IGG MYELOMA WITH CLOSED TETRAMERIC BENCE JONES PROTEINEMIA

A forty-one year old woman with multiple myeloma of sixteen months' duration died with the clinical picture of plasma cell leukemia. During the course of her illness her serum contained λ type IgG myeloma protein and λ, type Bence Jones protein, but concomitant Bence Jones proteinuria was absent. The serum Bence Jones protein was composed of two disulfide linked light chain dimers which were noncovalently bound to form a closed tetramer. The protein had a corrected sedimentation coefficient of 5.4 S and a molecular weight of about 88,000. The absence of Bence Jones proteinuria is explained by the high molecular weight of the tetramer. © 1969.