Table 3.

International Myeloma Working group diagnostic criteria for AL amyloidosis [20]

Presence of an amyloid-related systemic syndrome

(e.g., renal, liver, heart, gastrointestinal tract or peripheral nerve involvement- The organ damage must be felt to be related to amyloid deposition and not to another common disease, such as diabetes or hypertension)

Positive amyloid staining by Congo red in any tissue (e.g., fat aspirate, bone marrow or organ biopsy)

Evidence that the amyloid is light chain-related established by direct examination of the amyloid using spectrometry-based proteomic analysis or immunoelectron microscopy

Evidence of a monoclonal plasma cell proliferative disorder (e.g., presence of a serum or urine M protein, abnormal serum free light chain ratio, or clonal plasma cells in the bone marrow)