Amyloidosis (AL). Clinical and laboratory features in 229 cases.

At the Mayo Clinic from 1970 to 1980, 229 patients with primary systemic amyloidosis (AL) were examined. Nephrotic syndrome, congestive heart failure, orthostatic hypotension, carpal tunnel syndrome, and peripheral neuropathy were often associated features. Electrophoresis of the serum revealed a spike in only 40%, but immunoelectrophoresis disclosed a monoclonal protein in 68%. Eighty-nine percent of patients in whom it was sought had a monoclonal protein in the serum or urine. The diagnosis of amyloidosis was made before death in 96% of the patients. The preferred sites for biopsy were the bone marrow, rectum, kidney, carpal ligament, liver, small intestine, skin, and sural nerve. The median survival of the 229 patients was 12 months. The median survival of the 77 patients with congestive heart failure was 6 months after the onset of symptoms. Congestive heart failure or arrhythmias accounted for death in 40%. Treatment for amyloidosis is unsatisfactory but includes melphalan, prednisone, colchicine, and dimethyl sulfoxide.