Milk hypersensitivity: RAST studies using new antigens generated by pepsin hydrolysis of beta-lactoglobulin.

RAST was performed on sera from 28 patients with a variety of allergic symptoms, giving histories compatible with milk allergy, to investigate the occurrence of IgE antibodies to new antigens (NA) generated by in vitro pepsin hydrolysis. A variety of symptoms were associated with positive RAST scores. A positive correlation was found between the degree of RAST reactivity with undigested milk proteins and reactivity with the NA's. Reactivity to the NA's was always associated with reactivity to at least one of the undigested proteins. These findings suggest that undigested milk proteins are more reactive than digested proteins. Furthermore, antigens derived from pepsin digestion do not elicit a significant antibody response in individuals who do not allow show antibody responses to undigested proteins.