Allergenicity of Bos d 5 in Children with Cow's Milk Allergy is Reduced by Transglutaminase Polymerization

Abstract

<b><i>Background:</i></b> Cow's milk allergy in pediatric patients is an unresolved issue. Among the proteins in milk, bovine whey beta-lactoglobulin (Bos d 5) is the most commonly allergenic. Allergenicity to native cow's milk proteins in humans is a well-studied issue, but very little is known about the allergenicity of cross-linked proteins found in bioprocessed dairy products. <b><i>Objective:</i></b> The objective of this study was to evaluate the allergenicity of polymerized bovine whey beta-lactoglobulin in symptomatic children diagnosed with IgE-mediated Bos d 5 hypersensitivity. <b><i>Methods:</i></b> Side-by-side skin prick tests with native and polymerized bovine whey beta-lactoglobulin were performed in 22 symptomatic children allergic to cow's milk with detectable specific IgE to Bos d 5 by CAP Systems Pharmacia. A matched control group tolerant to cow's milk and undetectable specific IgE to Bos d 5 was established for comparison. Wheal mean diameter was compared between the native and polymerized groups by paired <i>t</i>-tests. <b><i>Results:</i></b> The mean difference in wheal mean diameter observed between native versus polymerized bovine whey beta-lactoglobulin in the paired skin prick test of the allergic group was 2.27 mm (<i>p</i>=0.02; 95% CI 0.38-4.16). <b><i>Conclusions:</i></b> The skin prick test showed a significant reduction in the allergenicity of polymerized compared with native bovine whey beta-lactoglobulin in children with IgE-mediated Bos d 5 hypersensitivity.