Immunohistochemistry of Liver in Alphab1-Antitrypsin Deficiency: A Comparative Study

Abstract

A retrospective light microscopic study was performed on liver tissue obtained at autopsy from three adults with alpha₁-antitrypsin deficiency and from eight additional patients with a variety of hepatic diseases. A comparison of the efficacy of immunofluorescent and immunoperoxidase methods for the identification of alphaj-antitrypsinpositive granules in liver cells was undertaken. In formalin-fixed frozen sections, specific intracellular globule staining was demonstrated in the deficiency state with all technics. While immunofluorescent methods failed to stain the globules in formalin-fixed, paraffin-embedded tissues, immunoperoxidase technics gave consistently positive and reproducible results. The immunoperoxidase technic utilizing an unlabeled antibody bridge was found to be better for demonstrating alpharantitrypsin deposits in paraffinembedded tissue specimens. The implications of these findings for retrospective studies of routinely processed paraffin-embedded tissue specimens as well as for ultrastructural studies are emphasized.