The use of subcutaneous fat tissue for amyloid typing by enzyme-linked immunosorbent assay

The amyloidoses are biochemically heterogeneous diseases with pathophysiolo gic deposits of various proteins. The clinical course, prognosis, and thera py are different for each type of amyloidosis and, therefore, a type-specif ic diagnosis is demanded as early as possible. We describe a method for typ ing the most common systemic amyloidoses of AL, AA, and transthyretin types by enzyme-linked immunosorbent assay (ELISA), using abdominal wall subcuta neous fat biopsy specimens. The method was tested on 21 abdominal fat biops y specimens that were sent to the laboratory. Of these, 15 contained amyloi d that was successfully characterized in 14 cases. One specimen contained a myloid that did not react with any antisera used. The 6 specimens without a myloid gave no reaction in ELISA. The described ELISA method is reliable an d easy to perform, and the tissue sample needed is obtained by minor surger y.