[Immunopathology of inflammatory neuropathies]

With the use of immunohistochemical technique, nerve biopsy is more informative for the diagnosis of inflammatory neuropathies. In chronic inflammatory demyelinating neuropathy, an increased number of T cells are frequently present in endoneurium, which is in contrast to hereditary neuropathies. In active demyelinating lesions, macrophages adhering nerve fibers showed stainings with TNF-alpha. NOS and cyclooxygenase-2 (COX-2). These molecules may act in concert to promote nerve damage. The inhibitor of COX-2, nimesulide, was effective on experimental allergic neuritis, even if given after the onset of clinical signs. A COX-2 inhibitor may have potential as an additional therapeutic agent in human inflammatory neuropathies. In vasculitic neuropathies, cell-mediated cytotoxicity may be involved in the pathogenesis of small vessel injury. Axonal injury may be caused by focal ischemia. However, an immune attack might be involved in nerve damage, since T cells and IL-12 positive cells were found in endoneurium of some patients with active vasculitis.