Intravenous immunoglobulin preparation attenuates neurological signs in rat experimental autoimmune neuritis with the suppression of macrophage inflammatory protein -1α expression

•IVIG showed a significant suppressive effect on the clinical symptoms of EAN.•IVIG significantry reduced the infiltration of macrophages to the sciatic nerve.•IVIG significantly suppressed MIP-1α production in the sciatic nerves.

To clarify the mechanism of action of an intravenous immunoglobulin (IVIG) preparation in chronic inflammatory demyelinating polyneuropathy, the effects of IVIG were investigated using an experimental autoimmune neuropathy model in the rat. IVIG significantly suppressed the progression of neurologic signs and sciatic nerve conduction velocity with the inhibition of inflammatory cell infiltration, mainly of macrophages, to the peripheral nerves. A significant suppressive effect on the expression of macrophage inflammatory protein 1-α (MIP-1α) was simultaneously observed in the nerves. These results suggest that IVIG is effective for inflammatory demyelinating polyneuropathy by inhibiting the chemotactic factor of macrophages.