A comparison of routine light microscopy, immunohistochemistry, and in situ hybridization for the detection of cytomegalovirus in gastrointestinal biopsies.

Eighty (80) paraffin-embedded intestinal biopsies from 35 AIDS patients were evaluated for the presence of cytomegalovirus by use of biotinylated DNA probe, immunohistochemical assay, and routine hematoxylin and eosin (H&E) staining. Cytomegalovirus was detected in 13 biopsies (16.3%) from five patients (14.2%). The distribution of positive biopsies was one in seven esophageal biopsies, three in 19 small bowel biopsies, six in 27 colonic biopsies, and three in 17 rectal biopsies. Immunoelectron microscopy was employed to confirm the presence of CMA in four of the positive in situ hybridization cases. In situ hybridization for CMV DNA was more sensitive than immunostaining, and both proved superior to routine H&E staining in terms of sensitivity.