Recently, markedly increased immunoreactivity of major histocompatibility complex (MHC) class II antigens and ICAM-1 was demonstrated in aganglionic bowel, suggesting the immunological mechanisms may be involved in the etiology of HD.
The authors studied expression of intercellular adhesion molecule-1 (ICAM-1) and major histocompatibility complex (MHC) class II antigen in the resected bowel specimens of 18 patients with HD who had no evidence of enterocolitis and in eight age- and site-matched controls, using indirect immunohistochemistry.