Milk Precipitins, Circulating Immune Complexes and IgA Deficiency

Abstract

It has been known for some years that the gastrointestinal tract of the newborn is permeable to macromolecules, and that undigested food antigens such as cow’s milk can enter the circulation and stimulate the production of antibodies (1–3). Many normal infants up to the age of 3 months develop precipitating antibodies after the introduction of cow’s milk into the diet but these antibodies disappear with age and are ultimately found in only 1–2% of the general population (3,4). However, in one immunodeficiency disease, selective IgA deficiency, milk precipitins are commonly found in all age groups (4).