Cytomegalovirus hepatitis: a histological and immunohistochemical study.

The histological features of hepatitis due to cytomegalovirus (CMV) infection were reevaluated in 11 human liver biopsies, previously diagnosed as CMV hepatitis. Ten biopsies were taken from renal transplant or hemodialysis patients. CMV antigens were detected in Bouin-fixed, paraffin-embedded tissue sections by an indirect immunofluorescence and immunoperoxidase technique. The serum of another renal transplant patient with a very high titer of complement-fixing antibodies to CMV (1/8,000) was used as specific antiserum. To the classical histological features of CMV hepatitis are added: the presence of small aggregates of neutrophil polymorphonuclear leukocytes, often centered by an infected hepatocyte with the diagnostic CMV inclusion body. It appears from immunohistochemical staining that basophilic cytoplasmic granularity in cells without the classical nuclear inclusions is due to the presence of viral material. It is concluded that the classical inclusion-bearing cell remains the most diagnostic histological parameter in the diagnosis of CMV hepatitis. Nevertheless, the basophilic cytoplasmic change associated with the histological features described is also diagnostic for CMV hepatitis.