Nodes of Ranvier in skin biopsies of patients with diabetes mellitus

Abstract Paranodal demyelination has been discussed as a potential mechanism of nerve fiber damage in diabetic neuropathy. Studies on human tissue are limited, as nerve biopsies are invasive and only rarely performed in patients with confirmed diabetic neuropathy. Skin biopsy has recently been suggested as a tool to analyze paranodal and nodal changes of myelinated fibers. We analyzed the myelinated fibers of skin biopsies of 35 patients with diabetic neuropathy, 17 patients with diabetes mellitus without neuropathy, and 30 normal controls. Immunofluorescence of skin sections with antibodies against Caspr, neurofascin, sodium channels and myelin basic protein was performed to assess paranodal/nodal architecture, segmental demyelination and myelinated nerve fibers. Staining with antibodies against protein gene product 9.5 was used to quantify unmyelinated nerve fibers. There was an increase of elongated Ranvier nodes and a dispersion of neurofascin at the distal leg in patients with diabetes mellitus with and without neuropathy and at the finger in patients with diabetic neuropathy. An increased dispersion of Caspr was only found in biopsies of the finger in patients with diabetic neuropathy. Skin biopsy may be an appropriate tool to analyze nodes of Ranvier in patients with diabetes mellitus. Structural nodal changes are detectable in diabetic neuropathy and even in diabetic patients without neuropathy.
Source: Journal of the Peripheral Nervous System - Category: Neurology Authors: Tags: RESEARCH REPORTS Source Type: research