Allograft inflammatory factor-1: a pathogenetic factor for vasculitic neuropathy.

Allograft inflammatory factor-1 (AIF-1) is a cytokine that plays a major role in the immune response and proliferative vasculopathy that occur during chronic allograft rejection. The purpose of this study was to characterize the cellular expression pattern and pathogenetic role of AIF-1 in nerve biopsies from patients with vasculitic neuropathy. We performed immunohistochemistry in human nerve biopsies of 10 patients with vasculitic neuropathies (VASs), 6 with chronic inflammatory demyelinating polyneuropathies (CIDPs), 5 with noninflammatory axonal neuropathies (NIANs), and 3 control nerves (CNs). In the CIDP and VAS nerves, AIF-1 expression was higher than in CN and NIAN nerves (P < 0.05). AIF-1 was increased in the arterial walls of VAS compared with CIDP nerves (P < 0.05). Vascular smooth muscle cells in vasculitic nerve express AIF-1 at a higher level compared with CIDP and NIAN. AIF-1 plays a role in inflammatory nerve disease and vascular smooth muscle cell proliferation and may be a new molecular target for treatment.