Allergenic proteins still present in both crude and refined peanut oil

Isolation and characterization of proteic allergens in refined peanut oil

OLSZEWSKI A. ; PONS L.; MOUTETE F. ; AIMONE-GASTIN I.; KANNY G. ; MONERET-VAUTRIN D. A. ; GUEANT J. L.
Laboratory of Cellular and Molecular Biology in Nutrition, Faculty of Medicine, University H. Poincaré of Nancy, Vandoeuvre-les-Nancy, FRANCE
Department of Allergology and Clinical Immunology, University Hospital Centre of Nancy, Nancy, FRANCE

Allergic reactions to peanut oil are very much debated, even if the responsibility of peanut oil has been evoked in several cases of adverse reactions, including death related to severe asthma.

The aim of the present study was to investigate the presence of allergenic proteins in peanut oil. Proteins were extracted from commercial refined peanut oil, with a relative content in the order of 0.1-0.2 μg per g of oil, and molecular sizes ranging from 14 up to 76 kDa in SDS-PAGE.

Eight protein bands were systematically observed in crude, neutralized and refined oils. with a molecular mass ranging from 14 to 76 kDa, including one at 18 kDa which was identified by Western blot performed with serum from two allergic patients.

The protein extract gave positive IgE-RIA with patient sera, positive in vitro leucocyte histamine release tests and positive skin-prick tests in allergic patients. The allergenic protein was purified by HPLC and [125I] iodide-labelled. It had an isoelectric point at 4.5 in isoelectrofocusing.

In conclusion. we have demonstrated the presence of allergenic proteins in crude and refined peanut oil. These proteins are the same size as two allergens previously described in peanut protein extracts.

Clinical and experimental allergy ISSN 0954-7894
1998, vol. 28, no7, pp. 850-859 (46 ref.)

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First published in 1998

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