Light chain deposition disease detected by antisera to a variable region of the kappa1 light chain subgroup

A 59-year-old male started maintenance hemodialysis, and 80 months later died of congestive heart failure. Just before death he had no urine, and no monoclonal immunoglobulin could be demonstrated in the serum on immunoelectrophoresis. An autopsy showed deposition of periodic acid-Schiff-positive and Congo red-negative material in the interstitium and vessel walls of almost all organs and tissues. In the glomeruli there was a multifocal nodular accumulation of the material. Electron microscopy showed finely granular, not fibrillar deposits. In spite of these impressive lesions on light microscopy, the material was not stained with commercially available antisera to light chains. However, the material was positive for antisera to the variable region of the kappa1 light chain subgroup. This is the first case with light chain deposition disease that showed positive staining only with antisera to the variable region of the light chain.