Glomerular deposition of antihemophilic factor antigen in various renal diseases.

Glomerular localization of antihemophilic factor (AHF, Factor VIII) antigen was studied by immunofluorescent microscopy in 114 diseased and in 3 normal kidneys. Deposition of AHF was detected in the endothelial cells of glomeruli and in blood vessels in renal tissues. These deposits were not eluted by acid buffer treatment. In the group with minimal change nephrotic syndrome and in some cases of proliferative glomerulonephritis, deposition of AHF was limited to the endothelial cells. In cases of the nephrotic syndrome with proliferative changes, deposits were confined to endothelial cells but were increased because of proliferation and/or swelling of the endothelial cells. In some cases of IgA glomerulonephritis, membranous glomerulonephritis, membranoproliferative glomerulonephritis and lupus nephritis, deposition of AHF was detected not only in the glomerular endothelial cells but also in the immune deposits. However, after acid buffer treatment, it remained only in the endothelial cells. In other cases of membranous glomerulonephritis (7/9), membranoproliferative glomerulonephritis (5/8), lupus nephritis (5/14) and Henoch-Schönlein nephritis (1/3), deposits of AHF were confined to the immune deposits. These findings suggest that deposition of AHF is closely related to the immune reaction, and that functional impairment of endothelial cells may occur in some cases with massive immune deposits along the glomerular capillary walls. The glomerular endothelial cells may be affected by massive immune complexes that pass through the endothelial fenestrae or cytoplasm and remain in the glomerular basement membrane for a long time.