Deposition of eosinophil-granule major basic protein and expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in the mucosa of the small intestine in infants with cow’s milk–sensitive enteropathy

Background: Cow’s milk–sensitive enteropathy (CMSE) is an important cause of chronic diarrhea and failure to thrive in infancy. The immunopathology of the mucosal lesion associated with CMSE has not yet been described. Objectives: This study investigated the eosinophil activation and the role of adhesion molecules in the pathogenesis of intestinal mucosal damage associated with CMSE. Methods: Twenty-one patients with chronic diarrhea and abnormal mucosa on duodenal biopsy specimens were included. The patients had negative responses to skin prick tests and RASTs with milk. Fourteen patients were diagnosed with CMSE by milk challenge test and were designated as the CMSE group. Seven patients with no milk intolerance were defined as the non-CMSE group. Four infants with frequent vomiting and no mucosal abnormalities were also studied as the control group. Immunohistochemical stains for eosinophil major basic protein (MBP), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 on endoscopic duodenal biopsy specimens were performed. Results: The degree of eosinophil degranulation, as evidenced by localization of extracellular MBP, was significantly greater in the CMSE group compared with the non-CMSE and control groups (P < .05). Expression of VCAM-1 on mononuclear cells was higher in the CMSE group compared with the non-CMSE and control groups (P < .05). The severity of villous atrophy was positively correlated with the deposition of MBP (r = 0.79, P < .001). Conclusion: These results strongly suggest eosinophils and VCAM-1 are implicated in the pathogenesis of mucosal damage associated with CMSE. (J Allergy Clin Immunol 1999;103:1195-201.)