Secondary amyloidosis diagnostic study of choice

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Sahar Memar Montazerin, M.D.[2]

Overview

The diagnostic study of choice in amyloidosis is tissue biopsy of the affected organ. Urinary protein measurement followed by renal biopsy is the gold standard of the diagnosis.

Since AA amyloidosis is a condition that occurred due to another illness, the diagnostic study of choice varies according to the primary disorder.
However, the amyloidosis itself should be confirmed through histologic examination of the affected organs.
A tissue biopsy of the affected organ is the gold standard test for amyloidosis. Particular stains can determine the subtype of amyloidosis.
Kidney is affected to a greater extent compared to other organs. The 24-hour urine collection with the assessment of urinary protein may be useful and in the case of renal involvement, a kidney biopsy is required.
Staining the tissue sample with antibodies that are specific for AA amyloidosis will confirm the final diagnosis.
Organ-specific labs: If a particular organ is affected, laboratory measurements that are specific to that organ can be measured. For example, if there is liver involvement, liver function tests (such as AST, ALT, total bilirubin, and alkaline phosphatase) should be measured.

Following diagnostic criteria has been used for AL amyloidosis. However, it may be applicable for AA amyloidosis as well.