[Usefulness of immunocytochemistry in the identification of Mallory bodies. Theoretical analysis about their formation].

BACKGROUND

Mallory bodies are hepatocyte intracytoplasmic inclusions frequently observed in liver diseases. They contain altered intermediary filaments that have immunoreactivity with epidermic antikeratin antibodies (A-QEp). They also contain ubiquitin (Ubq) a 76 residue polypeptide that has an important role in the proteolysis of rapid exchange and abnormal cytosol proteins.

AIM

To standardize an immunohistochemical method for the detection of Mallory bodies in percutaneous liver biopsies.

METHODS

A-QEP and A-Ubq polyclonal antibodies were used in the study of 131 percutaneous liver biopsies obtained from patients with different liver diseases. Mallory body immunoreactivity was confirmed with immunoelectron microscopy.

RESULTS

Mallory bodies had scanty immunostaining with A-QEp, specially in formalin fixed biopsies. There was a specific and sensitive staining with A-Uhq, that was not influenced by the fixation method. Immunoelectron microscopy demonstrated that Mallory bodies are partially formed by altered intermediate filaments.

CONCLUSIONS

Antibodies against ubiquitin may be very useful for the detection of Mallory bodies in liver biopsies.