Immunohistochemical Detection of Serum Amyloid A-Derived Amyloid Deposits in Poultry Using a Synthetic Peptide-Based Antibody.

Avian amyloidosis, mostly caused by the abnormal deposition of amyloid fibrils derived from serum amyloid A (SAA), is histologically diagnosed through the morphological identification of eosinophilic amyloid deposits in tissues. Congo red staining is a popular special staining method for detecting amyloid; however, immunohistochemical staining would allow precise identification and confirmation of SAA-derived amyloid by targeting its protein composition. The purpose of this study was to establish an immunohistochemical method for detecting amyloid deposits in poultry. A rabbit polyclonal antibody was generated against a synthetic peptide corresponding to the C-terminal region of chicken SAA. Immunohistochemistry was performed to detect amyloid deposits in six poultry species: chicken (Gallus gallus), helmeted guinea fowl (Numida meleagris), Japanese quail (Coturnix coturnix), mallard duck (Anas platyrhynchos), Muscovy duck (Cairina moschata), and turkey (Meleagris gallopavo). Positive signals of immunohistochemistry corresponded to histologically observed eosinophilic materials and Congo red-positive areas in all species. Our results indicate that the synthetic peptide-based antibody developed in the study is effective for detecting amyloid deposits in common poultry.