
<ArticleTitle>Identification of IgE and IgG binding epitopes on beta- and <prot>kappa-casein</prot> in cow's milk allergic patients.</ArticleTitle>
<AbstractText>BACKGROUND: Cow's milk allergy (CMA) affects 2.5% of children aged less than 2 years of age. Although beta- and <prot>kappa-casein</prot> are considered among the major allergens responsible for CMA, no data are available on their allergenic epitopes in humans. OBJECTIVE: The aim of the study was to identify IgE- and IgG-binding epitopes on beta- and <prot>kappa-casein</prot> and to determine whether the pattern of epitope recognition is associated with the natural history of CMA. METHODS: Overlapping decapeptides representing the entire length of beta- and <prot>kappa-casein</prot>, respectively, were synthesized on a cellulose-derivatized membrane. Sera from 15 milk-allergic children, 4-18 years of age, with high levels of specific IgE antibodies to cow's milk were used to identify IgE- and IgG-binding epitopes. In addition, IgE epitopes were screened with pooled or individual sera from younger patients aged less than 3 years and who had low levels of specific serum IgE, who are likely to outgrow CMA. RESULTS: Six major and three minor IgE-binding epitopes, as well as eight major and one minor IgG binding regions, were identified on <prot>beta-casein</prot>. Eight major IgE-binding epitopes, as well as two major and two minor IgG-binding epitopes, were detected on <prot>kappa-casein</prot>. Three of the IgE binding regions on <prot>beta-casein</prot> and six on <prot>kappa-casein</prot> were recognized by the majority of patients in the older age group, but not by the younger patients. CONCLUSION: Information regarding the immunodominant epitopes in beta- and <prot>kappa-casein</prot> may be important for understanding the pathophysiology and natural history of CMA. Differences in epitope recognition may be useful in identifying children who will have persistent milk hypersensitivity.</AbstractText>
