Increased titers of IgM antibodies that react with carbohydrate epitopes on GM1 are present in some patients with lower motor neuron disease, sensorimotor neuropathy, or motor neuropathy with or without conduction block. Therapeutic reduction of antibody concentrations can result in clinical improvement, suggesting that the antibodies may be pathogenic. The anti-GM1 antibodies react with carbohydrate epitopes, which are shared by several other glycolipids and glycoproteins in the central and peripheral nervous system. The antibodies might exert their effects at a number of sites, depending on the topographical distribution of the target antigens and on their accessibility. B-cells that express anti-GM1 antibodies are present at birth and are normally suppressed or rendered anergic. Under some circumstances, however, they might be activated to secrete autoantibodies that cause autoimmune neuropathy.
