Immunochemical study of the malabsorption syndrome with cow's milk intolerance.

The effect of cow's milk provocation on the immunoglobulins in the intestinal mucosa, intestinal juice, stool extracts, as well as on the levels of antibodies to cow's milk and beta-1C/A in serum, was studied in 18 infants with the malabsorption syndrome. The infants improved on breast milk and were therefore suspected to be intolerant to cow's milk and challenged with it. At the time of clinical relapse a marked and uniform increase in the numbers of IgA- and IgM-containing cells, 2.4 times as many on the average as before challenge, was observed in the jejunal mucosa of eight reacting patients at nine provocations with cow's milk. There was no abnormality in the immunoglobulin-containing cells before challenge or in biopsy specimens taken shortly after the resumption of the elimination diet (breast milk). The clinical reaction was preceded by a pronounced rise in the IgA and IgM contents of stool extracts, and a rise in the titre of haemagglutinating antibodies and serum IgA, changes which subsided rapidly after withdrawal of cow's milk. There was no evidence that the reaction was IgE-mediated or complement-consuming. In some of the 10 patients who tolerated cow's milk challenge clinically there was an increase in both IgA- and IgM-containing cells suggestive of a local immunological reaction although no clinical intolerance was provoked and other immunological signs were weak or absent. In other non-reacting patients no immunological reaction was noted. Therefore it is evident that cow's milk is the agent responsible for the strong local intestinal reaction coinciding with the clinical symptoms.