Immunohistochemical typing of amyloid on hydroxyethyl-methacrylate-embedded renal biopsies

Hydroxyethyl-methacrylate (GMA)-embedded renal biopsies containing amyloid were tested by the indirect immunoperoxidase method with antibodies against the following purified amyloid fibril proteins: AA, three different A lambda preparations, Ak and AF. The anti-AA reagent was monoclonal (mc13), all the others were polyclonal. In four biopsies from cases with generalized amyloidosis, two were found to be of the AA and two of the A lambda type. Two control cases of membranous glomerulonephritis showed only a marginal reaction with anti-A lambda. These results demonstrate that GMA-embedded tissue sections are suitable for immunohistochemical classification of amyloid diseases, because proteinaceous antigenic determinants of amyloid fibril are preserved.