Amyloidosis: diagnosis and management.

Amyloidosis is a rare plasma cell proliferative disorder. The annual incidence in Olmsted County, Minnesota, is 8 in 1,000,000 patients. This is a difficult disorder to diagnose, because the symptoms at presentation are vague and include dyspnea, paresthesias, edema, weight loss, and fatigue. The clinical syndromes at the time of presentation include nephrotic-range proteinuria with or without renal failure, cardiomyopathy, "atypical multiple myeloma," hepatomegaly, and autonomic or peripheral neuropathy. The serum immunoglobulin free light chain assay has been an important step forward in classifying systemic amyloidosis as an immunoglobulin light chain form and in monitoring therapy. Recently, the importance of serum cardiac biomarkers in assessing outcome has been recognized. New therapies developed over the past 5 years include high-dose chemotherapy with stem cell reconstitution, combinations of alkylating agents with dexamethasone, and, most recently, thalidomide.