseases, but their mechanisms of action in vivo are poorly understood. Therefore, we sought to investigate how recombinant major dust mite allergen Der p2-expressing Lactococcus lactis as a mucosal vaccine induced the immune tolerance against house dust mite allergy in a mouse model.MethodsThree strains of recombinant L. lactis producing Der p2 in different cell components (extracellular, intracellular and cell wall) were firstly constructed. Their prophylactic potential was evaluated in a Der p2-sensitised mouse model, and immunomodulation properties at the cellular level were determined by measuring cytokine production in vitro.ResultsDer p2 expressed in the different recombinant L. lactis strains was recognized by a polyclonal anti-Der p2 antibody. Oral treatment with the recombinant L. lactis prior sensitization significantly prevented the development of airway inflammation in the Der p2-sensitized mice, as determined by the attenuation of inflammatory cells infiltration in the lung tissues and decrease of Th2 cytokines IL-4 and IL-5 levels in bronchoalveolar lavage. In addition, the serum allergen-specific IgE levels were significantly reduced, and the levels of IL-4 in the spleen and mesenteric lymph nodes cell cultures were also markedly decreased upon allergen stimulation in the mice fed with the recombinant L. lactis strains. These protective effects correlated with a significant up-regulation of regulatory T cells in the mesenteric lymph nodes.ConclusionOral pretreatment with live recombinant L. lactis prevented the development of allergen-induced airway inflammation primarily by the induction of specific mucosal immune tolerance.

Application of moisturizer to neonates prevents development of atopic dermatitis

Recent studies have suggested that epidermal barrier dysfunction contributes to the development of atopic dermatitis (AD) and other allergic diseases. We performed a prospective, randomized controlled trial to investigate whether protecting the skin barrier with a moisturizer during the neonatal period prevents development of AD and allergic sensitization. An emulsion-type moisturizer was applied daily during the first 32 weeks of life to 59 of 118 neonates at high risk for AD (based on having a parent or sibling with AD) who were enrolled in this study. The onset of AD (eczematous symptoms lasting >4 weeks) and eczema (lasting >2 weeks) was assessed by a dermatology specialist on the basis of the modified Hanifin and Rajka criteria. The primary outcome was the cumulative incidence of AD plus eczema (AD/eczema) at week 32 of life. A secondary outcome, allergic sensitization, was evaluated based on serum levels of allergen-specific IgE determined by using a high-sensitivity allergen microarray of diamond-like carbon-coated chips. Approximately 32% fewer neonates who received the moisturizer had AD/eczema by week 32 than control subjects (P = .012, log-rank test). We did not show a statistically significant effect of emollient on allergic sensitization based on the level of IgE antibody against egg white at 0.34 kUA/L CAP-FEIA equivalents. However, the sensitization rate was significantly higher in infants who had AD/eczema than in those who did not (odds ratio, 2.86; 95% CI, 1.22-6.73). Daily application of moisturizer during the first 32 weeks of life reduces the risk of AD/eczema in infants. Allergic sensitization during this time period is associated with the presence of eczematous skin but not with moisturizer use.

Response to letter regarding article ‘Exploring the link between pholcodine exposure and neuromuscular blocking agent anaphylaxis’

Uyttebroek et al. [1] raise some pertinent questions regarding the utility of various testing modalities in the assessment of neuromuscular blocking agent (NMBA) hypersensitivity. In our cases, clinical history was the major assessment tool for identifying pholcodine as the inciting agent of anaphylaxis [2]. In both patients, the temporal association between pholcodine exposure and clinical reaction was in keeping with drug-induced anaphylaxis and no alternative causes were identified. The positive allergen-specific IgE levels to pholcodine (ImmunoCAP Phadia, Uppsala, Sweden) were used to substantiate the high index of clinical suspicion. As mentioned in the article, skin testing to pholcodine has limited utility because it causes wheal and flare reactions in normal control subjects. While drug provocation challenges are sometimes used to confirm allergy in situations where history and skin/allergen-specific IgE testing are ambiguous, in this circumstance this was not felt appropriate, owing to the severity of systemic reaction in both patients' index events. In one of our cases, a tramadol challenge was performed to give additional options if opiate analgesics were required, and the avoidance of codeine and its active metabolite morphine was recommended. Subsequent evaluation in both our patients was targeted toward the potential for NMBA hypersensitivity given previous studies [3–6], presented in the review, suggesting an association between pholcodine exposure and NMBA anaphylaxis. The recommendations regarding NMBA use in both patients were based on the outcome of skin testing and allergen-specific IgE testing. As Uyttebroek et al. [1] allude to, sensitization to a drug does not always equate with clinically meaningful allergy. However, provocation challenges with various NMBAs, as a means of demonstrating patient tolerance or allergy, are not feasible. Thus, the recommendations were made on the available testing at the time of assessment. The development of basophil activation tests as an adjunct to skin testing and specific IgE testing will no doubt help in the assessment of cases of suspected drug allergy. However, these tests are currently not validated or routinely available in most centres, and sensitivity may be lacking even when cases are carefully phenotyped and selected. The cases presented demonstrate the potential for sensitization to NMBA to occur in the context of pholcodine hypersensitivity. These case studies are reflective, at an individual patient level, of the population-based evidence cited previously [3,5,6]. We agree that consideration of whether the patients are able to tolerate opiates following true pholcodine immediate (IgE) hypersensitivity reactions is an important practical concern, and the specific haptenated products mediating such reactions are unknown. Indeed, codeine is metabolized by the genetically polymorphic isoform CYP2D6 to the active metabolite morphine, adding additional potential variability to potential cross-reactivity and patient tolerance. However, the focus of our article [2] was on the potential association of pholcodine exposure and NMBA allergy, and thus, the presentation of the case studies reflects this. Immunoglobulin E-mediated hypersensitivity reactions to pholcodine and morphine are rare, and this does indeed raise important questions regarding the pathogenesis of pholcodine sensitization and NMBA anaphylaxis. At present, the mechanisms underlying why exposure and sensitization to a substituted ammonium ion in pholcodine can prime NMBA anaphylaxis but not result in allergy to all compounds containing similar substituted ammonium ions remain unresolved.

Assessment of serum levels of allergen-specific immunoglobulin E in different seasons and breeds in healthy horses.

The present study was designed to asses specific IgE towards environment allergens in 42 healthy horses. Determination of this immunoglobulin in serum serve as diagnostic tools in allergic diseases to improve efficacy of the treatment and proper allergen selection to specific immunotherapy. Serum levels of allergen specific IgE were measured with equine monoclonal antibody, using 15 individual and 5 mix allergens in North European Panel. The study revealed season dependent increased levels of allergen specific IgE in normal horses. It is noteworthy that healthy horses show high percentage of positive reactions, most commonly towards to domestic mites D. farinae (80%), D. pteronyssinus (35.71%) and storage mites T. putrenscentiae (42.86%), Acarus siro (40.48%). These allergens play an important role in equine, canine and feline atopic dermatitis. We also demonstrated high IgE levels in the group of horse specific insect allergens. Tabanus sp. (35.71%), Culicoides sp. (28.57%) and Simulium sp. (26.19%) were the most frequent insect positive reaction allergens. No positive reactions in all groups of allergens were found in winter season, low and merely detectable levels of antibodies have been found relating to D. farianae and T. putrescentiae allergen. We observed elevated mould-IgE levels in horses that live in stables, while outdoor living horses showed very low levels. Amongst all positive reactions we observed only weak and moderate reactions but no strong positive reactions were found. No significant differences were observed between three breeds of horses with the exception of moulds and D. pteronyssinus allergens.

Association study on ADAM33 polymorphisms in mite-sensitized persistent allergic rhinitis in a Chinese population.

BackgroundThe ADAM33 gene has been identified as a potentially important asthma candidate gene and polymorphisms in this gene have been shown to be associated with asthma and seasonal allergic rhinitis.ObjectiveTo assess whether the ADAM33 polymorphisms are associated with persistent allergic rhinitis (PER) due to house dust mites in a Chinese population.MethodsIn a hospital-based case-control study of 515 patients with mite-sensitized PER and 495 healthy controls, we genotyped seven single nucleotide polymorphisms (SNPs) in ADAM33. Serum levels of eosinophil cationic protein, total IgE and allergen-specific IgE against Dermatophagoides pteronyssinus and Dermatophagoides farinae were measured by the ImmunoCAP assays.ResultsIn the single-locus analysis, three polymorphisms, rs3918392 (F1), rs528557 (S2) and rs2787093, were significantly associated with mite-sensitized PER. SNP S2 was associated with significantly increased risk both of asthmatic and nonasthmatic mite-sensitized PER. In the combined genotypes analysis, individuals with 2–4 risk alleles had a significantly higher risk of mite-sensitized PER (adjusted OR = 1.99, 95% CI = 1.50–2.62) than those with 0–1 risk alleles. Haplotype-based association analysis revealed that the ACAGCCT haplotype might have potential to protect against mite-sensitized PER (adjusted OR = 0.67; 95% CI = 0.49–0.90).ConclusionsPolymorphisms in the ADAM33 gene may contribute to susceptibility of mite-sensitized PER in this Chinese population.

Serum-soluble HLA-G is associated with specific IgE in patients with allergic rhinitis and asthma.

Allergic rhinitis (AR) and allergic asthma (AA) are characterized by T helper (Th)2-polarized immune response. Soluble human leukocyte antigen G (sHLA-G) molecule plays an immunomodulatory activity. Previously, it has been reported that children with AR or AA had higher sHLA-G levels in comparison with normal subjects. Thus, the present study aimed at confirming these data in adults and investigating whether there was a relationship between serum sHLA-G levels and serum IgE levels, in patients with AR or AA. One hundred twenty symptomatic patients, suffering from respiratory symptoms, were enrolled: 45 non-allergic and 75 allergic. A group of 44 healthy subjects was considered as control. Serum sHLA-G levels and serum allergen-specific IgE were determined by immunoenzymatic methods. Allergic patients had significantly higher levels of sHLA-G molecules than non-allergic patients and normal controls (p<0.0001). There was no difference between AR and AA. sHLA-G moderately related with allergen-specific IgE both in AR (r=0.468) and AA patients (r=0.479). The present study confirms that serum sHLA-G molecules are significantly increased in allergic disease and demonstrates that sHLA-G levels are related with allergen-specific IgE levels.

Predicting Outcomes of Oral Food Challenges by Using the Allergen-Specific IgE–Total IgE Ratio

Although allergists typically use allergen-specific IgE (sIgE) levels or skin prick test wheal sizes to identify food allergens that may provoke IgE-mediated food-induced allergic reactions, both tests have high rates of false positivity and mislabel patients who are tolerant as allergic to the food allergen. To examine the accuracy of the ratio of sIgE to total IgE ("Ratio") in predicting the outcome of challenges performed to confirm the development of tolerance. Medical records of children diagnosed with food allergy who participated in oral food challenge at an allergy outpatient clinic (2009-2013) were reviewed for IgE antifood serology and concomitant oral food challenge outcomes, which were analyzed for associations by using logistic regression models and receiver operator characteristics curves. The Ratio for participants who failed their challenge was higher than the Ratio of those who passed their challenge (failed 1.48% vs passed 0.49%; n= 195). Receiver operator characteristic curves showed that the Ratio was significantly more accurate than sIgE alone in predicting challenge outcome (Ratio 0.69 vs sIgE alone 0.55; P= .03). These trends were mostly associated with more persistent food allergens, such as peanut, tree nuts, shellfish, and seeds (failed 2.18% vs passed 0.41%; n= 93) (Ratio 0.81 vs sIgE alone 0.54; P < .01). Our findings suggest that the Ratio is more accurate than sIgE alone in predicting outcomes of challenges performed to confirm the development of tolerance toselect food allergens, especially to peanut and tree nuts. TheRatio may be useful in identifying patients most likely to passoral food challenge.

Evaluation of Reduced Allergenicity of Deamidated Gliadin in a Mouse Model of Wheat-Gliadin Allergy Using an Antibody Prepared by a Peptide Containing Three Epitopes

Gliadin is the principal allergen of wheat-dependent exercise-induced anaphylaxis (WDEIA). The primary structure of IgE-binding epitopes in wheat gliadin includes tandem sequencing sites of glutamine residues. Therefore, deamidation would be an effective approach to reduce the allergenicity of wheat proteins. In our previous study, we deamidated wheat gliadin without causing peptide-bond hydrolysis or polymerization by use of carboxylated cation-exchange resins, and we found that the deamidated gliadin scarcely reacted with the sera of patients radioallergosorbent test (RAST)-positive to wheat. In this study, we examined the allergenicity of deamidated gliadin in a mouse model of wheat-gliadin allergy. Oral administration of deamidated gliadin to gliadin-sensitized mice suppressed enhancement in intestinal permeability, serum allergen level, serum allergen-specific IgE level, mast-cell-surface expression of FcεRI, and serum and intestinal histamine levels. Our results indicate that gliadin deamidated with no peptide-bond hydrolysis by cation-exchange resins has low allergenicity even under in vivo conditions.

A molecular model system based on human monoclonal allergen-specific IgE antibodies to study basophil activation

Methods Monoclonal human IgE antibodies specific for the major birch pollen allergen Bet v 1 and for the major grass pollen allergen Phl p 5 and the corresponding allergens as well as a hybrid protein consisting of the Bet v 1 and Phl p 5 allergens were expressed. Using circular dichroism spectroscopy we compared the fold of the hybrid protein with that of the mixture of the two allergens. Rat basophil leukemia cells transfected with the human FceRI receptor were then loaded with the monoclonal IgE antibodies or patients serum containing polyclonal allergen-specific IgE and then exposed to the allergens and the hybrid protein to study basophil activation. Results We found that basophil activation was obtained with a mixture of two monoclonal IgE antibodies and the hybrid protein which increased in magnitude with rising concentrations of allergen-specific IgE antibodies. Thus increases in allergen-specific IgE lead to the release of larger amounts of mediators. When polyclonal IgE from allergic patients was used, basophil activation was obtained already with lower concentrations of the hybrid protein. An augmentation of the number of IgE epitopes thus increased the allergenic activity and thus the “potency” of the allergen. Preliminary titration experiments of the two monoclonal IgE antibodies also suggested that equimolar concentrations of the IgE antibodies with different specificity were most efficient in causing basophil activation, most likely due to the formation of large immune complexes. Conclusion Results obtained in our molecular model for human basophil activation show that the levels of allergen-specific IgE dictate the extent of basophil degranulation and that the number of IgE epitopes determines the potency of an allergen to induce degranulation. The model should be useful to explore the factors determining allergen-induced basophil activation and to study therapeutic strategies controlling this event. This study was supported by grant P23318-B11 and in part by grants P23350-B11 and F4605 of the Austrian Science Fund (FWF).

A novel IgE-neutralizing antibody for the treatment of severe uncontrolled asthma

The critical role played by IgE in allergic asthma is well-documented and clinically precedented, but some patients in whom IgE neutralization may still offer clinical benefit are excluded from treatment with the existing anti-IgE therapy, omalizumab, due to high total IgE levels or body mass. In this study, we sought to generate a novel high affinity anti-IgE antibody (MEDI4212) with potential to treat a broad severe asthma patient population. Analysis of body mass, total and allergen-specific IgE levels in a cohort of severe asthmatics was used to support the rationale for development of a high affinity IgE-targeted antibody therapeutic. Phage display technology was used to generate a human IgG1 lead antibody, MEDI4212, which was characterized in vitro using binding, signaling and functional assay systems. Protein crystallography was used to determine the details of the interaction between MEDI4212 and IgE. MEDI4212 bound human IgE with an affinity of 1.95 pM and was shown to target critical residues in the IgE Cε3 domain critical for interaction with FcεRI. MEDI4212 potently inhibited responses through FcεRI and also prevented the binding of IgE to CD23. When used ex vivo at identical concentration, MEDI4212 depleted free-IgE from human sera to levels ~1 log lower than omalizumab. Our results thus indicate that MEDI4212 is a novel, high affinity antibody that binds specifically to IgE and prevents IgE binding to its receptors. MEDI4212 effectively depleted free-IgE from human sera ex vivo to a level (1 IU/mL) anticipated to provide optimal IgE suppression in severe asthma patients.

P41 ‐ Preexposure prophylaxis of infants’ food allergy

Methods We observed 100 “mother and child” pairs, which were divided into two groups. All children had AD, associated to cow milk protein (CMP) allergy. Lactating mothers from both groups were treated by diet therapy with the replacement of the cow milk to the New Zealand goat milk (1 group: 43 “mother and child” pairs) or non-dairy diet (2 group: 57 “mother and child” pairs). The effect of diet therapy was assessed by dynamics of clinical and immunological AD symptoms in infants after 1-3 months of treatment. Immunological effect of the therapy was assessed by the dynamics of levels of allergen-specific IgE and IgG to CMP, casein, b-lactoglobulin and goat milk protein which were measured by uncompetitive immunoenzyme assay on special test-systems from Allergopharma (Germany). The level of IFN-g, IL-2, IL-4, IL-5, IL-12, IL-13 was measured by immunoenzyme ELISA method.

Identification of Sola l 4 as Bet v 1 homologous pathogenesis related-10 allergen in tomato fruits

The aim was to investigate the potential contribution of a major birch pollen Betv1-homologous allergen to birch pollen-associated tomato fruit allergy. Two isoforms of a Betv1-homologous protein (designated Solal4) from tomato fruit were identified by cDNA-cloning and produced as recombinant proteins. Allergen-specific IgE levels to tomato, birch pollen, Betv1, and Sola l 4 were determined in birch pollen allergic patients with allergy or tolerance to tomato. Solal4 was recognized in 76% of birch/tomato allergic patients, while tomato- and Betv1-specific IgE was detectable in 64% and 81% of sera. Almost all patients sensitized to Betv1 reacted with Solal4. Both Solal4 isoforms displayed allergenic potency and IgE-cross-reactivity with Betv1 as investigated by competitive ELISA and in vitro mediator release assay. Nevertheless, the reactivity pattern of patients' sera was diverse. Sola l 4, a novel pathogenesis related-10 protein, qualifies as major allergen in tomato fruits. Data suggest Sola l 4 as classII allergen. IgE-testing using Sola l 4 showed low clinical specificity, but high sensitivity in tomato allergic patients and will further improve component-resolved allergy diagnosis.

Component resolution reveals additional major allergens in patients with honeybee venom allergy

Detection of IgE to recombinant Hymenoptera venom allergens has been suggested to improve the diagnostic precision in Hymenoptera venom allergy. However, the frequency of sensitization to the only available recombinant honeybee venom (HBV) allergen, rApi m 1, in patients with HBV allergy is limited, suggesting that additional HBV allergens might be of relevance. We performed an analysis of sensitization profiles of patients with HBV allergy to a panel of HBV allergens. Diagnosis of HBV allergy (n = 144) was based on history, skin test results, and allergen-specific IgE levels to HBV. IgE reactivity to 6 HBV allergens devoid of cross-reactive carbohydrate determinants (CCD) was analyzed by ImmunoCAP. IgE reactivity to rApi m 1, rApi m 2, rApi m 3, nApi m 4, rApi m 5, and rApi m 10 was detected in 72.2%, 47.9%, 50.0%, 22.9%, 58.3%, and 61.8% of the patients with HBV allergy, respectively. Positive results to at least 1 HBV allergen were detected in 94.4%. IgE reactivity to Api m 3, Api m 10, or both was detected in 68.0% and represented the only HBV allergen-specific IgE in 5% of the patients. Limited inhibition of IgE binding by therapeutic HBV and limited induction of Api m 3- and Api m 10-specific IgG4 in patients obtaining immunotherapy supports recent reports on the underrepresentation of these allergens in therapeutic HBV preparations. Analysis of a panel of CCD-free HBV allergens improved diagnostic sensitivity compared with use of rApi m 1 alone, identified additional major allergens, and revealed sensitizations to allergens that have been reported to be absent or underrepresented in therapeutic HBV preparations.

Microarrayed dog, cat, and horse allergens show weak correlation between allergen-specific IgE and IgG responses⋆

Microarrayed dog, cat, and horse allergens show weak correlation between allergen-specific IgE and IgG responses⋆

Measurement of Japanese Cedar Pollen-Specific IgE in Nasal Secretions

Japanese cedar pollen (JCP) is the most common allergen for seasonal allergic rhinitis in Japan. Little is known about local production of immunoglobulin (Ig)E in people with or without Japanese cedar pollinosis. The aims of this study were to measure levels of JCP-specific IgE in nasal secretions and determine correlations with levels in serum. Forty-six subjects were enrolled in this study, comprising 24 symptomatic subjects, 9 asymptomatic subjects sensitized to JCP, and 13 subjects not sensitized to JCP. Nasal secretions were obtained during a period of Japanese cedar dispersal, and levels of JCP-specific IgE were measured with CAP-fluorescent enzyme immunoassay. Serum JCP-specific IgE and total IgE were also measured using the same method. Among the 46 subjects enrolled, JCP-specific IgE in nasal secretions was measureable in 43 subjects. Irrespective of symptom development, sensitized subjects showed higher levels of JCP-specific IgE in nasal secretions than non-sensitized subjects. A significant moderate correlation was observed between JCP-specific IgE levels in nasal secretions and serum in all 43 subjects. With stratification by subject group, only symptomatic subjects showed a substantial correlation between JCP-specific IgE levels in nasal secretions and serum. Our results imply a certain association between JCP-specific IgE in nasal secretions and sensitization of Japanese cedar pollinosis. Therefore, levels of allergen-specific IgE in nasal secretions can be used as an alternative diagnostic marker for allergic rhinitis patients.

Paradoxical Increase of IgE Binding Components during Allergen-Specific Immunotherapy in Pollinosis Patients

Allergen-specific immunotherapy (SIT) reduces allergen specific IgE (sIgE) levels and achieves clinical and immunological tolerance by modulating innate and adaptive immunological responses. Increased temperature and CO2 concentrations caused by climate changes contribute to an increase of pollen count and allergenicity that influences clinical SIT outcomes. In this study, we investigated the changes of IgE binding components to tree and weed pollens in pollinosis patients who showed a paradoxical increase of serum sIgE level during pollen-SIT. We enrolled nine patients who showed an increasing pattern of serum sIgE level to alder, birch, ragweed and mugwort pollens by enzyme-linked immunosorbant assay. IgE immunoblot analysis confirmed the intensification or new generation of major IgE binding components that could be induced by climate change. The findings suggest that the regular monitoring of sIgE levels and symptom changes is required to improve the clinical outcomes of SIT in patients undergoing SIT for tree and weed pollens.Graphical

Use of humanized rat basophil leukemia (RBL) reporter systems for detection of allergen-specific IgE sensitization in human serum.

Determination of allergen-specific IgE levels in human blood samples is an important diagnostic technology for assessment of allergic sensitization. The presence of specific IgE in human serum samples can be measured by sensitizing humanized rat basophil leukemia (RBL) cell lines with diluted serum and measuring cellular activation after challenge with the suspected allergens. This has been traditionally performed by measuring the levels of β-hexosaminidase released upon RBL degranulation. Here, we describe the use of two recently developed humanized RBL reporter cell lines which offer higher sensitivity and are amenable to high-throughput-scale experiments.