Standardization of food allergen extracts for skin prick test

Citation
Ks. Hansen et al., Standardization of food allergen extracts for skin prick test, J CHROMAT B, 756(1-2), 2001, pp. 57-69
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry & Analysis
Journal title
JOURNAL OF CHROMATOGRAPHY B
ISSN journal
1387-2273 → ACNP
Volume
756
Issue
1-2
Year of publication
2001
Pages
57 - 69
Database
ISI
SICI code
1387-2273(20010525)756:1-2<57:SOFAEF>2.0.ZU;2-5
Abstract
The aim of the study was to standardize and evaluate technically optimized food allergen extracts fbr use in skin prick test (SPT). The standardizatio n procedure comprised 36 allergic histories in 32 food allergic patients wi th 21 healthy, non-atopic individuals serving as controls. The patients had a history of allergic symptoms upon ingestion of either cow's milk (n = 3) , hen's egg (n = 9), wheat (n = 4), hazelnut (n = 14) or cod (n = 6). They also had specific IgE in serum to the food in question and a positive SPT w ith a fresh preparation of the food. The diagnosis had been confirmed by a double-blind, placebo-controlled food challenge, except for the hazelnut-al lergic patients. The controls were subjected to an open food challenge with all the foods to ensure tolerance. The standardization was performed by me ans of titrated SPT in accordance with the guidelines on biological standar dization from the Nordic Council on Medicine. Regression analysis of the sk in wheal areas was performed for each patient and the median protein concen tration of allergen preparation (median C-h10) eliciting a wheal area of th e same size as histamine 10 mg/ml was calculated. The median C-h10 was 0.56 mg/ml for milk, 0.88 mg/ml for egg, 5.4 mg/ml for wheat, 2.1 mg/ml for haz elnut and 0.017 mg/ml for the cod extract. The sensitivity of the median C- h10 estimated from the SPT data was 1 for milk, 0.98 for egg, 1 for wheat, 1 for hazelnut and 0.87 for the cod extract. The allergenic activity of the hazelnut extract was further investigated by leukocyte histamine release ( HR) and immunoblotting experiments using sera from 27 hazelnut allergic pat ients. The clinical sensitivity of the optimized hazelnut extract evaluated by HR was 0.78 compared to 0.30 for a commercially available hazelnut extr act (Soluprick). Immunoblotting results showed a stronger IgE binding capac ity and additional IgE-binding bands of the optimized hazelnut extract comp ared with the Soluprick extract. (C) 2001 Elsevier Science B.V. All rights reserved.