Guidelines for the use and interpretation of diagnostic methods in adult food allergy

Association between Food-Specific Immunoglobulin G4 Antibodies in Adults with Self-Reported Signs and Symptoms Attributed to Adverse Reactions to Foodstuffs

Signs and symptoms attributed to adverse reactions to foodstuffs (ARFS) need tools for research and evaluation in clinical practice. The objectives of this study were (a) to evaluate the most frequent self-reported signs and symptoms attributed to ARFS in Spanish adults, (b) to determine the prevalence of food-specific IgG4 antibody reactions (AbRs), and (c) to investigate the association between self-reported ARFS symptomatology and food-specific IgG4 AbRs. Food-specific IgG4 AbRs against 57 common food and beverages (AESKUCARE-T2FA® in vitro point-of-care test kit, Aesku.Diagnostics GmbH, Germany) were determined in capillary blood samples of 205 volunteers living in the Region of Madrid (Spain). The most frequent self-reported signs and symptoms were related to skin (43%), digestive (41%), and nervous system (NS, 33%) problems. The prevalence of food-specific IgG4 AbRs was cow's milk (73%), sheep's milk (70%), casein (66%), and goat's milk (56.10%). Positive IgG4 AbRs against tomato had a profile consisting of 3/4 of skin problems, more than half of digestive, and 2/5 of NS self-reported signs and symptoms. In conclusion, at least 1/3 of the studied sample reported skin, digestive, and NS signs and symptoms. The most frequent food-specific IgG4 AbRs were related to dairy. Skin problems were more frequent in positive tomato IgG4 AbRs.

Prevalence of self-reported food allergy among adults in Jiangxi, China

Background

Food allergy has become an increasingly important public health problem. However, information regarding epidemiological studies of food allergy among Chinese adults is very limited. This study aims to estimate the prevalence of self-reported food allergy among adults in China.

Method

A population-based cross-sectional study was administered to estimate the prevalence of self-reported food allergy on the basis of a face-to-face questionnaire survey. The participants were recruited by cluster random sampling from three prefectures in Jiangxi Province, China.

Results

A total of 12 082 questionnaires were distributed, and 11 935 (98.8%) of completed ones were collected. The prevalence of self-reported food allergy was 4.0% (3.1% in men and 4.8% in women), self-reported doctor-diagnosed food allergy accounted for 1.4%. The most common allergic symptom was skin reaction showing in 63.9% of the participants with self-reported food allergy. The main allergic foods were shrimp, mollusks, and mango, accounting for the prevalence of 39.8%, 20.8%, and 18.7%, respectively. The self-reported food allergy was significantly linked with gender, age group, body height and other allergic conditions.

Conclusions

The prevalence of self-reported food allergy is about 4.0% among adults in China. The three most common allergenic foods were shrimp, mollusks and mango. Gender, age, and other allergic diseases could be contributing factors associated with food allergy in adults. These findings will provide scientific basis for the further research and prevention of food allergy in adults.

Nutritional management of food allergies: Prevention and treatment

An individualized allergen avoidance plan is the cornerstone of the nutritional management of food allergy (FA). In pediatric age, the main objective is preventing the occurrence of acute and chronic symptoms by avoiding the offending food(s) and providing an adequate, nutritionally balanced and personalized diet at the same time. For this reason, the presence of a trained dietitian is recommended in order to meet nutritional needs of patients with FA and to provide a tailored nutritional plan, minimizing the impact of FA on quality of life and maintaining optimal growth.

Real-life evaluation of molecular multiplex IgE test methods in the diagnosis of pollen associated food allergy

BACKGROUND

Diagnosis of food allergies is challenging, as combining information from specific IgE (sIgE)-sensitization pattern and skin prick tests (SPTs) with clinical history is necessary for a personalized management of allergic patients. The aim of this study was to compare two molecular tests, the ImmunoCAP ISAC (ISAC) and the Allergy Explorer, version 2 (ALEX² ) in the context of pollen food syndrome (PFS) diagnosis in a real-life scenario, to assess the benefit of multiplex testing in PFS patients.

METHODS

Diagnosis of food allergy was performed in 53 patients. Allergen-sIgE concentrations were measured with ISAC and ALEX² . Results for sIgE were statistically compared with each other, with SPT results and with clinical presentation of the patients.

RESULTS

Using ISAC as reference test for sIgE measurements, the average sensitivity of ALEX² for PR-10 allergens was 83.2% and the average specificity 88.0%. If only low sIgE concentrations were included, the sensitivity was 60.8% and the specificity 91.1%. Apple and hazelnut sensitizations were confirmed in most patients by concordance of sIgE and SPT results. Significant correlations were shown between clinical symptoms and Mal d 1- and Gly m 4-sIgE levels measured by both tests and for Cor a 1-sIgE levels measured by ALEX² . In eight patients, profilin related symptoms were supported by Hev b 8-sensitization.

CONCLUSION

Multiplex testing is beneficial to understand patient-specific individual sensitization profiles and to providing personalized management recommendations. In the future, custom-designed test kits might enable reducing costs of multiplex testing for specific patient groups without compromising the diagnostic value.

Food Allergy Insights: A Changing Landscape

The panorama of food allergies (FA) has changed profoundly in recent years. In light of recent advances in knowledge of pathogenetic mechanisms and a greater attention to the multifaceted range of possible clinical manifestations, there is a need for a critical review of past classifications. Changes in nutrition, environment and lifestyles around the world are modifying the global FA epidemiology and new FA phenotypes are also emerging. Furthermore, both biotechnological advances in this field and recent personalized therapies have improved the diagnostic and therapeutic approach to FA. Consequently, both the prevention and clinical management of FA are rapidly changing and new therapeutic strategies are emerging, even revolutionizing the current medical practice. Given the significant increase in the prevalence of FA in recent years, the objective of this review is to provide an updated and complete overview of current knowledge in its etiopathogenesis, diagnostics and therapy, useful not only for a better understanding of this frequent and complex pathology but also for practical guidance in its clinical management.

Immunization of Cats against Fel d 1 Results in Reduced Allergic Symptoms of Owners

An innovative approach was tested to treat cat allergy in humans by vaccinating cats with Fel-CuMV (HypoCat^TM), a vaccine against the major cat allergen Fel d 1 based on virus-like particles derived from cucumber mosaic virus (CuMV-VLPs). Upon vaccination, cats develop neutralizing antibodies against the allergen Fel d 1, which reduces the level of reactive allergen, thus lowering the symptoms or even preventing allergic reactions in humans. The combined methodological field study included ten cat-allergic participants who lived together with their cats (n = 13), that were immunized with Fel-CuMV. The aim was to determine methods for measuring a change in allergic symptoms. A home-based provocation test (petting time and organ specific symptom score (OSSS)) and a general weekly (or monthly) symptom score (G(W)SS) were used to assess changes in allergic symptoms. The petting time until a pre-defined level of allergic symptoms was reached increased already early after vaccination of the cats and was apparent over the course of the study. In addition, the OSSS after provocation and G(W)SS recorded a persistent reduction in symptoms over the study period and could serve for long-term assessment. Hence, the immunization of cats with HypoCat^TM (Fel-CuMV) may have a positive impact on the cat allergy of the owner, and changes could be assessed by the provocation test as well as G(W)SS.

Immunization of Cats against Fel d 1 Results in Reduced Allergic Symptoms of Owners

An innovative approach was tested to treat cat allergy in humans by vaccinating cats with Fel-CuMV (HypoCat^TM), a vaccine against the major cat allergen Fel d 1 based on virus-like particles derived from cucumber mosaic virus (CuMV-VLPs). Upon vaccination, cats develop neutralizing antibodies against the allergen Fel d 1, which reduces the level of reactive allergen, thus lowering the symptoms or even preventing allergic reactions in humans. The combined methodological field study included ten cat-allergic participants who lived together with their cats (n = 13), that were immunized with Fel-CuMV. The aim was to determine methods for measuring a change in allergic symptoms. A home-based provocation test (petting time and organ specific symptom score (OSSS)) and a general weekly (or monthly) symptom score (G(W)SS) were used to assess changes in allergic symptoms. The petting time until a pre-defined level of allergic symptoms was reached increased already early after vaccination of the cats and was apparent over the course of the study. In addition, the OSSS after provocation and G(W)SS recorded a persistent reduction in symptoms over the study period and could serve for long-term assessment. Hence, the immunization of cats with HypoCat^TM (Fel-CuMV) may have a positive impact on the cat allergy of the owner, and changes could be assessed by the provocation test as well as G(W)SS.

New Perspectives in Food Allergy

The improvement of the knowledge of the pathophysiological mechanisms underlying the tolerance and sensitization to food antigens has recently led to a radical change in the clinical approach to food allergies. Epidemiological studies show a global increase in the prevalence of food allergy all over the world and manifestations of food allergy appear increasingly frequent also in elderly subjects. Environmental and nutritional changes have partly changed the epidemiology of allergic reactions to foods and new food allergic syndromes have emerged in recent years. The deepening of the study of the intestinal microbiota has highlighted important mechanisms of immunological adaptation of the mucosal immune system to food antigens, leading to a revolution in the concept of immunological tolerance. As a consequence, new prevention models and innovative therapeutic strategies aimed at a personalized approach to the patient affected by food allergy are emerging. This review focuses on these new perspectives and their practical implications in the management of food allergy, providing an updated view of this complex pathology.

IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen.

The Intriguing Role of Interleukin 13 in the Pathophysiology of Asthma

Approximately 5–10% of asthmatic patients worldwide suffer from severe asthma. Experimental and clinical studies have demonstrated that IL-13 is an important cytokine in chronic airways inflammation. IL-13 is involved in Th2 inflammation and has been identified as a possible therapeutic target in the treatment of asthma. Two different human monoclonal antibodies (mAbs) anti-IL-13 (tralokinumab and lebrikizumab) block binding and signaling of IL-13 to its receptors, IL-13Rα1 and IL-13Rα2. Several randomized, double-blind, placebo-controlled multicenter studies have evaluated the safety and efficacy of tralokinumab and lebrikizumab in the treatment of adult patients with severe asthma, but all have failed to meet their primary endpoints. No serious adverse events related to the treatment with these anti-IL-13 mAbs have been reported in these studies. These negative clinical results contrast with positive findings from blocking IL-13 signaling in experimental models of asthma, raising doubts about the transferrable value of some models. Interestingly, dupilumab, a mAb which blocks both IL-4 and IL-13 signaling reduces exacerbation rates and improves lung function in severe asthmatics. These results suggest that IL-4 and IL-13 share some, but not all functional activities in airway inflammation. Tralokinumab might show efficacy in a highly selected cohort of asthmatics characterized by overexpression of IL-13.

Molecular diagnostics improves diagnosis and treatment of respiratory allergy and food allergy with economic optimization and cost saving

BACKGROUND

Component resolved diagnosis (CRD) allows to precisely identify the sensitization to specific molecules of a given allergenic source, resulting in an important improvement in clinical management, particularly of polysensitized subjects. This will end in the correct prescription of allergen immunotherapy (AIT) for respiratory allergy and in adequate avoidance diets or prescription of self-injectable adrenaline in food allergy.

OBJECTIVE

The aim of this multicenter, real life study is to evaluate the percentage change of the diagnostic-therapeutic choice in polysensitized patients with respiratory allergy and in patients with food allergy, after using CRD compared to a first level diagnosis, along with an economic analysis of the patient's overall management according to the two different approaches.

METHODS

An overall number of 462 polysensitized patients, as suggested by skin prick tests (SPT), and with clinical symptoms related to a respiratory (275 pts) or food (187 pts) allergy, were recruited. All patients underwent CRD for specific IgE against food or inhalant recombinant molecules, which were chosen according to medical history and positivity to SPT. The first diagnostic-therapeutic hypothesis, based only on medical history and SPT, was recorded for each patient while the final diagnostic-therapeutic choice was based on the results from CRD. The rate of change of the diagnostic-therapeutic choice from the first hypothesis to the final choice was statistically evaluated. The economic impact of CRD on the overall management of the allergic patients was analyzed to evaluate whether the increase in the diagnostic costs would be compensated and eventually exceeded by savings coming from the improved diagnostic-therapeutic appropriateness.

RESULTS

An approximate 50% change (k index 0.54) in the prescription of AIT for respiratory allergy as well as a change in the prescription of self-injectable adrenaline (k index 0.56) was measured; an overall saving of financial resources along with a higher diagnostic-therapeutic appropriateness was also detected.

CONCLUSION

There is moderate agreement concerning prescription of AIT and self-injectable adrenaline before and after performing CRD: this highlights the usefulness of CRD, at least in polysensitized patients, in indicating the risk assessment and therefore the correct therapy of respiratory and food allergy, which results in a cost-saving approach.

Glycation of ovalbumin after high-intensity ultrasound pretreatment: effects on conformation, immunoglobulin (Ig)G/IgE binding ability and antioxidant activity

BACKGROUND

Ovalbumin (OVA), a protein with excellent nutritional and processing properties, is the major allergen of hen egg white. High-intensity ultrasound treatment increases the immunoglobulin (Ig)G and IgE binding abilities by unfolding the conformational structure of OVA. This may allow a modification of the IgG and IgE binding of OVA by combining high-intensity ultrasound with other methods, such as glycation, thus representing a promising method for the improvement of protein properties.

RESULTS

Glycation with mannose (M) after ultrasound pretreatment at 0-600 W significantly reduced the IgG and IgE binding abilities and dramatically enhanced the antioxidant activity of OVA-M conjugates, with the lowest values of IgG and IgE binding and highest values of antioxidant capacity observed at 600 W. Polyacrylamide gel electrophoresis showed that the molecular weight of OVA-M conjugates with ultrasound pretreatment increased more than non-pretreatment sample, implying that ultrasound pretreatment promoted glycation. The α-helix content and ultraviolet absorption of OVA were observably increased, whereas β-sheet content, intrinsic fluorescence and surface hydrophobicity were notably decreased, indicating that the tertiary and secondary structures of OVA were markedly changed.

CONCLUSION

High-intensity ultrasound pretreatment can be conducive to reducing the binding abilities of IgG and IgE and enhancing the antioxidant activity of OVA-M conjugates. Therefore, glycation combined with high-intensity ultrasound pretreatment might be a promising method for producing hypo-allergenic and high-antioxidant OVA products. © 2018 Society of Chemical Industry.

Eating jellyfish: safety, chemical and sensory properties

BACKGROUND

People's preference for fish with a high trophic level, like Atlantic cod and tuna, leads to a large food footprint. Responsible seafood consumption should include underutilised local products; hence the culinary use of edible jellyfish can be an effective contribution. The present work focused on Catostylus tagi to contribute to the consumption of edible jellyfish in the West.

RESULTS

A questionnaire conducted with 192 young people showed an interest in tasting jellyfish-based food (64.6%). The resulting product, obtained by an alternative cooking process to traditional Asian ones, was chemically characterised and underwent microbiological and heavy metals control. The results indicated its non-toxicity. Patients who were allergic to seafood as well as non-allergic volunteers revealed no allergic reaction to the jellyfish umbrella product (intakes up to 5 mg/kg body weight and 8 mg/kg, respectively). Seafood-trained panellists defined the product's main impact on the mouth as freshness (72 mg/kg body weight). The preliminary snack, a pâté, was positively accepted by allergic (7 in 9; n = 20) and non-allergic volunteers (6 in 7; n = 21).

CONCLUSION

The present study confirmed that jellyfish intake is safe, even for allergic individuals, and its organoleptic properties were accepted by the study population. © 2018 Society of Chemical Industry.

Thymic Stromal Lymphopoietin Isoforms, Inflammatory Disorders, and Cancer

Thymic stromal lymphopoietin (TSLP) is a pleiotropic cytokine originally isolated from a murine thymic stromal cell line. TSLP exerts its biological effects by binding to a high-affinity heteromeric complex composed of thymic stromal lymphopoietin receptor chain and IL-7Rα. TSLP is primarily expressed by activated lung and intestinal epithelial cells, keratinocytes, and fibroblasts. However, dendritic cells (DCs), mast cells, and presumably other immune cells can also produce TSLP. Different groups of investigators have demonstrated the existence of two variants for TSLP in human tissues: the main isoform expressed in steady state is the short form (sf TSLP), which plays a homeostatic role, whereas the long form (lfTSLP) is upregulated in inflammatory conditions. In addition, there is evidence that in pathological conditions, TSLP can be cleaved by several endogenous proteases. Several cellular targets for TSLP have been identified, including immune (DCs, ILC2, T and B cells, NKT and Treg cells, eosinophils, neutrophils, basophils, monocytes, mast cells, and macrophages) and non-immune cells (platelets and sensory neurons). TSLP has been originally implicated in a variety of allergic diseases (e.g., atopic dermatitis, bronchial asthma, eosinophilic esophagitis). Emerging evidence indicates that TSLP is also involved in chronic inflammatory (i.e., chronic obstructive pulmonary disease and celiac disease) and autoimmune (e.g., psoriasis, rheumatoid arthritis) disorders and several cancers. These emerging observations greatly widen the role of TSLP in different human diseases. Most of these studies have not used tools to analyze the expression of the two TSLP isoforms. The broad pathophysiologic profile of TSLP has motivated therapeutic targeting of this cytokine. Tezepelumab is a first-in-class human monoclonal antibody (1) that binds to TSLP inhibiting its interaction with TSLP receptor complex. Tezepelumab given as an add-on-therapy to patients with severe uncontrolled asthma has shown safety and efficacy. Several clinical trials are evaluating the safety and the efficacy of tezepelumab in different inflammatory disorders. Monoclonal antibodies used to neutralize TSLP should not interact or hamper the homeostatic effects of sf TSLP.

Precision medicine in cow's milk allergy: proteomics perspectives from allergens to patients

Cow's milk allergy (CMA) is one of the most common food allergies, especially during childhood. CMA is an immunological mediated adverse reaction to one or more cow's milk proteins, which are normally harmless to a non-allergic individual, as the result of a failure of oral tolerance. To make a correct diagnosis of CMA and a proper treatment is critical in clinical practice. Application of proteomics along with new bio-informatics tools in the field of food allergy is one of the hot topics presented in recent years. In the present review, we focus on recent applications of proteomics to the field of cow's milk allergy, from allergens quantification to the diagnosis, treatment and prognosis. Furthermore, we also shed a light on potential future directions and developments, that are parts of personalized medicine but also of the One Health approach.

SIGNIFICANCE

The field of food allergies is becoming a milestone in public health. Food allergies, in fact, can cause life-threatening reactions and profoundly influence the quality of life. Precise, fast and reliable diagnosis of food allergies, and in particular milk allergies is essential to avoid severe allergic reactions and also to prevent dangerous and eventually unnecessary dietary restrictions; but this can be difficult also due to a complex interaction of genetic background, environment, and microbiota. In this sense, proteomics represents steps toward researching food and milk allergy integrated with the clinic to improve pathophysiology, diagnosis, therapy, and prognosis.

Diagnosis of exercise-induced anaphylaxis: current insights

Exercise-induced anaphylaxis (EIAn) is defined as the occurrence of anaphylactic symptoms (skin, respiratory, gastrointestinal, and cardiovascular symptoms) after physical activity. In about a third of cases, cofactors, such as food intake, temperature (warm or cold), and drugs (especially nonsteroidal anti-inflammatory drugs) can be identified. When the associated cofactor is food ingestion, the correct diagnosis is food-dependent EIAn (FDEIAn). The literature describes numerous reports of FDEIAn after intake of very different foods, from vegetables and nuts to meats and seafood. One of the best-characterized types of FDEIAn is that due to ω5-gliadin of wheat, though cases of FDEIAn after wheat ingestion by sensitization to wheat lipid transfer protien (LTP) are described. Some pathophysiological mechanisms underlying EIAn have been hypothesized, such as increase/alteration in gastrointestinal permeability, alteration of tissue transglutaminase promoting IgE cross-linking, enhanced expression of cytokines, redistribution of blood during physical exercise leading to altered mast-cell degranulation, and also changes in the acid–base balance. Nevertheless, until now, none of these hypotheses has been validated. The diagnosis of EIAn and FDEIAn is achieved by means of a challenge, with physical exercise alone for EIAn, and with the assumption of the suspected food followed by physical exercise for FDEIAn; in cases of doubtful results, a double-blind placebo-controlled combined food–exercise challenge should be performed. The prevention of this particular kind of anaphylaxis is the avoidance of the specific trigger, ie, physical exercise for EIAn, the assumption of the culprit food before exercise for FDEIAn, and in general the avoidance of the recognized cofactors. Patients must be supplied with an epinephrine autoinjector, as epinephrine has been clearly recognized as the first-line intervention for anaphylaxis.

New pharmaceutical approaches for the treatment of food allergies

INTRODUCTION

Allergic diseases constitute one of the most common causes of chronic illness in developed countries. The main mechanism determining allergy is an imbalance between Th1 and Th2 response towards Th2.

AREAS COVERED

This review describes the mechanisms underlying the natural tolerance to food components and the development of an allergic response in sensitized individuals. Furthermore, therapeutic approaches proposed to manage these abnormal immunologic responses food are also presented and discussed.

EXPERT OPINION

In the past, management of food allergies has consisted of the education of patients to avoid the ingestion of the culprit food and to initiate the therapy (e.g. self-injectable epinephrine) in case of accidental ingestion. In recent years, sublingual/oral immunotherapies based on the continuous administration of small amounts of the allergen have been developed. However, the long periods of time needed to obtain significant desensitization and the generation of adverse effects, limit their use. In order to solve these drawbacks, strategies to induce tolerance are being studied, such as the use of either adjuvant immunotherapy in order to facilitate the reversion of the Th2 response towards Th1 or the use of monoclonal antibodies to block the main immunogenic elements.

Allergen extracts and recombinant proteins: comparison of efficiency of in vitro allergy diagnostics using multiplex assay on a biological microchip

BACKGROUND

Immunological test systems for diagnostics of type I hypersensitivity involve the following types of antigens: whole allergen extracts, individual highly purified proteins and their recombinant analogues. The goal of this study was to compare the results obtained with whole allergen extracts (birch pollen, cat dander, and timothy grass pollen) and their respective recombinant proteins in biochip-based immunoassay.

METHODS

Multiplex fluorescent immunoassay of 139 patients' blood serum samples was carried out using biological microchips (biochips). sIgE concentrations for the chosen allergens and their recombinant components were measured. ROC analysis was used for comparison of the results and determination of diagnostic accuracy.

RESULTS

The results for the birch pollen extract and its recombinant allergens have shown that the diagnostic accuracy of the methods utilizing the whole allergen extract, its major component Bet v 1 and the combination of major and minor components (Bet v 1 and Bet v 2) was the same. Values for diagnostic accuracy for the cat dander extract and its major recombinant component Fel d 1 were equal. In contrast with birch pollen and cat dander allergens, using of recombinant components of timothy grass pollen (Phl p 1, Phl p 5, Phl p 7 and Phl p 12) did not allow reaching the diagnostic accuracy of using natural extract.

CONCLUSIONS

Multiplex analysis of samples obtained from patients with allergy to birch pollen and cat dander using biological microchips has shown that comparable accuracy was observed for the assay with natural extracts and recombinant allergens. In the case of timothy grass allergen, using the recombinant components may be insufficient.

Allergen extracts and recombinant proteins: comparison of efficiency of in vitro allergy diagnostics using multiplex assay on a biological microchip

Background

Immunological test systems for diagnostics of type I hypersensitivity involve the following types of antigens: whole allergen extracts, individual highly purified proteins and their recombinant analogues. The goal of this study was to compare the results obtained with whole allergen extracts (birch pollen, cat dander, and timothy grass pollen) and their respective recombinant proteins in biochip-based immunoassay.

Methods

Multiplex fluorescent immunoassay of 139 patients’ blood serum samples was carried out using biological microchips (biochips). sIgE concentrations for the chosen allergens and their recombinant components were measured. ROC analysis was used for comparison of the results and determination of diagnostic accuracy.

Results

The results for the birch pollen extract and its recombinant allergens have shown that the diagnostic accuracy of the methods utilizing the whole allergen extract, its major component Bet v 1 and the combination of major and minor components (Bet v 1 and Bet v 2) was the same. Values for diagnostic accuracy for the cat dander extract and its major recombinant component Fel d 1 were equal. In contrast with birch pollen and cat dander allergens, using of recombinant components of timothy grass pollen (Phl p 1, Phl p 5, Phl p 7 and Phl p 12) did not allow reaching the diagnostic accuracy of using natural extract.

Conclusions

Multiplex analysis of samples obtained from patients with allergy to birch pollen and cat dander using biological microchips has shown that comparable accuracy was observed for the assay with natural extracts and recombinant allergens. In the case of timothy grass allergen, using the recombinant components may be insufficient.

Comparing the ability of molecular diagnosis and CAP-inhibition in identifying the really causative venom in patients with positive tests to Vespula and Polistes species

Background

Cross-reactivity among Hymenoptera venoms is an important issue when prescribing venom immunotherapy (VIT). Using all venoms eliciting a positive response results in treatment excess and unjustified cost increase. The first in vitro method that helped to identify the really causative venom was RAST-inhibition, but in latest years also molecular allergy (MA) diagnostics, that detects specific sIgE to single venom allergens, was introduced. We compared the two methods in patients with double sensitization to Vespula spp. and Polistes spp.

Methods

Fifty-four patients with anaphylactic reactions to Hymenoptera stings and positive results to skin tests and sIgE measurement with whole venom from Vespula spp. and Polistes dominula were included in the study. Sera from all patients were analyzed by CAP-inhibition (Thermo Fisher Scientific, Uppsala, Sweden) and MA diagnostics with recombinant Ves v 1, Ves v 5 and Pol d 5.

Results

By the data obtained from MA technique, VIT would have been prescribed to 7 patients for Polistes, to 6 for Vespula, and to 41 for both venoms. With the data from CAP inhibition, it would have been a prescription to 15 patients for Polistes, to 28 for Vespula, and to 11 for both venoms. A good concordance between the results of MA and CAP-inhibition was found only when the value in kU/l of Ves v 5 were about twice those of Pol d 5, and vice versa.

Conclusions

These findings suggest that in the choice of the venom to be used for VIT CAP-inhibition remains a pivotal tool, because the significance of in vitro inhibition is definite and provides a diagnostic importance higher than MA in patients with positive tests to both Vespula and Polistes spp.