Small intestinal mucosa IgE plasma cells and specific anti-cow milk IgE in children with cow milk protein intolerance.

In a prospective study we looked for the presence of both IgE plasma cells in small bowel mucosa and specific serum IgE antibodies to cow milk in children suspected of cow milk protein intolerance. Thirty-one children with complaints possibly due to cow milk intolerance were submitted to two consecutive cow milk elimination/challenge tests. The diagnosis of cow milk protein intolerance was confirmed in 16 of our 31 patients on the basis of two positive elimination/challenge tests. IgE plasma cells were found in nine of 16 patients with proven cow milk protein intolerance and in only one of the 15 patients without cow milk protein intolerance (p < .01). The RAST for cow milk was positive in six of 16 infants with cow milk protein intolerance and in two of the 15 other infants. Serum IgE level was of no value for the diagnosis of cow milk protein intolerance. Neither of these diagnostic procedures was sensitive enough to be used as a screening test for cow milk protein intolerance. Furthermore, the relationship between specific IgE antibodies for cow milk and the presence of mucosal IgE plasma cells was poor: five of nine infants with cow milk protein intolerance and the presence of mucosal IgE plasma cells had negative RASTs for cow milk.