Occurrence of immunohistochemically detected small Mallory bodies in liver disease.

To determine the diagnostic significance of immunohistochemically detected small Mallory bodies (MBs) which are invisible by conventional stainings, we investigated the occurrence of MBs in liver tissue with alcoholic and nonalcoholic liver disease by immunoperoxidase staining with monoclonal anti-MB antibody, anti-NMB-3. In conventional stainings, MBs were detected in only six of 26 (23%) patients with alcoholic liver disease, and nine of 63 (14%) patients with nonalcoholic liver disease. On the other hand, MBs were detected in 20 of 26 (77%) patients with alcoholic liver disease, and 25 of 63 (40%) patients with nonalcoholic liver disease by immunoperoxidase staining. Immunohistochemically detected MBs were shown to possess the ultrastructural characteristics of MBs by immunoelectronmicroscopy in the four specimens. Our result indicates that the small MBs are not rare in nonalcoholic liver disease, and the presence of immunohistochemically detected small MBs is not a good marker of an alcoholic etiology.