TNF and vascular disorder: The present study demonstrates that immunoglobulin G (IgG) antibodies derived from kidney transplant (KTx) recipients with allograft vasculopathy (KTx-IgG), but not IgG antibodies from healthy control individuals (Con-IgG) or KTx-IgG from patients without vasculopathy, are capable of stimulating TNF-α production in HMECs and monocytic cells (THP-1 model).