Vascular and renal distribution of HLA--DR-like antigens

Tissue sections of ethanol-fixed, paraffin-embedded specimens from human kidney, placenta and umbilical cord were studied by indirect immunofluorescence with a rabbit antiserum to HLA--DR antigens from B lymphocytes. Capillary walls in the kidney showed specific staining both in glomeruli and around tubuli. Conversely, HLA--DR-like antigens were not detected in the walls of larger vessels, in tubular cells, or in the epithelium of Bowman's capsule. HLA-DR-like antigens of kidney elements thus seemed to be restricted to capillary endothelial cells. In specimens from umbilical cord and placenta, HLA--DR-like antigens were not detected in the walls of capillaries or larger vessels. Isolated endothelial cells from the umbilical vein were likewise negative.