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Case Report


Phosphorylation Reduces the Allergenicity of Cow Casein in Children With Selective Allergy to Goat and Sheep Milk


B Cases,1,2,* C García-Ara,3,* MT Boyano,3 M Pérez-Gordo,1 M Pedrosa,3 F Vivanco,1,4 S Quirce,3 C Pastor-Vargas4

1Instituto de Investigación Sanitaria-Fundación Jiménez Díaz, Madrid, Spain
2Hospital Nacional de Parapléjicos, Toledo, Spain
3Department of Allergy, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
4Universidad Complutense, Madrid, Spain
*Both authors contributed equally to this work

J Investig Allergol Clin Immunol 2011; Vol. 21(5): 398-400



This study aimed to characterize the role of phosphorylation of caseins in selective allergy to goat milk (GM) and sheep milk (SM) in patients with good tolerance to cow milk (CM). We performed skin prick tests with milk and caseins from CM, GM, and SM and immunoblotting and specific immunoglobulin (Ig) E determinations with milk and casein from cow and GM and SM. Sensitization to milk and caseins from goat and sheep was demonstrated in all 3 patients by skin tests, determination of specifi c IgE, or
both. Immunoblotting confi rmed that GM/SM proteins but not CM proteins were involved in the allergic symptoms. IgE reacted with several protein bands from the caseins and milk extracts of both sheep and goat. Phosphorylation was involved in the different allergenicity of CM caseins. We report the implication of phosphorylation in the allergenicity of caseins involved in selective allergy to GM and SM.

Key words: Casein. Cow milk allergy. Food allergens. Phosphorylation.