Allergen-specific IgE Antibodies Research Articles

RAST, Inmunoblot, Immunocap and ISAC in food allergy

skin tests; Sensitization; IgE-mediated allergy; allergenic extract. After the discovery of IgE, technological advances have provided new laboratory tools for the quantification of allergen-specific IgE antibodies in serum and on the surface of basophils-mast cells. In vitro testing offers numerous advantages: accurate quantitation, lack of drug interference, safety, and long-term storage of samples. Quantitative immunoassays for IgE antibodies can be an adjunct to skin testing. The allergen reagent in solid phase (allergosorbent) or liquid is the main component of the assay that confers specificity to the IgE antibody test. It is the most complex and highly variable reagent in IgE antibody assays. The choice to use diagnostic recombinants on a single rather than multiple platforms is made on a case-by-case basis (considering prior history and clinical profile) and in an allergen-dependent manner. Although most food allergies are limited to a small number of possible triggers, these foods are very complex when evaluating their allergenic potential. The possibility of fractionating the allergen and understanding some of its components as potentially important to define the risk of clinical reaction, cross-reactivity, or persistence of allergy, opened a new era in the field of allergy, called molecular allergy. The identification of the allergenic component responsible for the reactions is an important tool to confirm the information and severity of the symptoms, natural history of the disease, possibility of cross-reactivity and clinical symptoms (allergy markers).

Allergic sensitization does not influence advancement or survival in oral cancer

A history of allergies has been said to be associated with a lower risk of head and neck cancer compared to the general population. However, it is not known whether having an allergic sensitization influences the prognosis and advancement of cancer disease. Thus, the aim of the study was to investigate the relationship between allergic sensitization and oral cancer advancement and patient survival. Allergen-specific IgE antibodies were investigated by ImmunoCAP™ Rapid in consecutive 80 patients with oral cancer. ImmunoCAP Rapid system tests a mix of representative inhalant allergens such as birch, timothy grass, mugwort, house dust mite, cat, dog, cockroach, olive (pollen), wall pellitory and mold. Eighty patients met the inclusion criteria for the study. Fifteen patients (19%) had positive ImmunoCAP test. There was no statistically significant difference in primary tumour size (T-stage) between groups (60% in allergy vs 68% in non-allergy had T1–T2 stage and 40% vs 32% T3–T4, respectively, p = 0.570). 27% of patients with allergy had nodal metastases compared with 37% of patients without allergy (p = 0.557). Both groups had comparable short-term survival. In conclusion, allergic sensitization does not seem to influence either the advancement or the short-term survival of patients with oral squamous cell carcinoma.

History and Utility of Specific IgE Cutoff levels: What is the Relevance for Allergy Diagnosis?

Allergy is defined clinically, by symptoms on allergen exposure. A patient is considered sensitized when allergen-specific IgE (sIgE) antibody can be detected in serum or plasma or a skin test result is positive, even if no clinical reaction has been experienced. Sensitization should be regarded as a requisite and risk factor for allergy but is not synonymous with an allergy diagnosis. To provide a correct allergy diagnosis, test results regarding allergen-sIgE must always be considered in view of the patient's case history and clinical observations. Correct assessment of a patient's sensitization to specific allergens relies on the use of accurate and quantitative methods for detection of sIgE antibodies. The evolution of sIgE immunoassays toward higher analytical performance and the use of different cutoff levels in the interpretation of test results sometimes cause confusion. Earlier versions of sIgE assays offered a limit of quantitation of 0.35 kilounits of sIgE per liter (kUA/L), which also became an established cutoff level for a positive test result in the clinical use of the assays. Current sIgE assays are capable of reliably measuring sIgE levels as low as 0.1 kUA/L and can thereby demonstrate sensitization in cases in which previous assays could not. When the outcome of sIgE test results is evaluated, it is critically important to distinguish between the analytical data as such and their clinical interpretation. Even though sIgE may be present in the absence of symptoms of allergy, available information suggests that sIgE concentrations between 0.1 kUA/L and 0.35 kUA/L may be clinically relevant in some individuals, not least among children, although this should be further evaluated for various allergies. Moreover, it is becoming widely adopted that nondichotomous interpretation of sIgE levels may offer a diagnostic benefit compared with using a predefined cutoff level.

Associations of exposure to metals with total and allergen-specific IgE: An NHANES analysis (2005–2006)

BackgroundImmunoglobulin E (IgE) is a diagnostic biomarker for allergic diseases. While some metal exposure has been found to be associated with allergic diseases, there are still a lot of knowledge gaps regarding the relationship between metal exposure and allergen-specific IgE antibodies, particularly in adults. MethodsWe included a total of 1433 adult participants from the 2005–2006 National Health and Nutrition Examination Survey (NHANES), all of whom had concentrations of 10 metals (including Barium (Ba), Cadmium (Cd), Cobalt (Co), Cesium (Cs), Molybdenum (Mo), Lead (Pb), Antimony (Sb), Thallium (Tl), Tungsten (Tu), and Uranium (Ur)) in urine, as well as measurements of 19 allergen-specific IgE and total IgE antibodies. Linear regression, logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) were used to estimate associations between metals and total and allergen-specific IgE. ResultsLinear regression models revealed a positive correlation between Pb and Cd levels and the total IgE levels. Furthermore, the WQS and BKMR models suggested a positive association between mixed metals and total IgE levels, with the WQS model highlighting Pb and Cd as the major contributors. Logistic regression models showed positive correlations between Pb and food sensitization, Ur and plant sensitization, negative correlations between Cs and plant sensitization, Co and dust mite and pet sensitization, Mo and dust mite and cockroach sensitization, and Tl and mold sensitization. Moreover, the BKMR results indicated a statistically significant negative correlation between mixed metals and mold sensitization. ConclusionAccording to the research findings, exposure to metals is associated with total and allergen-specific IgE in American adults. Further assessment of these relationships is necessary in representative populations of other countries.

Allergy patient-specific IgE antibody shows significantly stability during 3 months of storage at multiple temperatures from -80 to 25°C.

The detection of allergen-specific IgE antibodies is an important biomarker for the diagnosis and treatment monitoring of allergic diseases. And the pre-analytical phase is an important part of the overall quality of the laboratory. In this study, 44 patients with allergic diseases (including 23 patients with allergic rhinitis, 12 patients with allergic rhinitis and asthma, and 9 patients with allergic dermatitis) were included in the outpatient center of the Department of Allergy, the First Affiliated Hospital of Guangzhou Medical University. We mixed the serums of the above 44 patients (approximately 0.8 ml of serum volume per patient) into a large volume of serum pool (about 35 ml in total) and divided into 26 parts. And 26 serum samples were stored at 4 different temperatures for 90 days to observe the stability of sIgE antibodies to 16 allergens in serum. The results show that serum sIgE antibody titers in patients with allergic diseases show significant stability during 90 days of storage, even at room temperature. Good stability even after up to 10 freeze-thaw cycles under low temperature storage conditions.

Associations between functional constipation and non-IgE-mediated food allergy in infants and children.

The non-IgE-mediated food allergy (non-IgE-FA) is less prevalent than IgE-mediated food allergy, and their relationship with functional constipation (FC) needs to be clarified. A total of 305 infants and children with constipation treated in the Department of Pediatric Gastroenterology, Children's Hospital of Nanjing Medical University, from July 2020 to December 2021 were included in this study. Four cases with organic lesions were excluded. Among 301 diagnosed with FC, according to ROME IV criteria, 81 cases with allergy-related indicators were further evaluated for food allergy by food-specific IgG antibody test, allergen- specific IgE antibody detection, skin prick test, and food avoidance and reintroduction. A total of 45 cases with FC were diagnosed with food allergy, and the incidence rate was 15%. Among the 45 patients, 35 cases (77.8%) had FC with non-IgE-FA. The main clinical symptoms or signs included anal fissure, abdominal pain, and pain during defecation. The most prevalent allergic foods were cow's milk, eggs, fish, and shrimp. Ten (22.2%) cases reported FC with mixed food allergy, including both non-IgE-mediated and IgE-mediated food allergy. This study focused on non-IgE-mediated food allergy-related FC. Our results showed that the incidence of food allergy in infants and children with FC was 15%, which was mainly mediated by non-IgE-FA. The main clinical symptoms or signs in these cases included anal fissure, abdominal pain, and pain during defecation, and the main allergens included milk, eggs, fish, and shrimp.

Topical Administration of Gardenia jasminoides Extract Regulates Th2 Immunity in OVA-Induced Mice.

A key feature of an allergic immune response is a T helper type 2 (Th2)-mediated response with production of allergen-specific IgE antibodies. Gardenia jasminoides extract with the crocin removed (GJExCR) has been shown to inhibit IgE-mediated allergic disease. To evaluate the efficacy and mechanism-of-action of this inhibition, GJExCR was used in an ovalbumin (OVA)-induced allergy model in BALB/C mice. Sensitization of BALB/C mice with OVA and aluminum hydroxide was performed on days 1 and 14 by intraperitoneal injection, followed by OVA challenge to the dorsal skin for 2 weeks before removal. Seven days post-challenge, mice were treated with GJExCR topically every day for 11 days. Enzyme-linked immunosorbent assay, flow cytometry analysis, real-time PCR, and western blot were performed to determine IgE and Th2 cytokine levels. Following OVA challenge, Th2 cytokine expression and both total and OVA-specific serum IgE levels increased, of which OVA-specific IgE and Th2 cytokine levels decreased after GJExCR treatment. Flow cytometry analysis revealed that GJExCR treatment decreased CD4+ and CD8+ T cell populations in the spleen and lymph nodes. In addition, treatment with GJExCR downregulated signal transducer and activator of transcription 1 (STAT1) activation and Th2 cytokine levels as compared to control. GJExCR containing geniposide downregulated STAT1 activation in HaCaT cells. These findings demonstrate that GJExCR exerts its anti-allergy effect via inhibition of STAT1 activation, thus regulating the immune response via modulation of Th2 cytokine release and IgE levels. Therefore, we propose GJExCR as a potential treatment for allergic hypersensitivity reactions.

Environmental influences on childhood asthma: Allergens

Allergen exposure is associated with the development of allergen-specific sensitization, but their relationship is influenced by other contemporaneous exposures (such as microbial exposure) and the genetic predisposition of the host. Clinical outcomes of the primary prevention studies that tested the effectiveness of allergen avoidance in pregnancy and early life on the subsequent development of sensitization and asthma published to date are inconsistent. Therefore, we cannot provide any evidence-based advice on the use of allergen avoidance for the primary prevention of these conditions. The evidence about the impact of allergen exposure among and among sensitized children with asthma is more consistent, and the combination of sensitization and high exposure to sensitizing allergen increases airway inflammation, triggers symptoms, adversely impacts upon disease control, and is associated with poorer lung function in preschool age. However, there are differing opinions about the role of inhalant allergen avoidance in asthma management, and recommendations differ in different guidelines. Evidence from more recent high-quality trials suggests that mite allergen-impermeable bed encasings reduce hospital attendance with asthma attacks and that multifaceted targeted environmental control improves asthma control in children. We therefore suggest a pragmatic approach to allergen avoidance in the management of childhood asthma for clinical practice, including the recommendations to: (1) tailor the intervention to the patient's sensitization and exposure status by using titer of allergen-specific IgE antibodies and/or the size of the skin test as indicators of potential response; (2) use a multifaceted allergen control regime to reduce exposure as much as possible; and (3) start intervention as early as possible upon diagnosis.

Treatment with pollen allergen immunotherapy improves health-related quality of life in children and adolescents: a three-year follow-up-study

BackgroundThe immunological effect of allergen-specific immunotherapy is well documented, but few studies have examined the long-term effects of pollen subcutaneous immunotherapy (SCIT) on health-related quality of life (HRQoL) in children and adolescents. Therefore, the aims of this study were to evaluate the effect of pollen SCIT on HRQoL and to assess the association between HRQoL and symptoms among children and adolescents with allergic rhinoconjunctivitis in a 3-year follow-up.MethodsA prospective cohort study was conducted at a paediatric clinic in Sweden, including 158 children (5–16 years) on SCIT (birch and/or grass). Health-related quality of life, measured with DISABKIDS, symptom scores and allergen-specific IgE and IgG4 antibodies (blood test), were assessed at start, and after 1, 2 and 3 years of treatment. ANOVA and t-test were used to analyse differences over time, between groups and linear mixed model for the association between HRQoL and influencing factors.ResultsAfter 1 year of pollen SCIT, HRQoL improved from 79.5 to 85.1 (p < 0.001), and the improvements were maintained (mean 1 years, 84.8, 3 years 87.2). Symptom scores decreased after 1 year, mean 19.9 to 11.5 (p < 0.001) and were maintained for year two (11.9) and year three (10.3). The proportion of children with severe or very severe symptoms decreased from 35.6% to 4.5% after 1 year of SCIT. Health-related quality of life was associated with symptoms at all measured timepoints (p = 0.001–0.031); higher symptom scores were associated with lower perceived HRQoL. Allergen-specific IgE antibodies decreased, birch from 151.0 to 76.8 kU/L (p < 0.001), and IgG4 antibodies increased, birch from 2.2 to 17.6 g/L (p < 0.001), grass from 0.5 to 14.3 g/L (p < 0.001), during the study period.ConclusionAfter 1 year of pollen SCIT, HRQoL improved, and symptoms decreased; these changes were maintained during the study period. The proportion of severe and very severe symptoms significantly decreased.

Age-related features of sensitization to chicken egg white in children with allergic diseases

BACKGROUND: International studies have shown that egg allergy is one of the main causes of IgE-mediated food allergies in children.&#x0D; THIS STUDY AIMED TO analyze the frequency and rate of sensitization to white egg of Russian children, depending on the sex and age.&#x0D; MATERIALS AND METHODS: Anti-egg white-specific IgE antibodies were measured in children with symptoms of food allergy, such as nausea, vomiting, stool disorder developing after eating, mucosal edema, upper respiratory tract edema, urticaria, and exacerbation of eczema (4981 patients aged 6 months to 18 years). The frequency and degree of sensitization in various age groups were analyzed.&#x0D; RESULTS: In this study, 29.5% of the children had anti-egg white IgE antibodies. Low (31.6%, IgE=0.350.69 kU/L) and moderate (40.2%, IgE=0.703.5 kU/L) sensitizations were the most common. An extremely high level of anti-egg white antibodies (IgE 50.0 kU/L) was observed in 6.2% of the patients. In the first year of life, sensitization was detected in 39% of the cases. In older age groups, the frequency of positive responses decreased. compared with those in the younger groups. The dependence of sensitization frequencies on sex was found in children aged 12 years. Frequencies of egg sensitization in girls aged 1214 and 1418 were statistically significantly lower than those in boys of the same age. The dependence of the response severity on the patients age was also noted: a decrease in the frequency of highly positive responses and an increase in proportion of patients with medium or low IgE levels in the older group. The severity of the IgE response decreased by age 12 and 14 years in girls and boys, respectively.&#x0D; CONCLUSION: The detection frequency of specific IgE antibodies to the extract of allergens of chicken egg white was the highest in children in the first year of life. These parameters decrease in older children; аfter the age of 12, the response severity and frequency were associated with the patients sex. The tendency of the number of patients with chicken egg white allergen-specific IgE antibodies and their quantitative level in adolescence to decrease may be evidence of the development of tolerance to this food product.

Efficacy and safety of house dust mite subcutaneous immunotherapy in polysensitized children with allergic asthma

IntroductionThe aim of this study was to compare the efficacy and safety of 3 years of HDM subcutaneous immunotherapy (HDM-SCIT) in allergic asthma (AA) children with mono- and polysensitized. MethodsThis was a retrospective observational study, 51 AA children (aged 4–14 years) who had completed 3 years of standardized HDM-SCIT were enrolled in. Based on skin prick tests (SPT) and allergen-specific IgE antibody (sIgE) test results, children were classified into two groups: the monosensitized group (n = 31) and the polysensitized group (n = 20). Total asthma symptoms score (TASS), total medication score (TMS), visual analog scale (VAS) scores, fractional exhaled nitric oxide (FeNO), lung function parameters, and adverse reactions were evaluated before treatment and at 6 months, 1, 2, 3 years of HDM-SCIT. ResultsIn terms of effectiveness, compared to baseline, TASS, TMS, VAS, FeNO and lung function parameters were significantly improved in both groups after 3 years of HDM-SCIT (all P < 0.05). The comparison between the two groups showed that efficacy indicators were no statistically significant difference at follow-up time points (all P > 0.05) except PEF%pred at 6 months (P = 0.048). In terms of security, the number of adverse reactions in both groups also no statistical difference between the two groups (all P > 0.05). ConclusionThis study confirmed that no significant difference was observed in the clinical efficacy and safety of HDM-SCIT between mono-and polysensitized children with allergic asthma.

Оценка иммунного статуса у беременных женщин с отягощенным аллергологическим анамнезом

Most researchers emphasize that in the structure of diseases of infants, there is a predominance of pathological conditions that occur precisely in the perinatal period, which indicate the correlation of these diseases with the health of the mother and the course of her pregnancy. Objective. Assessment of the immune status and effectiveness of diet therapy in pregnant women with burdened allergic history. Patients and methods. The observation groups consisted of 118 pregnant women. The first group included 83 pregnant women who received a hypoallergenic diet with the exclusion of main allergens, with the replacement of cow's milk with goat's milk, or the exclusion of dairy products as a causally significant allergen. The second group consisted of 35 pregnant women who followed the usual dietary recommendations offered in women's consultations, with the inclusion of cow's milk in the diet. The content of total IgE and allergen-specific IgE antibodies to food proteins in blood serum was determined by the immunoblot method using PROTIA Allergy-Q diagnostic panels. Results. 71.1% of pregnant women of the first group and 40% of women of the second group had the history of allergic diseases. According to skin scarification tests, these women had polyvalent sensitization. When studying the immunological status of pregnant women, attention was drawn to the fact that high levels of total serum IgE were in patients with allergies, with diseases of the gastrointestinal tract, as well as with a combination of these pathologies. 37.3% of the observed pregnant women of the first group, both with and without allergies, had high levels of total serum IgE. At the same time, the level of total IgE was higher in pregnant women suffering from allergic diseases. In addition, IgE sensitization to milk proteins was found in women with normal and high levels of total IgE in the blood. The concentration of allergen-specific IgE antibodies to cow's milk proteins was higher in women with IgE-mediated allergies. The use of a hypoallergenic diet in pregnant women caused the most pronounced decrease in the total IgE content in the blood compared with the indicators before treatment. The majority of the observed women showed a positive trend towards a decrease in IgE sensitization to milk proteins against the background of dietary therapy. Conclusion. All pregnant women with allergic diseases had food sensitization. Gastrointestinal pathology was observed in 34.7% of pregnant women, and its frequency in women with clinically confirmed allergies was 2.3 times higher than in women without allergies. A highly sensitive method for diagnosing food sensitization using PROTIA Allergy-Q panels has made it possible to most accurately identify causally significant allergen products, develop and effectively use personalized hypoallergenic diets for pregnant women. Considering the concept of food programming, the use of hypoallergenic diets in the diet of pregnant women with allergic diseases is one of the options for the prevention of allergic diseases in the future in children born to such mothers. Key words: pregnant women, allergy, food IgE sensitization, diet therapy

Targeted suppression of Dpt-specific B cells in humanized Rag2- γc- mouse model of HDM allergy.

Der p 1 is one of the major allergenic molecules of Dermatophagoides pteronyssinus, causing house dust mite (HDM) allergy. The pathological B cells produce allergen-specific IgE antibodies that mediate the hypersensitivity reaction, therefore the selective elimination of these B cells is a legitimate therapeutic goal in allergy. Chimeric molecule Dp51-72 able to cross-link B cell inhibitory complement receptor type 1 and BCR on Der p 1-specific B cells was constructed. The signalling capabilities of this molecule have been tested on human B cells. A humanized mouse model of HDM allergy has been used to test the in vivo effects of the chimeric molecule administration. Administering the chimeric molecule to immunodeficient Rag2- γc- mice transferred with PBMCs from allergic patients resulted in reduction of allergen-specific IgE antibodies in the sera, and reduced infiltration of immune cells in lung histology preparations. Reduced numbers of human CD45+ and CD4+ cells in the lungs as well as inhibition of mast cell degranulation were also observed. The treatment with Dp51-72 chimera significantly decreased the local levels of anti-Dpt IgE antibodies in the bronchoalveolar lavage fluid (BALF). The binding of the chimeric molecule to tonsillar B cells triggers the tyrosine phosphorylation of 30-32kDa protein, which is most likely involved in the inhibitory process. Administration of constructed chimeric molecules to humanized mice with developed inflammation resulted in specific suppression of disease-associated IgE antibody-producing cells and preserved lung histology. This effective approach could be further developed into a therapeutic agent for treatment of patients with HDM allergy.

Issues of specific &lt;i&gt;in vitro&lt;/i&gt; allergological diagnosis of atopic conditions

There is a steady increase in the prevalence of allergic diseases of atopic origin worldwide, e.g., atopic bronchial asthma (ABA) and atopic dermatitis (AD). Identification of a causally significant allergen in allergic patients is crucial for the diagnosis, therapy and prevention of allergic diseases. Korea has developed the Allergy-Q multiplex test to detect specific IgE. Allergy-Q is based on an immunoblotting method using a nitrocellulose membrane as a solid phase for allergen immobilization and can detect allergen-specific IgE simultaneously to 107 allergens. Our aim was to conduct a comparative analysis for detectable allergen-specific IgE antibodies to food, fungal, pollen, household, epidermal allergens in blood serum by immunoblotting method using the Allergy-Q test system in patients with atopic dermatitis, atopic bronchial asthma and psoriasis.&#x0D; The study included patients with atopic dermatitis (AD, group 1, n = 9), atopic bronchial asthma (ABA, group 2, n = 14) and psoriasis (PS, group 3, n = 17). The concentration of total immunoglobulin E and allergen-specific immunoglobulins of class E in blood serum to 32 most common food, fungal, pollen, household, epidermal allergens was determined by the immunoblotting method using the Allergy-Q test system (Korea).&#x0D; We have found that sensitization of atopic origin was observed in all patients with AD (n = 9), in 85.7% (n = 12) of patients with atopic bronchial asthma, and in 47.1% (n = 8) of patients with psoriasis. Polyvalent sensitization was shown to prevail in all groups of the examined persons. When studying the spectrum of sensitization to food allergens, a significantly increased frequency of positive reactions to cows milk protein was found in the group of patients with AAA as compared with AD and PS groups. Among all studied groups, sensitization to the Alternaria fungi was found at the highest frequency in the group of patients with ABA. Sensitization to ragweed pollen was very common in all groups of patients. Sensitization to household and epidermal allergens in the groups with AD and AAA was noted for all studied allergens with the highest positivity rates for the feline epithelium and dog dander.&#x0D; In the present study, the Allergy-Q system showed an agreement with preliminary data from a specific allergological examinations. This relationship suggests a potential for usage of the Allergy-Q immunoblotting method as a highly effective alternative to other in vitro tests for diagnosing atopy. An advantage of the Allergy-Q Multiplex Serum Allergen-Specific IgE Detection Kit is a short processing time, small amount of blood sample, and broader clinical information on the causative allergens.

Local Allergen-Specific IgE Production in Turbinate Tissue of Pediatric Patients.

The objective of this study is to compare serum allergen-specific IgE to IgE levels in nasal tissue taken from the inferior turbinates of pediatric patients undergoing turbinate reduction. Twenty-six pediatric patients were recruited at the time of turbinate reduction surgery. At the time of recruitment, parents of patients completed the validated 22 item Sinonasal Outcome Test (SNOT-22) to describe symptoms prior to surgery. A sample of turbinate tissue was taken during turbinate reduction and blood was collected. Tissue and serum IgE were measured and differences in the group characteristics were evaluated using Chi-square tests for binary variables and Wilcoxon-Mann-Whitney tests for continuous variables. Student's t test was used to assess differences in means of total SNOT-22 scoring between the groups, and Wilcoxon-Mann-Whitney tests were used again for the rest of the SNOT-22 analysis. Levels of IgE in the serum were compared to levels in the turbinate tissue from all patients for each individual allergen. Every allergen except Alternaria displayed significant correlation between the serum and turbinate IgE levels. Additionally, each allergen except Alternaria and oak tree resulted in a strong correlation (r > .7) based on the correlation coefficients. Levels of Alternaria were found to be poorly correlative between serum and turbinate tissue, and significance was not achieved (r = -.346, P = .11). Certain allergen-specific IgE antibodies in the nasal mucosa seem to be highly associated with those in the serum, based upon the significant correlations we found between the two.

Clinic and diagnostics of house dust mite allergy

SummaryHouse dust mite allergens are common triggers for allergic rhinoconjunctivitis and allergic asthma; they can aggravate atopic dermatitis and rarely lead to anaphylactic reactions due to dust mite allergens in food. Typical symptoms are nasal obstruction, sneezing, and irritation, and more often than in pollen allergy, allergic asthma also develops. The symptomatology exists in principle throughout the year with maximum complaints in autumn and winter. Of particular importance are sleep disturbances due to nasal obstruction, which lead to restrictions in the quality of life and performance of affected patients. Sensitization can be proven by skin tests and detection of serum allergen-specific IgE antibodies; proof of allergy is achieved by nasal or conjunctival provocation tests. The diagnosis of local allergic rhinitis can only be made by provocation or by determination of allergen-specific IgE antibodies in nasal secretions. The quality of the allergen extract used is essential for all tests; it must contain the allergens to which a patient is sensitized. The concentration of Der p 23 in house dust mite extracts is particularly critical.

Influence of the COVID-19 Pandemic on the Prevalence Pattern of Allergens

Introduction: The effect of the COVID-19 pandemic on allergic diseases is not certain, as people’s living habits and the environment have been affected by the pandemic. The present study described the influence of the COVID-19 pandemic on the allergen sensitization rate in patients with allergic diseases in central China. The results provide reliable epidemiological data for the prevention and control of allergic diseases during the COVID-19 epidemic. Methods: Data were collected from a total of 6,915 patients with symptoms of allergic diseases who visited the Third Xiangya Hospital of Central South University in China for allergen testing from January 1, 2018, to December 31, 2021. Patients were divided into a children group (<14 years old), youth group (15∼44 years old), middle-aged group (45∼59 years old), and elderly group (>60 years old). Immunoblotting was used to detect 20 serum allergen-specific IgE (sIgE) antibodies in patient serum samples. We compared the positive rates of various allergens in different age and sex groups before and during the COVID-19 epidemic, and the prevalence data of sIgE sensitization were analysed. Results: Among the 6,915 patients with symptoms of allergic diseases, 2,838 (41.04%) patients were positive for at least one of the allergens. The top three positive rates of inhaled allergens were Dermatophagoides farinae (1,764 cases, 25.51%), Dermatophagoides pteronyssinus (1,616 cases, 23.37%), and house dust (645 cases, 9.33%). The top three positive rates of food allergens were eggs (686 cases, 9.92%), milk (509 cases, 7.36%), and crabs (192 cases, 2.78%). The total positive rate of allergens was higher in men (46.99%) than in women (37.30%). Compared to 2 years before the COVID-19 epidemic, the rate of sensitization to indoor inhalant allergens increased, but outdoor inhalant allergens showed no significant change. The positive rates of milk and eggs peaked during the outbreak of COVID-19 (2020) then declined in 2021. The total positive rate of allergens was higher in males than females before and during the COVID-19 epidemic, but more allergens were different between males and females during the pandemic. Compared to middle-aged and older adults, the children and youth groups were more susceptible to allergic diseases, and they exhibited an increasing positive rate for most common allergens, especially indoor inhalant allergens, during the COVID-19 epidemic than before the pandemic. Conclusion: D. pteronyssinus and D. farinae are the most common allergens in South China. Under the background of normalization of epidemic prevention, indoor inhaled allergens should be first in the prevention and control of allergic diseases, and a combination of various indoor cleaning measures should be used to improve the efficiency of interventions.

Allergy Diagnostics 2021

Allergic diseases are among the most common diseases worldwide. For appropriate management knowledge of the allergy trigger is crucial. The clinical picture of allergic diseases is diverse and correct diagnosis is often a challenge. The allergist needs to distinguish intolerances from allergies and infectious diseases from non-infectious triggers. Test results have to be interpreted accordingly to differentiate sensitizations from allergies. In this review current state of the art diagnostic measures to diagnose type I and type IV allergies are described and discussed.Immediate type allergies such as allergic rhinoconjunctivitis, asthma and anaphylaxis are mediated by allergen-specific IgE antibodies detectable both in serum and tissue. Typical triggers are pollen, mites, animal epithelia, food, insect toxins and pharmaceuticals. In everyday practice, diagnostics are based on three complementary pillars: the allergy-specific anamnesis as a prerequisite of correct interpretation of subsequent diagnostic tests like skin testing and serological immunoglobulin detection. These can be supplemented as required and available by provocation tests to prove clinical reactivity and cellular assays to demonstrate the cellular immune response.Type IV allergic reactions are mediated by T cells causing contact allergy with a local eczematous reaction with a latency of several hours to days. Some 3,500 triggers, often from occupational environment, are known; e. g., nickel, chromium, cobalt, fragrances, rubber, plastics, preservatives, dyes, neomycin, benzocaine, sulfonamides, quinidine, wool wax, perubalsam, eye therapeutics, light filter substances, disinfectants, pesticides, technical oils or plants. Diagnosis of contact allergy combines the history of cutaneous exposure with associated symptoms and patch testing, with detection of a late phase clinical reaction after 6 to 48, up to a maximum of 96 hours after antigen contact.

Pre-treatment allergen-specific IgE analysis and outcomes of allergen immunotherapy.

Background. Patients show varied results to allergen immunotherapy (AIT. The reason for this variability is unclear. Objective. To describe the relationship between AIT efficacy and demographic characteristics, as well as pre-treatment plasma levels of specific IgE-antibodies to grass and birch pollen. Methods. A retrospective study was performed based on medical records of 128 patients who received AIT. The patients completed a questionnaire and pre-AIT plasma levels of allergen-specific IgE to grass and birch pollen were measured using EUROLINE DPA-Dx pollen 1 method. Results. Seventy percent of patients classified their allergic symptoms as less severe after AIT. Twenty-seven percent had received AIT targeting only grass pollen, 19% targeting only birch pollen, and 55% targeting both grass and birch. A total of 35 different IgE profiles were found across our study population. On comparison of the demographic characteristics and concentration of allergen-specific IgE-antibodies, no statistically significant differences could be found.Conclusions. The majority of patients rated their allergic symptoms as less severe after AIT. No clear relationship could be demonstrated between pre-treatment allergen-specific IgE concentration, or demographic characteristics, and effect of AIT. There may be other factors underlying the different responses to AIT.

PD-1 blockade in T follicular helper cells protects mice from peanut allergy by promoting production of low-affinity antibodies

Abstract Food allergy, such as peanut allergy can cause life-threatening anaphylaxis. While T follicular helper (Tfh) cells play a major role in production of allergen-specific IgE and IgG antibodies, the immunologic mechanisms that regulate the production of antibodies that mediate anaphylaxis are not well understood. While PD-1 is highly expressed on Tfh cells, our knowledge is limited regarding the role of the molecule in Tfh cells. Thus, the objective of this study was to investigate the roles of PD-1 in allergic immune responses using a mouse model of peanut allergy. Naïve wild-type mice were exposed to peanut flour intranasally (i.n.) and then challenged by intraperitoneal (i.p.) injection of peanut extract. The mice exposed i.n. to peanut flour produced peanut-specific IgE and IgG antibodies and developed anaphylaxis when challenged i.p. with peanut extract. PD-1 blockade with anti-PD-1 treatment Tfh and germinal center B cell numbers in mice exposed to peanut flour. Nonetheless, anti-PD-1 or anti-PD-L1 fully protected mice from anaphylaxis. Anti-PD-1 or genetic deficiency of PD-1 in CD4+ T cells reduced and increased levels of peanut-specific IgE and IgG, respectively. Anti-PD-1 promoted production of low-affinity IgE and IgG antibodies with no effect on high-affinity antibodies. By passive cutaneous anaphylaxis, peanut-specific antibodies generated in anti-PD1 treated mice failed to induce anaphylaxis, and plasma from these mice prevented anaphylaxis. Therefore, blockade of the PD-1 pathway is protective against allergic immune responses. The interaction between Tfh cells and B cells may play a pivotal role in controlling antibody quality and clinical manifestation of allergic diseases.