Determination Of IgE Antibodies Research Articles

Utility of Gal d 1-Specific IgE Levels in Predicting Reactivity to Boiled Egg in Chinese Children

Background: Many researchers have reported predicting the outcome of oral food challenges (OFCs) on the basis of specific IgE (sIgE) levels. However, the clinical usefulness of the determination of IgE antibodies to egg allergen components in Chinese children with suspected boiled egg allergy is not well studied. Objective: Our objective was to assess the diagnostic performance of sIgE to egg white and Gal d 1, 2, 3, and 5 based on the open challenge outcome for boiled egg. Methods: A total of 48 child patients with a suspect of boiled egg allergy were included. Serum egg white and Gal d 1, 2, 3, and 5 sIgE were measured by ImmunoCAP. Diagnostic value was assessed by area under the receiver operating characteristic curves (AUC). Results: Using the OFC results as the reference parameter, Gal d 1 sIgE had the highest AUC (0.84) compared with egg white (0.77) and other investigated components (ranging from 0.51 to 0.71). The clinical sensitivity and specificity for the sIgE to Gal d 1 at optimal cutoff (6.15 kUA/L) were 73.7% and 96.7%, respectively. Sensitization to Gal d 1 with a cutoff value of >7.48 kUA/L indicated a 90% probability of positive challenge. Conclusion: Quantitative measurements of Gal d 1 sIgE antibodies using ImmunoCAP are useful in the management of boiled egg allergy in Chinese children.

Food Intolerance of Unknown Origin: Caused by Mucosal Inflammation? A Pilot Study.

INTRODUCTION:The prevalence of patients with food intolerance (FI) has increased significantly. Immunoglobulin (Ig)E-mediated food allergies (FAs) are detected by determining IgE antibodies and skin prick test. Carbohydrate malabsorptions are clarified with breath tests. However, these diagnostic measures cannot capture all intolerances and have limitations in case of gut-mediated FI. The aims of this pilot study were to evaluate different methods to determine intestinal mucosal IgE in patients with FA and to characterize the intestinal mucosa in patients with FI of unknown origin (FH).METHODS:Patients with FA and FH were compared with healthy controls. To determine the IgE antibodies and the cytokines tumor necrosis factor (TNF)-α and interferon (IFN)-γ of the intestinal mucosal, a lavage was performed as part of an ileocolonoscopy and samples were taken using the cytobrush and biopsy forceps. In a subgroup, mucosal samples were also taken from the duodenum.RESULTS:Data in homogenates of intestinal mucosal samples yielded the highest sensitivity for IgE antibody titers compared with lavage and cytobrush. Patients with FA presented increased intestinal TNF-α and low IFN-γ values. This was in contrast to FH patients, who showed low intestinal IgE antibodies and TNF-α levels, but increased IFN-γ values.DISCUSSION:The determination of IgE antibodies to diagnose intestinal IgE-mediated FA is most reliable in intestinal mucosal samples. Increased TNF-α and low IFN-γ levels in patients with FA characterize an allergic reaction. Decreased TNF-α and increased IFN-γ levels in patients with FH indicate an inflammation-related intolerance reaction (see Visual , Supplementary Digital Content 1, http://links.lww.com/CTG/A520).

Utility of Serum Allergy Test In Patients With Chronic Urticaria

INTRODUCTION: Chronic urticaria (CU) is a common skin disorder affecting 15– 20% of the people in the general population. It is a frequent disease which presents with wheals, angiooedema or both and lasts for over six weeks or more. OBJECTIVES: To determine the etiology of IgE specific allergens in the causative of CU in the Nepalese population. MATERIALS & METHODS: A prospective cross sectional study was carried out between November 2014- October 2016 on all patients diagnosed as having CU. Blood samples were taken from all patients and asemiquantitative determination of IgE antibodies against a panel of individual allergens was done and data analyzed and interpreted in terms of numbers and percentages. RESULTS: Three hundred and fourteen patients were included in the study with 56% (175) being female and 44% (139) being male. The age of the patients ranged from 5years to 84 years with a mean of 37.33± 14.39 years. The duration of the disease also ranged from 0.15 to 20 years in which 116(36.9%) patients presented with disease of less than 6 months duration while 163(51.9%) patients had the disease for more than 6 months. Two hundred and seventy nine patients (88.9%) showed a positive test to the allergens amongst which most were allergic to plants which included weeds and grass.CONCLUSION: In patients with CU whenever possible it is advisable to send the patient for serum allergy test to determine the causative agent, the avoidance of which can help in the management of urticaria in troublesome patients.Journal of Universal College of Medical Sciences (2017) Vol.05 No.01 Issue 15, Page: 33-36

Sensitization pattern to inhalant and food allergens in symptomatic children at first evaluation.

BackgroundData on specific IgE sensitization prevalence in children with allergy-like symptoms seen in the primary care setting are rare. Early diagnosis of allergic diseases is important to prevent clinical manifestations, exacerbations or expansion of allergic diseases to other organ systems. The present study aims to assess the usefulness of early serological diagnosis in children with common allergic symptoms.Methods532 children (<15 years of age), with at least one of ten allergy-like symptoms, from 21 primary care centers in two geographic areas of Italy and Spain were included in the study. Patients were tested with, either Phadiatop® Infant (0–5 years of age) or Phadiatop® and food mix (fx5e) (>5 years of age) to discriminate atopic from non-atopic subjects. A blood sample of atopic subjects was taken for additional 6–26 specific IgE antibody determinations from a predefined panel using the ImmunoCAP® System.Results267 children (50.2 %) were positive in the initial test and were classified as atopic. 14 % were mono-sensitized, 37 % were sensitized to 2–3 allergens and 49 % to more than 3 allergens. The average number of symptoms in the atopic group was 3.3 vs 2.8 in the non-atopic group. The prevalence of sensitization to single allergens was highest for grass and ragweed pollen and house-dust mites (19–28 %). Sensitization to tree allergens was highest for olive tree (16.5 %). Cow’s milk and egg white were the most sensitizing foods (~15 %). Food allergen sensitization predominated in younger children (OR = 2.8) whereas the inverse occurred with inhalant allergens (OR = 2.5 to 5.6). A significant positive correlation between patient age and the number of sensitizations was found.ConclusionsSpecific IgE sensitization in children with allergy-like symptoms is common. Multiple sensitization is predominating. Number of clinical symptoms was higher in the atopic group compared to the non-atopic without a correlation with the number of positive allergens. Age seems to play a crucial role in the development of sensitization with a significant positive correlation between patient age and the number of sensitizations.

Clinical Utility of IgE Antibodies to ω-5 Gliadin in the Diagnosis of Wheat Allergy: A Pediatric Multicenter Challenge Study

Background: There are contradictory results regarding the clinical usefulness of the determination of IgE antibodies to ω-5 gliadin in children with a suspicion of wheat allergy (WA). Methods: The study comprised 311 children and young adults with suspected wheat intolerance treated at three separate pediatric clinics and, with the exception of 25, were found to be positive in specific IgE antibody determinations to wheat. Their ages ranged from 6 months to 20.4 years (median age, 2.3 years). Possible relationships between IgE antibodies to ω-5 gliadin and a physician’s diagnosis of WA and challenge symptoms were studied. Results: The mean concentration of IgE antibodies to ω-5 gliadin was 1.2 kU_A/l in WA patients and <0.35 kU_A/l in patients without WA (p < 0.0001). Seventy-two percent of the WA patients had positive ω-5 gliadin levels and 75% of the patients without WA had negative levels. Logistic regression showed a significant relationship between the probability of WA and the concentration of IgE antibodies to ω-5-gliadin with a 2.6-fold (95% CI: 2.0–3.3) increased risk. Age was an important factor to consider as the risk of WA increased 5.4-fold (95% CI: 1.4–21) for children ≤1 year of age and 2.5-fold (95% CI: 2.0–3.2) for children >1 year of age with increasing levels of IgE. Conclusion: Detection of IgE to ω-5 gliadin seems to be associated with responsiveness to the challenge test and is particularly useful in infants with a suspicion of WA.

Basophil allergen threshold sensitivity, CD-sens, is a measure of allergen sensitivity in asthma

Allergic asthma is IgE-mediated and the IgE-sensitisation is usually demonstrated by skin prick tests (SPT) and IgE antibody determinations in serum. The SPT and IgE-antibody values do not directly predict if the allergy clinically contributes to the asthma. There is therefore a need for new objective tests that may indicate the clinical importance of an IgE-sensitisation. To evaluate basophil allergen threshold sensitivity (CD-sens) as a measure of allergen sensitivity in allergic asthma. Twenty-six subjects with stable, intermittent allergic asthma were tested with SPT and spirometry, and methacholine and allergen inhalation challenges to determine methacholine PD(20) (provocative dose causing a 20% drop in forced expiratory volume in 1 s) and allergen PD(20) . The results were compared with CD-sens and serological parameters, i.e. IgE- and IgG4 antibodies to the relevant allergens. A significant correlation was found between CD-sens and allergen PD(20) (P = 0.01; r = 0.49; n = 26) as well as between CD-sens and the ratio of allergen PD(20) to methacholine PD(20) (P = 0.007; r = 0.52; n = 26). In patients with a moderate to low degree of bronchial hyperresponsiveness there was an excellent correlation (P = 0.0001; r = 0.88, n = 13) between CD-sens and allergen sensitivity. No relation to either allergen PD(20) or the ratio was found for basophil allergen reactivity measured as CD63 up-regulation at high concentrations of the respective allergen. CD-sens was found to be an objective marker of airway allergen sensitivity in stable allergic asthmatics, that may be used to predict airway responsiveness when bronchial challenge tests cannot be performed.

Cytomegalovirus infection and development of allergic diseases in early childhood: Interaction with EBV infection?

Chronic replication of cytomegalovirus and EBV in early life may affect the immune system and play a role in the development of allergy in children. To assess the relation between cytomegalovirus infection and allergic disorders in children, including a possible interaction with EBV infection. From a prospective birth cohort study in Stockholm, on factors of importance for development of allergy, 2581 four-year-old children were enrolled. The classification of allergic diseases was based on questionnaire answers and determination of IgE antibodies to common airborne and food allergens. IgG to cytomegalovirus was determined by a commercial ELISA and to EBV by indirect immunofluorescence. A total of 1191 (46%) children were cytomegalovirus-seropositive. There were no significant associations between seropositivity to cytomegalovirus and allergic manifestations, such as bronchial asthma, suspected allergic rhinitis, or atopic dermatitis. Seropositivity to cytomegalovirus alone, ie, without seropositivity to EBV, was related to IgE antibodies to airborne and food allergens (adjusted odds ratio, 1.8; 95% CI, 1.2-2.9). An antagonism between cytomegalovirus and EBV in relation to sensitization to airborne and food allergens was suggested ( P = .05). The study does not support the hypothesis that previous cytomegalovirus infection plays an important role in the pathogenesis of bronchial asthma, suspected allergic rhinitis, or atopic dermatitis in children. However, in the absence of EBV infection, cytomegalovirus infection may be related to sensitization to airborne and food allergens.

Accuracy of specific IgE antibody assays for diagnosis of cow's milk allergy

The primary objective of this report was to discuss the accuracy of specific immunoglobulin (Ig)E antibody determinations in the diagnosis and prognosis of reactions to allergens, especially cow's milk, in the context of other relevant clinical information. A review was undertaken of the relevant literature on IgE antibody assays in conjunction with some unpublished information from the authors' investigations. The pertinent data for this article were selected on the basis of the expert opinion of the authors. IgE antibody formation and allergy commence early in life, which can be reflected by specific IgE antibody determinations in serum samples with use of particular systems developed for commercial use. After the first such system was introduced in 1974, development of the technology has ensued. Some systems using excess of allergen extracts of good quality have proven to yield highly accurate results over time. Assays that detect all antibodies present in the serum sample and that demonstrate parallelism between dilutions of specific IgE antibodies and total IgE concentration also allow quantitative determinations of specific IgE antibodies. Such specific IgE antibody data can be used not only for a dichotomized evaluation of the presence or absence of sensitization in an individual patient, but also for an evaluation of the relative risk for a clinical reaction to an allergen such as cow's milk. Thus, the specific IgE antibody information can be used in the diagnosis, prediction of the course, and followup management of allergic disease, particularly when sensitization to multiple allergens is present. Specific IgE antibodies can be accurately determined with certain technologic systems. Such determinations provide information, not available by other means, for the diagnosis, prognosis, and followup of patients with allergy-like symptoms.

Quantitative IgE antibody assays in allergic diseases

During the past several years, immunoassays for specific IgE antibodies have been refined to permit reporting results in mass units. Thus quantitative immunoassays for IgE antibodies may be an adjunct to skin tests. In cases of food allergy among children with atopic dermatitis, cutoff values for IgE antibody concentrations to egg, milk, peanut, and fish have been derived to provide 95% positive and 90% negative predictive values. Food-specific IgE antibody determinations can also be used to predict which food allergies are resolving spontaneously. Elevated egg-specific IgE antibody levels in infancy are associated with significantly increased risk for development of inhalant allergies later in childhood. In cases of inhalant allergy, specific IgE antibody levels correlate closely with results of inhalation challenge studies in cat-sensitive persons. Also, mite-specific IgE antibody levels correlate significantly with the mite allergen contents of reservoir dust in the homes of mite-sensitive persons. Immunoassays for quantitation of specific IgE antibodies may be used to document allergen sensitization over time and to evaluate the risk of reaction on allergen exposure. However, immunoassays and skin tests are not entirely interchangeable, and neither will replace the other in appropriate circumstances. (J Allergy Clin Immunol 2000;105:1077-84.)

Determination of IgE antibodies to Candida albicans mannan with nitrocellulose-RAST in patients with atopic diseases.

A nitrocellulose-based radioallergosorbent test (RAST) was developed and used for the determination of IgE antibodies to Candida albicans mannan in patients with atopic dermatitis, asthma and allergic rhinitis. The results were expressed as mannan-RAST index values (an inter- and intra-assay coefficient for variation of 8.0-10.2%). The normal range for mannan-RAST index values was determined in 102 non-atopic adults. Fifty-three of 78 (67.9%) patients with atopic dermatitis showed elevated mannan-RAST index values with a significant correlation to the severity of the dermatitis (r = 0.33, P < 0.01). Sixteen of 30 (53.3%) patients with asthma had a positive mannan-RAST index value; however, 12 of the 16 asthmatics (75%) who were positive also suffered from atopic dermatitis. Those who had allergic rhinitis but not atopic dermatitis showed a positive mannan-RAST index value in 12 of 32 (37.5%) cases. Nitrocellulose-RAST offered a sensitive method for the determination of polysaccharide-specific IgE antibodies in atopic diseases. The results show that high values are observed mainly in atopic dermatitis and less sensitization to C. albicans occurs in respiratory allergy.

Determination of IgE antibodies to the benzyl penicilloyl determinant. A comparison between poly- l-lysine and human serum albumin as carriers

The influence of two different carriers, poly- l-lysine (PLL) and human serum albumin (HSA) in the binding of specific IgE antibodies to the benzyl penicilloyl hapten (BPO) was determined in a solid-phase assay. Serum samples from patients with a history of immediate reaction to penicillin and which had shown the presence of IgE antibodies to BPO were used. Benzyl penicilloyl derivatized cellulose discs were prepared using PLL of different molecular weight and HSA as carriers. These were treated with different molar ratios of benzyl penicillin. These reagents were compared for uptake of BPO-specific IgE using a pool of sera in a radioallergosorbent test (RAST) type assay. Two PLL systems and two HSA systems were finally compared using 26 individual sera. RAST values were compared by Kruskal-Wallis and Wilcoxon tests. The relationships between the four different assays were evaluated by determining Pearson correlation coefficients and the concordance by determining intraclass correlation coefficients (ICC). Analysis of means by the Wilcoxon test revealed significant differences ( P < 0.01) only when the different carrier assays were compared. The correlation coefficients between all the assays were significant ( P < 0.0001), but the ICC was low when the different carrier assays were compared. These results indicate that the nature of the carriers studied (PLL and HSA) influences the capacity for binding IgE antibodies in the RAST procedure. The differences observed indicate that one conjugate cannot be substituted for the other in the determination of IgE antibodies to BPO and that BPO-PLL is preferable.

Determination of IgE antibodies to Polistes dominulus, Vespula germanica and Vespa crabro in sera of patients allergic to vespids

The study was undertaken to investigate the presence of IgE antibodies to Polistes dominulus (PD), Vespula germanica (VG) and Vespa crabro (VC) in a large group of sera belonging to patients sensitized to Vespids in Spain. RAST values showed that although the majority of patients had IgE antibodies to PD, VG and VC, there was a marked predominance of PD. These results were related to the distribution of the insect in the areas where the sera were obtained. Due to geographical and insect distribution differences, the whole area was divided into three zones: Central, East and South. Comparison of the positive RAST values obtained indicated that, although the positivity to PD predominated over VG and this over VC, there were significant differences in percentage positivities to each vespid in the different regions studied. The results of the RAST absorption studies indicated that in most instances patients were originally sensitized to one vespid and were RAST positive to the other venoms due to cross-reactivity. Only in a minority of cases were coexisting antibodies to two insects present. These results show that PD and VG are the important vespids followed to a lesser extent by VC. This study provides relevant information concerning insect distribution sensitivity in a European country.

In vitro determination of IgE antibodies in the diagnosis of atopic allergy

The reaction of IgE antibodies is important in asthma and hay fever. Their role in skin diseases is more obscure and needs to be studied further. IgE antibodies play a role in contact urticaria and a more doubtful role in the triggering of atopic dermatitis. A well-standardized radioallergosorbent test is a valuable tool in the diagnosis of these diseases. A new test for the detection of atopy is discussed.

The development of negative skin tests in children treated with venom immunotherapy

Twenty-eight of 62 children (45%) with a history of sting-induced anaphylaxis and initially positive skin tests to venom(s) developed negative venom skin tests to one or more of the venoms used in their treatment after 3 yr or more of immunotherapy. Children who developed negative venom skin tests were less sensitive prior to treatment, as judged by venom skin tests and venom specific IgE antibody determinations, than children who maintained positive venom skin tests. Levels of venom-specific IgE antibodies declined with time in most children, but to lower levels in those with negative skin tests. Venom specific IgG antibody levels were similar in both patients with negative skin tests and those with persistently positive skin tests. The development of negative skin tests may reflect a loss of allergic sensitivity, which is sufficient to allow the physician to consider the discontinuation of venom injections.

IgE antibodies to bee venom, phospholipase A, melittin and wasp venom.

Specific IgE antibodies against bee venom, phospholipase A, melittin and wasp venom have been examined in fifty patients with an unusually severe reaction after bee or wasp sting. Two thirds of the bee venom-sensitive patients also have detectable IgE antibodies to wasp venom. More than 50% of the wasp venom-sensitive patients are also allergic to bee venom. Phospholipase A and melittin IgE antibodies were found, respectively, in two thirds and one third of the bee venom-sensitive cases. Specific IgE antibody determinations by the Radioallergosorbent test play an essential role in the diagnostic work. After a reaction to hymenoptera stings both bee and wasp venom tests are necessary due to the high incidence of a false or incomplete identification of the stinging insect. Melittin, known for its potent pharmacological activity and possibly responsible for most of the side effects in bee venom immunotherapy, can probably not be excluded from therapeutic venom preparations since IgE antibodies to the melittin preparation were detected in one third of the cases.

Absolute determination of IgE antibodies to grass pollen allergens.

Knowledge of specific IgE bound on immunosorbent as assayed by RAST is useful but cannot give a complete description of the biological states of patients concerning IgE antibodies. Using a computer program based on a least squares error method and knowing the amount of bound specific IgE antibodies to grass pollen antigens in a serum at each of the four tested dilutions it is possible to calculate the absolute value of specific IgE antibody level, the relative value of affinity constant and the relative proportion of IgE antibodies to the total amount of specific (IgE plus non-IgE) antibodies. It is found that specific IgE antibodies account for high percentages of the total IgE protein (mean of 20%). High differences in affinity constant and in the proportion of IgE antibodies to the total amount of antibodies could be found between sera. Severity of grass pollen allergy could be related to the absolute level of IgE antibody, but no definite conclusion could be made on the importance of affinity constant and the proportion of IgE antibodies to the total amount of antibodies.

A quantitative immunofluorescence method for the determination of IgE antibodies in comparison with the radioallergosorbent test (RAST)

A quantitative immunofluorescence technique, the defined antigen substrate spheres (DASS) system, was tested for its suitability for IgE antibody detection. The method is based on the binding of IgE antibodies to a Sepharose-coupled allergen and subsequent quantitation of the bound IgE by a fluorescent anti-IgE antibody. The sensitivity of the method was compared with that of the radioallergosorbent test (RAST), an equivalent radioactive technique. Although the DASS technique was found to be about 10 times less sensitive than the RAST, its sensitivity warrants clinical use, provided highly purified allergen extracts are applied. The method is also suitable for quantitation of the total IgE content in sera with a lower limit of detection of 10 IU/ml serum.