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

Olga Smoldovskaya,Yuriy Reznikov,Olga Ivashkina,Alla Rubina,Sergei Voloshin,Alla Arefieva,Guzel Feyzkhanova

doi:10.1186/s13223-016-0117-1

Olga Smoldovskaya, Yuriy Reznikov + Show 5 more

Open Access

https://doi.org/10.1186/s13223-016-0117-1

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Abstract

BackgroundImmunological 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.MethodsMultiplex 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.ResultsThe 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.ConclusionsMultiplex 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.

Highlights

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
For each allergen we determined the Analysis of diagnostic accuracy of using the cat dander allergen has shown that the areas under the curve (AUC) both for the extract and for the recombinant Fel d 1 was the same and equaled to 0.76
Sensitization to Fel d 1 occurs in 80–95 % of patients with hypersensitivity to cat dander, which results in a high efficiency of the diagnostic test employing this recombinant protein

Summary

Introduction

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. Extracts are heterogeneous protein mixtures isolated from natural materials containing allergenic and nonallergenic material. They allow estimating the reactivity of a patient’s serum toward all potentially allergenic components. Allergen extracts contain both species-specific proteins and components with epitopes demonstrating high cross-reactivity with proteins from other origins. This complicates the identification of the primary allergy source [1]. It has been shown in a number of studies that allergen extracts produced by number of manufacturers differ

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