NEPHRITIS INDUCED BY ANTILYMPHOCYTE SERUM - AN ELECTRON MICROSCOPIC AND IMMUNOHISTOCHEMICAL STUDY

Rabbit antirat thymoeyte serum (ATS) was injected i.v. into Lewis rats whose kidneys were examined for glomerular alterations by light, electron, and immunofluorescent microscopy. Glomerular alterations were evident in rats injected with ATS, ATS absorbed with rat red cells and rat serum proteins, or the purified IgG fraction of absorbed ATS (AT-IgG) over a 5-12-day period for a total of 6-25 mg of AT-IgG or its ATS equivalent. Expansion of glomerular mesangia was the principal light microscopic alteration. ATS, ATS absorbed, and AT-IgG administration were associated with glomerular alterations of decreasing severity, respectively. Electron microscopic examination also revealed expansion of mesangia. Rabbit IgG and rat IgG and βle globulin were demonstrated by immunohistochemical techniques in the altered glomeruli. Linear and semidiserete subendothelial basement membrane deposits were visualized by electron microscopy in animals receiving ATS or AT IgG. Additional subepithelial basement membrane deposits were present in ATS- but not AT-IgG-treated animals. © 1969 by The Williams and Wilkins Co.