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 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). There were 27 males and 15 females, aged from 9 to 84 years, and 13 had relapses. No 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-embedded fragments were present in every case and there were no T-lymphocytes. At ultrastructural examination macrophage-associated demyelination was observed in 17 cases, of which 6 had relapses separated by intervals of several months or years. Axonal lesions without associated primary demyelination were observed in 4 cases and 3 of these had relapses. Thirty-two patients had mixed lesions of demyelination and axonal involvement. This study confirms other recent data indicating that in all cases of CIDP, macrophages are present in the endoneurium. Macrophage-associated demyelination is the characteristic 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.

Chronic inflammatory demyelinating polyneuropathy associated with dysglobulinemia: a peripheral nerve biopsy study in 18 cases

The possible occurrence of chronic inflammatory demyelinating polyneuropathy (CIDP) in association with an identified dysglobulinemic status is recognized and a causal relationship between the two has been suggested. We had the opportunity to study 18 patients presenting with CIDP and dysglobulinemia. This was an IgG monoclonal gammopathy (IgG MG) in 8 cases, an IgM monoclonal gammopathy (IgM MG) in 8, an IgG-IgM biclonal gammopathy in 1 case and an IgM monoclonal cryoglobulinemia in another. A peripheral nerve biopsy specimen was available for all patients and the morphological findings in these specimens in the cases of CIDP with IgG MG or cryoglobulin did not differ from those without, whereas characteristic features were observed in the cases of CIDP with IgM MG and anti-myelin associated glycoprotein activity.