Chronic inflammatory demyelinating polyneuropathy: Immunopathological and ultrastructural study of peripheral nerve biopsy in 42 cases

The authors recently reexamined the peripheral nerve biopsies from 42 patie nts with chronic inflammatory demyelinating polyneuropathy (CIDP). There we re 27 males and 15 females, aged from 9 to 84 years, and 13 had relapses. N o patient had vasculitis, monoclonal gammopathy, tumor, diabetes mellitus. Lyme disease, familial neuropathy, HIV, or any other immune deficiency. In the endoneurium, perivascular inflammatory cell infiltrates were present in only one case, but scattered histiocytes marked by KP1 on paraffin-embedde d fragments were present in every case and there were no T-lymphocytes. At ultrastructural examination macrophage-associated demyelination was observe d in 17 cases, of which 6 had relapses separated by intervals of several mo nths or years. Axonal lesions without associated primary demyelination were observed in 4 cases and 3 of these had relapses. Thirty-two patients had m ixed lesions of demyelination and axonal involvement. This study confirms o ther recent data indicating that in all cases of CIDP. macrophages are pres ent in the endoneurium. Macrophage-associated demyelination is the characte ristic feature of demyelinating forms. On the other hand, isolated primary axonal forms, which have been known since 1989, are relatively frequent and prone to relapses.