title: Early lesions of the nephron in paraproteinemia.
abstract: Electron microscopy of renal biopsies in eight patients with paraproteinemia (six multiple myeloma, one Waldenström's disease, one idiopathic paraproteinemia) and without impairment of renal function demonstrates an increase of mesangial matrix and thickening of the lamina rara interna of the basement membrane in the glomerulus by fibrillar material without periodicity. These lesions are thought to exhibit precursors of amyloid deposits. The proximal tubules show signs of increased cellular activity probably because of handling an increased protein load. In the basement membranes there are proteins with a fibrillar structure and definite periodicity. These are suggested to be consistent with large aggregates of immunoglobulin fragments.
mesh_terms: D006801:Humans; D007668:Kidney / Q000473:pathology*; D007678:Kidney Glomerulus / Q000648:ultrastructure; D007687:Kidney Tubules, Proximal / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D009399:Nephrons / Q000473:pathology* / Q000648:ultrastructure; D010265:Paraproteinemias / Q000473:pathology*