VON-WILLEBRAND-FACTOR IN THE RAT-KIDNEY - ITS LOCALIZATION AND THE EFFECTS OF ITS IN-VIVO INTERACTION WITH SPECIFIC ANTIBODIES

Antiendothelial cell antibodies and increased von Willebrand factor (V WF) levels are observed in many renal diseases. We studied renal morph ology after administration of rabbit anti-human factor VIII-von Willeb rand factor (FVIII-vWFc) gamma-globulin (IgG) in rats. Isolated perfus ion of normal rat kidney with the antibodies disclosed rabbit IgG alon g glomerular endothelium and in mesangial areas. Systemic administrati on resulted in an identical antibody distribution. C3 deposits and few electron dense deposits were transiently noted. After 1 week the mesa ngial deposition of rabbit IgG had increased significantly, most likel y reflecting increased release of vWF by the endothelium. Thereafter, the deposits gradually relocated into mesangial stalk and into the glo merular vascular pole, and they had vanished after 6 weeks. Except for a mild influx of leukocytes, no renal injury occurred. In conclusion, although FVIII-vWFc antibodies cause mesangial immune deposits, antib odies against other endothelial antigens are apparently needed to infl ict renal damage.