Specificity of anti-albumin autoantibodies in liver diseases

Abstract

The reaction between glutaraldehyde-treated human albumin and the anti-albumin autoantibodies found in sera of hepatic patients was inhibited by: (1) peptides with a molecular weight around 10,000 daltons which were isolated from the pronase digest of glutaraldehyde-polymerized human albumin, (2) pyridinium compounds resulting from the reaction of glutaraldehyde with the amino groups of 6-aminohexanoic acid, and (3) other glutaraldehyde-treated proteins (rabbit albumin, bovine albumin, ovalbumin, peroxidase, human gamma globulin). Our results suggest that the anti-albumin autoantibodies recognize on glutaraldehyde-treated human albumin the new antigenic determinants containing at least partly pyridinium-like structures. This type of structure could also occur in vivo, in circulating albumin molecules, by inter- and intramolecular cross-linking reactions between aldehydic groups which appear by oxidative deamination and ε-amino groups of lysine residues, thus leading to non-self albumin which stimulates the synthesis of autoantibodies.