The role of macrophages in Guillain‐Barré syndrome and chronic inflammatory demyelinating polyneuropathy

Abstract

AbstractMacrophages play an important role in the pathogenesis of immune‐mediated neuropathies, particularly Guillain‐Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP). Early reports of pathological findings in patients with GBS and CIDP suggested demyelination resulting from phagocytosis of myelin by macrophages as the cause of aberrant nerve conduction in these diseases. Later studies established a concept that molecular mimicry of gangliosides in the peripheral nervous system to surface epitopes of pathogens results in the production of autoantibodies in patients with an axonal form of GBS. In some of the patients diagnosed with CIDP, IgG4 autoantibodies against paranodal junction proteins, such as neurofascin 155 and contactin 1, were found to induce aberrant nerve conduction resulting from the detachment of paranodal myelin terminal loops from axolemma. In contrast, the mechanisms of neuropathy in cases with classical macrophage‐induced demyelination are still to be elucidated. Electron microscopic examination suggested that macrophages recognize specific sites of myelinated fibers as the initial target of demyelination in both GBS and CIDP. It seems that the components that distinguish between the nodal regions, such as the nodes of Ranvier, paranodes, and internodes play a pivotal role in the behavior of macrophages that initiate the phagocytosis of myelin. Further studies are required to clarify the mechanisms of macrophage‐induced demyelination to facilitate the development of new therapeutic strategies directed against the pathology of macrophages.