Abstract
Pathogenesis of leprous neuropathy was studied from the standpoint of vasculitis. In vasculitic syndrome, mononeuritis multiplex is the most specific peripheral nerve injury. It ocurrs most frequently in small vessel vasculitis. Among them, the incidence is highest in microscopic polyangitis (MPO), Churg-Strauss Syndrome (CSS), and Wegener's granulomatosis (WG). All of them are categorized as ANCA associated disease. Because the disease activity is parallel with ANCA titer and ANCA is related directory to the pathogenesis of necrotizing vasculitis as well as the ocurrence of peripheral neuropathy. Other small vessel vasculitis, such as lupus or rhumatoid vasculitis which are believed to ocurr by immune complex mechanism, are accompanied seldom by periperal neuropathy. In WG, there are granulomatous lesions in upper and lower respiratory tracts which are supposed to be induced by Thl dominant CD4 T cell infiltration. In cases of leprosy, if peripheral neuropathy were related to small vessel vasculitis, there might be two different pathogenesis. One is granulomatous vasculitis like WG in tuberculoid type. The other is immune complex type necrotizing vasculitis like SLE in lepromatous type, especially ENL. The site of these events may be small vessel in epineurium. Further imunologic studies are needed to clarify detailed mechanisms of leprous neuropathy.
