Distribution of serum antibodies to wheat gliadin and bovine milk in atopic and non-atopic healthy adults.

Sera from 262 blood donors were tested against wheat gliadin and bovine milk antigens employing an ELISA system. 9.2% of the sera clearly contained antibodies, predominantly IgG but also including IgA and occasional IgM, reactive with either gliadin (11/262) or milk (13/262). There was no overlap between the gliadin and milk groups, and only one of these sera was also IgE-RAST-positive against wheat or milk. Five of 48 sera with raised IgE levels (greater than or equal to 100 iu/ml) were ELISA-positive against either gliadin or milk, a frequency comparable with that overall in this normal adult population. Six of these 48 sera with raised IgE levels were IgE-RAST-positive against wheat or milk, of which only one was ELISA-positive. These results have indicated that nearly 10% of normal adults have serum IgG/A/M antibodies to milk or gliadin, but that this population is separate from individuals (2.3%) who may be IgE-RAST-positive to the same dietary antigens.