Primary Amyloidosis with Plasmacytic Dyscrasia and a Tetramer of Bence Jones Type Lambda Globulin in the Serum and Urine

An abnormal protein has been isolated from both the serum and urine of a patient with generalized amyloidosis and plasmacytic dyscrasia. Immunological and biochemical techniques were used to demonstrate that the proteins isolated from each source were identical and were a tetramer of a lambda-type Bence Jones globulin. This appears to be the first reported occurrence of a urinary Bence Jones tetramer. The sedimentation coefficient of the protein was 5.0S, and its molecular weight 79,000. Reduction and alkylation, electrophoresis, and ultracentrifugation showed it to consist of four monomers covalently bonded to form two dimers, which were in turn noncovalently bonded to form the tetramer.