4 Interesting Facts of Primary amyloidosis
- Primary systemic light chain amyloidosis is a plasma cell dyscrasia caused by a pathologic clonal population of plasma cells in the bone marrow that produce monoclonal light chains that misfold and aggregate into a fibrillar pattern
- These amyloid fibrils’ monoclonal light chains have a high affinity for visceral organs, soft tissue, or nervous system
- Deposition causes end-organ dysfunction in various organs (eg, kidney, heart, liver) and autonomic or peripheral nervous system dysfunction
- Symptoms are diverse and include unexplained fatigue, edema, dyspnea, unintentional weight loss, orthostatic hypotension, and paresthesias
- Serum and urine protein electrophoresis, serum and urine immunofixation electrophoresis, and serum free light chain testing show results similar to those in multiple myeloma and monoclonal gammopathy of undetermined significance
- Monoclonal spike is seen on serum electrophoresis in about half of cases
- Elevated circulating serum free light chain levels, due to abnormalities of the κ or λ chains or the κ/λ ratio, are common
- Differentiated from multiple myeloma by histologic identification of amyloid deposits in affected tissues via tissue and bone marrow biopsy
- Most expeditious and safest way to confirm amyloidosis is to perform a needle aspiration of subcutaneous abdominal fat and stain both the fat and the bone marrow biopsy cellular specimen for amyloid
