Skin test results but not serology reflect immediate type respiratory sensitivity: a study performed with recombinant allergen molecules.

The diagnosis of type I allergy, an IgE-antibody-mediated hypersensitivity disease affecting more than 25% of the population, is based on the measurement of allergen-specific serum IgE levels and provocation testing. Whether the determination of allergen- specific serum IgE levels can replace in vivo provocation testing for allergy diagnosis is a controversial issue. We used purified recombinant timothy grass and birch pollen allergens to compare by skin prick and nasal provocation testing as well as by serology in vivo sensitivity with antibody-binding capacity in 24 pollen allergic patients and eight control individuals. Results from biologic tests were correlated with each other and with allergen-specific IgE and IgG1-4 levels. IgE-reactive allergens induced immediate skin and nasal reactions, but the intensity of the allergic tissue reactions was not correlated with either the levels of allergen-specific IgE or the levels of allergen-specific IgG antibodies. Less frequently detected allergens with low IgE-binding capacity were able to induce strong allergic reactions comparable to those caused by major allergens with high IgE-binding capacity. In contrast, skin test and nasal provocation results were significantly correlated (r = 0.63, p < 0.01). Our study thus demonstrates on a molecular level that skin testing provides a better reflection of immediate type respiratory sensitivity than serologic measurements. These results have implications for allergy diagnosis and, in particular, for the selection of relevant allergen components for specific immunotherapy.     

Rekombinante Allergene

Component-resolved diagnosis of allergies allows disease-specific patterns of sensitization in some conditions such as allergic bronchopulmonary aspergillosis ABPA). By determination of IgE against important pollen allergens such as Bet v 1, Ole e 1 or Phl p1/Phl p 5, more precise guidance for allergen-specific immunotherapy may be achieved, as pollen extracts contain mostly these major allergens. Sensitizations against minor allergens such as profilins or polcalcins influence the outcome of IgE measurements against full allergen sources, but are often of limited clinical relevance. In food allergy, frequent cross reactivity between pollens such as birch pollen via Bet v 1/PR10 proteins can be identified. Sensitization against some storage proteins such as peanut (Ara h 2) or lipid transfer proteins of peach (Pru p 3) or hazelnut (Cor a 8) may indicate an increased risk of severe anaphylactic reactions. Exercise-induced anaphylaxis, unclear sensitizations against latex or double-positivity in insect allergy are other useful indications for component-resolved diagnosis. Microarray-based allergen chip diagnosis makes possible today the detection of IgE against more than 100 allergens in tiny amounts of serum and is very promising, but still needs evaluation and optimization in regard to allergen selection and sensitivity.     

Cross-reactive allergen clusters in pollen-associated food allergy

Immediate symptoms caused by allergens without previous primary sensitization are commonly based on cross-reactive IgE antibodies. They are responsible for pollen-associated food allergies, i.e., fruit allergy in cases of birch pollen allergy or allergy to celery and spices in cases of mugwort pollen allergy. Similar structures between the major allergen of birch pollen (Bet v 1) and a variety of pathogenesis-related proteins from the same family (PR-10), abundant in hazelnuts, fruits, and vegetables, have been well established. Other candidates are profilins, ubiquitous panallergens with little clinical relevance, and stable lipid transfer proteins, responsible for systemic reactions predominantly in Mediterranean countries. Depending on stability, dose, and resorption of these proteins, clinical symptoms are limited to the oro-pharyngeal cavity or develop systemically far from the site of allergen exposure. Clinical diagnosis is based on a positive case history with corresponding allergic sensitization to pollen allergens. Targeted skin testing with native products (i.e., prick to prick test with fresh fruits) appears to be superior for unstable allergens compared to commercial extracts. Individuals should be familiar with cross-reactive patterns; however, allergen avoidance is only recommended in cases of clinical symptoms.     

Mutual boosting effects of sensitization with timothy grass pollen and latex glove extract on IgE antibody responses in a mouse model

Type I allergy to natural rubber latex can be an important health problem for latex-exposed individuals (e.g., health care workers, spina bifida children). Also beyond these risk groups, a high sensitization rate of varying and partly unknown clinical relevance has been reported. Atopy represents a risk factor for latex allergy and recent studies indicate that patients suffering from pollen allergies may have pollen allergen-specific IgE antibodies which cross-react with latex allergens. In order to investigate whether sensitization to pollen allergens can have priming effects on the production of IgE antibodies against latex in vivo, a mouse model was established. Groups of 10 BALB/C mice were immunized with Al(OH)3-adsorbed pollen extracts from timothy grass, ragweed, mugwort, or birch. For control purposes, one additional group received adjuvant only and another group was not immunized. Half of the mice of each group were subsequently immunized with Al(OH)3-adsorbed latex glove extract, the other half with adjuvant only. Pollen and latex-specific IgE- and IgG1-antibody responses were analyzed by enzyme-linked immunosorbent assay and statistically evaluated by analysis of variance. Antibody responses to cross-reactive antigens were investigated by immunoblotting. We found significantly increased IgE reactivities to latex after pollen sensitization and vice versa. Moreover, mice immunized with timothy grass pollen extract alone - without subsequent latex immunization - displayed IgE reactivity to latex. Cross-reactive antibodies were directed against pollen antigens of approximately 60 kDa molecular weight. Our results thus demonstrate a mutual boosting effect of pollen and latex sensitization in vivo which may be also operative in polysensitized plant allergic patients.     

Atopy patch test reaction to airborne allergens in the diagnosis of atopic dermatitis

The aim of the study was to evaluate the possible use of atopy patch test in the diagnosis of atopic dermatitis and to characterize an optimal standardized system for atopy patch test in terms of allergen concentrations and time of allergen exposure. The study included 36 patients with atopic dermatitis and IgE-mediated airborne allergy. Patients presented positive results of skin prick tests and serum antigen specific IgE against house dust mite allergens and/or selected grass pollen allergens. Control groups consisted either of patients with allergic rhinitis (control group 1) or healthy volunteers with no signs or symptoms of atopy (control group 2). Allergologic diagnostic workup consisted of skin prick test, serum antigen specific IgE and total IgE evaluation, atopy patch test with selected airborne allergens of different concentrations (0.1xSPT, 1xSPT and 10xSPT), time of allergen exposure (8, 24 and 48 h), and readings of the results (8, 24, 48 and 72 h). Positive results of atopy patch test with airborne allergens were obtained in 47.2% of atopic dermatitis patients and none of control subjects. Contact reaction itself and the intensity of reaction were demonstrated to correlate with allergen concentration and time of allergen exposure on atopy patch test. The dose and time response analysis showed the optimal concentration of allergens for atopy patch test to be 10xSPT, 500000 SBE/ml, and optimal evaluation time 24 and 48 h of allergen application. There was no correlation between atopy patch test results and mean serum concentrations of total or antigen specific IgE. Atopy patch test results did not correlate with localization of skin lesions, severity and extensiveness of skin inflammation. A significantly higher contact reactivity to airborne allergens was recorded in the group of atopic dermatitis patients with polyvalent allergy in comparison with atopic dermatitis patients allergic to only one aeroallergen. It is concluded that atopy patch test is the only provocation test currently available with clinical relevance for contact IgE-mediated sensitization in atopic dermatitis patients. Using petrolatum as a vehicle, allergen concentration of 500000 SBE/ml and evaluation time of 24 and 48 h of allergen application may lead to improved atopy patch test results.     

Correlation among skin prick test, total and specific IgE UniCAP tests in atopic patients from Zagreb, Croatia

The correlation of pollen allergens, Dermatophagoides pteronyssinus and animal dender was assessed during a two-year period. Results of skin prick test, total and specific IgE UniCAP tests were compared in atopic patients (AP) with the following diagnoses: atopic dermatitis, allergic rhinitis, allergic conjunctivitis, allergic bronchitis or asthma, allergic urticaria and angioedema. The study included total and specific IgE (in vitro) tests to allergen mixtures (grass, tree, weed) or to single allergens of Dermatophagoides pteronyssinus (Der p), cat and dog fur, feather, etc. Comparison of skin prick test with total and specific IgE UniCAP immunoassay was done in 173 patients, i.e. 107 female and 66 male atopic patients aged 9-76 years. Allergies were most commonly recorded in the 25-35 age group. Total IgE ranged from 8.63 kU/l to >4000 kU/l, with specific IgE ranging from class 1 to class 5. Skin prick test showed high correlation with specific IgE for grass and weed pollen in patients with repiratory allergy (50.28%). Good correlation among all three tests was quite frequently observed. The results suggest that the study should be continued using these three tests in further cases of atopic dermatitis.     

变应原特异性免疫治疗及其在特应性皮炎中的作用

变应原特异性免疫治疗是惟一可影响变态反应性疾病病程的治疗方法，通过调节抗原提呈细胞功能、诱生变应原特异性调节性T细胞、诱导抗体类别转换等机制起效。传统方法应用天然变应原提取物，近年发展出了重组变应原、肽疫苗、DNA疫苗等新型策略。临床试验表明，变应原特异性免疫治疗可用于部分特应性皮炎患者的治疗。     

Isolation of α-toxin-producing Staphylococcus aureus from the skin of highly sensitized adult patients with severe atopic dermatitis

Background  Staphylococcus aureus (S. aureus) is a well-known trigger factor of atopic dermatitis (AD). Besides staphylococcal superantigens, α-toxin may influence cutaneous inflammation via induction of T-cell proliferation and cytokine secretion.
Objectives  To investigate the association between sensitization to inhalant allergens and skin colonization with α-toxin-producing S. aureus in AD.
Patients and methods  We investigated 127 patients with AD, aged 14–65 years, who were on standard anti-inflammatory and antiseptic treatment before investigation. We evaluated skin colonization, medical history, severity of AD and sensitization to inhalant allergens.
Results  Forty-eight of 127 patients were colonized with S. aureus , suffered from more severe AD, had asthma more often and showed higher sensitization levels to inhalant allergens. Thirty of 48 patients with S. aureus skin-colonizing strains produced α-toxin and had higher total IgE and specific IgE to birch pollen and timothy grass pollen.
Conclusions  Under topical treatment with antiseptic and anti-inflammatory agents the colonization of lesional skin with S. aureus was clearly lower than commonly found in untreated patients with AD. Colonization with S. aureus was associated with a higher severity of AD, higher degree of sensitization, and a higher frequency of asthma. The proportion of patients whose skin was colonized with α-toxin-producing S. aureus was higher than expected from a former study. Cutaneous colonization with α-toxin-producing S. aureus was associated with a higher sensitization level to birch pollen allergen in AD. This may point to a higher susceptibility of patients with higher T-helper 2 polarization towards α-toxin-producing S. aureus .     

Kutane Symptome nach Genuss pollenassoziierter Nahrungsmittel

The molecular basis of pollen-related food allergy is the marked similarity in sequence and structure of allergenic proteins in pollens and food plants. In affected patients, specific IgE antibodies are primarily directed against pollen allergens but then recognize homologous allergens in plant food. In Central and Northern Europe up to 80% of birch pollen allergic subjects suffer from a food allergy, in particular to stone- and pip fruits, nuts and vegetables. The main clinical manifestation of pollen-related food allergy is the oral allergy syndrome (OAS), a contact urticaria of the oral mucosa. Other features include contact urticaria of the hands in those handling the foods, as well as generalized urticaria and angioedema following ingestion. The impact of pollen-related food allergy on the severity and course of atopic eczema remain to be elucidated.     

Curry spice allergy associated with pollen-food allergy syndrome and latex fruit-syndrome

We report a 22-year-old woman with urticaria, dyspnea and bronchial asthma-like attacks after eating curried rice. We found the symptoms to be due to an immediate-type allergy caused by spice antigens contained in curry spices by detailed questioning, skin test and measurement of specific immunoglobulin (Ig)E antibodies. This case was complicated with pollen-food allergy syndrome (PFAS) from melon and latex allergy (LA) to natural rubber latex (NRL) antigen and she had also had atopic dermatitis, allergic rhinitis and pollinosis. Serum specific IgE antibodies to birch profilin (Bet v 2), latex profilin (Hev b 8), and timothy profilin (Phl p 12) were detected. She also showed positive reactions to several Apiaceae families, fruits and latex antigens in skin prick test. Based on these findings, we considered her symptoms to be involved with spice allergy, PFAS and latex-fruit syndrome.     

Detection of IgE antibodies to latex allergens in human serum

Reports indicate increasing incidence of Type I allergic reactions to latex allergens. The proteins that act as allergens and produce such allergic reactions are found in the natural latex sap of Hevea brasiliensis. All those who are exposed to latex products, particularly healthcare workers, are potentially at risk. The lack of qualified allergen extracts makes it difficult to perform skin testing on individuals who are at high risk. Therefore, a reliable in vitro test system for the detection of IgE antibodies to latex would be of considerable utility. We have developed a serological test for the qualitative determination of specific IgE antibodies to latex. In our study, 75 sera from individuals with a history of latex allergy and 29 serum samples from healthcare workers were tested by both radioimmunoassay (RIA) and enzyme immunoassay (EIA). The allergen bound to paper discs was the same solid phase for the RIA and EIA assays. The allergen preparation used for coating the paper discs was a mixture of proteins obtained from raw latex. The data show a good correlation between the results of RIA and EIA methods with data obtained using an RIA assay at an independent laboratory and by skin prick testing. Comparing the performance of our test using our latex material with that of the latex material obtained from the Food and Drug Administration (FDA), along with results of other tests including skin tests, we found that the specificity and sensitivity of our assay method approaches 100%. The data show no significant cross-reactivity between latex and banana. A low level of cross-reactivity between latex and avocado was observed. We conclude that, by using correct selection of proteins, the detection of specific IgE to latex may be a valuable assay method for screening individuals and for the diagnosis of allergy to latex.     

Specific immunotherapy in atopic dermatitis--Four-year treatment in different age and airborne allergy type subgroups

Atopic dermatitis (AD) is a common inflammatory disease involving the skin and frequently other organs and systems such as respiratory system. The recently recognized atopic nature of the skin inflammation in AD has raised a growing interest in the treatment with allergen-specific immunotherapy (SIT). In this study, the efficacy of SIT was evaluated in a group of 37 AD patients aged 5-44 years: 14 allergic to house dust mites (HDM), 17 to grass pollen allergens, and 6 allergic to grass and mugwort pollen allergens. IgE-mediated airborne allergy was well documented in all cases. SIT was performed with Novo Helisen Depot allergy vaccines of appropriate composition. Control group included 29 patients with AD and confirmed IgE-mediated airborne allergy to analogous allergens: HDM, 14 patients; grass pollen allergens, 11 patients; and grass and mugwort pollen allergens, 4 patients. Conventional methods of AD treatment were used in the control group. Clinical evaluation of patients was performed with W-AZS index after 12, 24, 36 and 48 months of therapy. SIT was found to be an efficacious and safe method of treatment for selected patients with AD and IgE-mediated airborne allergy. The efficacy of this therapeutic method was significantly higher than that recorded by conventional methods used in the control group in all 3 age subgroups and all 3 types of airborne allergy (HDM, grass pollen, and grass and mugwort pollen). It is concluded that SIT may be highly promising method of controlling skin inflammation in AD with the potential to prevent the development of AD into respiratory allergy.     

Chronic spontaneous urticaria is not an allergic disease

The links between chronic urticaria, IgE sensitization and allergy have been much discussed but little studied. We investigated IgE sensitization and allergy in 128 adult chronic urticaria patients during 2006-2008. During a one-day hospitalisation, the patients answered a standardized questionnaire and underwent blood serum analysis, physical tests and skin prick-tests. IgE sensitization to environmental allergens was defined by the positivity of at least one skin prick test and/or elevated levels of serum IgE?≥?300 Kui/L. The chronic urticaria was considered allergic if: i) a high correlation between positive skin prick tests to a clinically relevant allergen and the case history was found; ii) complete remission of urticaria occurred within two months of allergen withdrawal. Of 105 patients with interpretable skin prick tests, 46.7% were IgE sensitized. Two patients had clinically relevant positive skin prick tests but their chronic urticaria had many other triggering factors and neither was in complete remission after withdrawal of these allergens. IgE sensitization is higher in chronic urticaria patients than in the global adult population, suggesting that it is one important etiopathogenic factor in chronic urticaria. However, it cannot be considered as the expression of an IgE-mediated allergy but as a chronic inflammatory disease, more frequent in IgE sensitized people and favoured by multiple factors, among which IgE-mediated allergy is exceptional.     

The sweat of patients with atopic dermatitis contains specific IgE antibodies to inhalant allergens

We have investigated levels of total and specific against inhalant allergens in the sweat of 15 patients with atopic dermatitis, 10 patients with allergic rhinitis and high levels of specific IgE in the serum, and five patients with psoriasis without atopy as controls, by means of various commercial methods such as fluorescence immunoassay, nephetometry, chemiluminescence assay, enzyme immunoassay and the radioallergosorbent lest. Total IgE and specific IgE antibodies were detectable in the sweat of patients with atopic dermatitis as well as of patients with allergic rhinitis alone. These levels of total IgE in the sweat correlated with the severity of the skin disease (P < 0·05). By means of the Ciba Corning assay (P < 0·001), the fluorescence immunoassay (P < 0·05) and the nephelometry assay (P < 0·05), positive correlations were then established between the levels of total IgE in the serum and the sweat. Moreover, specific IgE antibodies to birch pollen and Dermatophagoides pteronyssinus were detectable in the sweat and correlated positively with these specific IgE levels in the serum (P < 0·05). Further, the specific IgE levels against these allergens in the sweat also correlated with the severity of dermatitis (P < 0·05). It is suggested that these specific IgE antibodies against certain inhalant allergens in the sweat of patients with atopic dermatitis may play a role in allergen trapping in the skin.     

食物过敏诊断的研究进展

食物过敏是儿童常见的过敏性疾病,发病率逐年增高,故其诊断尤为重要,目前诊断方法包括皮肤点刺试验, 特异性IgE检测,组分过敏原测试及过敏原激发试验,本文对上述试验方法进行综述。     

过敏专科门诊3 051例湿疹皮炎患者血清特异性IgE检测结果分析

目的分析湿疹皮炎患者血清特异性IgE检测结果。方法回顾2021年4月1日至2022年3月31日于华山医院过敏专科门诊就诊的3 051例湿疹皮炎患者, 利用Phadia过敏原检测系统检测患者的血清特异性IgE水平, 计算各项过敏原的检测阳性率, 分析湿疹皮炎患者的常见吸入性过敏原和食物过敏原。计数资料组间比较采用χ2检验。结果 3 051例湿疹皮炎患者中, 特应性皮炎1 412例, 其他湿疹/皮炎1 639例。1 629例(53%)过敏原阳性, 阳性过敏原数为(3.0 ± 1.6)个。最常见的3种吸入性过敏原分别是粉尘螨(904/1 522例, 59%)、户尘螨(891/1 513例, 59%)和链格孢霉(206/1 068例, 19%);最常见的3种食物过敏原分别是虾(251/1 432例, 18%)、鸡蛋白(165/992例, 17%)和牛奶(149/994例, 15%)。3 051例中, 25例(1%)年龄< 2岁, 571例(19%)2 ～ 12岁, 285例(9%)12 ～ 18岁, 2 170例(71%) > 18岁。在< 2岁、2 ～ 12岁患者组中, 最...     

Eczematous reactions in atopic patients caused by epicutaneous testing with inhalant allergens

To determine whether inhalant allergens could induce eczematous lesions we studied 17 patients with atopic eczema (with or without allergic rhinitis), 13 patients with allergic rhinitis without atopic eczema and 10 healthy control subjects. The allergens, birch pollen (Betula verrucosa) and house dust mite (Dermatophagoides pteronyssinus), were applied in aluminium chambers for 48 h on clinically normal skin. In 17 patients with atopic eczema, six epicutaneous test reactions of the delayed type to birch pollen and three to house dust mite were seen at 48 or 72 h. In 13 patients with allergic rhinitis without eczema there was one delayed reaction to birch pollen and none to house dust mite. No delayed type test reactions to either allergen were seen in the controls. Biopsies of the positive test sites revealed an eczematous reaction with epidermal spongiosis and microvesiculation. Immunostaining of cryostat sections showed dermal cell infiltrates consisting of mainly T lymphocytes (ratio of T4:T8, 2-6:I) and to a lesser degree Langerhans and indeterminate T6+ cells. 50-90% of the cells were Ia+. The numbers of basophils and mast cells did not exceed 10-15%.     

Improved detection of allergen-specific T-cell responses in allergic contact dermatitis through the addition of 'cytokine cocktails'

The gold standard for the diagnosis of allergic hypersensitivity is skin patch testing with the suspected allergens. This diagnostic tool, however, has distinct disadvantages, and therefore the development of alternative or complementary in vitro tests is of great importance. In this study, we evaluate the applicability of an in vitro test method, as developed earlier for nickel allergy, to detect allergen-specific T cells in the blood of patients allergic to frequent sensitizers (chromate, cobalt, paraphenylenediamine, fragrances and chloromethyl-isothiazolinone). Peripheral blood mononuclear cells (PBMCs) of allergic patients and healthy controls were cultured in the absence or presence of allergen. Additionally, type 1 (IL-7 and IL-12) or type 2 (IL-7 and IL-4) stimulating cytokines were added; after 6-day proliferation, IFN-gamma and IL-5 secretions were determined. Without the addition of cytokines, consistent allergen-induced proliferation was observed in PBMCs of nickel-allergic patients only. By contrast, the addition of type 1 or type 2 stimulating cytokines resulted in a significantly enhanced allergen-specific proliferation for all allergens tested (sensitivity increased from 26 to 43% or 38%, respectively, P < 0.05). In these cultures, allergen-induced IFN-gamma and IL-5 secretion was also significantly increased, compared to healthy controls (P < 0.05, for IFN-gamma sensitivity 79%, specificity 93%; for IL-5 sensitivity 74%, specificity 81%). In conclusion, these results demonstrate an increased proliferative capacity and cytokine production by allergen-specific T cells from allergic patients, but not of healthy individuals upon stimulation with allergens in combination with type 1 or 2 skewing cytokines. The present data warrant further exploration of the application of this test to a broader set of allergens.     

三种变应性皮肤病162例血清总IgE和过敏原特异性IgE检测分析

目的：通过测定特应性皮炎、慢性特发性荨麻疹、慢性湿疹三种变应性皮肤病患者血清总IgE水平，以及对广州地区这三种疾病的致敏原进行初步分析，了解血清总Ig水平及致敏原在这三种疾病中的状况。方法：采用酶联免疫方法对89例慢性特发性荨麻疹、24例特应性皮炎(AD)、49例慢性湿疹、32例正常对照进行MAST—CLA致敏原检测。结果：这三种疾病患者血清总IgE水平显著高于正常对照，三者间无显著差异，在三种疾病主要致敏原：AD分别是：螨虫83．34％、蟑螂37．5％、狗毛或猫毛58．34％；慢性特发性荨麻疹：螨虫39．32％、蟑螂12．36％、牛肉与蟹10．11％、牛奶8．99％；慢性湿疹：螨虫24．48％、屋尘14．29％、狗毛或猫毛10．2％、棉花、青霉菌、蟑螂、牛肉均为8．16％。结论：在广州地区外原性致敏原诱发的Ⅰ型变态反应可能在这三种疾病中起了重要作用。     

慢性荨麻疹患者食物过敏原特异性IgE及IgG检测

目的 探讨慢性荨麻疹患者食物过敏原检测的意义。方法 对502例慢性荨麻疹患者进行食物过敏原特异性IgE与IgG检测,并进行统计学分析;同时对花生、黄豆、牛奶等过敏原的特异性IgE与IgG不同结果组进行双盲安慰剂食物激发试验。结果 １８８例患者食物过敏原特异性IgE阳性,阳性检出率为37.4%,其中腰果、花生黄豆阳性率较高;３６２例患者至少对１种食物过敏,IgG阳性检出率为72.1％,牛奶、鸡蛋、虾蟹为主要过敏原。双盲安慰剂食物激发试验证实,两种抗体检测都有假阳性与假阴性。结论 临床医生应在慢性荨麻疹的治疗中注意筛查食物过敏原,特别是IgG介导的过敏反应。