ABSTRACT
Quantification of amyloid A protein can be used to detect AA amyloid in fat tissue. The method confirms the AA-type of amyloid and can be automated to become observer-independent. To study the sensitivity of amyloid A protein quantification and Congo red method in fat tissue of patients with clinical AA amyloidosis. All patients had AA amyloidosis proven by a biopsy positively stained with Congo red as well as positive anti-AA immunohistology. The Congo red method is more sensitive than quantification of amyloid A protein to detect amyloid in fat tissue of patients with clinical AA amyloidosis. However, good equipment and experience remain prerequisites for reliable results of the Congo red stain, especially when deposits are minute. Amyloid A protein in fat tissue was quantified by ELISA using murine monoclonal anti-human SAA antibodies Reu86.1 and Reu86.5. All patients had AA amyloidosis proven by a biopsy positively stained with Congo red as well as positive anti-AA immunohistology.
