[Serum IgE in infants. Usual values and values in intolerance to cow's milk proteins (author's transl)].

The usual values of serum IgE were determined by age group (at birth, 3--8 days, 9--45 days, 46--75 days and 76--105 days) in 80 infants under 4 months using the paper-radioimmuno-sorbent test (PRIST). There was a highly significant correlation between these values and the infants' age. Systematic search for specific anti-cow's milk IgE by a related technique (RAST) consistently gave negative results. The same techniques were used in 38 infants with clinical symptoms of intolerance to cow's milk. It would appear that these patients can be divided into two groups according to the presence of absence of extra-digestive symptoms. In the first group, there was a significant increase in total serum IgE, and the RAST was positive in 14 out of 17 patients. In the second group (21 infants), IgE levels were not increased and the RAST was always negative, which suggests that this type of intolerance is not reagin-mediated.