Panel Of Recombinant Allergens Research Articles

Component resolved diagnosis by recombinant allergens in patients with allergies to inhalants.

Molecular characterization of IgE reactivity of specific individual components of allergenic extracts is now possible due to the technology of recombinant allergens derived from studies of molecular biology of allergic pathology. The identification of the immunoreactivity to single allergenic components in allergic subjects allows to specifically define her/his allergic profile and obtain the so-termed Component Resolved Diagnosis (CRD). Molecular allergens can be classified into those that induce the respiratory allergic reactivity and those that identify the food-related allergic pathology. It is also essential to identify those molecular allergens whose immunoreactivity is able to connect the two clinical conditions: respiratory symptoms and food allergy symptoms. The present study was conducted on 50 patients with a clinical history of hypersensitivity to pollen and/or allergy and positivity to Skin Prick Test. The sera were analyzed in our laboratories and the panel of recombinant allergens was applied in the case of positivity of the specific IgE. Of the 50 patients enrolled, 31 were selected as positive to 4 main pan-allergen Bet v1, Par j2, Art v1 and Phl p1; among these, 14 subjects showed one allergen-specific IgE towards natural extracts of tested foods even in absence of clinical history. CRD allows for an increased accuracy in allergy diagnosis and prognosis and plays an important role in: a) resolving genuine vs cross-reactive sensitization in poly-sensitized patients, b) assessing, in selected cases, the risk of severe, systemic vs mild, local reactions in food allergy, and c) identifying patients and triggering allergens for specific immunotherapy (ITS). In light of our results, we believe that the transition from a diagnostic based on the use of allergenic extracts to another one based on the use of single allergenic molecules that is able to define the specific allergenic profile of each patient, seems to be able to revolutionize the allergy diagnosis.

In vitro immunomonitoring of insect venom-allergic patients on immunotherapy

Objective Sting challenge is the gold standard method to evaluate the therapeutic efficiency of allergen specific immunotherapy (ASIT) in hymenoptera venom allergic patients. Unfortunately, this method is risky, expensive and time consuming. Therefore, the development of an in vitro method is desirable. Recently the basophil activation test (BAT) performed with natural venom has been shown to be a promising method. We aimed to improve the benefit of BAT technology by applying the panel of recombinant allergens Ves v 1, Ves v 2, Ves v 3 and Ves v 5.

90 Improving the Diagnosis of Hymenoptera Venom Allergy

BackgroundUp to 3% of the general population suffers from potentially life-threatening systemic reactions after honeybee and wasp stings. Unfortunately, there are still individuals who have a convincing history of an anaphylactic event, but lack the necessary diagnostic, making difficult the decision for immunotherapy. Our aims were to evaluate the feasibility of using recombinant allergens in the Basophil activation test (BAT) for the diagnosis of Hymenoptera allergy and to develop a high-throughput diagnostic device combining the advantages of basophil activation tests with a panel of recombinant allergens: rVes v 1, rVes v 2, rVes v 3, rVes v 5, rApi m 1, rApi m 2, rApi m 3 and rApi m 5.MethodsBasophil activation test (BAT) and measurement of specific IgE was performed on 47 wasp venom, 14 Honeybee venom allergic patients and 17 healthy controls. Specificity and sensitivity of BAT performed with recombinant His-tag purified wasp venom allergens Ves v 1, Ves v 2, Ves v 3 and Ves v 5, recombinant honeybee venom allergens Api m 1, Api m 2, Api m 3 and Api m 5 and commercial extracts have been compared. Each patient had a history of grade I or II anaphylaxis after an insect sting. All patient sera were collected before initiation of SIT.ResultsBAT performed with the panel of recombinant allergens markedly increased the specificity and the sensitivity in the detection of wasp venom allergic subjects.ConclusionsBasophil activation test provides a valuable new in vitro method for the detection of allergy to wasp venom and may supplement routine tests for allergy diagnosis in problematic cases. Recombinant allergens might help to dissect relevant allergens for basophil degranulation.

Kann es an der Nahrung liegen? Nahrungsmittelallergie, Nahrungsmittelintoleranz oder funktionell?

The term "food allergy" is widely misused for all sorts of symptoms and diseases caused by food. Food allergy (FA) is an adverse reaction to food (food hypersensitivity) occurring in susceptible individuals, which is mediated by a classical immune mechanism specific for the food itself. The best established mechanism in FA is due to the presence of IgE antibodies against the offending food. Food intolerance (FI) are all non-immune-mediated adverse reactions to food. The subgroups of FI are enzymatic (e.g. lactose intolerance due to lactase deficiency), pharmacological (reactions against biogenic amines, histamine intolerance), and undefined food intolerance (e.g. against some food additives). The diagnosis of an IgE-mediated FA is made by a carefully taken case history, supported by the demonstration of an IgE sensitization either by skin prick tests or by in vitro tests, and confirmed by positive oral provocation. For scientific purposes the only accepted test for the confirmation of FA/FI is a properly performed double-blind, placebo-controlled food challenge (DBPCFC). A panel of recombinant allergens, produced as single allergenic molecules, may in future improve the diagnosis of IgE-mediated FA. Due to a lack of causal treatment possibilities, the elimination of the culprit "food allergen" from the diet is the only therapeutic option for patients with real food allergy.

Die allergische bronchopulmonale Aspergillose (ABPA)

Allergic bronchopulmonary aspergillosis (ABPA) is the most common allergic bronchopulmonary mycosis in humans. The diagnosis of the complex disease is based on defined criteria. Five clinical stages of ABPA have been proposed. The extent of the defined criteria varies in the different stages, thus, making diagnosis difficult. Particularly the discrimination of ABPA in remission stage (stage II) and allergic asthma with A. fumigatus sensitization may be an important problem. Early diagnosis in stages without persistant changes of bronchial wall and lung parenchyma is needed to prevent severe end stages of ABPA. The up to now widely used commercial (crude) allergen extracts for in vitro and in vivo diagnosis show batch to batch variation, insufficient standardization and lack of reproducibility. Potentials and limitations of routine diagnostic procedures in ABPA are described. The production of a panel of recombinant allergens of A. fumigatus and their evaluation for in vivo and particularly in vitro use has brought an important step forward in the early and precise diagnosis of ABPA. A panel of recombinant allergens is now available for routine assay in CAP system. In cystic fibrosis, a higher prevalence of ABPA is reported. Although it appears that the patient with ABPA provides a favorable milieu for the occurrence ofAAS, it is surprising that in spite of similar histopathological features the coexistence of both diseases is infrequently recognized. Glucocorticosteroids play a central role in therapy of ABPA. The approach in exacerbation phase and the long-term therapy are described and also the indication for antimycotic drugs.