Electron microscopy and immunofluorescence of glomerular immune complex deposits in cancer patients.

Kidneys of 29 patients without clinical renal disease were studied by electron microscopy for the presence of glomerular basement membrane deposits: those from 11 of 20 patients with cancers of various sites, but only 1 of 9 patients without cancer contained electron-dense subendothelial deposits. The majority of these kidneys gave positive immunofluorescent reactions for immunoglobulin and complement. However, among a number of the cases studied, a lack of correlation between electron microscopic and immunofluorescence findings has yet to be investigated. Although the number of patients in this study is small because of the difficulty in obtaining tissue for electron microscopy, it is postulated that the deposition of immune complexes in the kidney occurs with a high frequency among cancer patients. The kidneys may thus be a valuable source for isolating tumor-associated antigens and corresponding antibodies.