Vascular permeability increasing factor (VPF) in IgA nephropathy.

Peripheral blood mononuclear cells (PBC) from non-nephrotic and nephrotic patients with different glomerulopathies were tested for their potential to produce vascular permeability increasing factor (VPF) after stimulation with Concanavalin-A (Con-A) in vitro. Supernatants from cultures of PBC from patients with IgA nephropathy were injected intradermally into the skins of normal Wistar rats which were given Evans blue dye solution intravenously. The mean extravasation of dye after 60 minutes was taken as a standard for the induction of local vascular permeability. Using a routine vascular permeability assay based on this principle similar studies were done with supernatants from cultures of PBC from nephrotic subjects with minimal change disease (MCD), or membranous nephropathy (MGN) and from healthy donors. The results show that cultures of PBC from non-nephrotic subjects with IgA nephropathy as well as from nephrotic MCD patients produced VPF in their supernatants whereas lymphocytes from nephrotic MGN subjects or normal donors did not. It is concluded that the production of VPF in stimulated PBC cultures from patients with IgA nephropathy or MCD might reflect altered T-cell function in these diseases, and that there is no direct relationship between VPF production and increased glomerular permeability.