[Histopathology and ultrastructure of opportunistic infections of the digestive tract in acquired immunodeficiency syndrome].

Light and electron microscopy studies of digestive tract biopsy specimens from AIDS patients are very useful for the detection of opportunistic pathogens which may be located in: the lumen (bacteria, Candida albicans, Giardia lamblia), enterocyte brush border (Cryptosporidium sp), enterocyte cytoplasm (Enterocytozoon bieneusi), enterocyte nuclei (cytomegalovirus), or cytoplasm of lamina propria macrophages (Mycobacterium avium intracellulare). These studies may also be useful to detect combinations of morbid conditions and to evaluate the effectiveness (if any) of therapeutic agents.