Immunohistochemical study of glomerular lesions in retroperitoneal lymphomas.

An immunohistochemical study was performed on the kidneys of 10 subjects with retroperitoneal lymphomas. Kidneys were first examined by light microscopy and six kidneys were further studied by immunofluorescence. Light microscopic evidence of damage found in 6 of 10 subjects was characterized by thickening of the basement membrane of glomerular capillaries and an increase in the mesangial matrix. In the areas of light microscopically visible damage, deposits of Schiff-positive material and argyrophilic material were present. No significant changes were found in the tubules. Four of the six kidneys which showed damage by light microscopy showed further evidence of histologic change in areas of glomerular damage when examined using the direct immunofluorescence technic. In 2 subjects, diffuse deposits of IgG and beta1C-beta1A globulin in basement membranes and the mesangial region were prominent, while in the remaining 2 subjects IgG and beta1C-beta1A globulin were localized as linear and/or beaded deposits, both inside and outside the basement membranes. Only focal deposits of these conjugates were seen in the mesangium. No localization of IgA, IgM, rabbit antihuman fibrin or fibrinogen was noted in any of the cases. The tubules yielded negative reactions for the localization of any of the conjugates. The results of this study seem to support the concept that, in some cases of retroperitoneal lymphomas, clinical and renal functional disturbances may be explained on the basis of an immunologic injury to the basement membranes of the glomeruli.