MULTIPLE MYELOMA WITH URINARY EXCRETION OF HEAVY CHAIN COMPONENTS OF IgG AND NODULAR GLOMERULOSCLEROSIS

A case of multiple myeloma with urinary excretion of considerable amounts of Fc fragments of IgG together with unusual glomerular lesions is reported. From the time of discovery of his disease the patient had heavy proteinuria, but renal function was otherwise well preserved and renal biopsy showed normal glomeruli. Over the course of 10 months severe renal insufficiency developed and death from uremia ensued. The urinary protein consisted mainly of Fc fragments from IgG and only small amounts of light chain fragments could be demonstrated. Kidney biopsies and autopsy revealed development of large mesangial nodules in the glomeruli, resembling the lesions in diabetic nodular glomerulosclerosis. Amyloid could not be demonstrated in these nodules.