RESPONSE OF THE JEJUNAL MUCOSA TO COW'S MILK IN THE MALABSORPTION SYNDROME WITH COW'S MILK INTOLERANCE A Light- and Electron-Microscopic Study

Three infants, in whom the malabsorption syndrome, small intestinal. mucosal damage and clinical cow's milk intolerance were found, were challenged with cow's milk after initial treatment with breast milk. The small intestinal mucosa was investigated with light and electron microscopy both before and after provocation. Clinically one patient reacted rapidly in a few hours and showed round cell infiltration in the surface epithelium and lamina propria 20 hours after a single challenge. Electron microscopy showed short microvilli, abnormal nuclei and thickened basement lamina in the surface epithelium. Two patients reacted slowly. One of them showed similar changes 4 days after commencement of the provocations, but the changes were much more evident 38 days later, when symptoms were also apparent. At this time large accumulations of lysosomes in the apical part of the surface epithelial cell and marked thickening of the basal lamina with accumulations of whirly collagen fibres were detected. The third patient reacted in a milder way, both clinically and morphologically. This study indicates that cow's milk, apparently through its protein fraction, may damage the surface epithelium of the small intestinal mucosa. These alterations during provocation periods resemble those found in coe-liac disease during gluten provocation.